superheater steam control using fuzzy logic
TRANSCRIPT
1
98-F-ACI-116
Superheater Steam Control Using Fuzzy Logic
H.Monsef 1,2 B.Moshiri 1 D.Rezaei 1,2
1- ECE Dept., Faculty of Eng. Univ. of Tehran
2- Niroo Technology Center(MATN)
Key words: Superheater, Superheated Steam Control, Fuzzy Control
Abstract In a steam power plant, the performance of superheater is very affected by load demand, and hence for control them using self-tune controllers is very common. In this paper a self-tune controller based on fuzzy logic is introduced. simulation results show the performance of the proposed method in comparison with other methods.
2
98-F-ACI-207
Modeling of pitch regulated constant speed wind turbine
M. Karrari - S.H. Edjtahed
Power Engineering Consultants Co. (Moshanir) Amir kabir University of technology
Tehran-Iran
Key words: Wind Turbine, Variable speed cage machine, Blade Pitch angle, Vector control
Abstract In this paper, we will present at the first a complete model for a wind turbine system with a VSCM generator which is connected via a gear box to a tree bladed pitch controlled horizontal axis wind turbine from one side, and via a PWM converter to the grid line from the other side. Then a controller, which is named “reference signal generator”, will be designed to lead the system to the optimum operating condition at various wind speeds. Control objectives are to regulate the terminal voltage of the generator, to increase generator efficiency, and to capture maximum power from the wind. The simulation results show that the proposed controller led the system to the optimum conditions whatever the wind speed. Since in this controller, the aim is the optimum steady state conditions, it could do little to improve transients and stability of the system.
3
98-E-ACI-407
Fault Diagnosis in Electrical Power substations using Soft Computing Methods
B Dehghan Shibany Fars Regional Electric Company
Shiraz, Iran
Key words: Electrical Power Substations, Fault Diagnosis, and Soft-computing
Abstract In this paper, applications of Soft-Computing paradigms i.e. Expert System, Neural Network, Fuzzy Logic and Genetic Algorithm (GA) Fault Diagnosis in power substations are discussed. Advantages of each paradigm are studied in a case study. Fault Diagnosis in a substation with “Double bus, one and half breakers” structure in Fars Regional Electric Company (FREC) has been chosen as the case study. A fuzzy logic expert system is proposed for fault diagnosis in this substation, which can be used to aid operators in detecting the main failed section of the substation. Simulation results shows the effectiveness of the proposed method
4
98-E-ACI-524
The development and implementation of current injection controller system based on FPGA on 25KA current injection machine
Rouhollah Afshari Hossein Haydari Abdolreza Rahmati High Voltage and Magnetic Materials Research Centre
Iran University of Science & Technology
Key words: Current Injection, Autotransformer, FPGA, Stepper Motor
Abstract In this paper we present the development and implementation of current injection controller system based on FPGA. The system receives information of output current from user, such as current value and time of flowing current to load, and controls the output current. The system turn the middle head of autotransformer and changing output current automatically between 0 and 25KA. This system consists of a mixed implementation of software and hardware. The hardware is consists of two part; first part is connecting to stepper motor, driving it and turning middle head of autotransformer to adjust output current and the next part of hardware sensing temperature of autotransformer and sends it to computer. The software is running in computer and gives this data and plot T-t diagram. The hardware were implemented by using FPGA and the software was implemented in C++Builder.
5
98-F-ACI-658
DESIGN ADAPTIVE MIMO DECENTRALIZED CONTROLER TO PSS SYSTEM IN SYNCHRONOUS
GENERATOR
Bijan Moaveni
Electrical Engineering Group Science and Research Branch
Azad University Iran
Seyed Hamid Tabatabaei
Computer- Mechateronics Engineering Group Science and Research Branch
Azad University Iran
Key words: Adaptive Control, Decentralized Control Structure, Synchronous Generator, Heffron-Phillips
Abstract Synchronous generators are one of the most effective and applicable devices in power systems. Analogue AVR or PSS controllers play an important rule in system stability. In past these controllers where used to stabilize synchronous generators. But widespread power systems and existence of unknown disturbances in systems, lead us to design controllers which be able to control the system load in this situation. For this purpose adaptive controllers are the best choice. We can summarize the adaptive controller's advantages as being cheap (in comparison with traditional controllers), simplicity, high speed and performance and easy installation. In this paper, in order to analyze and control the system, at first we model the system with Heffron-Phillips method, with less dependency to time domain and in multivariable category systems will be considered with two inputs and two outputs. After analyze the plant we propose the decentralized control structure to control the system and use the adaptive controller in this structure. At last, the simulation results will be presented.
6
98-F-ACI-688
Design and Construction of a System for Measuring the Differential Expansion between Crust and Rotor Turbine by
Using Radio Frequencies and Unconnected Sensors
A. Saadat,* S. R. Hossine, M. Madani
Esfahan Regional Electric Co. *Esfahan Electric Power Repairing Co.
IRAN
Key words: Unconnected Sensors, Air Gap, Crust and Rotor Turbine.
Abstract In this paper design and construction of a system for measuring the differential expansion between crust and rotor turbine by using radio frequencies and unconnected sensors are presented. This difference is due to discordant temperature between rotor and turbine crust . In this process changes of air gap between 1 to 6 millimeter turn in to voltage between 0 to 10 volt with 5% regulation and 95% correct rate.
7
98-F-CAM-277
Locally hardness increasing causes in powerplant rotors and its modification by tempering
E. Poursaeidi, A. R. Razavi, A. Ahmadi
The Center of Research and Laboratories-Iran Powerplant Repair Co.
Key words: Hardness, power plant rotor, and tempering heat treatment
Abstract Locally hardness increasing on the surface of power plant rotor especially in journal area can be made to even and severe damage. One of the major modifying solutions for the rapid repairing of the aforementioned rotors is adoptative tempering heat treatment. For this purpose, after identification the damaged rotor, initial considerations and tests (such as visual inspection,chemical analysis nondestructive hardness, replica or in-site metallography and run-out tests) performed on rotor journal. The results of above tests showed the occurrence of locally phase transformation (i.e.tempered bainitic to austenite and finally martensite), has been the essential factors. Finally base on afformentioned resutls, the tempering heat treatment method selected as a modifying solutions by following purposes: 1) decreasing of hardness in embrittlement places (i.e.400-660HV) 2) Invariable or admissible decreasing of hardness in undamaged parts (250-300HV). In this scope, the results of experimental and experience investigations showed that, the 640C /4hr as a optimum temperature and holding time in tempering heat treatment can be provide these two considered requirements.
8
98-F-CAM-327
Straightening of Bent Powerplant Rotors By Hotspotting
A. R. Razavi, E. Poursaeidi,S.Rash Ahmadi The Center of Research and Laboratories-Iran Powerplant Repair Co.
Key words: distorsion, power plant rotor, Straightening and Hotspotting
Abstract Permanently turbine rotor distorsion or bends (espicially HP rotor) may be caused by a number of factors , So that it can be made to trip (emergency stop ) of turbines . One of the major modifying solutions for rapid repairing of bent rotors is Hot spotting . For this purpose, after initial tests ( visual inspection, chemical analysis, nondestructive hardness), the hot spotting performed in six times. The results of experimental and experince investigations in different temperatures and times showed that , the 690+20C and 210sec as a optimum temperature and time in hot spotting can be provide a noticeable straightening in bent area in addition to no affectting on mecanical properties . Also , this results were simulated by F.E.M in the view point of heat distribution in different temperatunes and in three state (without isolation and with wet and dry isolation) in order to findout the optimum restraint effects around hot spot area.
9
98-E-CAM-344
PCBs Removal From Transformer Oil By Liquid Extraction
B.B. Alamdari , A. Ahmadi , F. Borhanazad
Chemistry and Process Dept. Chemical and Materials Research Center
Niroo Research Institute (NRI) IRAN
Key words: Polychlorinated Biphenyls, PCBs, contamination removal, extraction, analysis
Abstract Extraction and destruction of Polychlorinated Biphenyls (PCBs) as a major persistent organic pollutants (POPs) compound, has been attracted many environmental research activities. Mostly, this compound had been produced for electrical instrument uses, especially transformer oil. PCBs problem has caused to quarantine an enormous volume of such expensive oil. This study has been directed towards the development of a cost – effective technology for removing PCBs from contaminated transformer oils to methanol, so that oil remains useable. PCBs extraction by methanol has two benefits: 1- easy destruction by Pd/Fe catalyst in aqueous solutions. 2- oil’s usefulness without necessary to apply additional processes. In this research, PCBs extraction data and its behaviour in oil – methanol phases have been presented. Extraction effects on oil characteristics and results have been inspected. L2000-Dexil analyzer as a choice for PCBs analysis among standard approaches, has restrictions in methanol. Solving this problem, a new method has been introduced to analyze PCBs in methanol solutions.
10
98-F-CAM-493
The Effect of Microwave Radiation Power and Pd/Fe Catalyst Specifications on PCBs Decomposition Reaction
S.A.Ahmadi , B.B.Aladmari
Chemistry & Process Dept Chemistry & Material Research Center NRI
Tehran _ Iran
Key words: PCBs, Contaminated Oil, Decomposition, Microwave, Pd/Fe Catalysis
Abstract The attractive physical and chemical properties of PCBs such as electrical insulating specification, low flammability and high stability to bio – and chemical degradation have resulted in their widespread use as insulating liquids in transformers and capacitors. While the general toxic effects of human exposure to PCBs are still uncertain, it is known that dermatology, neuralgic and enzymatic disorders can be used by exposure to these chemicals. Therefore development of safe methods for its decomposition is obligatory. The purpose of this research is development a safe and efficient method for PCBs removal from contaminated oils. This method is composed of two main stages. At the first stage the oil is decontaminated by a liquid extraction process, using methanol as solvent till PCBs concentration in oil reached to less than 50 ppm. At the second stage the extracted PCBs in methanol is destructed in a series of reactions by Pd/Fe powder (as a catalyst) and water under microwave irradiation in PTFE reactor. reaction efficiency was more than 97%. In this paper the effect of microwave radiation power and Pd/Fe powder specifications on PCBs decomposition efficiency are presented.
11
98-F-CAM-495
Corrosion Reduction of condenser tubes by Oxygen removal from make up water
Adnan Moradian Mohsen Karegar Ghavibazoo Niroo Research Institute
Iran
Key words: catalytic reduction, dissolved oxygen, corrosion, condenser
Abstract In this paper corrosion of condenser's steam side tubes has been studied. This corrosion occurs because of hydrazine decomposition and ammonia production and it's reaction in presence of oxygen. The oxygen source is dissolved oxygen in make up water which escape due to pressure reduction. In fact, hydrazine is added to water to eliminate dissolved oxygen, but it decomposes due to high temperature in some parts of cycle such as boiler. Therefore in addition to increased corrosion problems, dissolved oxygen can not be effectively removed. In this paper we show that among different types of alloys, the copper alloy tubes are corroded more severe by this type of corrosion. Different methods for oxygen removal from make up water have been studied in this paper. Then we introduce catalytic reduction by hydrogen as a modern and effective method for this purpose. Furthermore, in this paper we consider feasibility and economic study of catalytic reduction method.
12
98-F-CAM-639
Technical, Economical and Ecological Research on Operation of Water & Steam Cycle of Shahid Mohammad Montazeri Power
Plant for Alkaline, semi-Alkaline and neutral methods
Kianoush Zarrin naghsh Mahmoud Paykary Gholamabbas Parsafar Mostafa Shanesazzadeh Marine Research Center
(Isfahan) Petroleum University of Technology(Ahvaz)
Sharif University of Technology(Tehran)
Regional Electric Co.(Isfahan)
Iran Iran Iran Iran
Key words: Hydrazine, Heating Cycle, Chemical Control, Operation
Abstract For chemical control of water and steam cycle in power plants usually is used three methods that are as following: Alkaline, semi-Alkaline, neutral or a combine of them. Combine of methods are used at different parts of a system. Limitations of operation methods at power plants that has dried cooling tower (Heller System) are more than other kind power plants. In the other hand most of the power plant use hydrazine for preparing passive layer. Therefore, with omission of hydrazine the result as the point of economy and environment is more beneficial. At this study we have so tried determination of optimum conditions from technical, economical and environmental viewpoint. And we have done following items: 1- Which operation prepare most suitable passive layer? 2- Which layer has lower growth? 3- Comparing passive layer of three different methods of operation. 4- With attention to change of definitions of water and feeding and injection of spray water in super heaters, what change will be happen in super heaters systems? 5- Examining and selecting the different parameter from technical, economic and environmental viewpoint. For examining of mentioned above, the lab method and information of old units that are working many years and also the new units that are working about too years has been considered.
13
98-F-CAP-231
High Impedance Fault Detection Based on Wavelet Transform and Bayes Classifier
Alireza Sedighi Anaraki Mahmood Reza Haghifam Yazd University Tarbiat Modarres University Faculty of Eng. Dep. of Electrical Eng. Faculty of Eng. Dep. of Electrical Eng. IRAN IRAN
Key words: High impedance fault, Wavelet transform, Principal component analysis, Bayes classifier
Abstract In this paper, High impedance faults (HIFs), usually occur at primary network in electric distribution systems. Detection of HIFs is generally difficult by conventional over-current protection devices, because they have high impedance at the fault point and don’t cause an excessive change of current in the affected line. When this type of fault happens, energized high voltage conductor may fall within reach of personnel. In addition, as the arcing often accompanies these faults, it further poses a fire hazard. Therefore, from both public safety and operational reliability viewpoints, the detection of HIFs is critically important. In this paper a novel method is presented for HIF detection. Using this method HIFs discriminate from others transients state such as capacitor switching, load switching (high /low voltage), ground fault, inrush current and no load line switching. In this method wavelet transform is used for decomposition of signals and feature extraction. Principal component analysis is used for feature selection and Bayes classifier is used for classification of data. In this research HIF data was gathered from real network tests. Due to some practical limitations other transient data were obtained by a simulation of the feeder using EMTP program. Results show that the proposed method is efficient for HIF detection.
14
82-E-CAP-444
Study on the establishment of dynamic performance test environment for the digital protective relay using RTDS
Byung Tae Jang, Chang Youl Choe KEPRI
KOREA
Key words: Dynamic test, RTDS, performance test procedures
Abstract A performance test of digital relay is divided into three parts ; a static test, a dynamic test, a EMC test. Among these, a dynamic test is increasingly important, but the supply of corresponding technique is difficult because of the intricate approach of real time digital simulator. In order to solve these problems, KEPRI has established an environment for performance test, which consists of a system model and a performance test procedure for the dynamic performance test.
15
98-F-CAP-531
Evaluation and Performance Comparisons of Power Swing Detection Algorithms
H. Khorashadi-Zadeh Department of Power Engineering
The University of Birjand Birjand, Iran
Key words: Power swing, Distance relay, Fault and Fault resistance
Abstract This paper presents performance comparisons and evaluations of four different power swing detection algorithms. Any sudden change in the configuration or the loading of an electrical network causes power swing between the load concentrations of the network. In order to prevent the distance protection from tripping during such conditions, a power swing blocking devices cannot cope with very fast power swings. In this work, behavior of the algorithms is evaluated. Different conditions have been generated by EMTDC software and voltage and current waveforms have been given to the power swing detectors. Operation of the power swing detection has been investigated for different conditions and the operation of different algorithms were compared.
16
98-F-CAP-571
An Adaptive Auto Reclosure Scheme using Wavelet Transform on Sirjan-bandar Abbas 400 Kv Line Ali Kadivar
Faculty of Electric and Computer University of Tehran
Tehran, Iran
Majid Sanaye Pasand Faculty of Electric and Computer
University of Tehran Scientific Pole of Control and Intelligent Processing
Tehran, Iran Abstract This paper presents application of wavelet transform in identification of transient and permanent faults by processing the fault generated high frequency voltage transients. It can be utilised to achieve adaptive reclosure with capturing extinction time. Also a nonlinear time dependent dynamic resistance representation of the primary and secondary arcs is proposed with emphasis on an empirical approach which is formulated by differential equations. In addition, some simulations are carried out on a typical 400 kV circuit between sirjan and Bandar abbas for various system and fault conditions using an electromagnetic transient program. About 80-90% of faults on overhead EHV transmission network are transient in nature. The remaining 10%-20% of faults are either semi-permanent or permanent [1],[2]. Transient faults are commonly caused by lightning and temporary contact with foreign objects. The immediate tripping of one or more circuit breakers clears the fault. Subsequent re-energizing of the line is usually successful. Single phase autoreclosing (SPAR) provides a means of improving the transient stability of transmission systems, reducing the torsional impact on generator shafts and reducing reclosing over-voltages. Furthermore, SPAR may become an absolute necessity in applications where construction of additional circuits is prohibitive because of costs or public opinion. However, unsuccessful reclosure with a fixed dead time or reclosure onto a permanent fault may aggravate the potential damage to the system and the equipment due to a restrike of a fault [2],[3]. An intelligent time varying auto-reclosing scheme which can adaptively change reclosure time could be very useful for an EHV transmission system. This paper first develops a mathematical method to determine all the parameters involved in arc transients. It then presents a new technique for adaptive auto-reclosing using wavelet transform for distinguish between permanent and transient faults and determining extinction time of the secondary arc.
17
98-F-CAP-633
A Hardware for Microprocessor Based Distance Relay; Design and Development
Hassan khorashadi-Zadeh, Majid Sanaye-Pasand Department of Electrical and Computer Engineering,
University of Tehran
Abstract This paper presents the design and development of hardware for a microprocessor based distance relay. The major emphasis of the paper will be on the detailed description of the hardware for a distance relay. The relay hardware consists of a data acquisition board, a microcomputer board and input/output board. The microcomputer board controls the data-acquisition process. It also processes the acquired signals and implements the digital distance algorithm. Active low pass filters, sample holders, an analog multiplexer and an A/D converter are furnished for sampling and analog-to-digital conversion of the instantaneous voltage and current data. The I/O board is an interface circuit between digital input/output signals and the relaying logic processor. Additional I/O boards can be connected to the input/output (I/O) channel. The designed hardware can be used for developing and testing different digital distance algorithms.
18
98-F-CAP-640
Measured Impedance by Distance Relay Considering Line Capacitance
H. Shateri S. Jamali Iran University of Science and Technology
Tehran - Iran
Key words: Distance protection, Fault resistance, Measured impedance, Line capacitance, Transmission line
Abstract Distance relays are widely used in the protective systems of transmission lines. These relays provide both the main and back-up protection of the lines. Presence of the fault resistance in the fault loop is one of the factors causing mal-operation of the distance relay. Fault resistance is an unknown quantity, and even if its magnitude is known, then the imposed impedance to the measured impedance at the relaying point is unknown. In the presence of the fault resistance, the imposed impedance might not be pure resistive. In addition to the fault resistance, the amount of the measured impedance deviation is affected by the system structural and operational conditions. In addition to the fault resistance, transmission line capacitance also deviate the measured impedance from its actual value. This deviation also depends on the system conditions. This paper studies the measured impedance considering transmission line capacitance and presents the required equations for the measured impedance in the presence of shunt capacitance. A practical system is simulated to study the effects of changing conditions of the system on the measured impedance at the relaying point. The results show the influence of the capacitance on the relay reach point.
19
98-F-CAP-659
Optimal Frequency Load Shedding with Inclusion of Voltage Stability and Interruption Cost
Mahdi Davarpanah (1),(2) Majid Sanaye-Pasand(1) Electrical and Computer Engineering Department
University of Tehran, Iran
Key words: Adaptive Load Shedding, Wide area protection, Interruption Cost, Static Voltage Stability, Genetic Algorithm
Abstract A New optimal adaptive load shedding algorithm based on wide area protection scheme using genetic algorithm is introduced in this paper. The objective function of the protection scheme is customer interruption cost and the operational restrictions and minimum of static voltage stability margin have been considered. The proposed algorithm uses the synchronized real time power system data. It selects the optimal load shedding pattern for generator tripping contingencies. A comprehensive software package is prepared by MATLAB software. The mathematic formulation of proposed multidimensional objective function is introduced in this paper. The mentioned algorithm is tested on the IEEE 30-bus system after generator tripping or generator and line tripping contingencies.
20
98-F-CAP-673
Simulation of an Out-of-Step Condition Under Two Simultaneous Faults Using Transmission
Lines Sensitivity Coefficients
H. Askarian Abyaneh S.S. Taheri K. MazlumiElectrical Engineering Faculty
Amirkabir University of Technology Iran
Key words: Power Swing, Coordination, Protection, Distance Relays
Abstract Some disturbances like short circuits, load shedding operation or trip a generator or a line, in the system may results an out-of-step condition. This phenomenon takes a long term of time, so we can detect it by some of methods and recognize it from fault condition. In this condition, relays misoperation may cause cascading blackouts. One of those methods is that we coordinate Power Swing Blocking relays for worst out-of-step condition may occur in the system. In this paper, we could simulate that condition, use useful software that programmed for simulation of two simultaneous faulty conditions. This faults occurred on the two most sensitive lines, that selected by “Lines Sensitivity Coefficients Analyzer” module. This simulation enables us, see the impedance behavior of the studying line and coordinate the PSB relay for this condition.
21
98-E-CAP-682
Coordination of Over Current and Distance Relays for Interconnected Power Systems Using Optimization
Technique Optimal coordination
Matin Meshkin Hossein Askarian Abyaneh Hossein Kazemi Kargar Amirkabir University Amirkabir University Zanjan University of Technology of Technology
Iran-Tehran
Key words: Optimal Co-ordination, Critical Points, Overcurrent Relay, Distance Relay
Abstract In detecting the fault and isolating the faulty element in a power system, the protective system must be very selective. It means that when a fault occurs the main protection is required to operate and if it si not operated the backup protection must be operate after a time delay. Therefore, backup and main relays must be coordinated for all operating situation. Several methods have been proposed for the coordination of main and backup relays but Ordinary coordination algorithms have not effective in ac interconnected network so in the new years, using the optimization method for coordinating are considered. Optimal coordination of over current and distance relays is the new subject that consider in this paper. They must be coordinated such that the time delay between the clearance time of the over-current relays and the distance relays is in allowable margins. However there are points, which if a fault happens to be there, the selectivity between the over-current and the distance relays will goes under question and will not be allowed. These points are named critical points. The equations governing the relays constraints are constructed by putting short circuit on these points. The optimization problem just described is solved with using a new optimal method. The new method that was previously used for coordinating of overcurrent relays, is only based on these constraints and don’t need objective function, initial condition and auxiliary variables. Also this method can consider linear and nonlinear relay characteristics. The effectiveness of the new method is tested on some sample networks.
22
98-E-CAP-683
Modelling of Overcurrent Relay Characteristics Based on Neural Network
Matin Meshkin Karim Faez Hossein Askarian Abyaneh Hossein Kazemi Kargar
Amirkabir University of technology
Iran-Tehran
Key words: Overcurrent Relay, Relay Coordination, Relay Modelling, Neural Network, Cascade Correlation
Abstract Accurate models of Overcurrent (OC) with inverse time relay characteristics play an important role for coordination of power system protection schemes. This paper proposes a new method for modelling OC relays curves. The model is based on artificial neural networks. The cascade correlation neural network is used to calculate operating times of OC relays for various Time Dial Settings (TDS) or Time Multiplier Settings (TMS). The new model is more accurate than traditional models. The model is validated by comparing the results obtained from the new method with nonlinear analytical, perceptron and backpropagation neural networks models as applied for various types of overcurrent relays.
23
98-F-CAP-685
Hardware Implementation of Fault Detection, Classification, and Location in Transmission Lines
S. Jamali H. Sardari S. Ramezan-Jamaat H. Shateri
Iran University of Science and Technology Tehran-Iran
Key words: Fault detection, Fault classification, Fault location, Transmission line, Phasor extraction
Abstract In this paper, design and implementation of a prototype digital fault locator is presented which can independently detect the fault occurrence time, fault type, and fault location on a transmission line. In order to detect the fault occurrence, the instantaneous setting is used and for determining the fault type, the Clarke Method is employed. The fault location method is based on the fundamental components of single end measurements of the line voltage and current signals. In this work, a compensation method is used in order to improve the precision of fault location which takes into account the effect of remote-end infeed using the complete network model. Fault locator hardware and software are also presented. To show the effectiveness of the developed software and hardware, the results of fault location method utilizing the created fault data by Electromagnetic Transient Program (EMTP) are given. Results show that the implemented software and hardware have an acceptable accuracy and the product can be used in real systems.
24
98-F-CAP-711
Protection Scheme for Distribution System with Distributed Generation Using Neural Network
N. Rezaei M.-R. Haghifam Sazeh Engineering Consultant Tarbiat Modarres University
Key words: Distributed generation, fault location, neural network, protection, recloser.
Abstract Interconnection of distributed generation to radial distribution system has an impact on the coordination of protection devices. New technologies for protection are therefore necessary to be introduced in order to isolate only faulted section from system. Most faults which in feed sources from both ends, especially fault with resistance is very difficult to be identified and located. This paper presents a novel approach that can overcome the above difficulties. Feed forward neural network is used to identify fault location. The predicted results from the algorithm proves the effectiveness of proposed procedure for identifying fault location and then protection of the system for a wide range of the system condition.
25
98-F-CAP-756
Analysis and Simulation of Problem With Distance Protection For Series Compensated Lines
P. Jafarian M. Sanaye-pasand K.N.Toosi University of Technology, Tehran, Iran
University of Tehran, Tehran, Iran
Abstract Parallel combination of capacitive reactance and non-linear resistance (caused by series capacitor protection devices) in compensated lines causes many problems on correct impedance calculation by line protective distance relays. Most problems with distance protection of series compensated transmission lines occur in cases that fault currents are smaller than protection threshold of capacitor protection devices. In these cases protective devices for capacitor are not able to bypass the capacitor efficiently. This may result in voltage inversion, current inversion, subsynchronous resonance and overreaching of distance relay. Different algorithms can be used to calculate fault loop impedance. In most of these algorithms, fundamental frequency components of sampled voltages and currents are used to estimate positive sequence component of fault loop impedance. The speed and accuracy of relay response depends on data window length and employed algorithm to a great extent. Generally there is an inverse relationship between accuracy and speed of algorithms. In this paper, simulation results of a distance relay performance is illustrated when short circuit faults occur in different location of a compensated line. For this purpose a system consisted of a transmission line, series capacitor at both ends of the line and capacitor protection devices against over voltages is modeled by ATP-EMTP software package. Simulation results of short circuit faults are used in Matlab software to calculate the impedance seen by an ordinary distance relay through voltage and current phasor estimation.
26
98-F-DTC-212
A novel speed-sensitive bidirectional overflow and hand-down resource allocation strategy
for hierarchical cellular networks
Mohammad Reza Dehbozorgi **
Arash Aziminejad *
** Iran Telecommunications Industries
* Department of Electrical Engineering, Iran University of Science & Technology (IUST),
Narmak, Tehran, 16844, IRAN
** Iran Telecommunications Industries
Key words: Resource management, Hierarchical cellular structure, Speed estimation and segregation, Teletraffic performance
Abstract Next generation cellular systems are expected to use multilayered, multi-sized cells to cover non-homogeneous populated areas. In this paper , a new method for managing users with different mobility characteristics (slow and fast) in a two-layer cellular structure, through utilizing a combination of overflow and take-back (hand-down) schemes is presented. A novel speed-responsive overflow and hand-down mechanism implemented in a single unified hierarchical channel assignment scheme called O&H-HCA, jointly handles the overflow traffic from lower layer to higher layer and directs the handoff calls to the specific layer dependent on the speed class of the mobile units. Numerical results obtained from comprehensive and detailed teletraffic performance assessment reveal superiority of O&H-HCA over traditional hierarchical schemes.
27
98-E-DTC-282
Implementation of UCA Based Inter and Intra Substation Communication Architecture
Alireza Bakhtar Mahni Kooshavar Azerbaijan Power Engineering Consultants (MONA)
Tabriz, Iran
Key words: Automation, Protocols, Communication, UCA, GOOSE, DCS
Abstract Modern electric power systems have been called "The largest human made machine" because they are physically large, literally thousands of miles, which are operating in precise synchronism. The paper provides a concise explanation of the automation and supervisory Control and data acquisition (SCADA) requirements in grace of maturing next generation microprocessor based IEDs, which is found crucial, by the Azerbaijan Power Engineering Consultancy (MONA) Company for the substations in Iran. Protocols play a major task in communication systems, therefore commonly accepted communication protocols RS232, RS485, DNP3.0 and IEC 60870 are discussed briefly and the state-of-the-art data communication protocol IEC61850/ utility Communication Architecture (UCA) are explored in depth. With the promising advantages and maturing of the IEC61850/ UCA, utility companies are forced to begin implementation of substation protection, control system, which is based on this technology. Also, this paper describes such a design for Sahand 230/132/20 kV substation, pretty important power station, with regard to the control, protection, and information flow, control sequence and reliability, which is required and expected by Azerbaijan Regional Electric Company. In addition to mentioned points, this paper includes a brief tutorial on IEC61850/UCA.
28
82-E-DTC-459
Development of the Composite Communication System for Distribution Automation System
Seong-ho Ju*, Byung-seok Park, Tae-young Lee, Kwi-il Kwak, Duck-hwa Hyun Korea Electric Power Research Institute
Key words: communication system, PLC, DAS, TRS, Satellite, Optic
Abstract Powerline communication (PLC) is one of the latest progressive technology in the field of communication. It has many advantages if it is commonly used in life because it uses powerline as communication media : no new wire, reduced construction cost, easy management and repair, and the like. However it is not exactly reliable when it’s uses in long-distance network, especially power distribution network. Therefore, PLC need to be complemented with other existing technologies, which will be helpful to construct reliable, flexible, and extensible communication system for the power distribution network. In this paper, we propose a very reliable and flexible communication system consisted of hight/low-speed PLC, TRS, satellite, optic fiber, and many other communication technologies.
29
98-F-DTC-485
The Design of Software System for Authenticating Data for Control Data transmission Secondary Protection in HV
Substation with Magnetic Shield
H. Heydari, F. Faghihi, Z. Saberi, E. Moshtaghi, V. Abbasi, S. Adelkhani Iran University Science and Technology
High Voltage and Magnetic Material Research Center
Key words: Electromagnetic compatibility, Data authentication, Shielding, Hash function
Abstract Considerable electromagnetic permanent and transient interferences are mainly near HV substations. It is because of huge currents and voltages and switching operations. Hence electromagnetic compatibility (EMC) in HV substations gets scientists attentions. One of the main aspects of EMC is security of transmitted digital control data from outdoor to dispatching room which needs suitable design due to compatibility which requires control cables with suit shields and paths that have minimum interference. Sometimes there are some transient fields which cause changes in control signals, despite of all solutions. As a solution in this paper, besides designing suitable magnetic shields for control cables, use of Hash function which has high speed and low interference under UMAC title in dispatch and receive control signal for transmitted data secondary protection is suggested.
30
98-F-DTC-519
Fiber Optic Network Infrastructure for Future Power System Communication
M. R. Tajdani,M. A. Kazerooni , P. Setayeshgar, R. Dehbozorgian Fars Regional Electric Company,Shiraz,Iran
Key words: Fiber Optic,data Communicate,Real Time , Monitoring , WDM, IP
Abstract From high-speed substation control and protection data communication to wide area power system monitoring and measurement data transmission, the increasing incorporation of computer network throughout the utility as well as the forces of deregulation are compelling power system communications into new realms with new requirements and challenges. Expanding network services such as real time wide area control and FACTS (Flexible AC Transmission System) device coordination are also driving the need for evermore bandwidth in the network backbone. These needs will grow further as new real-time service, protection and control applications become more feasible and pervasive. Electric utilities often employ several types of communication media for different functions. With more and more bandwidth required by the power system data communication, the current transmission media cannot meet all the high capacity and quality of service requirement. Fiber optic provides the ideal alternative for the future power system communication infrastructure design.
31
98-F-DTC-550
An introduction to the protocol of spread spectrum radio modem
Kamran Ghavami Niroo Research Institute
Iran
Key words: Spread spectrum, Frequency hopping, Synchronization
Abstract As the wireless communications field has grown over the last few years, the method of communication known as spread spectrum has gained a great deal of prominence. Spread spectrum signals are best characterized by their bandwidth which is considerably larger than their information rate. In this paper the communications protocol of a frequency hopping spread spectrum radio modem is described. This system is specifically designed and implemented for SCADA systems of power industry and uses ISM band for communications. Because this band is too crowded, the protocol is designed to be adaptive and automatically avoid occupied bands. As the hop synchronization has the most important role in frequency hopping systems, most of protocol concerns achieving the best hop synchronization between transmitter and receiver. After a brief introduction to the structure of designed protocol and its restrictions, different modes of synchronization, the methods of using equal frequency bands in transmitter and receiver and finally the techniques of adaptive frequency hopping is expressed.
32
98-F-DTC-746
Performance analyzing in optical communication and it's protections
Akram Bayat K.N. University of Technology Electrical engineering
department Control group Tehran - Iran
Seyyed Sadegh Mottaghian Niroo Reserch Institute Communication Group
Tehran - Iran
Abstract Communication requirements are increasing in the world and the optical communication networks have rising growth in the country as in the world. More complicated networks have been formed due to the increasing in the number of communication systems and the link points between them (communication nodes). Furthermore, in network protection part, because of the importance of most of the services, designing network preservations is of great interest. Another factor in designing vast communication networks is the economical considerations. In this case a thorough utilization of network facilities, different dispatching levels of optical communications and choosing proper levels for the case of transmission in the different routes of the network will be considerable in the process of design. In this article the significant factor in the network design have been scrutinized, important network protections and the methods to determine the transmission levels and also some treads to optimize the network designing have offered.
33
98-F-DTC-779
“Design and Implementation of a Multiplexer For 8 Data Channels”
Alireza Kasaeifard ,Maryam Shabro
Communication Dept., Niroo Research Institute Tehran-Iran
Key words: Multiplexer, PLC1, Data port
Abstract SCADA2 data transmission is achievable by the PLC system. Regarding existing Analog PLC links that support maximum two 600bps data channels, it seems that the number of PLC equipment will be raised, when the number of SCADA data exceeds two. However by means of a data channel multiplexer system, a link of PLC can be used for transmission of high number of SCADA data and this could be a solution for the problems such as frequency planning. As an illustration, according to the present Power Industry’s plan, the unmanned operation for 63 KV substations is taken in to consideration. Since in the stated cases voice channel establishment is not mandatory, so data channel multiplexer can be regarded as a proper solution. The designed and implemented multiplexer supports 8 asynchronous data channels with maximum 1200bps data rate. The method of multiplexing is TDM and the HDLC3 has been used as a protocol between two multiplexer units.
1. Power Line Carrier 2. Supervisory Control And Data Acquisition 3. High Level Data Link Control
34
98-F-DTC-788
Design a New Semi Digital PLC With Improved Specification
Hamid Reza Hafez Aghili Niroo Research Institute
Iran
Key words: Probability of error, Differential PSK, M-ary Modulation, FSK, QPSK
Abstract PLCs are always categorized in three classes . These three classes are : Analog , Semi digital and Digital PLCs. Studies show that in future the power transmission systems will be so desire in data transmission . A new semi digital PLC is introduced that has the capability of transmission of data lines with the capacity of two or three times more than analog and popular semi digital versions. The multilevel modulation has been used for design of system , also we use PSK or exactly DPSK modulation so that we can use the same power level as the analog system with the same probability of error.
35
98-F-DTC-789
Downconversion Techniques for Software Radio System
Hamideh Bahadori Niroo Research Institute
Iran
Key words: Software Radio, Sampling, DSP
Abstract Software radio is an enabling technology which may provide a solution for the realisation of multiband, multimode radio terminals by defining radio functionality in software. This allows the radio terminal to be adapted to different systems or Protocols for various services by reprogramming the radio functionality. The work presented in this paper describes a short overview of software radio and some of the problems faced by this concept. The methods of downconversion mentioned, bandpass sampling and direct conversion are reviewed and then compared by means of computer simulation. The effects of the RF bandpass filter on the performance of each downconversion architecture are observed.
36
98-F-DTC-821
A Power Line Carrier Communication System for Automatic Device Control
Alireza Dehghani Department of Electrical & Electronic Engineering
Marvdasht Islamic azad University, Iran
Key words: Device control, PLC, Low voltage power line, Microcotroller, Power line modem
Abstract Technology in today’s world is improving rapidly. Today hundreds of millions of users at homes and businesses use computer. A growing trend in using of computers is industrial control and home automation, a practice in which electrical devices are controlled with little or no human interaction. Therefore various numbers of commercially systems have designed and the new version of them will become available. Between these systems, the most reliable ones are expensive. The inexpensive ones are unreliable and must be controlled locally. To solve these problems, a system that is reliable, affordable, and easily accessible is needed. In this paper I introduce an efficient system, which meet the mentioned requirements. The proposed system gains the addressed issues by utilizing the capabilities of both hardware and software. This system by using of low voltage Power line as communication medium reached to low cost. Users by a host computer in this system can program and even change schedules for efficient controlling of the appliances. This made the system user friendly.
37
98-F-DTC-841
The fastest way of Finding the best substation for installation of RTUs
ghassem karami NRI Iran
Key words: Automation, RTU, Reliability, Distribution Network, SAIDI
Abstract Distribution section is the widest and closest to customers part of electrical networks so it has most important effect on people. This section is the only part which is involved with people directly. In addition 70% of faults occurs in MV network. So it seems distribution automation has main rule to satisfy customers and people and reduce effects of faults. Switching devices such as breakers and disconnections also have important rule in electrical networks and automation. Fast fault finding and switching has most effect in automation but everybody knows that there are lots of switching devices in distribution network and automation of all switches isn't possible due to unexpected costs. So we should find the best place to automate switches which leads us to find the best substations in distribution network (MV network). In this paper we have tried to propose a fast way to find the best substation to for installation of RTU. This way is based on reduction of duration of faults on MV networks and we try to minimize SAIDI in each feeder of MV/MV stations. In this way we will consider RTU in each substation and calculate SAIDI, then with moving RTU in other substations, find the substation with minimum SAIDI. Then we propose a experienced way based on theoretical aspects to find the best substation in each feeder of distribution network.
38
11-E-DTC-898
A survey on Electric Power T&D Automation around the World
Charles W. Newton- Mahmood Makhdoomi Newton- Evans Research Company- Niroo Research Institute
USA-IRAN
Key words: SCADA, EMS, DMS, T&D Automation
Abstract Progress is being made on securing investment in many countries at the Energy Ministry level to enable forward movements on one or more delivery reliability enhancement programs. Any rapidly developing country simply must recognize that electric power is the fundamental building block for a modern economy and should invest strongly in grid infrastructure modernization and expansion. Utilities are continuing to make slow progresses on T&D automation and integration initiatives, proceeding with caution until the implications of the new federal energy law are fully understood and there is clear long-term direction from state regulators regarding restructuring and deregulation, if any, within their states. The single biggest obstacle to further investment in grid-related reliability enhancement programs and activities lies in the personnel realm. Scant attention is being paid by utility staff to make “the business case” for these programs to a new generation of top-level executives -- who likely did not come from a power utility background and may not see the rationale for such spending. Although the technology case seems adequate, a business rationale must also be put forth. At present most notable trends include: 1) Utilities are forging ahead with increased levels of T&D automation. 2) Utilities are increasing the scope of their IT systems and addressing 21st
century network security concerns. 3) Increased “plug and play” in T&D automation and integration environments. 4) Striving toward the “self-healing” grid. 5) Near-term effects of the energy law. In this paper trends of development of Control Center Systems, EMS, SCADA, DMS for networks, Distribution Automation and IED, Protection and Control and at last but not least Data Communication in Power System networks are analyzed and investigated. It is shown that the major concern among various parties are the extention of system Automation reliability and Security, to overcome in Power System requirements, especially in the new restructured Power Systems.
39
98-F-ELM-105
Performance Analysis of Three-phase Induction Motor Under Misalignment Condition Based on Winding Function Approach
and Experimental Results
H. R. Akbari Rokenabadi1 H. Meshgin-Kelk2 Jafar Milimonfared3
1, 3 - Amirkabir University of Technology
2 - Tafresh University
Key words: three-phase induction motor, misalignment, winding function approach.
Abstract In this paper, three-phase induction motor is simulated under healthy and misalignment conditions. Simulation results show that in the case of misalignment condition, motor is started faster than in the healthy condition. Also power factor of the machine vary in the case of misalignment. Simulation results are verified by experimental results.
40
98-F-ELM-119
Finding optimum parameters for vector control of silent pole synchronies motor using Fuzzy - Genetic algorithm
Mohammad Reza Zareh1, 3, 5
Mosa Marzband2, 3, 4 Syeed Morteza Saghayeyan nejad1
Esfahan University of technology, Iran1
Mazandaran University, Iran2
National Petrochemical Company of Iran, Iran 3
Abstract silent pole synchronous motor because of having non_ cylindrical rotor has a fast dynamic response and the possibility of designing self controlling synchronies drivers at high voltage, power, current and speed levels has caused it to become distinguished compared to other DC and induction drivers. In this paper, the method of tracing flux of rotors turn has been used to control the drive. Because of the robustness of Fuzzy controllers in the cases of load interruption and noise production this controller is used for setting the drive. For finding optimum parameters and ordinary controllers coefficients, we have used the Genetic algorithm. In this paper, the design of controllers according to Fuzzy_ Logic and Genetic algorithm and also the performance of synchronies drive in the case of applying FG1 controller is analysis and the relating computer results are presented. Finally, the results obtained in this paper are compared with the results relating to vector control of projected pole synchronies motor that have used common controllers (PI controller) for controlling the drive. During the execution of Genetic algorithm in order to get to the optimum solution faster, we placed the parameters of the ordinary controllers that were obtained by trial and error into the primary sequences. Also, noticing the slowness of SIMULINK/MATLAB software, Borland C++ software has been used for simulating.
1 Fuzzy_ Genetic
41
98-F-ELM-243
Analysis of motor efficiency determining techniques in industries and giving a new method on genetic algorithm basis
Razmara Zakerifar Mohammad Aliyan Mazandaran R.E.C
Key words: Energy audit ,Motor efficiency ,Genetic Algorithm
Abstract Manufacturer , are reluctant to replace otherwise satisfactory motors without evidence that cost of new premium-efficient motors. To provide this evidence on-site energy audits are the best solution. Of course, there are exact methods to determine electrical motors efficiency in laboratory on existing standard basis. but the method given in the standards con not be used for motor efficiency evaluations under practical conditions because ,the electric motors in industrial are operated under different conditions toward nominal conditions such as low load, different temperature ,line supply voltage fluctuations, voltage unbalance and voltage harmonics,…. Determining of actual motor efficiencies is certainly a valid tool to justify the use of premium-efficient motor over usual motor .It must be noticed that exactly determining of motor load and efficiency is not necessary but these used method must be capable to can compute above values with minimum difference to decide on that basis. In this paper, we attempt to introduce several method of motor energy audit in industrial and analysis benefit and defects of each method to can use each of them with perfect awareness.
42
98-F-ELM-294
A New Method in Improvement of Robust Position Control in DC Motor by Fuzzy Sliding Mode Control
Dr.Mostafa Mohamadian Dr.Ali Yazdian Varjan Mehdi Hendijani Zadeh
Tarbiat Modares University IRAN
Key words: Position Control, Sliding Mode, Fuzzy Control, DC Motor
Abstract In spite of development of AC system, DC motivations are still so usable for driving system in technology. One of the problems that may cause these effects useless are variable parameters, which are used during system's operation. For solving this problem, the best proposal is using modern controlling method. we should pay attention to two points for these methods 1.nonsensitive 2.having suitable response .One of the modern method to control is sliding mode control .This method is defined by state variable, however it has some faults which one of them is constant of parameters of controller. Although in this case the response is more suitable than classic methods but it is not the best one. The best response is identified in low settling time, low overshoot and high stability. In this paper we reach to the best response for controlling the exact position of DC motor by using fuzzy logic for flexibility of sliding mode control.
43
98-F-ELM-394
Modeling of Permanent Magnet Motors and Analysis of Magnetic Forces under Air-gap Asymetry
Homayoun Meshgin Kelk Electrical Engineering Department
Tafresh University
Key words: Synchronous motor, modeling, air gap asymetry, vibration
Abstract Electromagnetic forces are the source of vibration and noise in electric machines. Estimation of these forces is necessary for the design, construction and analysis of electric machines. Due to the increasing application of permanent magnet motors in modern industry, more researches are required to study the performance of these machines. This paper presents a simplified magnetic equivalent circuit method for the modeling of permanent magnet machines. Transient and steady state analysis of unbalanced magnetic forces are studied.
44
98-F-ELM-408
Single Phase Induction Motor Soft Dynamometry with Electrical & Mechanical Parameter Identification
Farid tootoonchian Abolfazl Vahedi Davod Arab Khaburi Iran University of Science & Tech. (IUST)
Key words: Single Phase Induction Motor, Dynamometry, Parameter Identification
Abstract After manufacturing of electric motors, kinds of tests will be implemented, in order to evaluate the performance of the motors. This procedure is known as “Dynamometry”, an expensive & time consuming tool, which needs special mechanical tools with an expert technician. In this paper a new soft dynamometry method is proposed. That is not only inexpensive but also, timesaving. In this method motor’s electrical & mechanical parameters should be identified and then dynamometry curves will be plotted using dynamic & steady state simulation. To evaluate validity of the proposed method it is applied to the single-phase capacitor run induction motor. Comparison of results to the conventional method shows that the results are quit acceptable.
45
98-F-ELM-409
Parameter sensitivity analysis of indirect vector controlled induction motor drive system
Abolfazl Vahedi Abbas Shiri Hossein Azizi Iran University of Science and Technology (IUST)
Key words: induction motor- vector control- parameter varying- sensitivity analysis
Abstract Nowadays, control of ac induction motors using the vector control techniques is more popular in industry applications. Using vector control in induction motors requires an exact knowledge of the machine parameters. Any mismatch between motor parameters and those instrumented in the vector controller will result in the deterioration of performance of the system. Changes in temperature and saturation levels of the machine vary the motor parameters. In this paper, analytical functions for “output torque and rotor flux” are defined and analyzed. Referring to the defined functions, the effect of parameter variation over outputs of vector controller can be foreseen. Matlab/simulink based simulations is carried out to confirm the results of the analytical functions.
46
49-E-ELM-442
Dielectric Response Studies on Insulating System of High Voltage Rotating Machines
Mohsen Farahani, Hossein Borsi, Ernst Gockenbach
University of Hannover, Institute of Electric Power System (Schering-institute), Germany
Key words: Rotating machine Insulation, Dielectric response measurement, Polarization, Diagnostics, Aging, Moisture
Abstract A significant method to characterize the electrical properties of materials and to evaluate the condition of the insulating systems is the dielectric response study which can be done in the time or frequency domain. The dielectric response measuring results can be affected by different parameters like measuring voltage, temperature, water content and aging condition of insulating system. In this work numerous measurements are presented, thus to understand, how the dielectric response measurement results can be affected by the water content and aging condition of insulating system of high voltage rotating machines in the time and frequency domain. Because of the importance of the dielectric response application as a non-destructive diagnostic method the possibilities and limitations of this method to reflect the deterioration processes due to thermal and electrical stress were investigated. As test object, actual stator bars were used, that were manufactured with Epoxy VPI technology.
47
98-F-ELM-473
Torque Ripple Minimization in Switched Reluctance Machine
Key words: Switched Reluctance Motor,Torque Ripple, Motor Modeling
Abstract Ripple in output torque of switched reluctance motors are higher in comparison with conventional motors. This disadvantage, has limited its usage in servo systems. In this paper, a method for reducing torque ripple is presented which has two advantages of sufficient values for peaks and rates of change of reference currents. Simulation is based on a model which by that, saturated behavior of motor has been carefully taken into account. This model does not need neither measured nor finite element data which are the strongest requirements of other modeling techniques. Mentioned model requirements are only machine geometry and its magnetic material characteristics. Finally, simulation results for torque ripple minimization drive at low and high speeds in comparison with conventional one are presented. Also, some practical drive implementation features have been emphasized.
Amin Hassan Yazdavar AmirKabir Univ. of Tech.
Mojtaba Mirsalim AmirKabir Univ. of Tech.
48
98-F-ELM-612
Recognition of Partial Discharge Pulse Patterns In Generator Stator Bars Using Statistical Features
And Probabilistic Neural Networks
M. Rafiee H.A. Shayanfar Iranian University of Science and Technology
Key words: Partial Discharge, Statistical Features, Probabilistic Neural Networks, Stator Bar
Abstract This paper describes the results of partial discharge measurement in stator bars using a computer based measuring system. In 9 hydro generator stator bars as test objects, two type of artificial insulation defects are made including semiconductor paint defect in the "out of slot" section and conductor paint defect "in the slot" section and experiments are done in 3 cases called defect #1, defect#2 and "with no defect". Preprocessing of PD signals is made using specially developed software and two statistical PD pulse distributions are calculated. 8 statistical features of these distributions including skewness and kurtosis for positive and negative polarity of PD signals are extracted. Half of these experimental data is used for training and the rest is used for testing of a neural network. Because real stator bars are used for these experiments and artificial defects made on them are not completely similar, a special type of neural networks named probabilistic neural network is used for classification of defects. The results show that this type of neural networks can successfully recognize PD patterns even if it trains with an uncertain training data set.
49
98-F-ELM-616
Recognition of Partial Discharge Defects In Generator Stator Bars by Using Weibull Analysis
M. Rafiee H.A. Shayanfar Iranian University of Science and Technology
IRAN
Key words: Partial Discharge, Weibull Function, Stator Bar, Statistical Analysis
Abstract Results of investigations performed in order to evaluate the ability of Weibull analysis for recognition of different PD phenomena accruing in a real stator bar are presented in this paper. Two types of surface insulation defects creating different PD patterns are made artificially in an unused real stator bar and PD measurements are performed in 3 cases namely "defect#1", "defect#2" and "with no defects" all at two test voltage level. Preprocessing of raw PD data is performed by the APDA software developed by authors for this purpose. PDHD and its related cdf are obtained. A Weibull function is fitted on each cdf distribution and its shape and scale parameters are calculated using LMS cure fitting method. Meaningful difference between shape and scale parameters of Weibull function for each type of defect shows that these parameters can be used for separation of different PD patterns in a real stator bar.
50
98-F-ELM-765
A Self-Tunable Sensorless Method for Rotor Position Detection in Switched Reluctance Motor Drives
E. AFJEI, M.M. NEZAMABADI, and M.A.M. SAATI Dept. Electrical & Computer Engineering
Shahid Beheshti University Saadat Research Institute
Iran-Tehran
Key words: Switch Reluctance motor, Sensorless operation of SRM, Indirect rotor position sensing in SRM, Motor control
Abstract This paper presents a complete self-tunable method that is designed to detect the rotor position at standstill, low and high speeds in switched reluctance motors for different motor power ratings. In this method, high frequency diagnostic pulses with different pulse width are applied to the three stator pole windings and then the proper size pulse width is determined for that particular motor at standstill. It then continues to sense the rotor positions with the selected pulse width while the motor running at low speeds by applying the pulse to the un-energized phase winding and sensing the rotor position from the resulting phase winding current magnitude. At high speeds (beyond motor rated speed) the rotor position is detected by the current magnitude produced by the injected pulses and at the same time advancing the phase on time according to the motor speed. This controller is then tested on the different motor ratings from 20 W to 2 KW range. Finally, this scheme applied to a vacuum cleaner using switched reluctance motor as its driving force successfully which demonstrate the feasibility and practicability of the method.
51
98-F-ELM-828
A New Method Based on Park's Vectors Approach for Bearing Fault Detection
Jafar Zarei, Javad Poshtan
Iran University of Science & Technology Department of Electrical engineering
Narmak 16844, Tehran, Iran
Key words: Fault Detection, Induction Motor, Bearing, Park vector
Abstract Induction motors vibrations, caused by bearing defects, result in the modulation of the stator current. In this research, a new method based on park vector approach for bearing fault detection using 3 phase stator current analysis is presented. In order to evaluate the ability of the proposed method several experiments are done, and Localized defect in outer and inner race is evaluated using this method.
52
98-F-ENV-173
An Analysis of the Anaerobic Digestion of Saveh City’s Environmental Pollutants for Building Iran’s first Bio-gas power Plant
Ali Nazari , Akbar Shabani Kia , Javad sheikholeslami Ministry Of Energy – Renewable Energy Organization Of Iran ( SUNA)
Iran
Key words: bio-gas, bio-gas power plant, anaerobic digestion, municipal solid waste (MSW)
Abstract In absence of oxygen, Bio-gas is produced by the anaerobic digestion of organic compounds. This gas is flammable and composed of 60%-70% methane, and 30%-40% Carbon Dioxide and could be a suitable substitute for fossil fuels. Taking Bio-gas into consideration, it can provide part of the community energy requirements and it will also be a great help in resulting the consequential difficulties of ever increasing varieties of garbage’s, waste waters of different food and agricultural industries and sludge’s of the sewage water and water filtration plants. In this article, while expounding on the activities that led to the construction of the first Bio-gas plant in Iran in the city of Saveh; anaerobic digestion of four groups of main environmental pollutants of Saveh city (municipal solid waste, sludges of the industrial city’s filtration plant, slaughter house waste water, and sludge of leaching pit) by taking the relative share of each pollutant in the city into consideration, will also be analyzed.
53
98-F-ENV-214
Results of Feasibility Study for Power Generation from Landfill Gas (LFG) in Shiraz
Mehrdad Adl1 , Reza Goodarzi Rad2 Behrooz BoghlanDashti3 , Shahriar Bozorgmehri1 , Hamid Reza Lari1
1-Renewable Energy Department , Energy & Environment Research Center, NRI
2- Energy Planning Dept., Deputy of Energy 3-Renewable Energy Organization of Iran(SUNA), Biomass Dept.
Iran
Key words: Landfill , Electrical Power, Biogas, Electricity Generation, Economical study
Abstract This paper is allocated to feasibility study of a biogas-fueled power generation plant in landfill site of Shiraz. Shiraz city is the capital of Fars province in Iran, in which the Municipal Solid Wastes(MSW) are disposed in a sanitary landfill. The main target is assessment and feasibility study of electricity generation from “waste-degradation” derived biogas to achieve useful energy, as well as reduction of methane emission to atmosphere(which is 21 times more destructive than carbon dioxide).This feasibility study consists of several steps as follows: a) gas generation modelling and prediction of Landfill Gas(LFG) flow in future, b) thoretical estimation of long-term power capacity based on gas generation trends, c) camparison of existing technologies for conversion of LFG to energy and selection of appropriate technology for Shiraz Landfill site, d) technical assessment of commercial power generation equipments for LFG utilization, e) indentification of power generation approaches in Shiraz Landfill, f) economical study of proposed approaches, and selection of the best approach. The theoretical yield of biogas estimated as 143 Nm3 per ton of raw MSW in Shiraz city. In current site conditions, at least 220kW power is achievable from existing gas extraction system until 2015. By development of gas extraction system to coming waste layers up to 2010, it is feasible to install the power generation plant with 670kW and increase it’s capacity to around 1065kW at the third year which will be confident until 2017. The economical assessment showed the recent approach as the best option. Electricity price in this option is estimated as 275 Rials/kWh (3.1 UScents/kWh) based on 16% discount rate.
54
98-F-ENV-794
Fish protection development at the Neka power plant
Morteza Jalali Lichaei
Niroo Research Institute (NRI), Environmental protection Dept. Iran
Key words: fish deflection, electric pulse, physical barrier, behavioral, threshold voltage
Abstract One of the major environmental problems in Neka power plant is fish entrainment and losses at its water intake system. After unsuccessful installation of a strobe light fish retaining system, an electrical fish protection system have been installed in front of channel openings. According to improper fish guidance efficiency of this system, several methods including mechanical and behavioral fish barriers were studied to attain better efficiencies, and electrical method was considered as the most suitable method. Pilot tests performed in order to assign the effect of various parameters on fish retaining rates and finding optimal operating conditions. Considering the importance of underwater electric field distribution as the major parameter, a software program for three-dimensional simulation of underwater electric field has been developed. Simulation result shows that effective electric field is limited to high water velocity area inside the input channel causes improper deflection, so electric field should be extended to areas with lower flow velocities. After surveying several methods for electric field development, installation of some accessory electrodes in front of the main electrodes selected as the suitable method. After calculating required excess electric current after system development, two methods of system modification were selected Applying these modifications, up to 60-80% reduction of fish mortality at water intake is expected.
55
98-F-ENV-845
Determination of human health effect and environmental damage due to air pollution emission of power plant stack
M.Ghiasseddin, PhD-K. Feyzbakhsh-M.Lotfalikhani Matn-Co.
IRAN
Key words: damage, air Polltion, environment, Power Plant, externality
Abstract One of the main concern of industrial managers are high cost of environmental control implementation. Their argument is that the cost of pollution control has no benefit for the industry. In this regard power industry is not an exception. In this project it has been tried to investigate damages imposed to the environment by some of selective power plant to be able to analyse the cost of Pollution control for confirming the economical aspects. 3 Power plants in different locations and different processes were selected for this survey. In these Power plants gasous Pollutants and their dispersion in surrounding environment were investigated. To determine the proportion of power plant share to the other available sources gaussian model (Screen 3 software) was employed. Then the externality according to Rials Per kilo watt for human health and agricultural prodects was calculated. The cost of pollution damages for Peak and normal conditions, for Power plant number one were 25.33, 28.51, number two 22.82, 22.92 and number three 17.30 , 20.77 Rials per kilo watt of produced electricity respectly.
56
12-E-EPG-130
Development of a Stand Alone Micro-Hydro System using Pump as Turbine Technology for Low Head Sites in Remote Areas
Salil Joshi1 A. Gordon L.Holloway2
Liuchen Chang1 Hossein Madadi Kojabadi3
1Dept. of Electrical & Computer Eng., University of New Brunswick, Fredericton, NB, E3B 5A3 CANADA
2Dept. of Mechanical Eng., University of New Brunswick, Fredericton, NB, E3B 5A3 CANADA 3Dept. of Electrical Eng., Sahand University of Technology, Tabriz 51335-1996 IRAN
Key words: Stand Alone Systems, Low head Micro-Hydro, Pump as Turbine, Self Excited Induction Generator, Inverter
Abstract In the world there are many villages without electricity. Due to remoteness of these communities it is difficult to connect these with grid. This condition makes them eligible for the decentralized remote power technologies. This case study illustrates how simple technology can be applied to micro-hydro power system to provide a viable form of energy to off-grid communities. Small-scale hydroelectric power systems are emerging as a promising source of renewable energy generation, but they require low cost hydraulic and electric equipment to make them economically feasible. Using a pump as turbine (PAT) and induction motor as generator can save substantial capital investment. Recent power electronics development can produce equipment rated electrical voltage and frequency for a wide range of generator speeds, providing additional flexibility. Specifically direct drive systems can be operated over a range of head conditions without flow control. A selection of correct pump for the turbine service has been difficult due to the lack of PAT performance data and non availability of standard method. This is especially true for low head sites. This paper presents a simple approach to predict PAT performance to aid in pump selection. A low head micro-hydro site producing 25 kW electric power from 5.5 meters of gross head is presented as a case study. Chan’s approach is then implemented to simulate unregulated PAT directly coupled to Self Excited Induction Generator (SEIG). The performance analysis of PAT-SEIG gives useful inputs for inverter-distribution transformer operation.
57
98-F-EPG-162
CFD study on tube failure in the Bisotoun Power Plant boiler
Masoud Rahimi, Abbas Khoshhal, Seyed Mehdi Shariati
Chemical Engineering Department, Faculty of Engineering, Razi University IRAN
Key words: Boiler, CFD, Modeling, Combustion, Power plant
Abstract In the present research, the fluid flow, heat transfer and combustion phenomenon were modeled in the Bisotoun Power Plant boiler, using Computational Fluid Dynamics (CFD) technique. Finding the reason of damage in the long length superheater tubes was the main aim of this research. A 60 oC over-design temperature at the elbow's of the long tube, where is the place of damage, was predicted. The photomicrograph images also show that these tubes are working in a temperature higher than sustaining temperature of tubes. These experimental results confirmed the modeling predictions. Using of an air blower system was proposed as a new way to solve this problem. The cooling effect of the air blower system on tubes was predicted by modeling.
58
98-F-EPG-395
Simulation of burners in the Shazand power plant and study of primary air effect on the shape and location of flame
Dr. S. E. Moussavi Torshizy , Eng. A. Rafiei and Eng. E. A. Saadati Failure Analysis Lab.
Power and Water University of Technology Tehran – Iran
Key words: boiler, furnace, combustion, CFD, burner
Abstract In this paper effort has been made to simulate burners used in 325 MW boilers at Shazand thermal power plant in Arak by Computational Fluid Dynamic (CFD). With respect to high thermal requirements of these boilers, burners have high heating potential and therefore have a special complexity. One of very important problems is the proper adjustment of combustion air and its distribution in different channel for entrance to the furnace. Non adjustment ratio of air entrance from different burner channels (primary, secondary, …) in some burners of this power plant resulting in unacceptable damages. Final purpose of this simulation is the effect of each adjustment on the shape and location of flame configuration and ultimately combustion state. To analysis this problem there are different practical and analytical methods, but with respect to complexity of mentioned burner, classical methods do not have potential of detailed analysis for this problem and ultimately have not capability of desirable presentation of results. Therefore, these burners are analyzed by using CFD methods by aid of powerful software "Fluent". Although this problem has been solved adopting oil and natural gas fuels, but the sake of abbreviation in this paper, only the results of burner simulation in the state of the use of natural gas has been presented.
59
98-F-EPG-476
Design of an Incineration Furnace
Ramin Mehrabian , Shahriar Bozorgmehri Renewable Energy Department , Energy & Environment Research Center, NRI, Iran
Key words: Renewable Energy , Incineration, Biomass, Furnace
Abstract According to the importance of the sanitation of Municipal Solid waste disposal and energy recovery, Incineration power plant has been accepted as an appropriate choice in several countries. Therefore, the landfill of flammable wastes will be prohibited by 2010 in Europe Union and only focus on incineration. Incineration power plant is more complex than common power plant and the main element of this power plant is furnace as heart of the station. Thus, Design of Incineration power plant is completed in this paper on based of the condition of Tehran’s waste. The moisture of Tehran’s waste is high and this item decreases the heat value. Therefore, the moisture should be reduced to 30% until the heat value becomes 11.375 Mj/kg. Consequently, The Furnace with 400 TPD of the dry waste generates 52.7 MW heat and also the incineration plant with 1200 TPD capacity of 3 Furnace lines produces about 32 MW Electricity.
60
98-F-EPG-547
Inspection of the cause of GE.F5 gas turbines bearing babbit destruction
Hassan Akbarzadeh-Mahmood Hosseini-M.hossein Nakhaei Khorasan gas power plants production management Co.
Key words: Journal bearing, Reynolds equation, GMRes Method
Abstract In this paper the subject has been investigated in tow different aspects. First, from solid mechanic's point of view, different parts of a bearing assembly such as, bearing sit and support, as well as bearing lube oil piping, wholly presented as a model. Meanwhile by applying the method of energy in the main system and model, the amount of housing displacement due to thermal expansion of exhaust hood and bending moment due to lube oil piping of which have been applied to bearing housing is calculate. Second, in the next stage by applying GMRes1 method, three dimensional solution of Reynold's equation has been achieved. And under different conditions, both alignment and misalignment of bearing housing and journal together with changes of hydrodynamic pressure and oil thickness, in turn, have drawn and analyzed. By knowing the amount of clearances and rotor angular velocity, "half speed whirl" phenomena is investigated too. Result may lead to "Resonance" which may occur in some Particular conditions of bearing clearances and finally would come up with sever damage to the bearing. Recommended P.M.S2 program such as certain limitation of clearances can possibly prevent further damage.
1. Generalized Minimal Residual 2. Preventive Maintenance Schedule
61
98-F-EPG-654
Analysis of Microturbine Cycle with Heat Recovery by Energy and Exergy Method
Ehsan Sadeghi1 Mohammad Bagher Ghofrani2 Hiva Khaledi3 Masoud Soltani Hoseini4 Sharif University of Technology, Mechanical Department
Iran
Key words: Microturbine, Recuperator, Exergy Destruction Ratio, Efficiency- Bypass ratio
Abstract In recent years, the development of distributed power generation has resulted in significant reduction in network losses and transmission costs while increased reliability. Microturbine is one of these power generators that in spite of its small volume has the ability of relatively high power generation. In this paper, advanced microturbine cycles are analyzed. In order to increase efficiency, exhaust gases from turbine enter in the compact heat exchanger named recuperator. To use energy of flue gases in steam generation, a heat recovery boiler is used. In present study, each part of cycle is analyzed by first and second laws of thermodynamics. Variations of quantities such as compressor pressure ratio, bypass ratio and recuperator effectiveness are studied. Simple assumptions such as constant heat capacity ratio and regarding steam as an ideal gas aren’t used in this study. Properties of air and water are assumed as functions of temperature and pressure. Irreversibility of each part are interpreted in term of exergy destruction ratio. Results show that in normal configuration without bypass optimum pressure ratio is about 3.3. also exergy destruction ratio is minimized at bypass ratio of 0.2 and then increased by bypass ratio.
1. Sharif University of Technology, Mechanical Department 2. Sharif University of Technology, Mechanical Department 3. Sharif University of Technology, Mechanical Department 4. Niroo Research Institute(NRI), Mechanical Systems Department
62
98-F-EPG-781
Thermal and Economic Analysis of Besat Power Plant Repowering
Sepehr Sanye Younes Hamzeie
Energy Systems Laboratory Department of Mechanical Engineering
Iran University of Science and Technology (IUST)
Abstract There is a rapid growth of electricity consumption in the world. This problem needs enough resources for capital investment for construction of new power plants. It also dictates to make all efforts to increase the thermal efficiency of existing power generation cycles. These lead power generation industry to repower and modify the existing steam power plants which are constructed in the recent three or four decades. In this paper one of important methods for repowering of old steam power plants using a gas turbine is analyzed. Hot Wind Box (HWB) repowering has been thermally and economically evaluated to increase the Basat steam power plant efficiency. This power plant is constructed and exploited in 1967 in Tehran. Optimum design parameters such as gas turbine power output, compressor and turbine isentropic efficiency, pressure ratio, and the ratio of turbine inlet temperature to compressor inlet temperature were system decision variables which were found using minimizing the objective function, the total cost (investment and operation costs) of the system.
63
98-F-EPG-785
Modelling and Performance Analysis of the Evaporative Coolers for Power Augmentation of GE-F9 Gas Turbines of Fars
Combined Cycle Power Plant
Masoud Soltani-Hosseini *, Reza Hosseini**, Ahmad Beshkani **
* Mechanical Systems Dep., NRI ** Mechanical Eng. Dep, Amirkabir University of Technology
Key words: Evaporative Cooler, Media, Gas Turbine, Modelling, Air Cooling
Abstract The media and fogging systems has higher priority for power augmentation of gas turbines compared with other inlet air cooling methods. In this paper the Media system, that implemented for Fars power plant, has been modelled and the design parameters such as face velocity, the dimensions of media, pressure drop has been analyzed. Based on the performance analysis and test results, the power output of units increases 11 MW at the ambient temperature of 38°C and the relative humidity 8%. Therefore according to the electricity production of this system (5280 kWh per year) and the electricity costs (2 Cents/kWh) the pay-back period is five years.
64
98-E-EPG-850
MODERN TRENDS IN DETECTION OF CAVITATION EROSION IN HYDRO POWER PLANTS
Abdolreza Davari Shahid Abbaspur Power&Water Institute of technology
Ahmad Noorbakhsh
Department of MechanicalEngineering , Faculty of Engineering, University of Tehran
Key words: Fluid power, Cavitation, Cavitation erosion, Detection of cavitation
Abstract Cavitation consists of evaporation and condensation of a liquid. Cavitation normally occurs when liquid at constant temperature is subjected to vapor pressure. In fluid power applications the evaporation pressure is reached when flow velocity is increased sufficiently. The occurrence of cavitation in fluid power is mostly detrimental .One of the devastating consequences of cavitation is the mechanical degradation of a solid material (cavitation erosion). Because cavitation is mostly harmful to the system it is to be avoided as far as possible. When actions for preventing cavitation are considered, it is essential to recognise the existence of cavitation and location of cavitation inception point. Direct detection of cavitation is often impossible due to the complicated constructions of fluid power components. Due to restrictions of direct detection of cavities, various indirect methods can be used. In this paper, cavitation phenomenon is explained and effects of cavitation on the system are dealt with. Cavitation erosion mechanisms are described and parameters affecting the degree of formed cavitation erosion are discussed.Modern methods for cavitation detection are presented.
65
98-E-EPG-868
Evaluation of Design Parameters For HRSG Cost Optimization
F.Mosallat M.R.Shahnazari M.Ziabasharhag
Mechanical Faculty of K.N.Toosi University of Technology Iran
Key words: heat recovery, HRSG, investment cost, pressure drop, design
Abstract Now a day due to the increasing cost of fuel and energy, heat recovery requirement is more sensible. For this reason, using of HRSGs which have been designed to operate in high pressure and temperature conditions is necessary for recovery of flue gas waste energy of gas turbine. In HRSGs, the amount of recovered heat, maximum steam temperature and maximum working pressure of boiler is depended on the capability of adjusting the difference temperature of gases and heating surfaces. Many parameters have been considered for each HRSG’s heating surfaces. All of these parameters affect on the HRSG’s cost and size, but it is not necessary to consider all these factors in all designs. In this paper, these parameters and the amount of their effect on HRSG’s cost has been investigated in order to design the most efficient boiler. The effect of parameters variations on HRSG’s width, height and pressure drop has been studied. The parameters that have been considered were tube arrangement, fin density, super heater and reheater tube diameter. Finally, the values of these parameters in order to HRSG’s cost optimization have been presented.
66
98-E-HVS-345
Computer Aided Low Voltage Short Circuit Laboratory Design and Simulation
Hossein Kazemi Karegar
Zanjan University Iran
Key words: HPL, LV-SCL, Low Voltage, Short Circuit Laboratory, Short Circuit Test
Abstract Short circuit laboratories are the main part of the electrical industries. Electrical components test in these laboratories and their qualities approved. In this paper a low voltage short circuit laboratory for testing circuit breakers up to 125 A, 400 volt and 125 kA short circuit rating has been designed and simulated. This laboratory is direct type and connected to the power network. The short circuit power required for the test has been determined.
67
98-F-HVS-357
Magnetic and Thermal Analysis of Current Transformers Using ANSYS Software
K. Banan Ali-Abbasi* A. Gahrami* E. Amini**
*Azarbaijan Higher Education and Research Center Power Ministry, Tabriz, Iran
**Local Electrical Company of Azarbaijan, Tabriz, Iran
Key words: Current transformers, Magnetic and thermal analysis, ANSYS
Abstract calculation of magnetic and thermal parameters of current transformers analysis is very complex due to dependency of mentioned analysis to used material in instruction of CT, non-linearity of magnetic property of core and complexity of design. Using of finite element method in situations similar to CT analysis has many advantages. In this paper ANSYS software are selected to analyzing of a CT with 5-400/5-800 specifications. This analysis includes the thermal analysis of CT in normal, open circuit of secondary circuit and short circuit cases. The results of magnetic and thermal analysis of CT are achieved and the important points of CT from the view of magnetic and thermal points are determined.
68
98-F-HVS-363
Analytical Study and Simulation of Transient Recovery Voltage in Circuit Breaker in Series Compensated Transmission Lines
Mohsen Ghayeni1 Graduated student
Javad Sadeh1,2 Assistant Professor
1. Electrical Group, Faculty of Engineering, Ferdowsi University of Mashhad, IRAN 2. Central Research Board of Khorasan Region
Key words: Electromagnetic Transient, Transient Recovery Voltage, Circuit Breaker, Series Compensated Transmission Line
Abstract The transient recovery voltage (TRV) represents the voltage appearing across the terminals of CBs, following fault currents interruption. The application of series capacitors (SCs) in an EHV transmission system can create severe transient voltages across circuit breaker (CB) interrupting equipment. One of the most important factors in designing the CBs is the maximum TRV. Therefore in this paper effect of series capacitor compensation on TRV is investigated. This is done analytically and also by simulations. This investigation is performed in two cases of capacitor installation, e.g. the capacitor is in the middle of line and the capacitors are installed in two end of the line. Results show that TRV usually increased due to SC existence. Therefore to have proper design of CBs and their protection schemes when the transmission line is equipped by SC, transient studies should be done. While deterministic method is used for simulations, effect of some uncertainties such as fault type and fault location on maximum TRV is investigated.
69
12-E-HVS-378
Electric Field Calculations in Rod-plane Gap Using Hyperbolic Approximation and Finite Element Method: a Comparison
Hamid Javadi* and Masoud Farzaneh
NSERC / Hydro-Quebec / UQAC Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE) and Canada Research Chair on Engineering of Power Network Atmospheric
Icing (INGIVRE), Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada, G7H 2B1 * On leave from Power and Water University of Technology, Tehran, Iran
Key words: Electric field, hyperbolic approximation, finite element method, Rod- plane electrodes
Abstract In order to understand the behavior of arc inception and its transient propagation till complete breakdown across an insulator it is necessary to find out the maximum electric strength, Emax , at the arc tip in an air gap and investigate the relationship of the dimensions of this particular geometry to Emax. The most widely used model is a rod-plane one. Because of the strong non-uniformity of the field distribution it is impossible to derive an equation by using conventional electromagnetic methods such as Laplace’s equation to find Emax. In fact, there is only one well-known method, Roy’s equation, which is commonly used for a rod-plane system to calculate Emax, i.e. by solving Laplace’s equation based on a parabolic approximation. In this paper, the validity of the results obtained by Roy’s equation is discussed and its results are compared with those obtained by finite element methods. It will also allow obtaining a better spectrum of the rod electrode system field distribution. It is found that applying the approximation is acceptable only insofar as the rod radius is comparable with the axial distance between the two electrodes and gives the huge discrepancy in maximum electric field calculation for the rod electrode too sharp.
70
98-F-HVS-379
Economical Assessment of Application of Fault Current Limiter in Firouzbahram’s High Voltage Substation
Hamid JAVADI
Power and Water University of Technology (PWUT) Electrical Engineering department
Tehran, IRAN
Key words: Fault current limiter, Bus sectionalizing, Series resonance impedance, Circuit breaker, Short circuit calculation, Economical evaluation
Abstract In this paper, the necessity and procedure for application of series Fault Current Limiter (FCL) composed to bus sectionalizing in power network of IRAN is discussed. In this regard, all of the high voltage substations in the power network of IRAN were evaluated in point of view of the fault current amplitude. The short circuit analysis of the power network was done based on the actual and future network specifications designed and published by TAVANIR organization (the manager of the electrical network in IRAN). The overall results of this analysis and the detail data of using FCL together bus sectionalizing for one of the most important high voltage substations of Iran is presented. This method allows decreasing of 28% in fault current amplitude. Economical assessment of application of mentioned fault current limiter in Firouzbahram’s high voltage substation shown this application will be only useful for the high voltage substations which contain more than twelve circuit breakers.
71
49-E-HVS-437
Surface Degradation of Outdoor Polymeric Insulators Resulting from Electrical and Environmental Stress
Morteza Ehsani1, Gholam Reza Bakhshandeh1, Jalil Morshedian1
Hossein Borsi2, Ernst Gockenbach2
1 Iran Polymer and Petrochemical Institute, Tehran, Iran,
2University of Hannover, Institute of Electric Power System (Schering-institute), Germany
Key words: Insulator, Tracking, Hydrophobicity, Silicone Rubber, EPDM, Erosion
Abstract The use of polymer material in outdoor insulation applications has been steadily increasing over time. This paper reports on experimental investigation on electrical and surface properties of new polymeric alloy compared with silicone rubber (SIR), ethylene-propylene–diene monomer (EPDM), and alloy of SIR-EPDM. In this study a few kinds of a ternary blend of silicone rubber - ethylene-propylene diene monomer -TP (Thermoplastic polymer) with many different proportions were prepared and consequently the surface and electrical (tracking and erosion resistance) properties of them have been studied. The results of tests showed that the surface properties such as water repellency and electrical properties such as tracking and erosion resistance in different condition (UV aging, water salinity aging, and humidity salt spray stress) are improved compared to known polymeric insulators.
72
98-F-HVS-486
Measurement and Simulation of magnetic fields in Medium voltage panel for improvement of Electromagnetic Compatibility
H.Haydari, V.Abbasi, F.Faghihi, E.Moshtaghi, S.Adelkhane, Z.Saberi Iran University of Science and Technology High Voltage and magnetic material Research Centre
Key words: Electromagnetic Compatibility, Electromagnetic Interference, shielding
Abstract Medium voltage panels are one of important sources for Interference electromagnetic fields in Substation .These fields due to their effects on sensitive Equipments and operator are noticeable for Researchers. Reduction methods for these malfunctioning are very attractive discussions. For submitting solution for Interference fields, Identification of critical places of fields is very important. In this paper, measurement and Simulation for Identification of electromagnetic fields is used. All off Results are compared .Measurement is done by Gauss meter and ANSYS (FEM software ) is used for simulation. In according to Results, probality of existing of non compatibility is surveyed and method for their avoiding is suggested.
73
98-F-HVS-487
Using Simulation based on Finite element for identification Stable Magnetic Source in
High Voltage Substation for EMC consideration
H.Haydari, V.Abbasi, F.Faghihi, E.Moshtaghi, S.Adelkhane, Z.Saberi, M.Farhadi
Iran University of Science and Technology
High Voltage and magnetic material Research Centre
Key words: Electromagnetic Compatibility , Electromagnetic Interference
Abstract Nowadays, existing and increasing of Digital system, importance of Electromagnetic Compatibility is very attractive for researcher so, investigation about EMC in substation which has high values of magnetic and electric fields is interesting subject. EMC considerations have three main discussions include of source transmission environment, and victims identification, we focus on magnetic source and its field distribution. Our work is based on Finite Element Method (FEM) with ANSYS software. In this paper, parts of 230kV/63kV substation include of power transformer and bus bar has been considered. Power Transformer and High Voltage bus bar are two magnetic sources which has been produced Interference fields. More ever, for showing effect of unwanted fields, we discuss a case study for safety of operator lead to bus bar distance from ground.
74
98-F-HVS-488
New Method for Optimization of Low Voltage Cabling in High Voltage Substation lead to Electromagnetic Compatibility
H.Haydari, V.Abbasi, F.Faghihi Iran University of Science and Technology
High Voltage and magnetic material Research Centre
Key words: Electromagnetic Compatibility, Electromagnetic Interference, economical function
Abstract Correct operation and security for Equipment in High Voltage substation when Transient states occur are very important points in substation design .These Discussions lead to Electromagnetic Compatibility in High Voltage substation as a electromagnetic system. We have compatibility in a system with two steps: redesigning system, and defense Method for Interference Fields ( sheilding , filtering , and grounding ). In this paper, Low Voltage Cabling has been redesigned according to electromagnetic Compatibility due to Circuit Breaker switching. New Approach with has been submitted improves Electromagnetic Compatibility with identification, Reduction area of transient magnetic field that has been Simulated by Finite element Method (FEM software (ANSYS)). Furthermore Cabling optimization, Minimum length of cable has been considered even more importance than optimization of EMC and Cabling; new practical Method with consideration EMC in substation designing has been explained.
75
98-F-HVS-515
Modeling and simulation of metal oxide surge arrester dynamic behavior in transient studies involving fast front surges
Reza Dowlatabadi Javad Sadeh
Electrical Group, Faculty of Engineering, Ferdowsi University of Mashhad Mashhad, IRAN
Key words: Electromagnetic transients, Surge arrester model, Fast front transient
Abstract Metal oxide surge arresters (MOSA) are widely used as protective devices against switching and lightning over-voltages in electrical power systems. Wide application of metal oxide surge arresters and importance of their dynamic behavior in surge arrester location and insulation coordination indicate the necessity of using an accurate model for simulation of this dynamic behavior. Until now, several models have been proposed to describe the arrester behavior for different kinds of stress, but the hard point is the identification of model parameters. These models have at least one of the following disadvantages: 1) The model needs some information which not reported on the manufacturer’s datasheets 2) The model may loose accuracy for different kinds of surge with different amplitudes and/or different rise-times 3) The model may loose accuracy for different voltage ratings The goal of this paper is to present a simple and accurate model for simulation of MOSA under electromagnetic transient involving fast front surges. The proposed model is accurate for different kinds of surges with different amplitudes and/or different rise-times. All the required data are to be found in manufacturer’s datasheet. The simulations were performed using the Alternative Transient Program (ATP) for several arresters and the results were compared with the data reported on the manufacturer’s catalogue.
76
98-F-HVS-624
ABOUTE DESTRUCTIV HIGH VOLTAGE SUBSTATION ON EARTHQUAKE
REZA SHAHRAEENI K.C.E.D.C. CO
MASHHAD,IRAN
Key words: earthquake, high voltage substations
Abstract In this paper , after study situation of high voltage equipment 132 KV in the site of H.V.substations such as power transformes , arrester , P.T , C.T , circuit breaker ,basbar , ect. Earthquake effect such as bam & zarand & manjil study about H.V.equipment and offer experiences for decrease failures in high voltage substations.
77
98-F-HVS-636
Aging Study of Silicone Rubber by Electrical and Heating fields
S. A. Kamali 1 A. Gholami1 A.Vahedi1 M. Ghahremani2 M. A. Talebi1
1. Iran University of Science & Technology
2. Tehran Regional Electric Company Iran
Key words: silicone rubber, heating aging, electrical aging, life time, loss factor
Abstract In the recent years, several polymeric materials such as EPDM, polyethylene, epoxy, silicone rubber, the last one has been preferred for the outdoor insulators for high voltage due to its excellent characteristics compared to those of ceramic insulator. Silicone rubber has various advantages as light, hydrophobicity, endurance, hydrophobicity, relatively high resistance to tracking and easy maintenance. Using of this type of polymer in the insulators and surge arresters, also its aging behavior studying are subjected at the research centers. The degradation of material regularly starts from the surface and is usually accelerated with increasing temperature and voltage. But considering many works performed by different research laboratories, they have been limited to carry out electrical and chemical measurements and comparison on these materials without suggesting any fundamental aging mechanism related to the possible aging factors. In this paper, aging characteristics of silicone rubber have been investigated by accelerated aging test on the electrical and heating fields. In order to determine life time of silicone rubber, loss factor is used. The results show that silicone rubber has high temperature stability. Also, it is illustrated that this material can't become aged only by voltage and aging test should be performed with severe environmental conditions as salt-fog.
78
98-F-HVS-757
Optimization of an existing old substation by implementing substation automation system
Maryam Vadiaty, Bahieh Shabazi, Mehdi Rassaie Niroo Research Institue
IRAN
Key words: substation automation system, control and monitoring system, optimization of old substations
Abstract Performance of high voltage substations with different voltage levels plays an important role in preserving stability and permanence of power networks, but various factors like erosion of components and malfunction of circuits in old substations unfortunately bring about incidents and lead to large outages in power networks. Thus increasing of reliability of power networks and optimization of old substations has a significant importance, but considering that the most of existing old substations are energized and are situated in key points of the system, interruption of the service for substitution and maintenance of the components are not practicable. This paper presents an efficient and cost saving countermeasure for optimization of existing old substations that is based on DCS or substation automation system. By this practice, substitution of new power systems with old ones without disturbance and interruption of service is feasible and meanwhile we can benefit from automation system advantages in operation, maintenance, faultdiagnostic, extension and etc.
79
98-F-HVS-768
Genetic algorithm based approach to calculate the arc constants in polluted insulators
Kazem Yaghouti Ahmad Gholami Iran University of Science and Technology
Iran
Abstract The phenomenon of flashover in polluted insulators has not yet been described accurately through a mathematical model. The main difficulty lies in the definition of the constants of the arc, which is formed in the dry bands when the voltage exceeds its critical value. The authors present a complex optimisation method based on genetic algorithms for the determination of the arc constants, using experimental results from artificially polluted insulators. First the well known model of Obenhaus for pollution flashover is used. This model results in a system of equations which cannot be solved with conventional arithmetic methods. The application of genetic algorithms enables the definition of the arc constants, resulting also in the calculation of the critical conditions at the beginning of the pollution flashover mechanism. In this way a mathematical model is established, which simulates accurately the experimental results.
80
98-F-HVS-876
Seismic Performance evaluation of Tehranpars 230/400kv Substation’s Structures &equipments
A.H.Khalvati Matn Co
IRAN
Key words: earthquake,substations,control buildings,breaker,transformers
Abstract Tehranpars Substation in eastern region of Tehran plays a vital key role in the capital power network,on the other hand it is located in a very high seismic potential area ,according to that evaluating the seismic performance of the structures and equipments of the substation was the main subject of the study.In this study which had three phases ,first the needed information about the elements were collected through investing the available documents, in the next phase the seismic hazard analysis was carried out, Which through this analysis the PGAs for different levels of earthquakes were calculated .The main stage of the project was the third phase ,in which the control building structure and the electrical Components in the switchyard were evaluated and their failure modes and the ways to retrofit them were expressed.
81
98-F-ITP-804
Studying The Application of RCM Strategy in Maintenance Planning of Power Transmission Network
Habib Rajabi Mashhadi Sara Mohtashami
Engineering Faculty of Ferdowsi University of Mashhad In corporation with Maham Shargh Company
Key words: Maintenance Planning, Transmission Network, RCM, AHP
Abstract In this article, we will discus about how to use RCM protective strategy in the maintenance planning of transmission grids. In many grids maintenance planning is almost the same for different sub stations, without considering their level of importance in their network or how they have functioned in the past. Also, geographic condition of posts location like the amount of moisture, storm or rain will affects on its equipments functions. Equipment’s quality is also effective in probability of failures. In this paper we are trying to present a way to consider these factors in maintenance planning of high voltage grids. We will use RCM (Reliability Centred Maintenance) strategy which contains the latest methods in maintenance planning. In this way we can improve network reliability and meanwhile have financial efficiency.
82
98-F-ITP-888
Design of GIS Conceptual Model and Standard for Distribution Networks of Electrical Industry
Hamid Ebadi, Mohammad Javad Valadan zoej, Mohammad Karimi, Salman Ahmadi
Faculty of Geodesy and Geomatics Eng, K.N.Toosi university of Technology
Nahid Nikpoor Tavanir Inc.
Key words: conceptual model, standard, spatial database, guidance
Abstract Nowadays, it is being difficult to manage electrical distribution networks due to the Complexity of network in urban and rural areas, huge number of network equipments, and quick changes of information of network equipments. Managers and experts of electrical distribution Corporations require to use advanced technology for design, management, and maintenance of the distribution network. Since features of electrical distribution network are spatial objects, applying GIS as a technology and science for optimum management of spatial information, makes it possible to optimize various operations of electrical distribution. In order to establish a spatial data infrastructure and appropriate system in electrical distribution incorporations, office of information technology in Tavanir incorporation in collaboration with Faculty of Geodesy and Geomatics Engineering at K.N.Toosi University of Technology have defined studying phase of GIS electrical industry for distribution networks. The goal of this study is to prepare GIS data infrastructure for electrical distribution including determination of user needs, conceptual model, standard of geographical database, a series of guidance and selection of hardware and software. This paper describes the outcome of this study and represents various outputs of each stage of the project. Based on these outputs, electrical distribution incorporations in IRAN can produce required spatial and non- spatial information and develop electrical network DBMS.
83
98-F-LEM-109
Optimizing the Operation of Siah-Bishe Pumped Storage Plant (for weekly periods)
A. Moazedi, J. Saiy Moshanir Power Engineering Consultants, Elec. Machines Dept.
IRAN
Key words: Pumped storage plant, Optimal control Theory, Operation, Energy and Load Management
Abstract In this Paper, first of all the concept of Pumped Storage Plants (PSP) is reviewed and a software that has been developed for simulation and optimization of operation in the PSPs is introduced. Then through some examples the performance of the software is checked. In order to have a more realistic investigation, we have to consider the situation of the Siah-Bishe PSP in its operating period, after the year 2010. So, necessarily we will estimate some parameters (e.g. Load and Increamental Cost curves) for those years. Finally the provided software is used to optimize the operation of Siah-Bishe PSP. The results mainly shows the importance of these software for optimal operation. Also they demonstrate that a weekly period schedule may have more benefits compared to daily period one.
84
99-E-LEM-134
DEMAND-SIDE-MANAGEMENT (DSM) FOR JORDAN (Actual Cases from Small Industries)
Eng. Falah Q. Ababneh National Electric Power Co. (NEPCO)
Amman – JORDAN
Key words: Demand Side Management (DSM) Integrated Resource Planning (IRP)
Abstract Demand Side management (DSM) is a part of the Integrated Resource Planning (IRP) and it is one of the tools that used by planners for the development of electricity sector. The main reason of these (DSM) programs is to achieve more cost-effective supply system to the end users and to reduce growth in energy demand by improving the efficiency in the usage of electricity. The paper will take into consideration the examination of the demand forecast and specific usage of the electricity and the detailed analysis of the following: ●Typical Daily Load curve ●Electrical consumption during peak period ●Specific consumption. This paper represents the (DSM) programs applicable for Jordan market and aims at the following: ●To provide the electricity serves at the best lowest cost to customer. ●To reduce environmental impacts by reducing atmospheric pollution, reducing climatic change linked to the greenhouse effect. ●To enhance social and economic benefits. The target of this case study is to choose the best option resulted from the evaluation of the potential and profitability from the point view of technical and economical aspects.
85
98-F-LEM-156
Evaluate the Quantities Potential of Residential Electric Energy Reduction for Yazd, Meybod and Mehriz Cities Using Load
Decomposition
Farrokh Amini Zohreh Salimian Niroo Research Institute
Key words: Load Decomposition, Evaluate Load Components, Load Management
Abstract In this paper, it is tried to evaluate quantitative potential of residential electric energy redaction for Yazd, meybod and Mehriz cities of Yazd province. An algorithm is used in this regard for load decomposition to its components for selected residential low voltage feeders. The algorithm had been checked for accuracy and reliability by different methods. So on this basis, that is load decomposition to it’s components, quantitative potential for residential electricity reduction for aforementioned cities has been evaluated according to different load and energy management options and the results are shown.
86
98-F-LEM-217
Optimizing of Energy Consumption in Niru Battery Mfg.co
Jabbari Fariborz eng. Niru Battery Mfg Co.
Iran
Key words: energy consumption management (ECM), energy efficiency(EE), to decrease energy losses (ELD)
Abstract None of human activity has one hundred percent efficiency . That is why optimum use and preventing the loss of facilities is of a high significance and fundamental issue . This issue becomes more important and more serious, when we talk about energy the essence of every activity . It can be claimed that with regard to the exiting limitations in energy resources and the importance of energy costs in the final price of the products , existence of high potential of economization , necessity of decresing the final price of products in order to increase the competition potential , necessity of control and decrease of costs in energy sector within the field of properties and expenses management , etc , to implement a management system in energy consumption is an inevitable and persistent issue.This article refers to how the projects have been implemented and have resulted savings worth some 1300 millions rials in 1383 (This saving is conspicuous comparing with the electricity bills in 1382 and 1383 ).IT is also provided a summary of the implemented projects in previous years (specially 1383) and future plans in energy management in three modes of almost cost – free , low cost , and high cost in the fields of load management , light , heating and cooling .
87
98-F-LEM-221
Incentive Based Demand Management Program of Industrial Loads using Game Theory
Mohammad Saeed Koupaei Niya Ashkan Rahimikian Control & Intelligent Processing Center of Excellent, ECE Dept, University of Tehran
Iran
Key words: game theory, Leader-Follower theory, Benefit Function, Incentive Demand management
Abstract In this paper we propose an Incentive based Demand Management Program using game theory. We will use the Leader-Follower theory. We consider a distribution network that consists of a power utility (Leader) and two industrial consumers (Followers). We study the effect of trust between the leader and its’ followers in power cost and consumption optimization. Through simulation studies we will show the benefits of this load management program for both the power utility (Leader) and industrial consumers (Followers). We consider two types of load control by the leader:
1. Time shifting of the followers’ consumption. 2. Optimization of the followers’ consumption based on their benefit
function together with the leader benefit function. We will show that this method of demand management could increase the reliability of the distribution network.
88
98-F-LEM-234
Energy Efficiency Improvement with Variable Speed Drives, Case Study: Power Plant Energy Consumption Reduction
M.Parsa Moghadam A.Yazdian M.Norouzbeigi M.Mohamadian Electrical and Computer Eng. Dept., Tarbiat Modares University, Tehran, Iran
Key words: Boiler fan, Energy, Efficiency, Power plant, variable speed Drive
Abstract More than 70 percent of electric energy in industry is used by electric motors. Improving the energy efficiency in the systems using electric motors will improve the total efficiency of the plant. In this paper, using variable speed drive for improving electric motor systems efficiency is investigated. Energy efficiency of different kind of variable speed and constant speed systems are compared. Also using a variable speed drive system for boiler fan of a boiler in Arak power plant is studied in this paper. The centrifugal fan, the inverter and the induction motor in this plant is simulated and the energy efficiency is compared with a damper controlled system.
89
98-F-LEM-350
Electricity load Unbalance consumption tariff
Hosein Arghavani Mansoor Rafii Hosein Sajjadi Nasrin Mohaddes Iraj Hassanzadeh
Tehran power distribution co. -Abbass poor univ. - Tehran regional electric co –Tavanir co.
Tehran –Iran
Key words: load unbalance consumption, power consumption quality tariff - consumer loss factor-power consumptin quality factor
Abstract The all of power quality factors are defined as duties of power supply side in accordance of power quality istandards. The tariff of reactive consumption in accordance of power factor is the only power consumption quality tariff that is calculated by consumer loss factor formula defined in electricity law. But there are no tariffs for other power consuption quality factors as load unbalance consumption . This article has presented a new model for correction and expantion of the existence consumer loss factor formula is used.for designing a tariff for this quality factor, expansive and usable for other power consumption quality factors. By using of this model the power quality istandards and power electric tariff law are related to each other so the power qualitiy istandars became the common duty of both supply and demand sides. Therefore the power consumer must pay the tariff of its power consumption quality further of power quantity consumption.
90
98-F-LEM-391
Technical-Economics Studies of Automated Lighting Control
Ramin Nader.D GholamReza Naderi Javad Sharifei ECE Department of Tehran
University Industrial Design Art University of Tehran
ECE Department of Tehran University
[email protected] [email protected] [email protected]
Key words: Lighting Control, Occupancy Sensor, Time Scheduling, Photo Sensor
Abstract One of simplest ways to conserve energy is to turn lighting systems off when they are not necessary. Since lighting consumes 30 to 50% of buildings total electric load, even a slight reduction in lighting can bring significant savings. Automatic lighting controls are either programmed, or controlled by a sensor to turn off lights when a building space is either unoccupied or occupied by workers performing tasks that do not requite full light levels. There are several different kinds of controls such as; occupancy sensors, daylighting dimming and time scheduling. The choice of control type should be based on lighting usage patterns and the type of space served. To justify the use of automatic controls, energy saving compared to the initial cost should be analyzed.
91
98-F-LEM-455
Short Term Load Forecasting of Iran’s Power Network using Artificial Neural Networks and Fuzzy Logic
Hadi Razmi Mohammad-Taghi Vakil-Baghmisheh Faculty of Electrical and Computer Engineering of Tabriz University
Iran
Key words: Short Term Load Forecasting, Artificial Neural Networks, Multilayer Perceptron, Fuzzy Logic
Abstract Short term load forecasting has an essential role in optimal operation of electric power systems. This paper proposes a model for short term load forecasting using a modular multilayer perceptron neural networks and fuzzy logic. This model divides the problem into two parts. Forecasting the normalized load curve and forecasting the minimum and maximum loads of the day. The normalized load curve is forecasted using a neural network composed of 16 modules of multilayer perceptron. Every module is used for predicting a normalized load curve of four types of days in four seasons. The maximum and minimum loads are forecasted using fuzzy inference models. The climate conditions, monthly variations, day type and holiday information are included in the model. The validity of the model is verified on the load data obtained from “the Dispatching Center of Iran”, and an average absolute error of 1.6% is obtained, which is meaningfully better than the results reported by other researchers.
92
98-E-LEM-481
Consumption of electricity in buildings Could be able to reduce that or not?
Shahin Heidari – Bsc- MA – PhD Former Researcher in the Sheffiled Hallam University – ENGLAND
Assistant Professor and Deputy of Chancellor Faculty of Engineering
Ilam University IRAN
Key words: Electricity consumption, Buildings, Energy, Thermal comfort
Abstract The functions of buildings are basically the same everywhere: to provide shelter for a comfortable living and working environment and to avoid extreme weather; but the designs and processes for buildings in different climates are significantly different. All elements of buildings and any building types should be designed whenever possible to respond to the climate as priority and to provide delightful living conditions for occupants. This is a part of the relationship between humans and their environments whose physical elements, in a complex composition, consist of light, sound, climate and space. The suggestions on design in this paper aim to achieve comfort by means of passive approaches. The problems with current designs have prompted designers to rethink their designs, particularly because of an increasing awareness of sustainability. To conserve electricity energy and reduce Co2 emissions. It is important to design energy efficient buildings. However, this study addresses the effectiveness of a good Standard for electricity use according to human comfort. Due to experimental needs in this field, the researcher did use a place, just as a model, which is Ilam. There is no reason that these results could not be applied to other places.
93
98-F-LEM-535
Increase in compact fluorescent lamp (CFL) life with correct selection of environmental conditions
M. Bagheri Z. Hessari M.F.Hanifi
Noorgostar Co. LTD. (Lighting Consulter)
IRAN
Key words: Ambient temperature, Luminaires with compact fluorescent lamp, Amalgam lamps
Abstract Over the past several years, compact fluorescent lamps have been promoted as replacements for incandescent lamps in interior and exterior luminaires. Extended lamp life is one of the main reasons for using CFL products, compared to incandescent lamps. Lamp manufacturers usually introduce equivalent CFL for each wattage of incandescent lamp based on equivalency of luminous flux under standard test conditions. A consumer may choose a CFL for its rated light output but use it in unsuitable positions or ambient temperatures out of the scope of lamp operational conditions ex. in luminaires and lustres, so the light output and lamp life might decline to values under expected levels. The effect of ambient temperature on CFL life is specified by performing a thermal test on different samples of various products. Test results demonstrate that temperature evaluation leads to ballast failure in most cases except for amalgam CFLs. In other words amalgam lamps have less sensitivity to ambient temperatures. So, the main objectives of CFL technology would be fulfilled by the use of amalgam lamps in luminaires and lustres with manufacturing of lighting fixtures corresponding to special conditions of CFLs.
94
98-F-LEM-549
Non Intrusive Load Monitoring
Hassan Karimi* Ebrahim Farjah** Alireza Seifi** Parham Shenavar**
* Kohgiloyeh & Boyrahmad Electric Distribution Co.
** Engineering Department of Shiraz University
Key words: Demand Side Management, Load Monitoring, Neural Network, Fourier Transform, Harmonic
Abstract To Provide the Electric Energy for Customers, with increase the electric power plant, electrical utility consider load management. In fact load and energy management is an important subject and it can’t be ignore. load and energy management have two methods: ● Supply Side Management or SSM ● Demand Side Management or DSM
In this methods, Demand Side Management or DSM due to achieved to better results and expanded used is very important and has an essential role in electric load and energy management. One of the important factors for successfully DSM is the monitoring of electrical load in power systems. In fact if we can recognize loads with the bus current, we can develop load management more and more. In this paper we evaluate the load monitoring with the current of each load and we suggested a special technique for load monitoring by the bus current.
95
98-F-LEM-773
Combination Of Normalized Residuals & Curve Fitting Methods in Identification and Modification of Improper Load Data
V.Vahidinasab S. Barghinia P. Ansarimehr Electrical Power System Research Center – Niroo Research Institute
Tehran – Iran
Key words: Bad Data Identification, Improper Load Data, Short Term Load Forecast, Absolute Normalized Residual
Abstract Short term load forecasting (STLF) plays an important role for the power system operational planners and also most of the participants in the nowadays power markets. Data used for STLF is mostly historical hourly load and weather parameters. Hourly load data is subject to errors made by instruments and/or operators and also unwanted or unplanned changes in the power system. In this paper, an approach to identification and modification of improper load data used in STLF is proposed. The results for Bakhtar Regional Electric Company (Bakhtar REC), a part of Iran national power system (INPS), shows that the idea of modifying improper input load data used for STLF can improve greatly the performance of the STLF itself.
96
98-F-LEM-783
Electric Motor Systems Energy Saving Methodologies
Issa Farmani Sharif University of Technology
IRAN
Key words: Electric motor, Energy Saving, Efficiency
Abstract Electric motor systems represent the largest electrical end use in many countries. They are widely used in industrial, residential, commercial and agricultural sectors. In 1994, electric motor-driven systems consumed 69% of all electricity used in industrial sector in the United States. They accounted for approximately 65% of the electricity consumed by EU industry in 2000. In 1994, they consumed 38.5% of all electricity used in Iran and also 65.5% of Iranian industry. As there are large energy saving potentials with these high levels of electric motors energy use, and also many environmental benefits through GHG and pollution reduction, it is so important to focus on electric motor systems energy management. This paper provides a brief description of industrial energy efficiency methodologies related to electric motor systems like power quality improvements, electric motor and load matching, higher efficiency motors, speed reduction, ESD1, operating and time management, permanent star connection, higher efficiency torque transmission devices and finally maintenance of motor systems.
1. Energy Saving Device
97
98-F-MNG-142
Investigation of the relationship between off Thursdays and staff efficiency
Vafaii Hossien M.A. in Educational Management and Public & Iternational Relations
IRAN- Sabzevar Teacher Training University
Key words: off days, efficiency, the staff
Abstract The main objective of this study is comparatively investigate the efficiency of the staff in terms of Herzberg’s theory of motivation-hygiene. The major research questions include: Evaluation of self-responsibility, coping with one’s personal problems, professional promotion, workforce/facilities economy, improvement of the staff knowledge, and professional motivation with regard to sociological variables such as gender, type of service, level of education, and professional background. As to research methodology, it is a descriptive study of survey type. The sample included 150 randomly-selected males and females of the staff. The only instrument for gathering data has been a questionnaire developed by the researcher himself. Finally, the findings were as follows: Off Thursdays cause a significant difference in terms of self-responsibility, coping with one’s personal problems, efficiency and job promotion, workforce/facilities economy, improving one’s general knowledge, gender, type of employment, level of education, and record of service.
98
98-F-MNG-328
Application of Gap Analysis Model to Measure the Quality Level of Services in Electricity Distribution Companies
(Case:Customer Affairs Unit Of Yazd Electric Distribution Co.)
Seyyed Habib Mirghafoori Assistant Professor of Yazd University
Iran
Key words: Quality of Services , Servqual , Gap Analysis Model , Electricity Industry , Customer Affairs Unit
Abstract In recent years, the managers of service organizations are trying to develope the customer-oriented culture in their organizations and concentrate on their customers’ needs to improve their competitive advantages,efficiency and effectiveness of their organization.In the process of sustainable development,electricity industry as a main one, plays a key role and other industries’ development is related to this industry.For doing its role better,this industry needs to create a customer-oriented culture and designs continuous improvement programs for its services. Servqual or Gap Analysis Model that is developed by Parasuraman, Zeithaml (1988) is one of the best techniques that helps managers to evaluate the perceived level of quality of their services and apply corrective actions to improve those.This article with using the Servqual model tries to understand relationships between factors affecting quality of services presented in Customer Affairs of Yazd Electric Energy Distribution Co.Outcomes of this research shows that there is a gap between customer expectations and perceptions in different dimensions of quality.Finally some suggestiuons are presented for reducing this gap.
99
98-F-MNG-578
Recognition of obstructive elements for partnership method Case study – khorasan generation gas turbine power plants
Hasan Allahdadi Mostafa ragabi mashhadi
Khorasan region electric company – Khorasan generation gas turbine power plants Company Iran
Key words: Partnership system, offer, personnel, increasing performance, bonus, Electricity market
Abstract The specialty tasks and jobs in power plants alongside of importance of power generation as a source of energy in our country is worthy of observation. Limitations of supply and scarcity of spare parts and continual need for optimization and modification of present systems foregoing in order to promote their performance lead to more authorities attention to personnel activity due to their offers and partnership. In other word partnership is an effective method and useful relationship of “ boss and personnel “. Implementation of electric market and economical conducting of plant activities resulted in Partnership method which could be more practical and beneficial to field of power generation. In this paper while analysis personnel activities and comments for years 81 – 83 . recognition of obstructive elements as well as making efforts to remove these related difficulties have been studied.
100
98-F-MNG-720
Application of RCM Strategy in Power Systems and Utilization AHP for Equipment Prioritization
Leila Mohseni Mohsen Mohseni Mahdi Zarif Mohsen Ghayeni
Maham Shargh Company In corporation with Engineering Faculty of Ferdowsi University of Mashhad
Key words: RCM, Reliability, Budget management, Failure rate, AHP
Abstract In this article we are trying to present application of Reliability Centered Maintenance (RCM) strategy in power systems. This method with considering some criteria such as importance of equipments in system, their performance in the past and environment conditions improve reliability and manage budget. In fact RCM focus on maintenance activities that more effective in system reliability. In this paper AHP have used for Prioritization equipments that it can apply in RCM. For substation prioritization must attention to failure rate of all equipments and their level of importance in substation. This study has used statistic of equipment failure in 1382 for some transmission substation in khorasan regional electric.
101
98-F-MNG-744
The Role of Technology Transfer in Industrial Development of Countries and Comparing It With
The Experiences in Niroo Research Institute
Nazanin Ahmadizadeh Maryam Mohseni Farid Monavari International Affairs & Scientific Cooperation Bureau- Niroo Resarch Institute (NRI)
Tehran-Iran
Key words: Research, Development, Production Lines, Research Prototypes, Economic Development
Abstract Niroo Research Institute (NRI) is the most important research organization of the Ministry of Energy. NRI has been accomplished more than 400 research projects up to now. Research experiences shows that performing the research projects by itself wouldn’t be sufficient and won’t make enough motivation. Besides, the lack of practical usage of the results in the industry will lead to the waste of national resources. Therefore a specific policy should be defined for using the research results in industry, which subsequently will lead to the country development. In NRI in parallel with the research activities in order to increase the level of national production and creating more occupational opportunities, the results of several research projec
102
98-F-MNG-824
Peresenting a Model Based on Borda for Personnel Performance Appraisal
M. Aniseh1 A. Toloie2 M.A. Afshar kazemi2
1- UE&CRC Corp 2- Islamic Azad University
Key words: Performance evaluation, MADM, Group Decision Making, Borda
Abstract Hence personnel performance appraisal is mean to diagnose their weak and strength points, increase the abilities, suitabities, and managerial decision making; it is a read for a dynamic management. In thise paper the performance appraisal is seen as an element of group decision making and therefore, the personnel are evaluated from different points of view, (Boss, colleagues (co-worker), Inferior, employee him/herself, customer and etc...). Keeping in mind the attributes weights, and relative importonce of auditors evaluations weights, a model has been used based on Borda for personnel ranking . The foregoing method has been used in a case study and the result and data have been evaluated from different points of view.
103
98-F-MNG-830
ANALYSIS OF THE NECESSARY THECHNOLOGIES OF THE POWER INDUSTRY OF IRAN IN THE FUTURE
(ONE OR TWO DECADES LATER)
H. Ghanimi Fard Petroleum University
of Technology
M. S. Ghazi Zadeh Ministry of Energy
F. Poursoleimanian Ministry of Energy (The Bureau R&D)
IRAN
Key words: Forcasting, Futuring, Technology, Power Industry, Energy
Abstract Nowadays for developing suitable technological strategies, we need to the futuring and forcasting processes at the first. In this article, we will discribe about the importance of these processes for formulating strategic planing in a system approach. Then we will say about the history, performance and the new structure of the Power Industry of Iran. Also we will discuss about the technologies which have been used in it at the past and will be applied for doing its development plans at the next decade. We will also express the famous scenarios, the development programs and the trend of evolution technologies of different countries and unions and etc., till to predict the core and strategic technologies of the power industries of the world in the future. Then by reviewing, comparing, updating and analysing the similar studies and forming the exsitance information in our country, we will suggest the important technologies which are necessary for this industry in the future (one or two decades later). At least the validity of these technologies will be asked again from some especialists (Delphi method).
104
98-F-MNG-851
A Method for Determining Attributes Heavy Demand Customers Case Study
Hassan Lajvardi MATN CO
Division Of Social & Economical Studying I.R.OF. IRAN
Key words: Attributes, Customer satisfaction, heavy demand electrisity
Abstract Determining of Power attributes are the most important part in measuring customer satisfaction, so it is essential to survey the method of specifying these attributes and define it’s phases. This Paper tries to study the attributes for heavy demand customers case, using the steps of characteristics determination.
105
98-F-MNG-890
Productivity Enhancement in Iran Power Industry Using Homeopathy Medicine
Dr. S.M. Tabatabaee
Niroo Technology Center (MATN) (Tehran/Iran)
Abstract Human resource has a crucial roll in productivity enhancement. Nowadays, in most of the organizations , empluoyment is based on talent, interest, intelligency and level of skillys of people and other charachteristics are not paid attention enough. This inattention caused productivity decrease. In this paper it is discussed that coordination between constitution of people and their job is neccessary and the level of this coordination defines the productivity and effectiveness of human resources. In some of the pioneer companies, psychological tests are applied for this reason. Here the application of Homeopathy medicine is proposed. It is proposed that in employment interviews, the constitution of applicant would be studied and regarding to it, he or she be appointed for the best job and best position appropriate to him. It is possible to do job rotation or raise for employees based on homeopathic tests, to find the best positions according to their constitutions.
106
98-F-MNG-895
A Proposal for Global Electricity Network Construction
Dr. S.M. Tabatabaee Dr. Z. Besharati Rad
Niroo Technology Center ( MATN) (Tehran/Iran)
Abstract Electricity Consumption as a clean and reliable form of energy is increasing. Studies show that the rate of electricity consumption will grow more than other forms of energy in the future, so electricity will be one of the profitable businesses in the next years. At the present time, some of the countries have mutual transaction of electricity. These transactions will increase in the future. According to electricity requirment and market situation, a global electricity network is proposed here. This network is depicted as 2 lines, Bipolar HVDC 800 kv that connects different continents (except than Australia) in its different paths. The network will be administrated by “Global Electricity Company”that its shareholders are different countries. These countries export their additional generation or import their needs from this network. For this reason global electricity market should be activated under supervision of global electricity company. There are lots of advantages for global electricity network. In our country it is possible to export electricity through global electricity network, instead of export of other forms of energy . According to geography, Iran will be located in main way of this network, so it is worthable for Iran power Industry to follow this subjects.
107
98-F-MNG-897
Technology Development in Power Industry Using “GAP Doctorine”
Dr. S.M. Tabatabaee
Niroo Technology Center (MATN) (Tehran/Iran)
Abstract GAP Doctrine discuss about seeking future problems in advance, and solving them with considering past and present situation and also other countries’ experiences. In this paper, formulation of power industry strategy in technological field, using GAP Doctrine”, is studied. Strenghts and weakness, opportunities and threats are stated and Iran power Industry is compared with other countries’ power system. In this way, the vision of the future is figured, and technology development strategies are stated. Possible strategies based on strengths-opportunities, strengths-threats, weaknesses - opportunities, weaknesses-threats are discussed and at last they are categorized as technological, educational, research information system, policy making, investment and environmental strategies.
108
98-F-PDS-161
An Application of Fuzzy Regression Models to Estimate a Residential Feeder’s Peak Load in Yazd
Farrokh Amini Zohreh Salimian Niroo Research Institute
IRAN
Key words: Fuzzy Linear Regression, Fuzzy Coefficients, Peak Load, Load Estimation, Distribution Networks
Abstract Linear fuzzy regression model using linear programming under some constraints, where input data are non-fuzzy and output data represented by triangular or trapezoidal fuzzy numbers, was proposed by Tanaka (1982). The purpose of this article is to revisit the fuzzy regression portions and to discuss issues related to Tanaka approach. After that the result of two estimation methods (Standard Regression and Fuzzy Regression) will be compared using a residential feeder’s data in Yazd. As mentioned before we will use these methods to estimate the peak load of this feeder in two conditions where the outputs are triangular or trapezoidal fuzzy numbers. It is necessary to say that we used Win QSB (LP-ILP Version 1.00) to solve the linear programming problems.
109
98-F-PDS-193
Reconfiguration with fuzzy constraints for effective loss reduction in the distribution network on the east of hozestan
Elahe Mashhoor Rahmat allah Hooshmand Phd Student-Kntoosi Associate professor-Isfahan University
Key words:
Abstract This paper is the study and researh results for reconfiguration of the distribution network on the east of Khozestan in order to loss reduction with use heuristic search method, which explained with Goswami, and fuzzy constraints.The priamery network on the east of Khozestan contains both 11kv and 33kv voltages.The aim of this project is reconfiguration of both 11kv and 33kv networks in normal condition (without any fault) in order to reduces power losses and so energy losses. If the power loss in the high demand period reduces, the energy loss will significantly reduces in the same period.So the purposal method for both 11kv and 33kv networks in the warm season is performed and network parameters such as loss and network load balancing index in optimal configuration are calculated. For nodes voltage, currents and line transportation powers aren't crisp and have fuzzy nature , in order to consider the operator ideas , problem is solved with fuzzy constraints and results are showed and annalized.
110
98-F-PDS-220
Identification of share of loss elements and Technical - operative - economic precedence of the
reduction ways of it in electrical power distribution network S.R. Kiani A. Abbaszadeh Niroo consulting engineers Co.
Iran Key words: Power loss, Elements of loss making, Load balance,
Technical - Operative - economic factors Abstract The importance of paying attention to loss problem in electrical power distribution system in the country is not ignored by none of the power industry experts, because it contains considerable percent of entire network loss in throughout network. In this article we tried to evaluate potential of power loss reduction scale in electrical energy distribution part in country electricity industry. In addition to that in order to identify role and share of the elements of losses in distribution network, we took help of real results of materializing some operated projects in some city of different areas with different atmospheric, geographic, social and cultural condition. With analysis of elements and consideration of technical, operative and economic parameters the precedence of them was specified. We did that to use its results in writing total policy of country power industry. All of them were done for energy and power loss scale reduction every more. To investigate the state of distribution network power loss reduction in pilot areas, electrical parameters recorders for specification of present network status were installed. To achieve to allowable power loss, on the base of this attained expenditure parameters for each of these areas as studies and calculations were done. In this article in addition to showing of loss quantity and their percent in before and after offered designs materializing for loss reduction in every pilot area. On the base of surveys the scale of loss reduction in each area is summarized in following table:
Pilot area
Loss scale(%) Takestan Ghorveh Ilam Azadshahr (Yazd) Azna
Before design 16.31 14.28 12.84 14.12 15.83 After design 7.46 7.48 7.91 7.54 7.82
111
98-F-PDS-222
Classified Methods of Decreasing The Losses In Tehran South West Power Distribution Company
A-Salmany M-B-Kharazy M-S-Sepasian Tehran South West Power Distribution Company Power And Water Industrial Technology IRAN IRAN
Key words: losses energy, losses power, methods of decreasing the losses
Abstract According to available information 18% of the energy lost in transmission between the power station and users which about 67% is relevant to the distribution division. From the other hand, budget deficit in distribution power companies and the varieties of the parts as well as the methods of decreasing the losses caused to classified the necessary methods of decreasing the losses in these companies. In this article we made some models of the main methods of decreasing the losses in Tehran South West Power Distribution Company which are estimated and classified the matters from point of project benefits performance facility and investment on potential ability to decrease the losses.
112
98-F-PDS-330
Optimal Placement of Distributed Generation for Voltage Profile Improvement and Reduction of
Voltage Unbalance
Babak Mohammadi Mohsen Parsa Moghaddam Tarbiat Modares University Tarbiat Modares University
Key words: Genetic Algorithm, Distributed Generation, Voltage Profile, Voltage Unbalance, Optimal Placement
Abstract The use of distributed generation units aiming at providing power to distribution networks can have significant influence on the distribution networks. Nowadays, some of the problems related to distribution networks are voltage unbalance, high power loss and improper voltage profile. It is possible to resolve these problems using optimal placement of distributed generation sources. In the present article we will present two methods which uses genetic algorithm for the placement of distributed generation in order to improve voltage profile and reduce voltage unbalance. The purpose of our research is to determine the optimal number, capacity and location of distributed generation units. The results obtained from simulations show the efficiency of the method presented.
113
98-F-PDS-346
Multi Voltage Levels Distribution Network Planning with Supplying Area Algorithm
Hassan Siahkali Reza Roshanfekr
Niroo Research Institute (NRI)
Tehran - Iran
Key words: Supplying Area Algorithm, Loss Cost, Annual Invesment Cost and Sensitivity Analysis
Abstract The optimal distribution system planning is recognized as a very complex problem because of the large number of variables and candidate network configurations. Many factors have been effected distribution planning problem such as load forecasting, load growth, load density, substation sizing and siting, feeder sizing and routing and so on. Most of models and mathematical methods have been developed and applied to one voltage level distribution network planning. In this paper, new algorithm for distribution network planning and optimizing has been shown with practical assumption in three voltage levels (medium (20 kV), Intermediate (6.6 kV) and low (400 v) voltage levels). This method for optimum planning is presented sizing and routing of each voltage levels of radial distribution networks with low-density load areas. At the end of this paper, this algorithm has been applied to test network that is extracted from Distribution network of Gilan Regional Electricity Company and the results have been shown.
114
98-F-PDS-347
Optimized Levels of Distribution Transformer Losses in Iran Considering Technical and Economic Aspects
M.R. Jahangiri 1, A. Yavartalab 2, M.R. Dehafarin 2, B. Ahmadzadeh 3
(1) Niroo Research Institute
(2) Tavanir Organization (3) Iran Transfo Company
Iran
Key words: Distribution Transformer, No Load Losses, Load Losses, Interest Rate, Energy Cost
Abstract Nowadays we have excessive energy losses in our power network in Iran. The distribution system has the main role in the total system loss. Our studies indicated that distribution transformers cause significant loss percentage in the distribution system. Therefore loss reduction and loss evaluation methods for distribution transformers are required to reduce distribution network losses. The present investigation shows that designinig and manufacturing of distribution transformers are not in the suitable qualifications in our country now. Considering energy price, transformer lifetimes and other important parameters, No-load and load losses of distribution transformers should decrease 20-25 %. If the energy price or inflation rate change in the future, other loss levels for transformers may be propounded.
115
98-F-PDS-356
Distribution Long Term Load Forecasting Using Fuzzy Logic
Navid Eghtedarpour Fars Regional Electrical Company
Mehdi Raoofat Shiraz University
Electrical Engineering Departement
Key words: Long term load forecasting, Fuzzy logic, Distribution systems
Abstract One of the most important aim of electric utilities is to provide reliable power with proper quality for their customers in the planning stage of system , utilities should provide an economic expansion plan to meet future demands , so a good forecast of future electric demand is a prerequisite stage , both from economic and quality aspects . Although different methods has been proposed for spatial load forecasting but most of them need accurate and enough data for a good forecast . This paper propose a method based an fuzzy logic to use available data same how not accurate - and also some linguistic information for a better spatial load fore cast. the performance of the method is evaluated using data prom a typical distribution network .
116
82-E-PDS-445
Operation Analysis of DSTATCOM using EMTDC Program
Jin-Boo Choo, Bang-Myung Kwak, No-Hong Kwak, Young-Soo Jeon, Sang-Ho Park
Korea Electric Power Research Institute
103-16, Munji-dong Yusung-gu Daejeon, 305-380, Korea (ROK)
Abstract The DSTATCOM(Distribution Static Synch- ronous Compensator) is one of the Custom Power Device that can regulate the voltage. DSTATCOM operated as a shunt connected static var compensator whose capacitive or inductive output current can be controlled independent of the system voltage. And the magnitude of compensated voltage is limited by characteristics of system and load. Compensation capability of DSTATCOM which can inject 1 MVAR reactive power was simulated by EMTDC under several condition. This paper analyzed effect of DSTATCOM’S compensation considering length and kind of distribution line, power factor and magnitude of load, duration and magnitude of voltage variation.
117
82-E-PDS-461
An Analysis of the Ground Fault Current Division of 22.9kV-Y Lines
Yong-Hun Lim*1, Duck-Hwa Hyun, Beom-Seok Lee, Hyo-Yul Choi, Kwi-Yil Gwak
Korea Electric Power Research Institute
103-16, MUJI-DON, YUSEONG-GU, DAEJEON 305-380, KOREA
Key words: Ground fault current, Division fault currents, Carson’s Equation, Earth return Path
Abstract During ground faults in power system , large current and raised potential appear at nearby places. This paper presents an analytical procedure of the ground fault current for the towers of a transmission line(154kV) and distribution line(22.9kV) of an arbitrary number of spans during ground faults. In order to protect against undesired consequences economically and securely, it is necessary to evaluate the value and distribution of the ground fault current as precisely as possible.
118
98-F-PDS-468
Overhead Covered Conductors and the Results of Semi-Industrial Production
M. Tarafdar Haque1, S. M. Seyed Giasi2, M. Mostofi S.2, F. Farnam2
Faculty of Electrical and Computer Engineering, Tabriz University, Tabriz1
SIMCAT Wire & Cable Co., Tabriz2 IRAN
Key words: Medium Voltage Electrical Distribution Networks, Covered Conductor, XLPE
Abstract This paper presents a brief review of specification of covered conductors in addition to the experimental results, which are obtained by semi-industrial production of covered conductors using Vinyl-Ceylon method. The most important electrical and mechanical specifications of this kind of conductors are presented and the popular production methods are explained. The thermal model of covered conductors is proposed and the its rated current is calculated and it has been explained that the rated current of covered conductors is more than popular bare conductors. The electrical and mechanical tests results are compared with the standards to show the good performance of produced covered conductor.
119
98-F-PDS-504
High Impedance Fault Detection Using Harmonics Energy Decision Tree Algorithm
Seyed Mohammad Shahrtash Mustafa Sarlak Electrical Engineering ِDepartment of Iran University of Science and Technology
Key words: Decision Tree, Pattern Recognition, High Impedance Fault (HIF), Distribution System Protection
Abstract In this paper a new pattern recognition based algorithm is presented for electric distribution high impedance fault detection. In this method the distortion of the sum of energy of odd, even and in-between harmonic energies up to 400Hz is recognized. The information related to the sum of energy is fed to a decision tree as a classifier for pattern recognition. The proposed scheme can successfully distinguish the HIFs from normal operations in power system such as load switching, capacitors switching, transformer energization and harmonic loads. The results show high accuracy of the proposed method.
120
98-F-PDS-511
Feasibility Study for Conversion of LV-Radial to LV-Mesh in One District of Tehran (TREC)
A. A. Bahmanpour Gh. Khakbaz Noorgostar Consulting Engineers Co. Niroo Consulting Eng. Co.
IRAN
Key words: LV-Mesh, LV-Radial, Reliability, Energy Not Supplied (ENS)
Abstract In comparisons of 2 types of LV distribution systems, i.e. LV-Radial and LV-Mesh, there are many claims of advantages and disadvantages. For LV-Mesh, high reliability, lower losses, and lower transformer capacity, in contrast to LV-Radial for which lower investment cost and simplicity of design and operation are claimed. To better determine exactly and quantitatively these advantages, a contract for project was signed in 1383 to do the feasibility studies for Ferdowsi Dirstrict of Tehran. This paper is based on Final Report of that project in which the selected area that is the service area of one 30 MVA transformer from Karimkhan S/S is introduced and the input data required for entry in ETAP software is described. Changing the present LV-Radial system to LV-Mesh system requires many alterations for which some of the diagrams and/or plans are given and the analyses of the changes required for the conversion are explained. Cost-benefit tables and program of work are other sections of the paper at the end of which there is this conclusion that conversion of LV-Radial to LV-Mesh is economically and rationally justifiable only if the power & energy losses and ENS have their real values in a utility.
121
98-F-PDS-512
Proposed Subtransmission System Philosophy for Tehran
Ahmad Ali Bahmanpour Noorgostar Consulting Engineers Co.
Key words: System Philosophy, Contingencies, Firm Capacity, Single Contingency
Abstract In the PSC 2004 paper titled « Subtransmission & Distribution System Philosophy », some necessities were mentioned. To execute these necessities a consultancy contract was signed with Tehran Regional Electricity Co. (TREC) that concluded to a system philosophy for Subtransmission system of Tehran. This paper will summarize the final report of the a/m contract. In the paper, after description of different philosophies of Tehran 63 kv system for the past 46 years, it is proposed that single contingency be chosen for that system which results in a theorem & model for firm capacity of each 63/20 kv substation. To utilize the model firstly the overloading capability of the equipment, secondly the use of reserve capacity of 20 kv system, and thirdly the probable interconnection of 63 kv or 20 kv system were studied. From the results of these studies and also from the restrictions set out by client forbidding overloading of power transformers, the firm capacities were calculated and the 63/20kv substations were categorized in 3 groups:
1- Those with firm capacities below 75% 2- Those with firm capacities between 75% and 85% 3- Those with firm capacities over 85%
The paper proposes first to increase the firm capacity of the substations of groups 1 and 2 and second to increase the normal loading of substations from the present 75% to 85%. This will result in a new (already unused) capacity of 500 MVA for TREC. Moreover, due to very high price and scarcity of land in Tehran, simple 63/20 kv substations lacking 63 kv bus bars (feeder- transformer type) are recommended.
122
98-F-PDS-513
Evaluation of Light Emitting Diodes (LED) For Street Lighting Application
M. F. Hanifi, T. Abdorrazaghzadeh, M. A. Abbassi Vardeh
Noorgostar Co. Ltd. (Lighting Consulters) IRAN
Key words: Light Emitting Diodes (LED), Street Luminarie, Saving
Abstract Recently propagandas of utilizing from LED for street lighting have been accomplished by different groups in Iran so that the authorities and responsible could not decide simply because of non-existence of complied and valid references. In this article the feasibility of street lighting by use of overall available LED productions has been studied. In spit of LED manufacturers claim about the replacement of lighting sources of residential streets and low traffic parking lots by LEDs, studies and researches demonstrate that LEDs could not be an alternative for 70&150 W HPS or 125 W MHV because of low light output and efficiency (16-30 lumen per watt). Their improved specifications such as low power consumption, long lifetime, high color rendering, … enable the best LEDs with output luminous flux 1100 Lm as a replacement of 100 W incandescent lamp. According to common economical calculations more LEDs are needed to implement the same lighting levels. Thus their higher production costs and larger quantity for an appropriate lighting level, make LEDs non-economized sources even with comparison to incandescent lamp. Light efficiency improvement of LEDs will contribute them in road lighting in the future but at present time products cannot be responsible for street lighting and good alternatives for available light sources.
123
98-F-PDS-536
Analysis of Road lighting Measurement Results and its Effect on Optimization of Energy Consumption
M. A. Abbassi, M.F.Hanifi, N.Sattar, F. Azad. Noorgostar Co. Ltd. (Lighting Consulter)
Key words: Road lighting, measuring, Optimization of Energy Consumption
Abstract One considerable factor in electrical energy demand growth, specially at peak hours is scaling lighting levels up and road lighting development that with due attention to other network loads and production capacity shortage, intensifies problems of power industry. Formerly, lack of required information, equipment and experiences at utilities, has led to inexistency of photometric data about lighting installations, which provide the possibility of quality management and optimization of energy consumption. On 2002, the Ministry of Energy with limitation of road lighting levels and obligation of photometric measurements in new and old installed lighting systems through a formal notification, carried out effective steps in data collecting required for road lighting optimization. So regional electrical companies proceeded road lighting measurements with collaboration of consulter companies. The result of measurements shows a few percent of road conformity with related standards. According to corrected system designs, if the annual mean costs of energy consumption for available lighting system has been considered about 52 million Rails per kilometer, it will be declined to 21 million Rails with optimizing which equals to 60% reduction.
124
98-F-PDS-557
Electrical Interruption Cost Evaluation from the viewpoint of Network and Customers in a Sample Network with NEPLAN Software
Khalil Banan Ali Abbasy Saeed Najafi Bakhche Jogy Ali Ramin Fard Tabriz University &
Azarbaijan Higher Education and Research Center
Azarbaijan Higher Education and Research Center
Electrical Distribution Company of Tabriz
Key words: Distribution Systems, Customers Load, Interruption Costs, NEPLAN
Abstract Electrical Interruptions always is encountered the networks with an important challenge. There is no doubt that the electrical interruptions is enforced so many costs and damages to many social areas such as security, economic and so on. The existence of many different interpretations in this subject is increased the complexity of the problem. In this paper with a analytical viewpoint, the electrical interruptions in a sample feeder is evaluated from the viewpoints of network and customers. The results of this evaluation, shows that the amount of interruption costs from the viewpoint of customers is very high and emphasizes on finding serious methods for reduction of this costs.
125
98-F-PDS-558
Design and Construction of Voltage&Current Measuring Insulator for 20KV Overhead Lines
R.Behzadi , M.Oskuei , M.S.Vafakish , D.Talebi Khanmiri , D.Habibinia
Niroo Research Institute, High Voltage Group IRAN
Key words: Voltage &Current Measuring Insulator, 20KV Overhead Lines, Electronic Measurement
Abstract In our country there are long and broad 20KV distribution overhead lines .It is necessary to have information-terminal from medium voltage overhead lines for optimized operation, selling & power quality improvement. Current and voltage information in medium voltage distribution overhead lines are the most important data to reach mentioned aims. The ordinary CT & PT cannot satisfy the supposed operation because of their magnetic core and magnetic saturation phenomenon; In addition they are so heavy, large size and expensive, also they need special tools &equipments for installation. In this paper we introduce design, simulation and construction of an insulator, which not only maintain 20KV overhead conductors but also measure their current &voltage accurately. This voltage ¤t measuring insulator can be install easily without any extra equipment on usual cross-arm and also display and store voltage ¤t of overhead lines data as digital data.
126
98-F-PDS-560
LONG TERM LOAD FORECASTING THE BASE OF ELECTRIC COMPERHENSIVE PLANNING
HOSEIN ZAKERI ALI REZA KARIM TEHRANI
MONIRAN KHORASAN POWER ENGINEERING CONSULTANT CO
IRAN
Key words: electric comprehensive planning, load density, urban consumer, model of demand
Abstract In recent years, the electric distribution comprehensive planning is considered as a main solution for distribution network problems. The lack of knowledge to the methods leads to vast researches in tree cities for several years. The results can be summarized to these categories:
- Electric load forecasting - Distribution substation optimization - Medium voltage grid planning - Annual plans
The statistics shows that these load forecasting of the cities don't have the necessary accuracy. This article introduces a practical solution with concentration on long term load forecasting. One of the most suitable methods for load forecasting is land use method. The basement of this method is obtaining the electric load behavior models for various consumers and the application of these models to urban areas. The following are some advantages of land use method.
- The estimation of peak demands - Load behavior of different combination of consumers - Load density of different consumers on developed city map
127
98-F-PDS-594
Tabriz- Jolfa Electrified Railway Influence on Voltage Imbalance of its Feeding Electric Distribution System and
Proposing Imbalance Improvement Methods
Farhad Shahnia1 Mitra Sarhangzadeh2 Seyed Hossein Hosseini3
1Research Office, Eastern Azarbayjan Electric Power Distribution Company, Tabriz, Iran
2 Tabriz Electric Power Distribution Company, Tabriz, Iran
3Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
Key words: Electrified Railway, Power Quality, Voltage and Current Imbalance, Imbalance Improvement
Abstract Single-phase or two-phase conventional power distribution systems used for feeding electrified railway systems can cause great problems for the electric power system of the region, resulting in a decrease in the system power quality. This seems of great importance due to the increasing interest in using electrified railway systems in Iran especially in Tehran- Isfahan and Tehran- Mashhad routes. In this paper, the voltage imbalance problems of the electrified railway system are studied and investigated on the power distribution system feeding the traction system. Later on, Tabriz- Jolfa electrified railway as an imbalance load of Azarbayjan electric power system has been studied and the imbalance problems are investigated through the simulation results. Then, the imbalance improvement solutions are described and investigated and the best solution method has been proposed.
128
98-F-PDS-655
OPTIMAL FEEDER SWITCH AUTOMATION IN ELECTRIC DISTRIBUTION NETWORKS
M. Ramezani H. Falaghi M.-R. Haghifam
Department of Electrical Engineering Tarbiat Modarres University
Tehran, Iran
Key words: Power Distribution Network, Reliability, Switch Automation
Abstract Reliability of supply is one of the most important aspects of power distribution engineering. One of the ways to improving the reliability of distribution networks is to automation of sectionalizers and tie points in MV feeders. In this paper a new and efficient algorithm for optimal selection of switches for automation in distribution networks is proposed. Cost of equipment, customer interruption cost, and maintenance cost of devices are incorporated in objective function. Dynamic programming is used for optimization procedure. Effectiveness of the proposed method is shown by case study in a real MV distribution network from Iran.
129
98-F-PDS-689
Determination of the Load Components Contribution by mean of GA
NAME NAME NAME NAME NEME
Key words: Key words: Key words: Key words: Key words: Key words:
Abstract For many studies in the subtransmission and distribution systems like system designing and planning, load forecasting, load management and calculating load parameters, data of load components are needed. And we know that there is no possibility for capturing and registering all the load components data. Therefore for using them, the data must be extracted from total load curve which is captured precisely. In this paper, we will make a simple mathematical model and then by changing it to an optimization problem will calculate the weights of each component and related factors using Genetic Algorithm (GA). We use inputs, like hourly total load curve, customers types (such as industrial, commercial and residential and so on), and the typical components load curve (which considers the social and environmental effective parameters, like the effect of changing the seasons or weekend on this model). The proposed method is tested on the real data of a feeder located in Afsarie of Tehran and the results are presented.
130
98-F-PDS-698
Establishment of First Research Site of Electric Equipments in Tropical Regions of south of Iran
M. Rezaei1 A. Moradian1 M. Oskouee1 M.R. Shariati1 M.S. Vafakish1 H. Monavvar2
1-Niroo Research Institute
2- Hormozgan Regional Electric Company IRAN
Key words: research site, tropical regions, regional laboratory, Environmental conditions
Abstract Operation of electric industry equipments in recent decades and specially transmission and distribution in southern regions of Iran indicates in spite of other common methods of operations in other regions of Iran, environmental conditions cause fast aging and age ratio diminution of electric equipments furthermore it cause not to use the equipments beneficially as other regions of Iran in spite of the immense investments. Since frontispiece of 20 year goals of the government is growth and development of dispossessed regions, therefore this urgency was felt that with centralization of potential peoples and financial and human investments to take arrangement in frame of codified research program and by establishment of research site of electric equipments for tropical regions of south of Iran in a specific period, with doing expanded research activities be able to surmount greater portion of problems and difficulties of electric industry in south of Iran, improve operation of equipments in environmental conditions of this region and provide this opportunity for regional electric and distribution companies to be able to develop the electric network and increase power electric quality instead of removing fault effect of this environmental conditions. In this paper, it will discussed and considered executive activities of establishment, equipping and potential ability of Hormozgan Regional Electric Research Site which established by supervision and consulting of Niroo Research Institute (NRI).
131
98-F-PDS-730
Economical Analysis of Using Energy Efficient Transformers in Distribution Networks of Iran
Ali Farsi * , ** Davod Hosein_puor *
* Azarbaijan Higher Education and Research Complex ** National Training Center of Energy Management
Key words: Distribution transformers, Total Cost of Ownership, Present value of payments
Abstract Utilization of the energy efficient distribution transformers will cause saving the energy resources because of large quantity of transformers in power distribution networks. On the other hand using these transformers can be economic. This paper discusses around losses and efficiency of transformers and then introduces distribution transformer standards. Total cost of ownership for transformers of transformers in different efficiency standards is used as economical comparing gauge. According calculation and economical analysis, it shown that the life cycle cost of energy efficient transformers is less in comparison with ordinary ones. Finally the sources of uncertainty of economical analysis are discussed.
132
98-F-PDS-740
TECHNICAL AND ECONOMICAL ANALSIS USE OF EFFICIENCY TRANSFORERS IN
THE DISTRIBUTION NETWORK
M.H.Amrollahi
Islamic Azad University of Zanjan Iran Transformer Research Institute
Iran
Key words: ِDistribution Transformer, Energy Efficiency, Loss Evaluation, Total Owning Cost, Capital Cost, Economical Analysis
Abstract The distribution transformers are one of important factors such effect on electrical energy losses. Although the efficiency of distribution transformers are high, the loss cost is still significant, because the majority of electricity passes through of them, and transformers are energized 24/7, energy consuming even in no load condition. Therefore a little efficiency improvement will be accompanied with accompanied with economic advantages. The distribution transformer efficiencies steadily increased with design, introduction of improved materials, manufacturing methods. It is possible to reduce their losses more than 70%. The use of energy efficient transformers in distribution network instead of erection and developing the network and power plant will be a significant saving in capital costs and fuel. So, loss evaluation of distribution transformers in duration of life cycle will help us to determine the best choice among alternative. In this paper presented a complete model for estimation of worth of losses, economic calculation to make decision for replacing of energy efficient transformers. In these calculation energy efficient transformer were been compared with normal transformers from technical and economic points and to determine the rate of payback period.
133
98-F-PDS-755
Determination of components of power and energy loss in 20 KV network
Mohammad Rahmanpouri Hajireza Teimori Alireza Sharafi Saeed Mosavi
Lorestan Province Power Distribution Co.
Iran
Key words: Medium voltage feeder, Power and energy loss, off- load, component of transformer
Abstract Development of distribution networks and their high power loss , causes that decrease of energy loss to be an important apprehension and anxiety of companies and persons who are engaged in electricity of industry . persen of losses of distribution networks always is measured and calculated totally ,but knowing elements of losses with distinction and determination of portions of all important factors can play a major role in managemaent and scheduling for reduction of losses in electricity distribution companies . this article is the results of research that was performed in lorestan province electricity distribution company in order to recognize and distinct elements of losses and determination of amount of each effective components in a sample medium voltage feeder . In this project by simultaneous readout of energy meters of customers and energy meter of fader in transmission stations in a readout time cycle , first totall amount of energy and power loss in sample feeder is measured and then separate recognized factors which generate losses in feeders network are determined that results in the determination of components of energy loss and by generalization of consequences , important factors of the losses in 20kv networks is recognized and determined.
134
98-F-PDS-776
Detrimental Effects of Using Non Standard ACSR Conductors in Medium Voltage Distribution Feeders
M. Rajabi1 M.A. Talebi1, 2 A. Gholami2 M. N. Golrokh1
1. Tehran South West Electrical Distribution Company
2. Iran University of Science and Technology Iran
Key words: ACSR Conductor, Standard test, Medium Voltage Feeders
Abstract Conductor in power systems, as electrical energy carrier is one of considerable components of distribution and transmission networks. Conductors should have suitable electrical traits for energy transmission, and acceptable mechanical properties for withstand against mechanical forces and stresses in overhead lines at several meteorological conditions. Recently, Aluminum-Steel conductors are applied in medium voltage distribution feeders because of their favourable properties. Regardless of these, simplicity of produce process of these conductors caused to appearance non standard manufactures in this field that using their products can exact some detriments in distribution systems. In this paper, ACSR conductor's properties are presented and standard process of their produce and related quality tests are investigated. Also, examples of application of non standard kind of these conductors and their laboratory tests are discussed. At last, undesirable effects of application these conductors in distribution feeders are simulated. Financial studies show that replacement this conductor by standard conductor in distribution feeders is optimal from economic point of view.
135
98-F-PQA-118
Optimal Design of Hybrid Active Filter by Differential Evolution Algorithm for Different Industrial Loads
Tahere Daemi, Ebrahim Farjah, Alireza Khayatian
Dept of Electrical Engineering, Shiraz University Shiraz, Iran
Key words: Hybrid Filter, Optimization, Differential Evolution Algorithm
Abstract The purpose of this paper is designing a hybrid filter (determining type, characteristic and rating of different elements of filter) for different industrial loads. Cost of filter consisting of investment cost and running cost (including losses cost of filter) is considered for cost optimization. Differential Evolution Algorithm is used for optimizing algorithm. Harmonic limitation, resonance prevention and reactive power compensation is considered as constraints. The results of filter design for some typical industrial load are presented and the effect of source voltage harmonics, load power factor and harmonic content of load on the filter structure and its characteristic is analyzed.
136
98-F-PQA-188
Harmonic Filter Design Based on Power Factor Correction for HVDC Converters
M.Joorabian S.GH.Seyfossadat M.A.Zamani
Shahid Chamran University of Ahvaz
Key words: Passive filters, Harmonic, Power Factor Correction, HVDC Converters
Abstract This paper presents a study of passive harmonic filters design to reduce harmonic distortion caused by harmonic sources and compensate power factor in electrical systems. In this paper, the design and performance of single tuned and high pass filters based on power factor correction and methodology used for analysis will be discussed and an algorithm is presented. The proposed method is used for harmonic reduction in AC side of a six pulse HVDC converter. The system has been simulated with MATLAB and simulation results clearly show the proper operation of designed filter.
137
98-F-PQA-226
Utilize Active & Reactive Current Components to Control Distributed Resources
Siamak Naderi Abdalreza Sheikh Aleslami Seyyed Ali Nabavi Niyaki
University of Mazandaran Iran
Key words: Distributed Resources, Voltage Source Inverter, Reactive Power Compensation, P.L.L
Abstract Power electronic converters are the most promising devices that can be used to link distributed resources to a distribution network. This can improve the power quality of such an electrical energy as well. In this paper the frequency independent method based on Instantaneous active and reactive current components are used as a control strategy. This control strategy applies to control voltage source inverter of non-linear link between the energy source and the distribution network. The proposed method not only removes P.L.L. from control circuit and resolves synchronism problems, but also provides required active and reactive power demands. Furthermore, it improves voltage profile and increases power factor of the load and as a result decreases power losses. The reduction of voltage and current harmonic distortion of non-linear link is noticeable. The simulation results illustrate high performance of this distributed generation system, which is controlled by means of this method.
138
98-F-PQA-232
Robust Control of Active Harmonic Rectifier to Reduce Utility Current THD
Mostafa Mohammadian Ali Yazdian Varjani Ramin Nasirpour
Tarbiat Modares Univ. Iran
Key words: Active Harmonic Rectifier, Power system, Total Harmonic Distortion
Abstract In this paper, a new robust control strategy for Active Harmonic Rectifier (AHR) is presented. AHR is controlled to reduce utility input current Total Harmonic Distortion (THD). Adaptive Hysteresis band, bang-bang current control is proposed to have robust and stable performance. The reference current generation for PWM converter and current control strategy is wholly done in time domain and DC bus voltage control is accomplished utilizing a Proportional-Integral (PI) controller. As result, this control strategy represents a robust and towardly transient and steady-state response against model variations. Closed loop system behavior for model uncertainties and model parameter misusing errors is closed rather than other current injection methods. Simulation results confirm the proposed system performance.
139
98-F-PQA-262
Impacts of Distributed Generation on Power Losses and power Quality of Zanjan Distribution Network by Using Digsilent
Hossein Kazemi Karegar Majid Moradloo
Zanjan University Zanjan/Iran
Key words: Distributed Generation, Power Quality, Power Losses, THD
Abstract Nowadays, distributed generation gets more attentions, because making central power plants takes more time and needs more investments. In addition, close competitions in electrical markets oblige electrical company to reduce power losses and improve power quality of the networks. This regards, distributed generation will be one of the attractive solutions. In this paper, the impacts of distributed generation on Zanjan distribution network will be investigated and the suitable size and their places will be found. It will be shown that the power losses of the network decrease and its power quality improve. In addition, the obtained results will be compared with the results of a central power station. The compared results show that small-distributed generation will be more effective than using central power plant.
140
98-E-PQA-310
Control of Active Power Line Conditioner with Neural- Genetic networks
M. P. Herfeh Tehran Reiogenal Electricity Company
A. Kazemi
Iran University of Sciense and Technology
M. S. Masoum Iran University of Sciense and Technology
Key words: Active power Line Condithioner, Neural Network, Genetic algorithm
Abstract In the recent years, non-linear devices based on the power electronic techniques are well-developed. These power apparatous are leading to serious problem regarding power quality. These converters are employed at different power levels, ranging from large speed drives to small power supplies for personal computers, etc. Some sensetive loads such as measurement devices, hospital diagonistic, industrial process controllers and computers may malfunction to operate when connected to ac line harmonics. Also, electric utility transmission and distribution equipments may be susceptible to ac line harmonics. Transformers and transmission lines have higher opertaing losses, capasitor banks, and therefore protective relays may fail. As mentioned above, it is objective of the electric utility to supply its customers with a sinousidal voltage of constant magnitude. A number of methods have been suggested to maintain sinousidal, some of which are inphase ac line currents: passive filtering, control of converter switching, and active power line conditioning. In this paper, a method to control an APLC using Neural Network and Genetic algorithm is presented. The simulation results show that the new system is a simple effective scheme to line harmonics compensation.
141
98-F-PQA-335
Voltage Flicker Modeling Due To Electric Arc Furnaces
J. rohi R. navayi A. sheikholeslami Noshirvani Engineering & Tecnology Higher Education complex- babol
Key words: Electric Arc Furnace, Voltage Flicker
Abstract Electric arc furneces (EAF’s) are the main consumers of the Electric power. EAF’s are the main cause of power quality problem’s (ie. voltage flicker) due to the interaction of the high demand currents of the loads with the supply system impedance. Inorder to adequalety understand and analyze the cffects on the power system form these loads, obtaining an accurate representation of characteristics of the loads is crucial In this paper, a dynamic EAF model is developed and arc eqution has solved in matlab simulink environment and it’s response that is arc voltage without flicker is modulated with a randome wave. Then the proposed model is connected to power system as a controled voltage sourse in this paper, Data of tabarestan steel factory has used in simulation. And prouen that, this is valid model to represent the EAF operation.
142
98-F-PQA-371
Finding of Suitable Place for Installing of Parallel Active Power Filter (With Constant and Controlled Gain) in Radial
Distribution Feeder In order to Decreasing Harmonic Propagation and Oscillation
Hamid Reza Ezzati Ali Yazdian Varjani Tarbiat Modarres University
Key words: Harmonic Propagation, Harmonic Oscillation, Characteristic impedance, Active filter gain
Abstract In order to damping harmonic propagation effect, The active power filters(APF) are installed on distribution systems. This installation also may cause harmonic oscillation effect named "Whack-a-mole". The objective is finding of suitable place for installing of parallel active power filter as are compensated efficiently harmonic propagation and oscillation. In this paper using simulation results, the two mentioned effects are decreased efficiently for a ten-bus power radial distribution feeder for any nonlinear load connections (harmonic current or voltage source ) by using constant gain
CV Z
K 1= The characteristic impedance , CZ , is nondeterministic and variable, so
the APF's gain should be controlled actively. The parallel active filter gain is designed such that by producing proper compensating current , the harmonic distortion on APF bus is controlled and the harmonic propagation and oscillation effects are prevented by keeping the harmonic distortion in an allowable interval.
143
98-F-PQA-383
A Simple Way for Parrallel Operation of UPS System
Abstract The parallel operation of UPS systems for improving the reliability can be performed in several methods. The most famous one is “The Active and Reactive Power Control”. This paper presents the results of the parallel operation of UPS’s by this method. All of the simulation results achieved by SIMULINK for the open-loop and closed-loop system are shown the validation of this approach. The control system is implemented by analog PID controller. The practical results are in agree with the simulation results and show the correctness of proposed control system.
144
98-F-PQA-402
Analysis and Design of Power Electronic Transformer for Medium Voltage Levels
Hossein Iman-Eini, Shahrokh Farhangi Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
Key words: Power electronic transformer, Power factor correction, Voltage regulator
Abstract Due to rapid decline in cost and the availability of highly reliable, low loss semiconductors with high frequency switching capability, it is expected that power electronic products and solutions will play an important role in future medium voltage (MV) electrical power distribution systems. One key component of the future automation is replacement of conventional copper and iron transformers by an all- solidstate (power-electronic) alternative. In this paper, the optimum design of a Power Electronic Transformer (PET) will be investigated. This transformer not only has the capabilities of conventional transformer, but also has the advantages such as power factor correction, voltage regulation, voltage sag and swell elimination, voltage flicker reduction and protection capability in fault situations. In addition, it has other benefits such as light weight, lower volume and no toxic dielectric coolants.
145
98-F-PQA-404
Design and Simulation if An Active Power Filter for Power Quality Improvement in a Computer Center
J. Khorasani 1 A.A. Gharaveisi2,3 S.E. Hosseini4 M. Rashidi-Nejad2,3
1. M. S. Student
2. Shahid Bahonar University of Kerman 3. International Center for Hitech. and Environmental Sciences, Mahan
4. Tarbiat Moalem University of Sabzevar
Key words: Active Filter, Computer, Power Quality
Abstract Computers are devices that are used in a vast majority of applications, such as household, commercial as well as industrial uses. These devices in which switching power supply are used can be treated as non-linear loads that can impose high harmonic currents to the network. The harmonical and distorted current may negatively influence on the power quality components, such as harmonical deviations in current and voltage. Considering a current model for PCs an active filter for a computer center is introduced, in this paper. Modeling of the proposed inverter active filter as well as computer center is done under Matlab platform, while solving the equations is implemented via the Euler method. The improved Fourier Transformation method is applied for calculation of main current component via a movable window. In part two a proportional controller is designed for DC bus voltage control. The proposed method in this paper is based up on a non-symmetrical hysteresis band modulation. Simulation results suggest that by omitting harmonical load current has been done correctly.
146
98-F-PQA-454
Dynamic Security Assessment of Tie Lines in Multipart Power Systems Using Neural Networks
Atabak Mashhadi Kashtiban Mohammad-Taghi Vakil-Baghmisheh
Mehrdad Tarafdar Haque
Faculty of Electrical and Computer Engineering, Tabriz University Iran
Key words: Dynamic Security, Tie Line, Neural Network, Multilayer Perceptron
Abstract In this paper multilayer perceptron neural networks are used for dynamic security assessment of tie lines on the IEEE-30-buses system. To this end, the over-load on all tie lines is defined as the performance index, and four security levels are defined. The system is divided into two parts; all loads in both parts are varied according to predefined load-time curves. Then, two scenarios are considered: in the first scenario there is no structural change in power system. In the second scenario it is assumed that some lines are tripped due to over-load. To speedup the neural network training, we use backpropagation algorithm with declining learning rate factor. Obtained results show that for the first scenario the average classification errors are 3.66% and 4.5% on the training set and the test set, respectively. For the second scenario, these error rates are increased to 5% and 6.5%.
147
98-F-PQA-538
Intelligent Detection and classification of Power Quality Event using S-Transform
Ali Dastfan1 Abdollah Shantiaee Zadeh1&2
Assistant Professor Department of Electrical & Robotic
Msc.Eng.Student Department of Electrical & Robotic
1-Industrial Univ. of Shahrood 2-Ghods Niroo Consulting Engineers
Key words: Power Qquality,S-Transform, Artificial Neural Network
Abstract A new method in detection and classification of power quality events is presented in this paper. Sience power quality events are recognize by nonstationary signals,these signals in power networks are classified via combination of S-transform and neural networks.The S-tansform provides frequency –dependent resolution that simultaneousely localize the real and imaginary spectra.The S-transform is similar to the wavelet transform but with a phase correction.This property is used to obtain useful features of nonstationary signals that make the pattern recognition much simpler in comparison to the wavelet multiresolution analysis.neural network configurations are traind with features from the S-transform for recognizing the waveform class. The classification accuracy for variety of power network disturbance signals is shown and is found to be significant improvement over multiresolution wavelet analysis with multiple neural networks.
148
98-E-PQA-565
Analysis and Simulation of FCL Effects on Voltage Sag in Power Systems
Alireza Jalilian, Hossein Heydari, Faramarz Faghihi, and Mojtaba Safdari
High Voltage & Magnetic Materials Research Center Iran University of Science and Technology
Key words: Voltage sags, Power quality, Fault Current Limiter (FCL), Power systems, Simulink
Abstract Voltage sag is a power quality event where the voltage magnitude is reduced to values between the 90 and 10% of the nominal voltage and which duration is extended from 0.5 cycles up to 60 seconds. The main causes for voltage sags are faults and short circuits, lightning strokes and inrush currents. In General, it is possible to consider voltage sags as the origin of between 70% and 90% of the industrial power quality problems. Dynamic voltage restorers (DVRs), FACTS device such as static compensator (STATCOM), static series synchronous Compensator (SSSC), and Unified Power Flow Controller (UPFC), energy storage devices and fault current limiters (FCLs) are used to protect sensitive loads from the effects of voltage sags in the power systems. This paper illustrates how the performance of FCLs in power system helps to enhance voltage quality. Three types of FCLs (superconducting based included resistor type and inductive type, and Thyristor based) are investigated in a case study of power system through computer simulation.
149
98-F-PQA-568
Determining Fire angle of TSC and TCR in control reactive power for minimizing
harmonic using Artificial Neural Network
Amir H. Gheisari Msc. Eng. Student
Department of Electrical Engineering Shiraz university
Mohammad M. Bazrafkan
Msc. Eng. Student Department of Electrical Engineering
Kerman University
Alireza Seifi Assistant Professor
Department of Electrical Engineering Shiraz university
Key words: Artificial Neural Network, Harmonic, FACTS elements
Abstract Producing minimum harmonic is one of the important parameters of reactive power compensators. Nowadays power systems are going to improve the power quality; and one of the most important parts of power quality is harmonic values of network. So, compensators should be designed that generate minimum harmonic. In this paper harmonic reduction in determining the fire angles of TCR1 & TSC2 which are the most common devices of FACTS3 reactive power control, is explained. Determining the fire angles in optimum THD4 production is brought; and finally artificial neural network is used for deciding in online control for more speed.
1. Thyristor Control Reactor 2. Thyristor Switched Capacitor 3. Flexible AC Transition Syste 4. Total Harmonic Distortion
150
98-F-PQA-591
Stability and Compensation Characteristics of Active Filters in Power Systems in Accordance with their Installation Position
Farhad Shahnia1, Seyed Hossein Hosseini2 1Research Office, Eastern Azarbayjan Electric Power Distribution Company, Tabriz, Iran
2Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
Key words: Active Filter, Power Quality, Harmonics, Voltage Sensitivity Analysis, Stability
Abstract Active filters are a useful means of harmonic elimination and reactive power compensation in electrical distribution systems. Since the active filters behave as current sources which inject harmonic currents to the distribution system for making the system currents as sine waves, the harmonics in the system can be increased if the active filters are not situated correctly in the distribution system, resulting in a decrease in the system power quality. In addition, the power system can also face instability, if the control scheme of the active filter is not chosen correctly. In this paper, the stability and compensation characteristics of active filters in the electric distribution systems are studied in accordance with the position of the installed active filters and a method has been applied for determination of best active filter position in a power system. In this method, the frequency response and sensitivity analysis has been carried out for all the buses of the distribution system for the active filters installed in different buses and the harmonic contents of the system are studied before and after the active filter installation which has been applied for a study case done with Matlab/Simulink.
151
98-F-PQA-593
Improving Passive Filter Characteristics in Power Systems Utilizing Active Filters
Farhad Shahnia1, Seyed Hossein Hosseini2
1Research Office, Eastern Azarbayjan Electric Power Distribution Company, Tabriz, Iran
2Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
Key words: Power Distribution System, Power Quality, Passive, Active and hybrid Filters, Harmonics
Abstract Hybrid filters involving active and passive filters with a control system are a great means of power quality improvement and harmonic reduction in electrical power systems. One of the hybrid filter structures used in the power systems are the series connection of active and passive filters through coupling transformers where the whole hybrid filter is in parallel with the nonlinear load. In this paper, harmonic compensation and power factor improvement of the electric distribution system with this hybrid filter structure are described and the parameters influencing the filter performance and filter designing parameters are investigated. A PSCAD/EMTDC simulated study case has been presented in the paper which studying the waveforms of the system prove the efficiency of the hybrid filter structure introduced in the paper and its applied control scheme in power quality improvement in power systems.
152
98-F-PQA-619
Determination of optimal monitor dip voltage emplacement in the power networks
Hossein Askarian Abyaneh Kazem Mazlumi Majid Amirdehi Ebrahim Amiri
AmirKabir University of Technology
Iran
Key words: power quality, voltage dip, distribution and transmission networks, optimization, Monitoring
Abstract This paper aims to optimize the measurement of voltage-dip in distribution and transmission systems such that the optimal number of the voltage-dip monitors and their locations are determined. First, the terms and basic concepts like voltage-dip matrix and monitor reach area are explained and formulated by using the mathematical relations. Then, the optimization problem is defined by using the governing equations on the voltage-dip matrix, monitor reach area, monitor position vector and their relationships. After surveying the different optimization methods, an appropriated optimization algorithm is chosen with respect to the complexity order of the optimization problem. We solved the optimization problem with Greedy algorithm. At the end of the paper, in order to test of this method, the result of the optimal monitor emplacement upon 41 bus from 230 Kv Tehran regional electric network is presented. In this method, in addition that total number of buses where monitored, none of the basic information of dip-voltage in the different buses is lost.
153
98-F-PQA-653
A Novel Minimal Energy Controller for DVR in Voltage Sag Compensation of Sensitive Loads
1M.R. Banaei 2S.H. Hosseini
1. Electrical Engineering, Faculty of Engineering, Azarbaijan University of Tarbiat Moallem, Tabriz, Iran
2. Center of Excellence for Mechatronics, University of Tabriz, 51666, Tabriz, Iran
Key words: Power quality, DVR, Control strategies, Minimal energy control
Abstract One of the most important power quality issues is voltage sags. The increasing usage of voltage sensitivity devices has made industrials processes more susceptible to supply voltage sags. Voltage sags may cause equipment tripping, shutdown for the domestic and industrial equipment, and miss-operation of drive systems. When a fault occurs in the system, the customer voltage drops below its nominal value on one or more phases. Dynamic voltage restorer (DVR) with energy storage can be used to correct the voltage sag at distribution system. A DVR is basically a controlled voltage source installed between the supply and a critical and sensitive load. It injects a voltage on the system in order to compensate any disturbance affecting the load voltage. The compensation capacity of a particular DVR depends on the active power which can be supplied by the DVR. When DVR restorers voltage disturbances, active power or energy should be injected from DVR to the distribution system. Energy storage devices, such as batteries or super-conducting magnetic energy storage systems (SMES) are required to provide active power to the load when voltage sags occur. Because of the energy limitations of these devices, it is necessary to minimize energy injection from DVR. In this paper the techniques of restoring voltage sag are discussed and then, a new control case study proposed to minimal energy strategy. The simulations carried out by PSCAD/EMTDC show the capability of proposed technique.
154
98-E-PQA-693
The Effects of Parallel Capacitors in a Reactive Compensating Filter Device on
Voltage non-sinusoidality and Current Resonance
Mohammad Hejri1 Hossein Mokhtari2
Azerbaijan Regional Electric Company1, Sharif University Of Technology1,2
Iran
Key words: passive filter design, harmonics, filter compensating devices
Abstract Parallel capacitors together with LC-tuned filters are used for reactive power compensation and higher harmonic suppression in distribution networks. The results of this paper show that the application of parallel capacitors cause current resonance at non-filtered harmonic frequencies. The effects of capacitance division among tuned filters and parallel capacitors on the network frequency characteristic and current resonance intensity and network voltage distortion are investigated. This paper confirms a design method for eliminating current resonance at non-filtered harmonic frequencies.
155
98-F-PQA-777
Design and Implementation of a Shunt Active Power Filter for Power Quality Improvement
M.Jabbari1 H.Farzanefard2
1Power Electronics Ph.D. student, Isfahan University of Technology
2Faculity Member, Elec. and Comp. Dep., Isfahan University of Technology IRAN
Key words: Active Power Filter, Power Quality, Harmonics, and Compensation
Abstract In this paper Active Power Filters as an approach to improve power quality is presence of harmonics pollution are analyzed. Furthermore, a shunt Active Power Filter structure containing a reference current extraction method and a novel output current control method is presented. The proposed method generates an adaptive switching pattern so that the switching frequency alters as required. In this method, maximum switching frequency can be adjusted, so that the system generates switching pattern with maximum frequency only when it is required and otherwise frequency is reduced adaptively as much as possible. Thus switching loss decreases without quality degradation. Experimental results of a non-linear prototype with two KVARH reactive load confirm the integrity of this method.
156
98-F-PQA-792
The design and control of three-phase shunt active power filter using the sliding mode control and energy feedback
Majid Nayeripoor Ali Yazdian Mahmod reza Haghifam Hamid reza Mohamadi Faculty of Engineering , Tarbiat Modares University , Tehran , Iran.
Key words: shunt active power filter, harmonic, inverter, sliding mode control, energy feedback
Abstract The presence of nonlinear and unbalance loads in a three-phase network causes harmonics generation and dissipation in power network. One of the usual methods used for decreasing and eliminating these effects is the application of active and passive filter. The passive filter is designed for a particular kind of frequency and therefore eliminates a particular harmonics. Its weakness, however, is the possibility of its resonance with the equivalent network impedance and the large size of its elements. The active filter helps to remove the above problems. Moreover, this filter causes the harmonics to be rejected individually or all together and prohibits the occurrence of resonance with the network. One of the problems of these filters is the limited dynamics response that considers the steady state of harmonics. In this paper, unlike the previous methods on single phase analysis, the inverter used in active filter is analyzed more precisely, i.e, the simultaneous three- phase analysis. The ohmic effect of phase-inductances is also taken into account. The inverter control system makes use of two internal and external loops. The external loop produces suitable signal for on/off switching through sliding mode control. The internal loop utilizes energy feedback to adjust the capacitor voltages. This new method effectively improves the speed of dynamic filter response in comparison with the previously reported methods and is able to quickly compensate harmonics and load unbalancing.
157
98-F-PQA-820
A New Method to Mitigation of AC Arc Furnace Voltage Flicker
Majid mohammadi Kerman Reginal Electric Company
Iran
Key words: Flicker, Ac Arc Furnace,Reactive Power
Abstract An A.C. arc fumace is an unbalanced, nonlinear and time varying load, which can cause many problems to the power system quality. An arc fumace load may cause unbalance, harmonic, interharmonics and voltage flicker. Light flicker, a phenomenon of annoying light intensity variation, caused by fluctuating electrical loads, has been a major concern for both industrial and residential customers. This paper introduces a new strategy to track and mitigate the voltage flicker produced by AC arc furnaces. Arc furnace model has been presented using the MATLAB/SIMULINK. The simulatons results demonstrate that this method has superior flicker reductipon .
158
98-F-PQA-893
Using FACTS Devices for Compensation the Coupling Capacitor between Phases
Dr. Seyed Mohammad Tabatabaee
Niroo Technology Center (MATN) (Tehran/Iran)
Abstract The coupling capacitors between healty phases and faulty phase in long EHV lines when using the single phase reclosing , Feeding the transient arc and don’t allow the arc to extinguish. There are some conventional methods for compensation the coupling capacitors. In this paper an Enhanced method presented which using a member of FACTS devices family named CSRT for omitting the coupling capacitors. The simulation with Pscad-Emtdc software show that it is possible to compensate compeletly the coupling capacitors and therefore energizing the faulty phase as soon as possible.
159
81-E-PSS-125
On Market-based Robust Load-frequency Control
H. Bevrani and T. Hiyama Dept. of Electrical & Computer Eng., Kumamoto University
Japan
Key words: LFC, Mixed ∞/HH 2 , Robust performance, Time delay, LMI
Abstract In a deregulated environment, Load-frequency control (LFC), as an ancillary service essential for maintaining the system reliability, acquires a fundamental role to enable power exchanges and to provide better conditions for the electricity trading. Since the LFC system is faced by new uncertainties in the liberalized electricity market, a reevaluation in traditional modeling and control structures is highly needed. In response to the coming challenge of integrating computation, communication and control into appropriate levels of system operation and control, a comprehensive scenario is proposed to perform the LFC task in a deregulated environment. As a part of the mentioned scenario, this paper addresses a new method to design of robust LFC with considering the communication delays. First the LFC problem is reduced to a static output feedback control synthesis for a multiple delays power system, and then the control parameters are easily carried out via a mixed ∞/HH 2 control technique, using a developed iterative linear matrix inequalities (ILMI) algorithm. The proposed method is applied to a 3-control area power system and the results are compared with the recently developed ∞H -based LFC designs.
160
98-E-PSS-148
Lead/Lag SSSC Based Controller for Stabilization of Frequency Oscillations in Multi-Area Power System
Ahad Kazemi Arman Amini
Department of Electrical Engineering Iran University of Science and Technology
Tehran-Iran
Key words: FACTS, SSSC, Overlapping decompositions, Power system stabilization, Frequency oscillations
Abstract This paper proposes a new application of Static Synchronous Series Compensator (SSSC) to stabilization of frequency oscillations in a multi-area power system. To stabilize the frequency oscillations, the dynamic power flow control of the Static Synchronous Series Compensator (SSSC) located in series with the tie line between interconnected power systems, is employed. By regarding the system interconnection as a control channel, the power flow control by an SSSC via the interconnection creates a sophisticated method of frequency stabilization. To implement this concept, the robust design method of lead/lag controller equipped with the SSSC is used. SSSC is located in two different areas and the best location for compensation is shown. The technique of overlapping decompositions is applied to reduce the order of the study power system; meanwhile the physical characteristic is still preserved. Simulation study exhibits the significant effect of designed controller on the study four-area interconnected power system under different load disturbances.
161
98-F-PSS-153
Radial Basis Function Neural Network For On-Line Power System Load Flow
A. Karami M. S. Mohammadi
Faculty of Engineering The University of Guilan
Rasht, IRAN
Key words: Load Flow, Radial Basis Function Neural Network, Electric Power Systems
Abstract This paper presents a new radial basis function (RBF) neural network based method for solving the load flow (LF) problem of electric power systems (EPS). LF evaluates the steady state operating condition of EPS and is a fundamental tool for planning, operation and control of modern power systems. The outputs of a LF program are obtained by solving a set of nonlinear algebraic equations by employing a numerical technique such as Newton-Raphson method. For computing the load flow outputs some initial conditions (values) are needed. Therefore, we may view the load flow outputs as functions of initial conditions. Indeed we are faced with a function approximation problem and this can be done by a RBF neural network. The RBF neural network has many advantages features such as optimized learning and recall times as compared to multi-layer perceptron (MLP) model. The proposed RBF neural network methodology has been successfully applied on the 10-machine and 39-bus New England test power system and the results are given.
162
98-E-PSS-311
Mixed H2/H∞ Based LFC of a Deregulated Power System
H. Shayeghi1, 2, 3 H. A. Shayanfar2 1. Electrical Eng. Dept., Azad University, Ardebil branch
2. Iran University of Science and Technology 3. Ardebil Electrical Distribution Company
Key words: LFC, Decentralized Control, Deregulated Power System, Mixed H2/H∞ control, Robust Control
Abstract In this paper, a decentralized robust controller for the Load Frequency Control (LFC) of a power system in the deregulated environment is proposed. A generalized model for the LFC scheme is developed based on the possible contracts in the new environment. The connections between each control area with the rest of the system and the effects of the load following contracts are consider-ed as a set of new input disturbances in the control area dynamical model to achieve decentralization. The idea of the mixed H2/H∞ control technique is used to solve of the LFC problem. The motivation for using this control strategy is both to achieve the desired level of robust performance against uncertainties and to minimize the effects of area load disturbances under contract variations. This newly developed design strategy combines advantage of the H2 and H∞ control synthesizes and gives a powerful multi-objectives design addressed by the Linear Matrix Inequalities (LMI) techniques. The proposed method is tested on a three-area power system with the possible contracted scenarios under large load demands. The results are shown to maintain robust performance in the presence of specified uncertainties and system nonlinearities for a wide range of area load demands and disturbances in comparison with the PI controller.
163
82-E-PSS-349
Application of a Digital PSS to 220MVA Pumped Storage Unit and Its Validation Using Real-Time Digital Simular
Jinboo Choo Jeonghoon Shin Seungtae Cha Taekyun Kim Bangmyung Kwak
Korea Electric Power Research Institute
103-16, Munji-dong Yusung-gu Daejoen, 305-380, Korea (ROK)
Key words: Power System Stabilizer, Tuning, Eigenvalue Analysis, Local-mode of Oscillation, RTDS
Abstract This paper desctibes practical tuning methods and testing of a digital PSS, which uses both frequency and power, with the 220MVA Chungpyung P/P #1 in the KEPCO system to enhance the damping of local modes. In the first step, the objective phase of PSS is computed through a phase leading function to provide compensation between the exciter reference point and the generator air-gap torque before tuning the PSS’s time constants. In addition, eigenvalue analysis was used to determine a range of PSS’s gain, which is the more useful for field testing rather than a single gain value. The Real-Time Digital Simulator was used to verify safe operations of the PSS in the presence of disturbances, such as A VR step and three Phase fault.
164
98-F-PSS-355
Dynamic Stability Assessment of Power Systems Using Prony Analysis for Determination of
Modal Content of Measured Response
Maryam Dehghani Mehdi Karrari Amirkabir University of Technology
Tehran-Iran
Key words: Dynamic Stability, Prony Analysis, Eigenvalues, Transient Analysis, Power System
Abstract A power system is a large scale system containing a large number of control loops including governors, automatic voltage excitation control, power system stabilizers, automatic generation loops and etc. This system is being continuosly perturbed by load fluctuations, network changes, short circuits, line faults and etc. To assure the security of the system, it is essential to monitor the frequency and degree of damping of the internal oscillatory signals of the system. The classic method of stability assessment, needs the exact system model and exact system parameters. This approach for power systems which are large scale systems, is too complex and difficult. In this paper, prony method which is feasible and easy for implementation, is used for stability assessment of power systems. This method just uses the experimental measurements and does not need the full system model. One important problem in this method is the system order. In this paper, a technique based on singular value decomposition is used to find the system order. The proposed method is used to assess the stability of two sample power systems: the 9 bus WECC grid and the single machine connected to an infinite bus.
165
98-F-PSS-365
A new Reduction Technique In Composite Power System Reliability evaluation
Alireza Babaee Habib Gharagozloo Tehran Regional Electric Co. & Tarbiat Modares Univercity
Iran
Key words: equivalent, Reliability, Composite System
Abstract In many applications, the requirements of static data and large computation times are still major concerns. This paper presents a practical equivalent model of a small area in a large scale system which needs less statistical data of system equipments with acceptable level of accuracy. In the proposed technique tie lines between the area of interest (AI) and the other parts of the network are cut and the network behavior is modeled with some load and generating units in marginal load points. The load at marginal load points is represented as a multi state load model with the associated state probability. Load uncertainty is modeled using the multi state load model considering the correlation between the load curves of marginal points. Finally, the presented technique has performed on Tehran generation and transmission network and its results in order to considering of their accuracy and credibility of method compared with complete analysis of basic network.
166
98-E-PSS-412
Transient Contingency Ranking Using Several Severity Indices Based on Hybrid Transient
Energy Function and Time Domain Simulation
A. Zangeneh S. Jadid A. Kazemi Iran University of Science and Technology
Key words: Severity indices, Contingency ranking, Hybrid transient energy function, Transient stability
Abstract This paper proposes 3 severity performance indices to detect transient instability of power systems and contingency ranking. The indices are based on state variables and transient energy function parameters such as kinetic and potential energy. They are tested and compared with other indices on the IEEE 9 and IEEE 39 test bus systems. Also in this paper, a comprehensive sensitivity and accuracy analysis is occurred to determine the severity index which has more appropriate performance to rank transient contingency of a power system. Then advantages and disadvantages of these indices are presented.
167
98-F-PSS-422
New Genetic Based Method for Economic Load Dispatch
H. Erfanian, Dr. S.H. Hoseinian Electrical Engineering Dept., Amirkabir University of Tech.
(Excellent Power Group) Tehran, Iran
Key words: Economic Dispatch, Optimal Power Flow, Genetic Algorithm, Evolutionary Algorithm
Abstract Economic Load Dispatch is an important optimization task in power system operation for allocating generation among the committed units such that the constraints imposed are satisfied and the energy requirements are minimized. Improvement in scheduling the unit outputs can lead to significant cost savings. Traditional dispatch algorithms employ classical methods that can’t consider the nonlinearity of incremental cost curves. Evolutionary programming has emerged as a useful optimization tool for handling nonlinear programming problems. The performance of different evolutionary algorithms on economic dispatch problem is examined and presented in this paper. Various modifications to the basic method have been proposed with the view to enhance robustness of the method. A 30 buses network is used to show the performance of the proposed method.
168
98-F-PSS-483
An approach for modeling the protection system in transmission network reliability evaluation
A.R. Alesaadi, M.R. Haghifam M. Fotuhi Firouzabad
N. Moslemi, and J. Abbasi
Key words: reliability, transmission network, protection system, switching devices, minimal cutsets
Abstract In this paper, reliability of transmission network, considering effect of protective systems is investigated. Protective system faults are one of the main sources of the cascade outages and may leads to vast blackouts. A simple model cannot be used for network switching devices (breakers, …), because the number of failure modes of them are more. In general, the types of failures that may be happened for a breaker are:
1- Component short circuit resulting in operation of backup protective devices;
2- Switching device opening without the proper command; 3- Switching device failures to open on command; 4- Protection system trips incorrectly due to a fault outside of protection
zone.
This paper discusses transmission and subtransmission network and subtransmission substations are considered as load points, also the generation units are assumed fully reliable. The proposed method is based on minimal cutsets. In this paper, the aimed at switching device, are those components which operate due to an active failure, automatically. Also it is considered, if one switching device is occurred a failure, that component can not isolate itself, rather other components should isolate it. This method can consider the expanded network scheme (with all details). The optimal algorithm to consider the protective system is presented, and then the mentioned approach is tested for a practical network of Iran (Azerbaijan transmission network). Finally effects of this method are compared to the other method, in which protection system has been neglected. Comparison is carried out through the reliability indices.
169
98-F-PSS-492
A New Approach for Dispatching Energy, Spinning Reserve and Load in Deregulated Environments
S. H. Reza Arabshahi H. Rajabi-Mashhadi M.H. Javidi-Dasht-Bayaz Graduate Student Assistant Professor Associate Professor
Department of Electrical Engineering
Ferdowsi University of Mashhad
Key words: Genetic algorithm, Spinning Reserve, Energy/Reserve Market, Demand Side Bidding
Abstract This paper proposes a new approach for dispatching generating units in open access electricity markets. In the proposed method, Energy, spinning reserve and load are dispatched optimally using genetic algorithm. The objective is to minimize generation and spinning reserve costs while maximizing costumers' (buyers') benefits. In the proposed model it is assumed that generating units are allowed to propose their prices for offering energy as well as their available capacity to energy and ancillary services markets. On the other hand, costumers offer their bids for buying electric energy simultaneously.
170
98-F-PSS-526
Unit Commitment Problem In Deregulated Power System
Alireza Khajeh Hasan Monsef ECE Dept., University of Tehran
Iran
Key words: Unit Commitment, Ant Colony Algorithm, Deregulation
Abstract In this paper at first the unit commitment problem is explained and will be shown that the existence of an algorithm to solve this problem are essential. Then the ant colony algorithm such as how coming into exictance, components of this algorithm and the manner of applying it to the unit commitment problem is described. The system test which has been used in this paper is IEEE_RTS with 24 buses. For preparing it to simulate on deregulated structure, 32 generating units have been separated into six independent generating company (according to the IEEE classification which the whole area is separated into seven zones)1. Then the unit commitment problem is solved with the ant colony algorithm in two famous market models, namely poolco and hybrid.
1. 3th zone have no generating unit.
171
98-F-PSS-542
On Line Power System Dynamic Security Assessment Using Neural Network
M. R. Aghamohammadi A. Maghami
Iran Dynamic Research Center Power & Water University of Technology
Tehran
Key words: Online Security Assessment, Transient Stability, Neural Network, Sensitivity Analysis
Abstract In this paper, a new approach based on the application of neural network has been proposed for assessment and enhancement of dynamic security of power systems. Operating variables, which have been used for evaluation of system security margin and also its enhancement could be active generation pattern of all generators in the network. In this approach, first a contingency analyzer neural network (CANN) adopted to be trained. Then in an operational environment for each given operating point the critical clearing time (CCT) associated with all lines could be evaluated by CANN. If some of the evaluated CCTs appear to be greater than critical values, then that point is recognized to be as insecure operating point and it requires some corrective or preventive actions to be taken in order to improve system security. One of the most interesting features of neural network application, which has been implemented in this paper, is its sensitivity characteristic. By using this characteristic one is able to evaluate the sensitivity of system security margin with respect to the active power of generators. This sensitivity is used as a guideline for selecting and applying the most effective preventive action for enhancing system security. The proposed approach has been demonstrated on IEEE 39-bus network with promising results.
172
98-F-PSS-561
Khorasan Power Transmission Network Optimization with Facts Devices
Ebadallah Kamyab4 Mohammad Ali Sadrnia1 Ali Akbar Gharaveici2 Mehdi Najjar1,3
1-Shahrood Technical University- Electrical Department
2-Bahonar Kerman University-Electrical Department 3-MONIRAN CO
4-Khorasan Regional Electrical Company
Key words: ??????????
Abstract A large amount of investment contributes to power system in any country. Improper operation of power system leads to many wasted investments and power system optimal operation is very important. Using FACTS devices has been resulted optimal operation of power system in many countries for example USA, Japan, China, Indonesia, Brazil, etc. In this paper all possible FACTS devices applications in Khorasan network, has been investigated. First application related to problem of large power swings in the line connected Khorasan to Iran network with using greater than 20% of line thermal capacity. Other problem is large investments in Khorasan power transmission system development. FACTS devices solve these two problems correctly and effectively. Final economic research shows that how much optimization has been got and technical simulations and studies conclude many improvements in system security and reliability.
173
98-F-PSS-609
Monthly energy consumption forecast in Iran by use of artificial neural networks and Arima
Reza Ramezani – Economics Ms Iran Power Development Company
Maryam-Ramezani- Electronics Engineer and Information Technology Ms Student
Tarbyat Modares University Iran
Key words: Energy consumption forecast, artificial neural networks, Arima
Abstract Long term Energy consumption forecast is necessary for the country power plant development and strategic management of the dependent organizations and electrical equipment manufacturing companies. In addition, shot term Energy consumption forecast also seems vital for controlling and improving the stability and reliability of the power systems. The goal of this paper is to optimize the energy consumption forecast as much as possible. For this reason the monthly energy consumption from 1991 to 2002 is used and the consumption from 2001 to 2002 is considered for evaluating the models. Two main prediction methods are used in this paper which is artificial neural networks and Arima. The result of comparison shows that artificial neural networks have a better operation than Arima.
174
98-F-PSS-660
Optimized Power System Stabilizer with Artificial Neural Network Structure
Meghdad Ansarian S. Mohammad Sadeghzadeh Hamed Shakouri G. Ali M. Nasrabadi
Shahed University Technical and Engineering Collage
Iran
Key words: Power System Stabilizer, Artificial Neural Network
Abstract An optimized configuration of a Power System Stabilizer (PSS) based on the Artificial Neural Network (ANN) and the Linear Optimal Control (LOC) is suggested in this paper. The suggested PSS has the best dynamic characteristics among other configurations of artificial neural network power system stabilizers (ANN-PSSs) which have studied in this paper. Also it is the only structure which has better dynamic characteristics than LOC stabilizer. The MATLAB software simulation results prove that proposed Power System Stabilizer improves the dynamic response of the power system under different disturbances due to adaptive nature of neural networks. Moreover it has a quick response due to parallel structure of neural networks.
175
98-F-PSS-665
A Hybrid Algorithm for Transmission Expansion Planning under Uncertainties
H. Seifi M.R. Hesamzadeh
Tarbiat Modarres University, Engineering College Electrical & Electronic Department
Iran Power System Engineering Research Center(IPSERC) Iran
Key words: Transmission expansion planning, Uncertainty, Genetic algorithm, Generalized Backward Method
Abstract Nowadays, transmission planners face various uncertainties; in the planning process this paper proposes an effective algorithm for transmission expansion planning under uncertainties. The algorithm uses scenario technique for modeling of power system uncertainties, genetic algorithm for optimization problem solution and generalized backward method for producing initial population of the genetic algorithm. Employing this approach results in a plan, robust for all scenarios. The capabilities of the proposed approach have been tested on 6-bus and 87-bus as well as Iran power system.
176
98-F-PSS-691
Load Shedding Technique Using Frequency Decreasing Rate
Abstract Velocity and accuracy of frequency load shedding has an emergency roll on system stability and load shedding schemes. In large interconnected power systems, serious frequency falls now require a very heavy loss of generation and should such event occur, the rate of frequency decline would be greater than had been consider at the time when under- frequency load shedding(UFLS) had been develop. In order to improve the under-frequency load shedding schemes, in this paper, a global load shedding scheme integrated with rate of frequency decline as an external variable is proposed. In proposed procedure, SCADA system has been used .at first we analysis behavior of different generator after occurrence of disturbance and then simulate proposed frequency load shedding scheme integrated with rate of frequency decline to improve system stability.
177
98-E-PSS-700
Reactive Power Market Simulation: A Particle Swarm Optimization Approach
B. Mozafari1, 2 T. Amraee1, 2 A.M. Ranjbar1, 2 N. Sadati1
1.Dept. of Electrical Engineering, Sharif University of Technology, Tehran, Iran 2. Niroo Research Institute, Tehran, Iran
Key words: Deregulation, Reactive Power market, Voltage Stability, Particle Swarm Optimization
Abstract This paper deals with the application of Particle Swarm Optimization algorithm (PSO) for reactive power scheduling in deregulated power system. Reactive power procurement is modeled as a security constraint optimal power flow incorporating voltage stability problem. The model attempts to minimize cost of reactive power procurement and energy losses as a main objective while technical criteria and voltage stability margin, in special, are treated as soft constraints. From mathematical points of view, reactive power market can be expressed as a nonlinear optimization problem. Thus PSO, as a powerful heuristic algorithm, is implemented to find equilibrium point of the reactive power market. Reactive power market is simulated over the IEEE30 bus system and obtained results are compared with another evolutionary programming such as genetic algorithm (GA) in terms of quantity and precision. Results show that the PSO has a good potential to converge to better feasible solution in less iteration and it can be successfully used for reactive power optimization in restructured environments.
178
98-E-PSS-731
Promoting the Optimal Maintenance Schedule of Generating Units in a Competitive Environment
Based on Genetic Algorithm
R. Eshraghnia1 H. Modir Shanehchi2 H. Rajabi Mashhadi3
1. Master of Engineering 2. Associate Professor 3. Assistant Professor
Department of Electrical Engineering Ferdwsi University of Mashhad Iran
Key words: genetic algorithm, maintenance scheduling, spot marginal price, maintenance investment loss
Abstract This paper presents a Genetic Algorithm methodology for finding the optimum preventive maintenance schedule of generating units of GENCOs in a restructured power system. In this environment, management of GENCOs and grid is separated, each maximizing its own benefit. Therefore, the principle to draw up the unit maintenance scheduling will be changed significantly. The profit of GENCO is defined as the total profit, which is the sum of the individual units’ profits from the auctions over the horizon. So each GENCO hopes to schedule its maintenance on the weeks when the spot marginal price (SMP) is lower, so that maintenance investment loss (MIL) is minimized. Therefore, objective function for the GENCO is to sell electricity as much as possible, according to the market clearing price forecast. Various technical constraints such as generation capacity, duration of maintenances and maintenance continuity are being taken in to account. The objective function of ISO is to maximize the reliability throughout the weeks of year. Various constraints such as minimum net reserve, duration of maintenance are being taken in to account. Therefore there are two objective functions for finding an optimum maintenance schedule in restructured power systems. Each GENCO specifies optimum maintenance schedule according to its objective function and hands it over to ISO. The ISO compares its own reliability index with reliability index related to maintenance schedule of GENCOs. If they are close enough in terms of reliability, it will be approved; otherwise the ISO sets up incentives and disincentives for each period to encourage GENCOs to modify their maintenance schedule so that the difference between reliability indices obtained by objective function of ISO and the GENCOs is minimized.
179
98-E-PSS-733
Computing and Analysis of Transfer Capability in Different Scenarios for Khorasan Transmission
Network Using Genetic Algorithm
Mohammad Amin Latifi M.Sc. Student
Habib Rajabi Mashhadi Assistant Professor
Mohammad Bagher Asadi M.Sc. Student
Electrical Department, Faculty of Engineering, Ferdowsi University of Mashhad
Research & Standards Department, Khorasan Electricity Utility
Key words: ATC, Simultaneous ATC, Contingency, GA, Transmission Planning
Abstract A key concept in restructuring of power industry is Available Transfer Capability (ATC). In several decision making problems and from different viewpoints, the ATC plays an important role and should be computed. In this paper the ATC is determined and analyzed from the planning aspect. The problem is formulated for a regional power system, namely Khorasan province transmission network. Computing of ATC through a specified path which determined in the network formulated as an optimization problem. The aim is to maximize amount of transferable power through the specified path subject to the load flow equations and transmission constraints. Regarding to geographical position of the province, the model is generalized to consider simultaneous transfer capability. Using a probabilistic model, effects of single contingencies on the ATC will be discussed. The Genetic Algorithm as a powerful optimizer is used for solving the problem. Analysis of results shows the proposed method is practical and it would help system planner in the expansion planning process.
180
45-E-PSS-752
QFT Framework for Robust Tuning of Power System Stabilizers
Seyyed Mohammad Mahdi Alavi, Roozbeh Izadi-Zamanabadi
Department of Control Engineering, Aalborg University, Denmark
Correspondence to: [email protected], [email protected]
Key words: Powers System Stabilizer (PSS), Quantitative Feedback Theory (QFT), Tunable PSS
Abstract This paper discusses the use of conventional quantitative feedback design for Power System Stabilizer (PSS). An appropriate control structure of the QFT that is directly applicable to PSS, is described. Two desired performances are also proposed in order to achieve an overall improvement in damping and robustness. The efficiency of the proposed method is demonstrated on Single Machine Infinite Bus (SMIB) power system with highly uncertainty.
181
98-E-PSS-825
DESIGN AND IMPLEMENTATION OF NETWORK PLANNING SYSTEMS
A. Sadegheih
Department of Industrial Engineering University of Yazd, P.O.Box: 89195-741
Yazd, Iran
Key words: System Planning, Tabu Search, Genetic Algorithm, Mathematical Programming, Artificial Intelligence, Iterative Improvement Methods
Abstract In this paper, system network planning expansion is formulated for mixed-integer programming, a genetic algorithm and tabu search. Compared with other optimisation methods, GA’s are suitable for traversing large search spaces since they can do this relatively rapidly and because the use of mutation diverts the method away from local minima, which will tend to become more common as the search space increases in size. GA’s give an excellent trade-off between solution quality and computing time and flexibility for taking into account specific constraints in real situations. TS has emerged as a new, highly efficient, search paradigm for finding quality solutions to combinatorial problems. It is characterised by gathering knowledge during the search, and subsequently profiting from this knowledge. The attractiveness of the technique comes from its ability to escape local optimality. The cost function of this problem consists of the capital investment cost in discrete form, the cost of transmission losses and the power generation costs. The DC load flow equations for the network are embedded in the constraints of the mathematical model to avoid sub-optimal solutions that can arise if the enforcement of such constraints is done in an indirect way. The solution of the model gives the best line additions, and also provides information regarding the optimal generation at each generation point. This method of solution is demonstrated on the expansion of a 10 bus-bar system to 18 bus-bars.
182
98-F-PSS-881
Power Plant Production Planning using Hierarchical Production Planning
Ghaderi, S.F., Gerei, A., Shakhse Niaee, M. Department of Industrial Engineering, Faculty of Engineering, University of Tehran
Iran
Key words: Hierarchical Production Planning, Analytical Hierarchy Process, Ranking, Demand forecasting
Abstract In this paper, we present a developed Hierarchical Production Planning structure for power plant production planning. In the firs level of our structure we forecast the total demand of each hour of several mount in the next year with a heuristic method. In the second level, we allocate several production technologies in order to satisfy the forecasted demand and in the last level, it is determined that which power plants would be online and which power plants would be offline in the several hours of each month in the next year. Final output of our model is a table that illustrates the plan for each power plant in the several hours of all mounts in the next year. This helps managers to be aware of the offline periods in order to plan some activities like short-time maintenance activities in it.
183
98-F-PTL-122
Calculation of Electromagnetic Transients in Underground Cables Realizing Frequency-Dependence of Modal
Transformation Matrices
Babak Porkar Majid Hasheminezhad Mehdi Vakilian
Department of Electrical Engineering Sharif University of Technology, Tehran, Iran
Key words: Frequency-Dependent, Modal Transformation, Underground Cable, Electromagnetic Transients
Abstract In modeling of underground cables by modal transformation and application of eigen values and eigen vectors, the related transformation matrices for determination of characteristic admittance Ycm and propagation function Hm are employed in modal domain. However although transformation matrices are complex and frequency dependent, the electromagnetic transient programs such as EMTP considers them as having real and constant parameter (determined in a single frequency) and this method although increases the computation efficiency, however in special cases in which frequency dependent of matrix elements are substantial, such as in cables leads to erratic and unreliable results. From other hand due to eigen vector switchover, the elements of transformation matrices of smooth and continuous functions will not be in the desired range of frequency. In this paper employing frequency dependent transformation matrices, a new algorithm is proposed to overcome the switchover problem. Also the effects of considering frequency dependent transformation matrix on determination of Ycm and Hm in compassion with the case where transformation matrix is computed in a special frequency and then considered for the whole range is studied.
184
98-F-PTL-179
The New Method To Available Transfer Capability Computation For Power Market
Seyed Mohamad Hadi Tabei Kerman Regional Electric Company - Kashan University
Iran
Key words: Power Market , ATC, PTDF, reactive power
Abstract A key concept in the restructuring of the electric power industry is the ability to accurately and rapidly quantify the capabilities of the transmission system. At the simplest level the Available Transfer Capability (ATC) is a measure of a transmission system’s capability to transfer energy above already committed levels without adversely affecting system reliability. In order to open access to electric power transmission networks and promote generation competition and customer choice, the power market requires that available transfer capability be made available on a publicly accessible Open Access Same-time Information System. Transmission transfer capability is limited by a number of different mechanisms, including thermal, voltage, and stability constraints. This paper discusses the ATC definitions and linear methods for computing ATC. It proposes a new approach that first determines the reactive power flows using the exact circle equation for the transmission line complex flow, and then determines ATC using active power distribution factors. The ideas are demonstrated on systems, and the results are discussed and compared with those obtained without reactive power considerations, and the actual ATC.
185
98-F-PTL-208
The effect of Creepage Extender on Electrical Properties of 33 kV Pin Type Insulator
N. Riahi, M. Moghadam, A. Omidvarnia
Niroo- Research Institute Khouzestan Regional Power Distribution Corporation
Key words: Creepage Extender, Electrical Properties, Creepage Distance, Flash Over
Abstract One of the main problems in distribution line is flash over. While during this flash over, maybe break off the power line and unlike damage occur in hospital, mechanism company and other industrial center. Today’s one of the best solution way for this problem is using of creepage extender. Creepage extenders are polymeric piece that install in the shed of insulators and creepage extender distance prevent from flash over problem. Generally for manufacturing of creepage extender, polyethylene was used as a basic material with EPDM, light stabilization, anti oxidant, flame retirement (ATH) and DCP. In this paper investigate the best ratio of LDPE and EPDM and this value obtained 8%, 56%. Tensile and compaction stress is respectively 13.27 MPa and 14.3 MPa. Also power frequency and impulse flashover voltage test of 33 kV pin type insulators increase respectively from 119 to 142.8 kV and 220.604 to 271.243 kV.
186
12-E-PTL-377
A new analytic model to simulate the electrical behavior of a snow-covered insulator
H. Javadi* and M. Farzaneh
NSERC / Hydro-Quebec / UQAC Industrial Chair on Atmospheric Icing of Power Network Equipment (CIGELE) and Canada Research Chair on
Engineering of Power Network Atmospheric Icing (INGIVRE), Université du Québec à Chicoutimi, Chicoutimi, Québec, Canada, G7H 2B1
* On leave from the Power and Water University of Technology, Tehran, Iran
Key words: Snow, Density, Conductivity, Flashover, Non-linear resistance, Analytic model
Abstract One of the most serious problems associated with snow and ice accumulation is insulator flashover. Though considerable research has been done on flashover of ice-covered insulators, there was relatively little on insulators covered with snow. So, further research was required on the electrical behavior of snow-covered insulator to yield an analytic model of the voltage-current characteristics of a snow-covered insulator. From the voltage-current characteristics of snow, which were measured from more than one hundred tests, it was found that the voltage across snow and the leakage current flowing through the snow-covered insulator are almost in the same phase. However, the resistance of snow is not linear, as it decreases with an increase in the voltage across snow. An analytic model to simulate the electrical behavior of a snow-covered insulator was developed. This model showed that the current flowing through the snow ‘I’ has an exponential relation with the applied voltage ‘V’. In this relation, the effects of snow density and conductivity of water melted from snow are considered. The analytical model developed yields the voltage-current characteristics of snow close to those obtained experimentally.
187
98-E-PTL-413
A New Method for Calculation of Corona Inception Voltage in Stranded Conductors of Overhead Transmission Lines
A. Zangeneh A. Gholami
Iran University of Science and Technology [email protected]
Key words: Corona inception voltage, Space charges, Electric field, Stranded conductors
Abstract In this paper a new method for onset voltages calculation of negative and positive corona are presented. This method is based on considering electric field and pressure in adjacent of the surface of conductors. This algorithm is simulated for different pressure and radius of conductors. The configuration of conductors are considered stranded as like as overhead high transmission lines. The calculated onset voltages which are obtained by this method agree with primary experimental measured values by researchers.
188
98-F-PTL-527
Insulators Contamination Monitoring and Optimum Timing of Insulators Washing in Coastal and Desert Areas
H. Atefatdoost*, A. Safari*, Sh. Khaleghi*, M. R. Khalil Abadi**
* Fars Regional Electric Company, Dispatching Group, Shiraz, IRAN ** Hydro-Physics Research Center, Malek Ashtar University of Technology,
Shiraz, IRAN
Key words: Insulator contamination, Flashover, Insulator washing, Insulator leakage current sensor, Insulator surface resistance
Abstract Insulator contamination is one of the factors that affect insulators selection in line and substations in coastal, desert and industrial pollution conditions. Because of high insulator washing costs in coastal-desert areas and forced and scheduled line and substations outages for insulator washing and also low reliability factor due to miss-detection of appropriate time and site of insulators contamination washing, the authors of this paper decided to consider this problem and give an appropriate solution. Aperiodic power system (lines and substations) outages in regional electrical companies with coastal and industrial insulator pollutions; so necessity of insulators pollution monitoring system is highlighted. In this research, the experiences of the countries with many islands such as Japan and countries with coastal-desert areas such as Saudi Arabia and practical measurements in Iran is used. Finally insulators pollution monitoring system and insulator washing timing predictions and appropriate insulator for different areas have been proposed.
189
98-F-PTL-537
Right of Way and Comments for Restructuring the Standard in Iran
1,2 S. Kamalinia, 1 M.P. Arabani, 3 A. Mehrtash
1Power Engineering Consultant (Moshanir) 2University of Tehran, Electrical Engineering Faculty
3K.N.T University IRAN
Key words: Right of way of Electrical Overhead Lines, Electromagnetic Fields, Standard
Abstract Electromagnetic fields exist around the overhead transmission lines and till now it was not any logical and scientific registered theory that shows, its side effects harm human health. Otherwise any reference does not prove the illness of human beings near the electrical utilities. So it is convenient to be established rules and instruction for reduction of any probabilistic dangerous. Unfortunately, there are no conventional international standards and instruction in so many countries, or those just valid within their political borders. In Iran the right of way rules approved in 1968 but by considering the significant development in transmission lines technology and diversity of climate condition in Iran it is necessitated to review these rules. In this paper by considering the latest revision of standards which have been used in the other countries and selection the results of researches in the field of right of way, a proposal for restructuring the existing standard is provided but the main good point of this paper is to show new instruction of safe domain in EMF fields instead of distance from electrical transmission lines which is the most common way to restrict the effects near EMF sources. For approaching this purpose the country divided to four sections according to their congestion and environmental conditions.
190
98-F-PTL-541
Improving life-cycle-cost (Lcc) using Silicon rubber insulator in bushehr province
A.Safari ,H.Roghanian, B.Bahmani H.Mohseni
F.R.E.C Tehran University Iran
Key words: Lcc, pollution, Silicon rubber insulator, Operation
Abstract Insulators are one of fundamental equipment in electrical lines. Insulators have an important role in electrical line and substation stability and are so effective that every fail on only one insulator (such as insulator crack, burring, punch ...) would be resulted in total line outgoings. Polymer insulator, because of their advantages, is extensively used. The best market of these insulators is us and also due to the lightness of them, they have a developing consume in Europe. One of the most important advantages of silicon insulators is electrical stability and not cutting in sever pollution and humid conditions. Regarding to the number of falls of sever pollution and humid condition, even economic consideration can not be on obstacle in using of this insulators. In this paper, due to the special weather condition of Bushehr Province, a review of operation experiences, the activities made to prevent of high cut in lines, because of insulation cut of insulator, and the experiment of using. Silicon rubber insulators are explained.
191
98-F-PTL-544
A New Strategy and Method for Transmission Expansion in Competitive Electricity Markets
H.Rajabi Mashhadi G.R. Kamyab Mashhad Ferdowsy University Gonabad Azad Eslami University
With Contribution of the Standards and Research Office of Khorasan regional electric power Company
Key words: Transmission expansion strategy, Transmission network, Competitive electricity market, Market power
Abstract Transmission network plays a critical role in providing access to all participants in a competitive market for supply and delivery of electric power. The traditional methods of transmission expansion planning are not strictly suitable for competitive market environment. In this paper, a new strategy is proposed that based on two goals. First goal is providing a complete competitive electricity market. Second goal is minimize investment cost for new transmission lines. Furthermore, a new method is developed to implement the new strategy. In the new method, we don’t need to know the generation unit costs and or amount of probably generation units. Moreover, we don’t need to model probably behavior of market. By this method, the transmission networks are expanded such that it is possible to supply maximum load by each power flow patterns. A numerical example is given to illustrate the ability of the proposed strategy and method.
192
98-F-PTL-584
The effect of conductors configuration in compact transmission lines on balancing electrical fields
to increase transmission capability
A. Perej A. Gholami Electrical Engineering Department
Iran University of Science and Technology (IUST)
Key words: Compact Line, Uninformed Factor, Electrical Field, Sub-conductor, Height Difference
Abstract It is necessary to use compact transmission line to improve electrical energy quality and to increase transfer capability. If capacitive properties between phases are not equal to each other, than on one hand it results in decreasing the average capacitive property of lines and on the other hand, causes the unequal dispatch of electrical charges on the surface of phases’ sub-conductors which finally increases the difference between electrical fields on the outer surface of phases’ sub-conductors. Consequently, this phenomenon decreases the usage factor of conductors which is proportional to the inverse of uninformed factor of electric field, and produces decrease in natural load of the line. Hence, approaching of the capacitive property of three phases to each other brings about a better balance for electrical charge distribution and electric field on the surface of sub-conductors, and consequently natural load of the line will increase. In this paper effective causes for uninformed electric field and balancing methods will be introduced and then their relationship with the effects of conductor’s configuration will be discussed.
193
98-F-PTL-597
New Methods for Optimizing the Transmission Lines Poles and its Characteristics on Right of Way,
Electrical Parameters and Costs
Farhad Shahnia1, Mehrdad Tarafdar Haque2
1Research Office, Eastern Azarbayjan Electric Power Distribution Company, Tabriz, Iran
2Faculty of Electrical and Computer Engineering, University of Tabriz, Tabriz, Iran
Key words: Compact Transmission Lines, Composite Corssarm and Insulators, Pole, Conductor Spacing
Abstract Right of way has been always a significant problem in installation of transmission lines. Therefore, ROW reduction and related subjects have been always investigated; which has resulted in utilization of compact transmission lines. Pole and conductor spacing, composite corssarm and insulators have great effect on optimizing the poles of the transmission lines and reducing ROW. In this paper, the characteristics of compact transmission lines are studied and investigated and the new methods used for optimization are discussed. Later on, the cost and electrical characteristics of compact transmission lines are compared with the conventional classic transmission lines which results in increasing the interest in utilizing compact transmission lines greatly.
194
98-F-PTL-627
DTM Nut Deliberation in Stability of Electrical Transmission Towers By Value Engineering
Mahdi Taher Solamany
Khorasan Clectricity Distribution Company
IRAN
Key words: Definite Torque, DTM, Torque Meter, Value Engineering
Abstract The mechanical stability of the installation such as electrical transmission towers, lighting towers and steel bridges are very important but not looked out. Some people may unscrew something sneaky and so it causes decreasing the stability of the installation. Therefore, a special nut is designed that in this paper it is called DTM (definite torque memory) nut. These nuts are tightened with a necessary and constant torque, so they don’t loose easily due to mechanical vibration, tensile stress and also don’t unscrew by usual wrenches. The necessary torque of DTM nut is provided by the strength of the head and body conjunction area. Also the torque is determined as a function of the material specific and heating process. With respect to importance of tower stability, the nuts should be tightened by definite torque. In this paper, usage of DTM nut is evaluated by VE (value engineering) method. Safe and certain connection between conductors, clamps and jumpers in transmission and distribution networks are very important. By using of DTM nuts and sheer-head nuts preventing tower downfall, jumper burning, power outage and decreasing events is available and so these result enhancement in productivity indexes.
195
98-F-PTL-656
A new modeling of UPFC for dynamic and power oscillation damping studies in power systems
D.nazarpour S.H.Hosseini G. B.Gharehpetian
Faculty of Electrical and Computer Engineering of Tabriz University Iran
Key words: Unified power Flow Controller UPFC
Abstract In this paper a new model of Unified Power Flow Controller for dynamic stability and power oscillation damping studies is proposed. The new model like the conventional model has four controller as active power controller, reactive power controller, DC bus bar of capacitor controller and AC bus bar controller. In this model the voltage of capacitor that links the shunt inverter and series inverter with each other is calculated from the instantaneous voltages and currents of shunt and series inverters. With the help of this model only the dynamics of switching is omitted and the speed of simulation is improved. Comparison of The static and dynamic simulations of example power system with the conventional model and new model show that new model can be used instead of detailed model for dynamic stability calculations with high speed and good accuracy.
196
98-F-PTL-758
A New Approach for Site Pollution Severity Measurement on Insulation in West Azerbaijan province
M. R. Shariati1, S. Abyazi1, S. J. A. Vaseai1, M. Rezaei1, R. Abadkon2
1. Niroo Research Institute 2. West Azarbayjan Electric Power Distribution Company
Key words: Insulation, ESDD, NSDD, DDG, Pollution Map, West Azarbayjan
Abstract High voltage insulators are exposed to various climates. Pollution resources and wetting condition affect on performance of insulators and cause failures, which will result in economic disadvantages. Development of power networks in one hand and necessity of having a reliable network in other cause knowing pollution and it’s effect to be of great importance. Climatic variations as well as natural and industrial pollution resources such as Uromiyeh Lake, gypsum and cement factories affect on the pollution measurement. Therefore proper insulation designation and efficient performance of high voltage insulators is strongly depending on the site pollution severity measurement. In this research ten test station were installed in west Azerbaijan province, By doing ESSD-NSDD & DDG periodically measurement, proper criteria is obtained. In order to assessment of climate variations and pollution deposition on insulation the most effective atmospheric parameters on pollution, relative and absolute humidity, dew, fog, rain are retrieved and for Uromiyeh & Khoy are compared. According to this research, it is needed to revise the related international standards. This paper present the new approach and discuss about the results of this field study.
197
98-F-PTL-760
Optimum Approach For Maintenance Strategy Selection and Carrying out on Hormozgan Regional Electric Company
S. J. A. Vaseai1, M. R. Shariati1, S. A. Kamali1, G. Alizadeh2
1.Niroo Research Institute 2. Hormozgan Regional Electric Company
Key words: Maintenance, Insulation, High Voltage insulators, Map Pollution, Technical & Economical Assessments
Abstract High voltage insulators have to be used as insulating supporters in power industry. Various climates and pollution resources affect on insulation. Through these sever conditions, especially in the southern of Iran, our utilities have face of many flashover problems and to over come these conditions, they spend time and money for maintenance on insulation. In recent years various methods were used for maintenance of insulation. Periodically washing, silicone grease, RTV coating, using shed extenders, bird guard and replacement. These methods have some limitation in practice from the technical and economical point of view. This paper serves to explore the various measures that can be adopted to reduce the probability of pollution flashover in terms of their applicability, cost and effectiveness. By doing field test studies pollution map were assessed which will be helpful for our study. In one of 230 kV Hormozgan transmission lines, Gharb – Niroogahe Hormozgan – Dorahi Minab, two methods were studied, washing and replacement and by comparing the results, we see that the replacement will be good solution. No failures have been reported after 2-3 years and initial cost would be returned after 6years and 5 months. Also, financial analyses for determination of maintenance strategy were done for a 230 kV substation in polluted area. This paper presents the results.
198
98-F-PTL-775
Evaluation of Leakage Current Measurement for Site Pollution Severity Assessment
S.M.H. Nabavi 1 A. Ggholami1 M.A. Talebi 2 M.A.S. Masoum 1
1. Department of Electrical Engineering Iran University of Science and Technology 2. Niror Research Center
Tehran, Iran
Key words: Reliability, Leakage Current Measurement, Site Pollution Severity, Flashover
Abstract Flashover of insulators in transmission and distribution systems may cause costly outages for the power company and their customers. Industrial and/or coastal pollution of external insulation is a major cause for such events at the normal power frequency voltage of the system. The power companies are now facing increasing competition resulting in pressure to lower the cost and to increase the system reliability. Different methods have been applied in the past to overcome or reduce the problems with flashover on insulators. Different methods have been applied in the past to overcome or reduce the problems with flashover on insulators. Methods are used should be provide reliable data under real physical conditions. In this paper several measuring methods to evaluate the pollution levels on outdoor insulators are described. According this comparison, Leakage Current Measurement ‘LCM’ method is reliable method for measurement leakage current in outdoor insulators and surge arresters.
199
98-F-PTL-829
Modeling and simulation of transmission lines with outdated profiles by PLS-CADD
Hadi Amiri Ghods Niroo Consulting Engineers
Iran
Key words: PLS-CADD, power transmission lines, sag, tension, profile, spotting
Abstract In this paper, properties and influences of pls-cadd software in transmission line design and then modeling & simulation of a real transmission line is presented . In first, graphical capabilities of software at simulation of terrain and providing plan & profile views and then how automatic spotting, stringing, and also implement sag-tension calculations and depicting 3-dimentional structures are considered. In other section of paper, some disregarded criteria in traditional design that could be simulated by pls-cadd are propounded. Modeling and simulation of a transmission line at Hamedan city that have voltage level 63 KV and length whereabouts 30 kilometrs with existing profiles and then peruse provided results is practical section of this paper.
200
98-E-PTL-896
Thermal design of housing tube, conductors and maximum permitted load current of sealed cable penetrations through
the steel containment of Nuclear Power Plant
S.D. Kholodniy Doctor of Technical Science, Corresponding Member of
Academy of Sciences of Russia, head scientific associate of OAO VNIIKP
M. Doostkam Technical Representative of Atomic Energy Organization of Iran in Russia,
“Bushehr” NPP
Abstract The calculations in previous publications [1,2,3] did not consider heat transfer along the steel housing tube and copper conductors of penetrations. The proposed calculations also take into account the fact that temperature in the clean zone (outside the containment wall) is 20 - 30 oС, while in the contaminated zone (inside the containment) it is 60 oС under nominal conditions, and can reach 90 and 150 oС under small and big leak conditions, accordingly. The sealed penetration construction is provided in Figure 1. The steel tube of the penetration (2) is fixed in the containment wall (1) by means of steel flanges (3) provided at the tube ends. Modules (6) with insulated copper conductors (5) run through the tube and the flanges. Stainless steel protection casings (4) are mounted on the flanges (3). The points where the modules pass through the flanges are fitted with tight seals. Each module of Elox sealed penetration contains from 1 to 40 insulated conductors, cross section of power and control cables varies from 0.81 to 254 mm2. Currents in durable mode are from 2.5 to 640 А. Each cable in the penetrations where КМЖ cables with magnesia insulation and copper tube sheathing are used is laid separately, with their sheathings soldered separately to the flanges.
201
86-E-REN-132
Wind Turbine Driven Grid-Connected Inverter Based on Predictive Current Control Technique
Hossein Madadi Kojabadi1 Kai Zhang 2 Mohsen Ghribi 3
1Dept. of Electrical Engineering, Sahand University of Technology Tabriz 51335-1996 Iran 2Dept. of Electrical Engineering, Huazhong University of Science & Tech. Wuhan, China
3Faculty of Engineering, Université de Moncton, Moncton, NB, E1A 3E9, Canada
Key words: Grid connected inverters, wind turbines, THD Abstract Global electricity consumption will increase from 13934 TWh in 2001 to 24673 TWh in 2025 at an average annual rate of 2.4%. As more countries have ratified the Kyoto protocol at a reduction in greenhouse gas emissions, the requirements for adding new generation capacity can no longer be met by traditional power generation methods of burning the primary fossil fuels such as coal, oil, natural gas, etc. Many very small villages in remote areas in Iran and in other developing countries are without decentralized commercial electrical power. Small-scale hydroelectric power systems, wind turbines, and solar systems are emerging as a promising source of renewable energy generation. Residential wind turbine driven grid connected inverters are modular distributed power generation devices that convert the AC power from the roof-top turbines to DC, and then to high quality AC power at the utility grid interface. In this paper the predictive current control method, which is normally suitable in low power schemes, is applied to modular grid connected inverter to improve the output current waveform with minimum THD. Many current-controlled PWM methods have been proposed to design high performance of current control for grid-connected inverters in distributed power generation systems. However none of them have good performance in providing low THD and, at the same time, good robustness to parameters mismatch. The proposed technique is superior to previously published schemes in achieving more precise current control with minimum distortion and harmonic noise, and at the same time, less sensitive to filter parameter mismatch. Experimental results demonstrate the superiority of the proposed method over existing methods. The experimental tests show that the inverter with the proposed predictive current controller has better robustness than the traditional predictive current controller. Available wind turbine-based grid connected inverters in the field show that the proposed method provides acceptable THD value based on IEEE standards.
202
98-F-REN-166
Development of a More Accurate Modular Model for Wind Turbines
Mohammad Monfared Hasan Rastegar Department of Electrical Engineering, Amirkabir University of Technology
Iran
Key words: wind turbine; modular modelling; dynamics; aerodynamics; Simulink
Abstract Utilization of wind energy for production of electricity has received more attention recently. Several models of wind turbines are already developed and are being used for simulation of dynamic interaction between wind turbines and the power system. Majority of currently available models are focused on some specific details of the system and, consequently, neglect impact of some others. Modular modelling of wind turbines is a good solution for this problem. In this paper, a more accurate modular model of wind turbines is developed. This model can be applied to any configuration of power system components and in all types of system studies. As previously stated, the model is a modular one and is consisted of several blocks each representing a part of the system or a physical phenomenon. The desired degree of accuracy is achievable provided that the required degree of computational complexity is sustained. Therefore, the model is completely physical and closely approximates the reality. It is also possible to modify the system for inclusion of other elements and/or exclusion of presenting elements. Change of elements is also possible. The basic idea of modular modelling is that ‘each element of model should make a contribution to the goals of study or otherwise it is deleted’. This strategy will optimise the computational costs of study. It is also possible to combine internal model of simulation package with physical blocks of wind turbine. The model can be used in all of studies of power system including but not limited to stability, power quality, and control strategies studies. This model can accurately predict voltage flicker and post-transient behaviour of the wind turbine included power system.
203
98-F-REN-269
Comparison of Photovoltaic systems Simulation by MLP and RBF Neural Networks
H.Amani Kh.Javani M.Sadeghierad M.A.Sherkat Maasoum
Abstract Photovoltaic systems (PV) are by nature nonlinear sources. Various methods have been proposed and implemented. Some of them are: nonlinear equations and mathematical modeling. These approaches however require detailed knowledge of physical parameters relating to the solar-cell material and manufacturing specifications. As such information may not be readily available to the users or, has given for a small range of V-I characteristic. In this article a two neural network – MLP and RBF - for solar-cell modeling is RBF networks propose. The network inputs for modeling are: radiation, temperature and load voltage; and the network output is cell current. After implementation these two networks, the data collected from a real solar-cell manufactured by the Iranian Optical Fiber Fabrication Co. is used for training and test the network. The results of network will explain.
204
98-F-REN-305
THE FABRICATION OF THE FIRST VANADIUM BATTERY FOR USAGE IN WIND & PV PLANTS
A. mosavi far B. ansar. D, A. younesi, M. hassani
Renewable Energy Organization Of Iran Keywords: Vanadium flow, Battery, Load leveling, Peak shaving, Distributed generation
Key words:
Abstract Flow Batteries are considered as a new system for applicable energy storage, especially ,their usage as load leveling of renewable power plants, Peak Shaving , decreasing the peak of energy generations and Frequency Control . The ability of these kinds of energy storage systems in the case of hybrid to new and renewable systems like wind , solar and other distributed generations have been made a particular attention to use of flow batteries. The advantages of these batteries are environmental friendly system ,low investment cost , low maintenance cost and long life time comparing to conventional lead acid batteries, high reliability, and finally independent capacity from power and body of battery . Fabrication of the first Vanadium Redox Battey (VRB) had been carried out by renewable energy organization as a research contract to TAVANIR Co. in Iran at year 2004 . In this paper characteristics of Vanadium Redox Batteries (VRB) from technical, economic and environmental points of view discussed .Also making procedure of the first single cell of VRB with the power of 10 watt and capacity of 20Ah described .
205
98-F-REN-338
Numerical simulation of using magnetic particle in cathode and its effect on output voltage of PEM fuel cell
Mitra Maghsoudi, Ramin Roshandel, Bijan Farhanie
Energy systems engineering department mechanical engineering faculty Sharif university of technology
Tehran , Iran
Key words: fuel cell, cathode diffusion layer ,magnetic field, voltages
Abstract Cathode flooding caused by excessive liquid water in generally recognized as the primary reason for poor cell performance . in this article we study a new method , based on using magnetic particle in cathode GDL . the results of this numerical simulation shows (1) the repulsive Kelvin force caused by the magnet particles manage the liquid water flow in porous electrode layer ; (2) the saturation level of liquid water (s) near the catalyst interface decreases with increasing the residual magnetic flux density of the magnetic particles ( rB ); (3) this method improve the fuel cell performance and output voltage by decreasing the value of s and making more pore space for oxygen gas , and decreasing the diffusion losses of potential .
206
98-F-REN-392
Maximum Power Point Tracking of Solar Modules using Fuzzy Controller
Hossein Iman-Eini Babak Najar Arrabi
Department of Electrical and Computer Engineering, University of Tehran, Tehran, Iran
Key words: Maximum power point tracking, Fuzzy control, Switching converter
Abstract During last two decades, photovoltaic systems have been considered as new clean energy sources. For economical reasons, the maximum power point of solar modules should be tracked. The current-voltage curve of solar modules is non-linear and the maximum power is generated only in one point. This point is dependent on temperature and light intensity. In this paper, a new control approach is proposed base on fuzzy sets theory in order to optimize the solar array modules and to reduce the cost of photovoltaic systems. In this method, despite temperature and light intensity variations, the switching duty cycle is controlled in some way that the maximum power point is tracked. The important advantages of this method in comparison with the previous methods are as following: the method is independent of solar module types, it has no need to reference signal or other physical information about solar modules, the method has no need to any temperature or light intensity sensors and fuzzy controller can track the maximum power point of modules even in unpredicted conditions.
207
98-F-REN-415
Improvement of Maximum Power Point Tracking in Photovoltaic Systems Using Fuzzy Logic
J. Khorasani 1 A.A. Gharaveisi2,3 M. Rashidi-Nejad2,3 A.M.Khajeh Zad4
1. Tarbiat Moalem University of Sabzevar 2. Shahid Bahonar University of Kerman
3. International Center for Hitech. and Environmental Sciences, Mahan 4. Electric Distribution CO. ,Kerman
Key words: Photovoltaic Systems, Maximum Power Point Tracker(MPPT), ANFIS
Abstract Now a days, renewable energies are of interest. In Iran there is a wide range of potential in this regards, whereas lost of capabilities are available associated with using renewable energies especially solar energy incorporating photovoltaic systems. It can be said that optimum utilization of these resources are very important. In this paper, a proposed fuzzy closed loop control method based up on ANFIS reference model is implemented. Simulation results show the effectiveness of the proposed method, while the performance are enough fast as well as precise.
208
98-F-REN-419
Stability Investigation of Induction Wind Generator Using Lyapunov Theory
S.R. Najafi S.H.Hosseinian M.Abedi PHD student Asistance professor Professor
AmirKabir University of Technology
(Tehran Polytechnic) Department of Electrical Engineering
Key words: Lypanouv Direct Method, CCT, Induction Generator
Abstract In this paper stability of asynchronous wind generator investigate. Such generators are today commonly used in Local Energy Systems and small power plants, for example wind parks. The concept of critical clearing time (CCT) is used to define stability limits of a generator. The Lyapunov’s stability theorem particular Lyapunov direct method is used as investigation method. This well-known method has been already used with synchronous generators and many power system dynamical elements. The approach used in this paper particularizes general considerations for rotating machines to asynchronous generators. The properties of the asynchronous generators are described with the help of a simplified equivalent circuit. Voltage drop at machine terminal, which follows fault clearance, is taken into account with simplified model. The maximal suitable power angle and the CCT are then evaluated. Analytical and numerical tests are shown and compared with simulations in MATLAB.
209
82-E-REN-446
Inclusion of Weather Effects in Reliability Evaluation for System Combining Photovoltaic Generation
Jin-Boo Choo Seung-Tae Cha Jeong-Hoon Shin Bang-Myung Kwak Tae-Kyun Kim Korea Electric Power Research Institute (KEPRI, KOREA)
Key words: Distributed Generation (DG), Distribution System, Photovoltaic (PV) Generation, Reliability, Weather
Abstract This paper presents a method for the reliability evaluation of distribution system, including the influence of the weather on the components and the photovoltaic (PV) generations. Unlike the generators of transmission system, those of distribution system have complexities in analyzing and determining the operation. Particularly, PV generation cannot carry out constant electric power and it has changeable output characteristics according to radiation and ambient temperature. In the process of evaluate reliability, it could be shown that many accidents occur mainly in adverse weather than in normal weather. It also increases the failure rate of PV system and reduces power output rapidly. Due to these characteristics, new approach methods that different from the previous are needed. Therefore, modeling technique of PV system to analysis distribution system reliability considering weather effects is proposed in this paper, and is compared with the other modeling method as a result of the distribution system reliability evaluation.
210
98-F-REN-474
A National Standard Development Proposal for Photovoltaic Grid-Connected Systems
Babak Farhangi, Shahrokh Farhangi, Majid Sanaye-Pasand
Dept. of Elect. and Computer Eng., Faculty of Eng. University of Tehran, Iran
Key words: Renewable Energy, PV Systems, Distributed Generation, Power Quality, Standards
Abstract In recent years, the use of photovoltaic energy has been accelerated in the world. The investigation of the PV scenarios proves continuous growth of this industry, where most of PV systems are grid-connected types. The PV grid-connected systems, beside other distributed sources, inject power into the grid. The integration of many small power sources, produce new problems. Preserving the grid stability and quality, in the case of the expansion of the distributed generation, requires new standards and regulations. In this paper, the necessity of a national standard development for PV grid-connected systems is discussed. The special issues of these systems are addressed, and a preliminary standard is proposed.
211
98-F-REN-692
WIND TURBINE POWER ESTIMATION USING NEURAL NETWORKS
aS.M.Moghdas-Tafreshi aD. Panahi bM. jamil
a Department of electrical engineering, K. N. Toosi University of technology Tehran- Iran b Energy and Metallurgy research center, Kara-j Iran
Key words: wind turbines, Estimation, wind speed, neural network
Abstract Generated power of wind turbines are more changeable because of continues changes in wind speed, direction, changing of wind characteristic and metrological conditions e.g.: pressure and air density. It is very important for electrical industries to be able to estimate output power of wind farms, using measured data of wind speed, direction and etc. In this research using data collected from a wind turbine in Manjil wind farm a method based on neural networks has been developed to estimate output power of wind turbine. This will help system operators, for example if out power of a turbine is less than a predicted or certain value it means that the turbine should be repaired. If this system were combined with a numerical whether prediction or a system that predict wind speed and direction, can predict wind power in different time horizons e.g.: 24 hours ahead. Accurate predictions of wind power to dispatch wind farms output, this phenomena helps wind power to be competitive with fossil fuel power plants. Nowadays according to the changes in power market, using this power prediction systems is so important.
212
98-F-REN-699
Optimal Photovoltaic Systems Siting in Distribution Networks to Reduce Losses
M. Parsa Moghadam* Sh. Yousefi* R. Dashti**
*Tarbiat Modares University **Tehran University
Key words: Photovoltaic systems, Distribution Systems, Siting, Cost Functions, Losses
Abstract Abstract:The necessity for flexible electric systems, changing regulatory scenarios and providing relief for overloaded components are providing impetus to the development of distributed generation (DG). Proper siting of DGs in the power systems makes it possible obtain their maximum potential benefits. This paper presents a successive method capable of identifying the number, size and location of grid-connected photovoltaic systems as one of the most useful distributed generators needed to provide relief for overloaded networks and optimally defer T&D expansion. The implemented technique is based on a graph algorithm considering existing surfaces and technical constraints, like feeder voltage profile in the network nodes. Finally the procedure is applied to the IEEE 34 bus radial distribution feeders and results are discussed to demonstrate the effectiveness of the proposed procedure.
213
98-E-REN-701
Dynamic and Power Quality Aspects of Interconnected Wind Turbine Using Universal Custom Power Conditioner
V. Salehi 1, 2 S. Kahrobaee 1, 2 S. Afsharnia 1
1- Electrical and Computer Engineering Department
University of Tehran, Tehran, Iran 2- MATN International Company
Abstract In this paper, dynamic and power quality aspects of wind turbine which is connected to utility at distribution level are presented. In order to power quality improvement and power flow control, a well-known structure, Universal Custom Power Conditioner (UCPC), is used. As a result of using instantaneous p-q theory as a control scheme, the multi-function operation such as harmonic elimination, reactive power control, voltage sags compensation and uninterruptible power supply, will be achieved. Dynamic modeling of wind turbine components and custom power conditioner are simulated in PSCAD/EMTDC environment. And the simulation results prove the efficiency of using the presented method on power flow controlling and power quality improvement.
214
98-E-REN-726
FORMULATE AND CALCULATE A NEW METHOD FOR WIND TURBINES GROUNDING
Hossein Kazemi Karegar Hossein Askarian Abyaneh
Zanjan University Amir Kabir University, Atomic Energy
Zanjan/Iran
Key words: Wind Turbine, Windfarm, Earthing System, Grounding Systems
Abstract Windfarms are becoming as a part of energy system and needs more attentions. One of the important things about the windfarms is grounding systems. In this paper, the grounding system of wind turbines and windfarms will be presented and a new method will be proposed. The proposed method has been applied on a real wind turbine and the results shows that the new method is more effective than the conventional methods.
215
98-F-REN-770
Wind Energy Potential Assessment at the NorthWest of Iran
Arash Haghparast Kashani Foad Kabinejadian Naser Faghfouri Hamid Reza Lari
Renewable Energy Department, Energy & Environment Research Center, NRI
Iran
Key words: Wind Assessment, Wind Energy, Wind Turbine, Weibull, Capacity Factor
Abstract The feasibility study of wind farm constructions at seven identified regions at the northwest of Iran including Kami Abad (Ardebil), Meinaq (Heris), Saien (Sarab), Tikmedash, Tasuj, Rashakan and Maien Bolagh (Tekab) is the major focus of this paper. The wind energy recorded data obtained from the so-called wind stations have been processed and the overall results for one year are presented. In this paper, the results of annual wind energy data analysis at Sarab region (as a sample) have been discussed. Also, the results of the seven wind stations have been compared and the quantity and quality of the electrical energy produced in these regions have been ranked on the basis of wind energy potential. Based on this criterion, the best site for construction of a wind farm is Sarab. The remaining locations can be arranged as follows: Ardebil, Heris, Tekab, Tikmedash, Tasuj and Rashakan.
216
98-F-REN-784
“Visual WIDA”- Wind Energy Data Analysis Software
Arash Haghparast Kashani, Ehsan sharbati, Foad Kabinejadian
Renewable Energy Department, Energy & Environment Research Center, NRI Iran
Key words: Wind Assessment, Wind Energy, Weibull, Rayleigh & Capacity Factor
Abstract The procedure of preparing a wind data analysis software, called Visual WIDA, is presented in this paper. To this end, the conventional theories and standards for wind data analysis, which are used in the software, are presented. Also, the new techniques obtained by the authors for computing some major parameters of wind data analysis are proposed. The capabilities of the Visual WIDA software are fully discussed in the current paper. For this purpose, the required input data of the software are introduced and the variety of tables and charts serving as the outputs of the program, are presented with the use of a practical sample.
217
98-F-REN-786
Data Evaluations of a 30 kW grid connected photovoltaic system
Ali Zarei Solmaz Bakhshi Sarabi Renewable energy organization of Iran (SUNA)
Key words: Photovoltaic System, Inverter, Module, Converter, MPPT Unit, Grid Connected
Abstract In respect to increasing demand for energy in the world and limited fossil fuel resources there is a great necessity for using renewable energies. Solar energy is an important kind of renewable energy. Iran country with more than 4.5 (kWh/m2. day) radiation has a great opportunity for attracting and converting it to electricity. One of the efforts done in the field of constructing and utilization solar plants is constructing 30kW grid connected photovoltaic power plant in Taleghan area. This power plant is located in a mountainous area with 50 degrees and 34 minute length, 36 degrees and 8 minute width and 1600 meter height from sea surface. This power plant is utilized in 1381. In this paper output data and information about Taleghan are evaluated. The aim of this paper is to achieve real data about grid connected photovoltaic systems, system efficiency and ambient conditions such as radiation, ambient temperature and module surface temperature. Furthermore parts of a grid connected power plant are investigated and operation of some of these parts will be illustrated.
218
98-F-SEA-138
TECHNO-ECONOMICAL COMPARISON BETWEEN ELECTRICITY & NATURAL
GAS TRANSMISSION IN IRAN
Majid Farmad - Parastoo Narimissa - Saed Raee Planning Department of Tavanir Co.
IRAN
Key words: Electricity Transmission, Natural Gas Transmission, HVDC, Electricity Generation Price
Abstract In this paper, two energy carriers (electrical network and natural gas pipeline) has been compared techno-economically for supplying final consumers demand . The considered amounts of transfered energy are 5000,10000 & 15000 MW with load factor equal to 0.6 or 1.5 , 3 & 4.5 million cubic meters of natural gas . The distance of energy route is equal 1000 KM . The existing electrical and natural gas network has not been considered . Different candidates for electricity transmission with AC & DC technologies and several cases for natural gas transfer has been compared . Finally electricity supplying cost for consumers including electricity generation in power plant , gas transfer , electricity transmission & losses for each cases has been calculated . Meanwhile , considering climate conditions and fuel prices , some sensitivity analyses have been performed and the best solution for minimizing the consumer’s tariff has been chosen . As a result , natural gas transfer via pipelines for power plants and installation of power plants as near as possible to the end users is the best choice in the above-mentioned cases .
219
98-F-SEA-359
Design and Application of a Hybrid Genetic Algorithm to Solve the Energy and Reserve Allocation Optimization
Mohammad Farshad M.Sc Student
Javad Sadeh Assistant Professor
Habib Rajabi Mashhadi Assistant Professor
Electrical Group, Faculty of Engineering, Ferdowsi University of Mashhad
Mashhad-Iran
Key words: Competitive Electricity Market, Reserve Market, Reserve and Energy Allocation, Hot and Cold Reserve
Abstract In the competitive environment of power industry, the needed reserve capacity procuring has more importance in comparison with other ancillary services. Reserve procuring through a competitive market could be effective to reach desirable reliability of system, more efficient use of capacities and moderate reserve procuring cost. Efficient and perfect design of reserve market can reduce its operation difficulties obviously. In this paper at first the reserve market concepts and different reserve commodities are introduced. Then, a possible design of reserve market is demonstrated to get operate in the restructured power systems. Finally a hybrid optimization method based on combination of Genetic Algorithm (GA) and Linear Programming (LR) will be proposed to solve simultaneously energy and reserve allocation problem. The proposed method takes advantages of both GA and LR and solves efficiently the optimization problem. In comparison with conventional GA, the convergence rate of the new method improved significantly, therefore it has capability to apply to the realistic power systems.
220
98-F-SEA-366
The importance of electricity demand forecasting in electricity price forecasting by decomposing electricity price into several
parts in competitive market for electrical power
Amir Ahmarinezhad Habib Rjabi Mashhadi Javad Sadeh Graduate Student Assistant Professor Assistant Professor
Electrical Department, Faculty of Engineering, Ferdowsi University of Mashhad
Central Research Committee, Khorasan Electric Utility, Mashhad, IRAN
Key words: Power Market, Electricity Price, Forecasting, Predictability, Neural Networks, Hurst Exponent
Abstract In the restructuring environment, one of the most important issues for Generation Companies (GenCos), Distribution Companies (DisCos) and Independent System Operator (ISO) is electricity price forecasting. In this area, due to uncertainties that occur in electricity price process, prediction of this quantity is much more complex than the load forecasting which has been done for a long time in the regulated environment. In this paper a new approach for electricity price forecasting is proposed. The basic idea is decomposition of electricity price into two parts and then forecasting each part separately. The first component is related to the electricity demand and another component is in relation with anything except the electricity demand such as participants' behaviors. In addition, the importance of electricity demand prediction is taken into account as an effective input for electricity price forecasting.
221
98-F-SEA-607
Optimum Selection of Bilateral Contracts from the Customer's View Point for Preserving Desired
Reliability in Restructured Power Systems
Mohsen Ghayeni Mohammad Hossein Javidi Graduated student Associate Professor
Department of Electrical Engineering
Ferdowsi University of Mashhad
Key words: Restructuring, Open access, Reliability, Bilateral Contract, Damage Function
Abstract This paper analysis the way a bilateral contract may be optimally selected by a customer while it preserves the desired reliability. In restructured power systems, it is possible for any customer to provide his required electric energy through bilateral contracts with different generating companies. In such a situation, the objective is normally to minimize the electricity costs while the reliability in providing the electricity is preserved within acceptable limits. In this environment, the customers propose their bids to the market or arrange their bilateral contracts with suppliers such that their costs are minimized while the reliability to supply their demand is kept within its acceptable range. They may also choose various contracts such that different levels of reliability are assigned to different levels of their demands.
222
98-F-SEA-617
Optimal Bidding Strategic of GENCOs for Competition in Day-ahead Energy Market
S. Soleymani1, A. M. Ranjbar1,2, A. R. Shirani2 1- Sharif University of Technology
2- Niroo Research Institute
Tehran – Iran
Key words: Bidding Strategic, Incomplete Information, Competition, Price, Energy Market
Abstract Recent changes in the electricity industry in several countries have lead to more competitive energy market where firms compete each other based on quantities and prices as strategy choices. In this new framework, each GENCO will try to maximize its own profit subject to the actions of its rivals and different types of constraints. In order to reach best strategies for the generating units, we should consider market structure. So this market modeling is the simulation of energy market in view of market agents. This simulation model of competitive generation market considers the market structure, the strategy of market participants and any other factor that lead to prices different from costs. This paper presents a model of day –ahead energy market based on simple bids, that estimates expected bid prices and quantities, system hourly prices and generation schedules, taking into account the bidding strategies of generators and the structure of the market. An IEEE six -bus system is employed to illustrate the proposed method. This model is simulated in GAMS (General Algebraic Modeling System) language using the DICOPT optimization software with mixed integer non- linear programming.
223
98-F-SEA-649
A New Approach for Bidding in Electricity Market using Game Theory
Mohsen Parsa Moghadam1 Nasser Baei1,2
1. Tarbiat Modares University 2. Moshanir Power Engineering Consultants – Power System Studies Dep.
Iran
Key words: Non-Cooperative Markets, Nash Equilibria Point, Genetic Algorithm, DCOPF
Abstract This paper, presents a new approach that allows non-cooperative companies in a spot market maximize their welfare. The use of such an approach in determining market equilibrium points, called Nash equilibria, is also shown. This approach uses a spot market, and by using of DCOPF that is a simpler model of OPF, the problem is solved. This DCOPF problem also extended to model consumer behavior. This approach for solving this problem and for avoiding reaching to local maximums uses Genetic Algorithm.
224
98-F-SEA-678
Optimal Ramsey Pricing For Fars Regional Electric Company (FREC)
ABBAS AMINIFARD MOHAMMAD ALLI FANNI
MORTEZA KHORSANDI
SHIRAZ UNIVERSITY and Fars Regional Electric Company (FREC)
IRAN
Key words: Pricing, Ramsey, Panel Data, Marginal Cost
Abstract The purpose of this research is to compute the Optimal Ramesy pricing for Fars Regional Electric Company (FREC). By this method, optimal price for each sector (residential, industry, agricultural and commercial) derive from estimation of demand and cost (or production) functions. After estimation of own elasticity demand for each sector, production function estimated for generations which producing electricity in (FREC) region and by using duality theorem, marginal cost calculation resulted in 200 Rial for one Kwh. By using of consumer and producer surplus maximization condition and put calculated own elasticity and marginal cost in this condition, price computed 427, 206, 468 and 194 Rial corresponded to residential, industry, agricultural and commercial sectors. The result of this research shows that in residential and agricultural sector electricity price is less than Ramsey price and in industry and commercial sector is upper than Ramsey price. Thus, for improvement social welfare, we should try to increase electricity price in residential and agricultural sectors and reduced it in industrial and commercial sectors.
225
98-F-SEA-735
Analysis's Bidding Strategies for Electricity Producers with limitations Electricity Market of Iran Case study:
Electricity market of khorasan
Mostafa rajabi mashhadi Mohhamd Amin Latifi Gholam reza Gholami zehab Hamid Mousavi
Khorasan region electric company Khorasan electricity market
Mehdi Oloomi Buygi Habib rajabi ashhadi
Ferdowsi university of Mashhad Faculty of Engineering
Iran
Key words: bidding, electricity market, unaccepted price minimum, accepted price maximum
Abstract After the starting of electricity market in Iran, Bidding Strategies for Electricity Producers is becoming an important problem. In the paper described bidding methods in another country and proposed method of forecasting unaccepted price minimum and accepted price maximum in Iran market place. The results of simulating proposed methods shows with present limitations, the power of electricity market of Iran has decreased and method of forecasting maximum of accepted price is effective method.
226
98-F-SEA-736
Development of electricity imports with application strategy based on Electricity Market rule of Iran Case study- Electricity imports from Turkmen
Mostafa rajabi mashhadi >! Mehdi Oloomi Buygi*
Mohammd Hossian Javidi >! Hamid Mousavi* Gholam reza Gholami zehab*
*) Khorasan region electric company - Khorasan electricity market
>! ) Ferdowsi university of Mashhad - Faculty of Engineering
Key words: Electricity imports, electricity market, economy assessment, losses of network
Abstract Imports of electricity have a little share of electrical usage in our country. In other side, the neighbor countries have resource that may be increasing imports. At present electricity imports in Iran from neighbor countries is buying with constant price contract. This subject increase losses of transmission network of neighbor regional electricity company and decrease power generation of power plants. This paper described the effect of electricity buying with constant price contracts. Also electricity imports is assessing base on electricity market rules of Iran. The results shows submission a part of imports to utility will improvement buying profile and decreasing loss of transmission network and so on.
227
98-F-SEA-797
Regulation Economy in Electricity Industry By Price Cap Method
Fatemeh Ziba Ministry Of Energy – business of Economy Surveys
Iran-Tehran
Key words: Natural Monopoly, Competition, Efficiency, Regulation, Price Cap, Electricity Industry
Abstract It is believed that economic regulation of prices and Conditions of public utilities improves efficiency (especially in natural monopoly sectors). A Regulatory reform requires a regulatory body in place to set the rule of the game and to monitor the Behavior of the firms engaged in the reform Processed. The regulator's main task is to calculate the optimal prices and the level of cost-reducing Effort for the firm and to instruct the firms to implement this solution. It is supposed that the result would furnish an environment in which Competition will be flourished and accordingly Efficiency and the quality of services will be improved. In this paper, we investigated regulatory reform and price cap method in Iranian Electricity Industry (IEI). This method Enable us to Screen the Involved Firms according To the Extent of Their Efficiency, Study the Development Of The firms Productivity in time Horizon and Development X- Factor Which in order to determine Price Cap Each Firm.
228
98-F-SEA-853
Decreasing Electricity Intensity of Industries by Purposely Defining Electricity Tariffs
S. F. Ghaderi- M. A. Azadeh- M. Khani- P. Mousavi
Research Institute in Energy Management and Planning Department of Industrial Engineering, Faculty of Engineering, University of Tehran- Iran
Key words: Electricity Intensity, Productivity, Electricity Tariff, Electricity Subsidy, Industry
Abstract Nowadays, productivity is known as one of the most important issues. For limited energy resources it would become even of more importance. As electricity power is mainly produced by using non-renewable fossil energy carriers, it can be comprehended that how important is productivity in consuming electricity power. In this work, productivity in industries has been evaluated through electricity intensity. The electricity intensity of Iranian industries has been compared with standard electricity intensity. (As no standard on electricity intensity could be find, electricity intensity for American industries has been used instead) Industries have been categorized in three groups according to their intensity: nearly productive industries, industries with low productivity and industries with very low productivity. Then the demand function of industries has been estimated, considering electricity price, value-added and the number of industrial facilities in each industry as variables. Using the demand function of each industry, price elasticity of demand has been calculated. Finally, electricity tariff of each group of industries has been determined in a way that leads to decrease in electricity consumption and intensity consequently by purposely defining electricity tariffs in industry.
229
98-F-SEA-855
Performance Assessment of Electricity Distribution Companies by Parametric and Non-Parametric Methods
M.A. Azadeh, S.F.Ghaderi, H. Omrani
Research Institute of Energy Management and Planning Department of Industrial Engineering, Faculty of Engineering, University of Tehran
Iran
Key words: Data Envelopment Analysis (DEA), Corrected Ordinary Least Square (COLS), efficiency
Abstract In electricity reform and restructuring, performance assessment of distribution companies is an important issue for regulators. For the performance assessment of electricity distribution companies parametric and non-parametric methods is used. In this paper, eighteen Iranian electricity distribution companies are evaluated by Data Envelopment Analysis (DEA) and Corrected Ordinary Least Square (COLS) techniques. Inputs and outputs used in this paper have been used in most of the previous studies. DEA and COLS results show that selected companies have good performance. Furthermore, correlation between DEA and COLS scores and ranks is strong respectively.
230
98-F-SEA-864
Financing Electric Energy Conservation in Iran: Problems and Solutions
Manzoor, Davood1; Fakhari, Morteza2
1- Assistant Professor, Imam Sadiq University 2- MA, Economics
Iran
Abstract Inadequacy of public financial resources to meet the increasing electric power demand and lack of private sector participation in energy supply chain can turn in a near future into a major barrier against the development of required power sector infrastructures. On the other hand, electricity price subsidies do not provide sufficient incentive for rational utilization of electric power and draws less attention to electric power conservation in Iran. In addition, the lack of sufficient financial resources to fund energy conservation projects has decelerated the development of this industry inside the country. Energy Service Companies (ESCO) are new institutions contributing to the financing and adoption of energy conservation measures in the developed and some developing countries. In this paper, besides examining electric power efficiency barriers, the ESCO model is presented as a solution.
231
98-F-SEA-872
Alteration in Hydro Power Projects` Economical Studies
Kazem Rauf Seresht, Mohssen Arbabian, Parinaz Pakniat Iran Water & Power Resources Development Company
Tehran-Iran
Key words: Hydro-Power, Gas, Benefit, Cost, Economical Study
Abstract Production of hydro-power energy as one of the cleanest sorts of energy, have been the centre of professions` attention. Furthermore, the astonishing improvement of this industry identifies "Economy of Hydro-Power Projects" as a controversial topic. However, comparisoning this projects with other kinds of power projects without consideration of secondary goals is not a logical analysis. In this paper effective factors in economy of hydro-power projects have been clarified. Real values of these factors, moreover, have been estimated. It should be mentioned that documentary evidence supports all information in this paper.
232
46-E-TRN-149
Maintenance decisions enabled through oil testing
Professor Pahlavanpour and Dr M Eklund
Nynas Naphthenics Ltd Wallis House, 76 North Street
Guildford Surrey UK
Key words: Maintenance, Oil testing, insulation ageing, Asset Condition Monitoring
Abstract One of the most important tools in a condition based maintenance strategy is to have a convenient, reliable and cost efficient method to identify deteriorating condition of a transformer. This method shall preferably be applicable whilst the transformer is on-line. Such a method will reduce the need for invasive maintenance substantially. For transformers, their tap changers, bushing, diverter and oil breakers this tool is the analysis of an oil sample, usually performed in a well equipped off site laboratory. Pump wear, abrasion, overheating, paper and oil ageing, discharge and arcing can all be diagnosed from such a test. An oil sample is taken in periodic intervals, depending on the asset.
233
98-F-TRN-197
Investigation the Cause of grounding Transformer Damages
H.R. Jahromi-A.R.Pishahang S. Jadid M.S.Roozitalab - A.R-Yazdani – GH-Nasiri Fars Regional Electric Company I.U.S.T
Key words: Grounding Transformer, Earth Fault, Earth Fault Relay, Accident, Simulation
Abstract Every year several of grounding transformers in various substations are damaged. So, it seems necessary to investigate and study the cause of transformer damages. According to statistics, there are more accident in substations that predicted only by fuse cutout, which means that their protection is not sufficient. If the cause of grounding transformer burning are divided into two groups, one over current and second the transient over voltage, investigations shows that effect of over current has been more damaging. In practice, usually there is no complete and sufficient information about operation, modeling, protection and function of grounding transformers. In this paper, using simulation and field study the cause of grounding transformer burning is determined. Finally it is suggested that with improvement of protection system and without any extra cost there will be a curtain reduction of grounding transformer damages.
234
98-F-TRN-274
Use of statistic Analysis for Understanding Distribution Transformer Problem
Reza Dashti Rahman Dashti Tehran Regional Co Iran University Science & Technology
Key words: transformer problem , distribution , statistic , operation
Abstract Transformer is one of most important equipment in power systems, influence of this equipment in system reliability and economic costs of transformer forced us to investigate and study the causes that damaged transformers and present the strategies for preventing that. A cording to damaged distribution transformer statistic of Tehran regional co in 1381 to 1384, investigation causes damaged transformers. This paper with present sum of burned transformer capacity and damage cost a cording to produces company that is installation location and damaged time. Also this paper investigate damage value impose Tehran regional co caused by main repair that with attention to low life time that after repair instead of replacing of new Transformers. Then aging curve is presenting for Tehran distribution transformer
235
98-F-TRN-301
Steady State Thermal Modeling and Temperature Prediction of the Cast-Resin Transformers
E. Rahimpour D. Azizian
Department of Electrical Engineering, Zanjan University - Iran Transformer Research Institute
Iran
Key words: Thermal Modeling, Dry Type Transformers, Cast Resin, Finite Difference, Winding Losses
Abstract Nowadays Dry-Type and especially Cast-Resin Transformers have interest so many researchers in transformer fields. Non-flammable characteristic of this transformers, make them suitable for residential and hospital usages. But because of the resin’s property, thermal behavior of the Cast-Resin Transformers is undesirable. So it is important to analyse the thermal behavior of these transformers. Thermal behavior of the Cast-Resin Transformers is modeled in this paper and the modeling results have been compared with the experimental data for a 800 kVA transformer as a test object to validate the model.
236
98-F-TRN-314
Detection and Acoustic Location of Partial Discharge by Using Fiber Optic Sensors
S.M.H. Hosseini 1, 2*, A. Sadeghi 2 and R. Rabii2
1Electrical Eng. Dept., Faculty of Eng., Islamic Azad University Science & Research Branch, Iran
2Electrical Eng. Dept., Faculty of Eng., Islamic Azad University South Tehran Branch, Iran
Key words: Partial Discharge, Transformer, Acoustic Propagation Method, Piezoelectric Sensors, Fiber Optic Sensors
Abstract According to the importance of transformers in power systems, many studies have been done on the insulation of these equipments. One of the most these researches is detection of partial discharge test to amend the transformers in order to prevent high expenses and time, during the scheduled maintenance. In total, there are fours methods of chemical, optical, electrical and acoustic in detection and location of partial discharge. Considering advantage and disadvantage each of them, it may be concluded that acoustic method can at least the best replacement of the other methods. In this article, by surveying the four methods of detection and location of partial discharges, the acoustic method has been emphasized. For this reason, acoustic basic discussions such as acoustic propagation paths, acoustic attenuation factors and different acoustic sensors have been surveyed and also, acoustic propagation paths and the methods of their analysis of them in transformers have been described. At the end, the tests have been done on two case studies and the result of this research shows that detection and acoustic location of partial discharge by using fiber optic sensors is the most appropriate suggested methods.
237
49-E-TRN-323
Properties of Alternative Liquids to Mineraloil for Transformers
H. Borsi, E. Gockenbach
University of Hannover, Institute of Electric Power Systems, Division of High Voltage Engineering, Schering-Institute
Callinstr. 25 A, D 30167 Hannover GERMANY
Key words: Transformer insulation, Mineral oil, ester liquid, breakdown voltage, gassing
Abstract Since many years ester liquids are in use as an alternative insulating liquid tomineral oil in distribution transformers.The major advantage, forcing the application of these fluids, is their improved environmental compatibility. But these liquids comprise several additional advantages, which are at first their lower inflammability. Power transformers contain several tons of insulating liquid, that may cause a long lasting pool fire in case of a transformer tank rupture due to winding failures. Meanwhile there are a lot of good experiences concerning the use of the ester liquid Midel 7131 in distribution transformers. This good experience encourages the manufacturer of transformers to use this liquid in power transformers. Due to larger dimensions of power transformers in comparison to distribution transformers special consideration is necessary. The contribution presents some results of investigations concerning the electric and dielectric behaviour of ester liquids in comparison to mineral based transformer oil. Furthermore the performance of ester liquid Midel 7131 and mineral oil mixtures concerning the electric behaviour is introduced.
238
46-E-TRN-325
ELECTRICAL INSULATION TESTS ON THE MODULAR 400 kV/AC LEAD EXIT SYSTEM FOR POWER
TRANSFORMERS
Bernhard HEINRICH 1) Christoph KRAUSE 1) Kurt WICK 2)
1)WEIDMANN Transformerboard Systems 2) WEIDMANN Systems International
CH-8640 Rapperswil, Switzerland
Key words: Lead exit, power transformer, prototype, testing, test models
Abstract This paper reports about the dielectric tests, which were conducted to prove the reliability of a new modular lead exit for use in 400 kV power transformers. Instead of testing many lead exits, the tests were carried out on few samples but at higher voltage levels and the voltages were applied more times than required according to the IEC standard. An additional series of tests was conducted on smaller, simplified test models, verifying the functionality of the moulding insulation of the electrode and of the copper tube. The measured values were compared with those calculated by applying design curves as used by the power transformer industry.
239
98-F-TRN-364
Investigation of Different Features of Partial Discharge Waveforms for PD Localization in Transformers
Ali Mazhab Jafari Asghar Akbari Hamid Abrishami Moghadam
Majid Raisi
Department of Electrical Engineering, K.N.Toosi University of Technology Tehran-Iran
Abstract Partial discharge (PD) pulses that are originated through transformers winding, will be attenuated and distorted due to passing along winding medium. So the features of PD waveforms that are measured at both ends of winding are different from original ones. By wide band PD measurement, the waveform of pulses will be available. Using these waveforms, it is possible to extract different features that are useful for diagnosing PD type and also PD location. In this contribution, a method based on using calibration pulses is introduced for PD localization. Then different features of PD waveforms will be investigated for the goal of localization. The investigation has been done using a 20kV/400V special transformer and then the method has been tested in a 132kV/11kV transformer.
240
49-E-TRN-441
A New Technique for On-line Monitoring of Transformer Bushings
Alireza Setayeshmehr, Alireza Akbari, Hossein Borsi, Ernst Gockenbach
Institute of Electric Power Systems, High Voltage Engineering Section (Schering – Institute), University of Hannover, Callinstr. 25 A, D-30167 Hannover, Germany
Key words: Power Transformer, Condenser Bushing Monitoring, Power Factor and Capacitance Measuring
Abstract Bushings are essential components of power transformers and are one of the common causes of catastrophic failure for transformers. The majority of bushings are as old as the transformers and therefore maintaining and monitoring of bushing condition is essential. The power factor and capacitance (PF&C) are the best indicators of the bushing’s condition. Off-line measurement of the PF&C needs to remove the power transformer from the network and a normal capacitance (NC) must be installed in the substation. In this contribution a novel method for on-line measuring of PF&C for power transformer condenser bushings with the software, hardware and sensors used in this method are introduced. According to laboratory measurement results this method can be used with acceptable accuracy in measurement of PF&C to detect a change in the bushing oil level, an increase in the oil moisture of the bushing and the temperature variation of the bushing oil.
241
49-E-TRN-443
Diagnostics of Power Transformers with Dielectric Response Measurements
Amir Abbas Shayegani*1 Hossein Mohseni1 Hossein Borsi2 Ernst Gockenbach2
1University of Tehran, Department of Electrical Engineering, Iran
2University of Hannover, Institute of Electric Power System (Schering-institute), Germany
Key words: Diagnostics, Dielectric Spectroscopy, Transformer insulation, Moisture, Aging
Abstract In recent years it has been an attention to dielectric response parameters for diagnosis of power transformers, high voltage cables etc. Determination of water content of pressboard, and aging state of solid insulation materials are claimed and some commercial measuring systems for these measurements are available. In this paper some measurement on oil-pressboard samples in laboratory condition at different states of samples are presented. The aim of the investigation is the determination of the effect of some parameters such as aging, water contents, geometry, etc on the dielectric response. The results show that separation of oil quality and pressboard state is possible and that aging has a similar effect as moisture.
242
98-E-TRN-484
Shielding Effectiveness Analysis of the Materials for High Current Systems in Low Frequency
HOSSEIN HEYDARI, MOHSEN FARHADY AND FARAMARZ FAGHIHI
Electrical Engineering Department, High Voltage & Magnetic Materials Research Center
Iran University of Science and Technology Narmak, Tehran, 16844
IRAN
Abstract Since current injection transformer as a high current systems are within the major group of the standard type test equipments in electrical industry, their performances are very important. When designing a high current devices, there are many factors to be considered from which, the compatibility of these devices with the internal and external propagation and generation of low frequency and high frequency disturbances within electromagnetic environment must be ensured. Up to the present time, as far as the authors are aware no report on shielding effectiveness analysis of the materials for high current systems in low frequency has been made. This paper attempts to fill this void in our knowledge by considering various issues related to shielding design consideration in a 25kA current injection transformer (CIT) as a high current system, using 3D electromagnetic fields (EMFs) simulation tools to calculate shielding effectiveness of various materials in low frequency. As matter of comparison of finite element method (FEM) simulations to measurements, a short circuit test was carried out on a typical CIT. This paper also reports the propagated and the generated low frequency near fields around the CIT and shielding effectiveness of variuos materials against these radiated fields.
243
98-F-TRN-489
Investigation on Condition and Life Assessment of Transformers and Challenges for their Establishment in IRAN
K.Anvarizadeh-T.Sarmasti NIROO RESEARCH INSTITUTE
IRAN
Key words: Condition Assessment, Transformer ,Insulation System
Abstract This paper briefly presents methods that developed by experts to assess condition & life of transformers . A complete assessment program includes the three main level: Transformer Engineering Analysis , Internal & external field Inspection , Testings & Diagnostics and engineer analysis. Such programs should appraise different factors that cause Transformer deterioration . In addition , This paper describes the main aspects which create problems to perform condition assessment in our country and proposed solutions to confront them .
244
98-F-TRN-516
Measuring the dielectric constant of transformer oil using microwave techniques
G. Moradi, A. Abdipour, M. Azizi and M. Modarresi Tehran Polytechnic University, Tehran Iran
Key words: Transformer oil, Microwave techniques, dielectric permittivity, measurement techniques
Abstract In this paper, a new approach has been developed for measuring the dielectric permittivity of transformer oil. Also an efficient extraction method has been proposed for solution of the governing transcendental equation. The developed routine uses microwave frequencies band to increase the accuracy and resolution of the results. Besides, some novel techniques have been applied in the physical implementation of the set-up. The obtained results are in well matched with the data given in data sheet. The important point in this approach is its susceptibility to slight changes on the characteristics of the material. This is superior to the existing methods of the measuring the material characteristics. Finally it has been shown that the performance of the material at microwave band can approximately predict the low frequency characteristics. This approach can be successfully applied to categorize other liquids such as polymers. It is noticeable that the applied set-up can be found in any microwave lab.
245
98-F-TRN-534
Thermal Modeling of Power Transformers for Optimal Loading
Asghar Akbari1 Reza Golpari 1,2 1-K.N.Toosi University of technology-Tehran-iran
2-Iran Transformer Research Institute
Key words: Power transformer, Thermal modeling, Top-oil temperature, Hot-spot, Loading
Abstract Power transformers are one of the most expensive equipment in power systems, so the efficiency and optimal utilization of them is very important. Some factors, like temperature, moisture and oxidation can affect the solid and liquid insulation and reduce the service life of power transformer. Temperature of a power transformer depends on ambient temperature and loading condition. Thus we should have a thermal model for a transformer to predict temperatures in different conditions to analyze useful life and improve loading and utilization of a power transformer. In this paper, a thermal model for power transformer was implemented to predict the Top-oil temperature in different loading conditions, and then this model was used in order to predict the Hot-spot temperature. Practical validation have been done on a load and temperature data of a power transformer with 180 MVA, 230/63 KV ratings.
246
98-F-TRN-580
Proposal of some guidline for decrease of events on transformers at distribution networks bassed on
statistical studies form failure distribution transformers
K. Kamyar G.Ghrapetian Metanir Company Amirkabir University Iran Iran
Key words: Transformer, Distribution Networks,Events,Coil,Over voltages
Abstract This paper has studied about failures of transformer at distribution networks of Regional Electric Companies of Iran ,then classified failures of transformer in repairing places,and compared with failures of distribution transformers .there fore it has discussed many factors which has caused such events ,and finally has propused suitable guidElines for decreasing similar events at distribution networks of Regional Electric Companies in Iran.
247
98-F-TRN-715
Analysis of the Laboratory Test Results of a Ferroresonance Test of a 33 kV Voltage Transformer
Afshin Rezaei-Zare Hossein Mohseni Majid Sanaye-Pasand Shahrokh Farhangi
Department of Electrical and Computer Engineering
Faculty of Engineering – University of Tehran Tehran – Iran
Key words: Ferroresonance, Voltage Transformer, Magnetization Characteristic, Hysteresis
Abstract Ferroresonance is a nonlinear resonance and occurs in all voltage levels of the power systems. One of the main elements of a ferroresonance circuit is saturable inductance. The existing electromagnetic transient programs present various methods for modeling the magnetization characteristics of saturable cores. However, to study ferroresonance phenomenon, the most efficient method must be used. In this paper, some of these methods have been reviewed. Then, the detail description of a ferroresonance test circuit and the procedure of testing of a 33kV voltage transformer and the results have been presented. Using the results of the transformer no-load test, the magnetization characteristic has been obtained and the magnetic core has been modeled by various methods. The comparison between the experimental and simulation results show that in analysis of the ferroresonance phenomenon, the core characteristic must be represented by hysteretic model. Otherwise, the simulation results may present significant errors.
248
44-E-TRN-745
Transformers dry out using filtration technique
Professor Pahlavanpour
Nynas Naphthenics Ltd, Wallis House, 76 North Street
Guildford Surrey UK
Key words: Transformer, Moisture, Drying, Degassing, Insulating paper
Abstract Presence of water in oil filled electrical equipment can seriously damage insulation system. Equipment owner are making every effort to keep the moisture low by using protective equipment to avoid ingress of moisture from air, but normal insulation deterioration lead to moisture formation and accumulates in solid insulation system. This moisture accumulation in the insulation system reduces life and performance of the equipment and can not be easily removed. To remove the moisture from insulation paper several techniques can be used but rapid removal of moisture from the oil is unable to dry the insulating paper. This paper describes a technique, which is capable of removing moisture from solid insulation, using absorbent filters. The system used on-line on live transformers with satisfactory results. It is safe easy and economic to operate.
249
98-F-TRN-836
Design and Manufacturing of Combined Instrument Transformer-24kV, CIT24
A. Rafiei, A. Goodarzi A. Adlband M. R. Hesamzadeh
Niroutrans Co. IRAN
Key words: Combined Instrument Transformer, Condenser Bushing, Current Transformer, Voltage Transformer
Abstract Nowadays, one of the main negotiations among different Disco’s concerns with metering of consumed energy. This paper embraces different steps in design, assessment, manufacturing, and testing of Combined Instrument Transformer 24kV, CIT24, for solving aforementioned problem. CIT24 includes three current transformers and three voltage transformers and has been designed for measuring voltage and current simultaneously as well as consumed energy. Two of the most important issues in designing of a High Voltage product are electromagnetic and insulation matters which mainly discussed in relevant sections of this paper.