Training report by shubham sachan
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Post on 19-Aug-2014
DESCRIPTIONTraining Report on Sub-Station
SIX WEEKS SUMMER TRAINNING REPORT On TRAINING UNDER KESCO SUB-STATION Submitted by (Shubham Sachan) Registration No-11104846 Program-Electrical and Electronics Engineering Section-E3108 Under the Guidance of Pursottam Yadav (Junior Engineer) School of Electronics and Electrical Engineering Lovely Professional University, Phagwara, Punjab (June-July, 2014) shubham sachan DECLARATION I hereby declare that I have completed my six weeks summer training at KESCO, Tatya Tope Nagar Sub-station from 25/6/2014 to 24/6/2014 under the guidance of (Pursottam Yadav). I have declare that I have worked with full dedication during these six weeks of training and my learning outcomes fulfill the requirements of training for the award of degree of Electronics and Electrical, Lovely Professional University, Phagwara, Punjab. (Signature of student) Name of Student Registration no: Date: shubham sachan ACKNOWLEDGEMENT I sincerely thank to The General Manager, Kanpur Electricity Supply Authority, Junior Engineer (Training), Sub-Station Officer (Training) & Training Coordinator. Who accepted my request for training without any hesitation and patiently answering all my queries, for providing clarity to my cluttered thought, They were instrumental in providing us good accommodation as well as very successful training at KESCO Tatya Tope Nagar Sub-Station. Last but not the least I am extremely grateful to all the Engineers and Staff members of Tatya Tope Nagar Sub-Station, and 132/33KV Armapur Sub-Station who could find time for us in spite of their busy schedule. Name of student: - Shubham Sachan Registration no.: - 11104846 shubham sachan OBJECTIVE OF TRAINING/PROJECT The main goal of this work is: How 33KV is step down to 11KV. To know about the Distribution of Electricity in area wise. Repairing of Electrical equipment like Transmission lines, Transformers etc. How to detect the faults and remove it as soon as possible. How electric connection is Provide to local user. shubham sachan Chapter 01- Organization Overview i. Company Profile ii. About 33/11 KV Sub-station Tatya Tope Nagar iii. Visit of 132/33 KV Armapur Chapter 02- Technology Learnt i. Electric Supply System ii. Types of Conductors iii. Transformer iv. Grounding System v. Controlling through Switch gear vi. Circuit Breaker Chapter 03- Motivation of the training Chapter 04- Learning Outcome Chapter 05- Gantt chart shubham sachan Table of Content 1. Company Profile 2. About 33/11 KV S/S Tatya Tope Nagar, Kanpur 3. Visit of 132KV Armapur S/S 4. Electric Supply System 5. Electrical S/S 5.1. Type of Substation i. Transmission Substation ii. Distribution Substation iii. Collector Substation 5.2. According to the service requirement 5.3. Classification of Substation 6. Conductors 6.1. Type of conductors i. AAC ii. AAAC iii. ACSR iv. ACAR v. ABC 6.2. Conductors Used in Substation Design 7. Transformer 7.1. Potential Transformer 7.2. Capacitor Voltage Transformer 7.3. Current Transformer 7.4. Auto Transformer 7.5. Power Transformer 8. Megger 9. Transformer Cooling 9.1. Air Natural cooling 9.2. Air Blast Cooling 9.3. Oil Natural cooling 9.4. Oil Blast Cooling 9.5. Forced Oil and Water shubham sachan 10. Transformer Protection 10.1. Conservator and Breather 10.2. Marshalling Box 10.3. Insulating Material 11. Transformer Tap Changing 12. Isolators 13. Grounding System 12.1 System Grounding 12.2 Neutral Grounding 14. Method of Neutral Grounding 13.1 Solid Grounding 13.2 Resistance Grounding 13.3 Reactance Grounding 13.4 Resonant Grounding 15. Capacitor Bank 16. Lightning Arresters 17. Main Bus-Bar 18. Wave Trap 19. Switchgear 20. Batteries 21. Fuse 22. Circuit Breaker 22.1. Oil Circuit Breaker 22.2. Vacuum Circuit Breaker 22.3. SF6 Circuit Breaker 22.4. Air Blast Circuit Breaker 23. Motivation 24. Gantt Chart 25. Learning Outcome 26. Reference 27. Abbreviation shubham sachan List of Figures Figure-No. Name of Figure Page-No Fig no 1 KESCO Logo 01 Fig no 2 33/11KV TT Nagar S/S 02 Fig no 3 Electric Supply System 04 Fig no 4 Type of Substation 05 Fig no 5 Out Door Substation 07 Fig no 6 Under-Ground Substation 07 Fig no 7 Pole-mounted Substation 08 Fig no 8 Current Transformer 10 Fig no 9 Potential Transformer 11 Fig no 10 Power transformer 12 Fig no 11 Breather 14 Fig no 12 Isolator 16 Fig no 13 Grounding 17 Fig no 14 Lightning Arresters 19 Fig no 15 Main Bus Bar 20 Fig no 16 Wave Trap 21 Fig no 17 Oil Circuit Breaker 23 Fig no 18 Vacuum Circuit Breaker 23 Fig no 18 SF6 Circuit Breaker 24 Fig no 19 Internal Structure of SF6 C.B 24 Fig no 20 Air Blast Circuit Breaker 24 Fig no 21 TT Nagar S/S View 26 shubham sachan 1 1. Company Profile Kanpur Electricity Supply Authority is the nerves system of Kanpur Electricity. KESCO is responsible for distribution and bulk supply of power in Kanpur and provides power to over 427,158 consumers, consisting of approximately 350,000 domestic, 73000 commercial, 8000 others including small, medium, large, and heavy power connections. Maintaining all the consumers through a network based on 61 electrical substation of 33/6.6 KV level, 333 feeders of 11 KV level and more than 3000 distribution transformers of different levels. KESCO head office is at Civil Lines. KESCO main moto is: Consumer Satisfaction Revenue improvement work Official Website of KESCO is www.kesco.co.in shubham sachan 2 2. About 33/11KV substation Tatya Tope Nagar Substation In T.T Nagar this substation is powered by 132KV S/S Barra-8 where 132KV is step down to 33KV and then fed to the Tatya Tope Nagar with the help of bus- bar this bus-bar is given to the Power Transformer into the primary side and this 33KV is further step down to the 11KV. With the parallel of 33KV bus-bar lightning arrester are also connected to protect the bus-bar. This 11KV is given to the switchgear box in the incoming chamber when this 11KV is given to the incomer then there is trolley in the incomer chamber which is to be up to supply the power to the next chamber, with this chamber several feeders are connected in Tatya Tope Nagar S/S with this feeder 16 villages are connected. This supply is provided to Meharbaan Singh Purva, Ambedkar Nagar, and Tatya Tope Nagar etc. From here 33KV is also provided to Meharbaan Singh Purva S/S. shubham sachan 3 3. Visit of 132/33KV Armapur S/S 132/33KV Armapur S/S is come under Uttar Pradesh Power Transmission Corporation Ltd. This S/S is only for giving the supply to the Kanpur Ordinance Factory. In this S/S 132KV is step down to the 33KV and then give it to the OFC. Here two 132KV main lines are taken as I/P from Panki Thermal power plant than with this line LA is attached after two PTs are attached in parallel, after PTs two CTs are attached in series here in this S/S two PTs & CTs are use because first PT is of KESCO department and second PT is of OFC Armapur S/S same as concept is used is CTs also. After this bus bar is used again LA is connected on further connections after this SF6 circuit breaker is used, this is done with both the lines, after this insulators are connected now this 132KV is then give to PT of rating 20MVA and converted to 33KV, in this PT oil circuit breaker are used with buchholz relay is used for this transformer protection. Then again insulators, PTs, CTs and bus bar are used for further supply before this 33KV is given to the OFC Vacuum circuit breaker is also used. This S/S is fully automatic and these all equipment are also controlled through control room. So before doing any kind of maintenance it is close it from the control room then also through isolators and if any maintenance in doing on C.Bs then there is an special feature to close it from there also. On the last day of my training. I get this opportunity to see the 132/33KV Armapur S/S. This S/S is installed in 2006 and give its service from 2007 this is Kanpurs first S/S with latest all technology. All the equipment which is used in this S/S are well grounded and fully protected. shubham sachan 4 4. Electric Supply System The conveyance of electric power from a power station to consumers premises is known as electric supply system. An electric supply system consists of three principal component, power station, transmission lines, and distribution system. Electric power is produced at the power stations which are located at favourable places, generally quite away from consumers. It is then transmitted over large distances to load centres with the help of conductors known as transmission lines. Finally, it is distributed to large number of small and big consumers through a distribution network. 5. Electrical Substation A substation is a part of an electrical generation, transmission and distribution system. Substation transforms voltage from high to low, or the reverse, or performs any of several other important functions. Between the generation station and consumer, electric power may flow through several S/S at different voltage level. shubham sachan 5 S/S may be owned and operated by an electrical utility, or may be owned by a large industrial or commercial customer. Generally Substation is unattended, relying on SCADA for remote supervision and control. A S/S may include transformers to change voltage level between high transmission voltage and lower distribution voltage, or at the interconnection of two different transmission voltage. As this project report is based on 33/11 KV Distribution S/S, Tatya Tope Nagar, Kanpur; so what are the component used in this Substation are described below. 5.1. Type of substation i. Transmission Substation A transmission S/S connects two or more transmission lines. The simplest case is where all transmission lines have the same voltage in such case, S/S contain high-voltage switch that that allow lines to connected or isolated for fault clearance or maintenance. A Transmission Station may have transformer to convert between two transmission voltage, voltage control power factor correction device such as capacitor, reactors or static VAR compensator. ii. Distribution Substation A distribution S/S transforms power from the transmission system to the distribution system of an area. It is an economical to directly connect electricity shubham sachan 6 consumers to the main transmission network, unless they use large amount of power, so the distribution station reduces voltage to a suitable for local distribution. The input for a distribution S/S is typically at least two transmission or sub transmission lines. Input voltage may be, for example, 115 KV, Distribution voltage are typically medium voltage, between 2.4KV and 33KV depending on the size of the area. iii. Collector Substation In distributed generation projects such as a wind farm, a collector S/S is required. It resembles a distribution S/S although power flow in the opposite direction, from many wind turbines up into the transmission grid. Usually for economy of construction the collector system operate around 35kv and the collector S/S steps up voltage to transmission voltage grid. 5.2. According to the service requirement i. Transformer S/S ii. Switch S/S iii. Power Factor Correction S/S iv. Frequency Change S/S v. Converting S/S vi. Industrial S/S 5.3. Classification of Substation A S/S has many components e.g. C.B, switches, fuses etc. S/S is classified as: i. Indoor Substation These type of S/S are used for voltage up to 11KV, the equipment of the S/S is installed because of economical consideration. ii. Outdoor Substation Voltage beyond 66KV as the name suggest these are installed outside, It is because for high voltage, the clearance between conductor and the space shubham sachan 7 required for switches, C.B and other equipment become so great that it is not economical to installed the equipment indoor. iii. Under Grounded Substation In thickly populated areas, the space available for equipment is limited and the cost of land is too high. Under such situation, the S/S is created underground. shubham sachan 8 iv. Pole-mounted Substation This is outdoor S/S with equipment installed over head on H-pole or 4-pole structure it is cheapest from S/S for voltage not exceeding 11KV. 6. Conductors In physics and in electrical engineering, a conductor is an object or type of material which permits the flow of electrical charges from one direction to other. In metals like Aluminium and copper the movable charged particle are electrons. * Aluminium in place of copper a. Much lower cost b. Lighter in weight c. Larger in diameter d. Low voltage gradient less ionization and corona 6.1. Type of conductor used in S/S i. AAC- All Aluminium Conductor AAC are used in primary for overhead transmission and also for primary and secondary distribution, where capacity must be maintained and a lighter conductor is desired, and when conductor strength is not a critical shubham sachan 9 factor. Class B, Class C are used primary as bus, apparatus connectors and jumpers, where additional flexibility is required. ii. AAAC-All Aluminium Alloy Conductor Used as bare overhead conductor for primary and secondary distribution. Designed utilizing a high-strength aluminium alloy to achieve a high strength to weight ratio; afford good sag ratio. iii. ACSR-Aluminium Conductor Steel Reinforced Used as bare overhead conductor for primary and secondary distribution conductor and distribution conductor. ACSR offers optimal strength for line design. iv. ACAR-Aluminium Conductor Aluminium Alloy Reinforced Used as bare overhead conductor for primary and secondary distribution cable. A good strength to weight ratio makes ACAR application where both ampacity and strength are prime considerations in line design. v. ABC lines-Aerial Bundled conductor Aerial bundled cables simply called ABC are overhead power lines using several insulated phase conductors bundled tightly together, usually with a bare neutral conductor. 6.2. Conductors Used In S/S Design An ideal conductor should fulfil the following requirements: 1. Should Capable of carrying the specific load. 2. Should be corona free at rated voltage. 3. Should have the minimum number of joints. 4. Should need the minimum number of supporting insulators. 5. Should be economic. * Most suitable material for conductor system is copper or aluminium. shubham sachan 10 7. Transformer A Transformer is a static electrical device that transfers energy by inductive coupling between its winding circuits. A varying current in the primary winding creates a varying magnetic flux in the transformer core and thus a varying magnetic flux through the secondary winding. The varying magnetic flux induces a varying electromotive force or voltage in the secondary winding. 7.1. Current Transformer Current transformers are basically used to take the readings of the currents entering the S/S. This transformer steps down the current from 800 amps to 1 amp. This is done because we have no instrument for measuring of such a large current. The main use of this transformer is: a. Distance Protection b. Backup Protection c. Measurement A current transformer is defined as an instrument transformer in which the secondary current is substantially proportional to the primary current and differs in phase from it by an angle which is approximately zero for an appropriate direction of the connections. This highlights the accuracy requirement of the current transformer but also important is the isolating function, which means no matter what the system voltage the secondary circuit need to be insulated only for a low voltage. The current transformer works on the principle of variable flux. In the ideal current transformer, secondary current would be exactly equal and opposite to the primary current. But, as in the voltage transformer, some of the primary current or the primary ampere-turns are utilized for magnetizing the core, thus leaving less than the actual primary ampere turns to be transformed into the secondary ampere-turns. This naturally shubham sachan 11 introduces an error in the transformation. The error is classified into current ratio error and the phase error. 7.2. Potential Transformer There are two potential transformers used in the bus connected both side of the bus. The potential transformer uses a bus isolator to protect itself. The main use of this transformer is to measure the voltage through the bus. This is done so as to get the detail information of the voltage passing through the bus to the instrument. There are two main parts in it a. Measurement b. Protection The standards define a voltage transformer as one in which the secondary voltage is substantially proportional to the primary voltage and differs in phase from it by an angle which is approximately equal to zero for an appropriate direction of the connections. This in essence means that the voltage transformer has to be as close as possible to the ideal transformer. In an ideal transformer, the secondary voltage vector is exactly opposite and equal to the primary voltage vector when multiplied by the turns ratio. In a practical transformer, errors are introduced because some current is drawn for the magnetization of the core and because of drops in the primary and secondary windings due to leakage reactance and winding resistance. One can thus talk of a voltage error which is the amount by which the voltage is less than the applied primary voltage and the phase error which is the phase angle by which the reversed secondary voltage vector is displaced from the primary voltage vector. CVT- Capacitor Voltage Transformer is a part of Power Transformer A capacitor voltage transformer (CVT) is a transformer used in power systems to step-down extra high voltage signals and provide low voltage signals either shubham sachan 12 for measurement or to operate a protective relay. In its most basic form the device consists of three parts: two capacitors across which the voltage signal is split, an inductive element used to tune the device to the supply frequency and a transformer used to isolate and further step- down the voltage for the instrumentation or protective relay. The device has at least four terminals, a high-voltage terminal for connection to the high voltage signal, a ground terminal and at least one set of secondary terminals for connection to the instrumentation or protective relay. CVTs are typically single-phase devices used for measuring voltages in excess of one hundred kilovolts where the use of voltage transformers would be uneconomical. In practice the first capacitor, C1, is often replaced by a stack of capacitors connected in series. This results in a large voltage drop across the stack of capacitors that replaced the first capacitor and a comparatively small voltage drop across the second capacitor, C2, and hence the secondary terminals. 7.3. Auto Transformer A Single phase Auto Transformer is a one winding transformer in which a part of the winding is common on both high voltage and low voltage side. A step down transformer is one in which the primary voltage is greater than the secondary voltage vice versa for step up transformer on which secondary voltage is greater than the primary voltage. 7.4. Power Transformer A transformer is a device that transfers electrical energy from one circuit to another by electromagnetic induction (also called transformer action). It is most often used to step up or step down voltage shubham sachan 13 8. Megger The Megger is a portable instrument used to measure insulation resistance. The Megger consists of a hand-driven DC generator and a direct reading ohm meter. 9. Transformer Cooling When the transformer is an operation heat is generated due to iron losses the removal of heat is called cooling. 9.1. Air Natural Cooling In a dry of self-cooled transformers, the natural circulation of surrounding air is used for its cooling. This type of cooling is suitable for low voltage small transformer. 9.2. Air Blast Cooling It is similar to that of dry type self-cooled transformers with to addition that continuous blast of filtered cool air is forced through the core and winding for better cooling. 9.3. Oil Natural Cooling For medium and large rating have their winding and core immersed in oil, which act as both cooling medium as well as insulating medium. 9.4. Oil Blast Cooling In this type of cooling, forced air is directed over cooling elements of transformers immersed in oil. 9.5. Forced Oil and Water Cooling In this type of cooling oil flow with water cooling of the oil in external water heat exchanger takes place. The water is circulated in cooling tubes in the heat exchanger. shubham sachan 14 10. Transformer Protection Transformers are totally enclosed static devices and generally oil immersed. Therefore chance of fault occurring on them are rare, however the consequence of even a rare fault may be very serious unless the transformer is quickly disconnected the faulty system. This provides accurate automatic protection for protection against fault. 10.1. Conservator and Breather When oil expands or contracts by the change in the temperature, oil level goes either up or down in main tank. A conservator is used to maintain the oil level up to predetermined value in the transformer main tank by placing it above the level of the top of the tank. Breather is connected to conservator tank for the purpose of extracting moisture as it spoils the insulating properties of the oil. During the contraction and expansion of oil air is drawn in or out through breather silica gel crystals impregnated with cobalt chloride. Silica gel is checked regularly and dried and replace when necessary. 10.2. Marshalling Box It has two meter which indicate the temperature of the oil and winding of main tank. If temperature of oil or winding exceeds than specific value, then relay operates to sound an alarm. If there is further increase in temperature than relay completes the trip circuit to open the circuit breaker protect the transformer. shubham sachan 15 10.3. Insulating Material Insulation is one of the most important constituent of a transformer. The durability and stability of the transformer depends upon the proper utilization of insulating materials in it. In transformers mainly three basically insulating materials are used. i. Transformer oil ii. Insulating paper iii. Press board Of the three, the major insulating material used is transformer oil. 11. Transformer Tap Changing Transformer tap changing is latest technology which is used now a days, this technology is come into picture after lots of damage. Tap changing means to set the transformer winding into certain no to get the output voltage basically tap winding are depend on manufacturer, most of manufacturer set there tap winding at 5 this gives us 33KV as O/P some of tap winding voltage are as follows Tap Winding Voltage 1 31476.0 V 2 31486.5 V 3 32787.8 V 4 32988.4 V 5 33000.0 V 6 33406.6 V 7 34608.7 V 8 34954.2 V 9 35226.2 V 10 35828.6 V 11 36458.2 V 12 36958.3 V 13 37406.1 V shubham sachan 16 At tap 5 winding we get 33KV but after some time its efficiency will reduce and it give O/P less than 33KV then we have to set them at tap winding level 6 which actual O/P is 33406.6 V but at this we get 33KV as O/P similarly as follows but at some time when it reach at tap level 8 the transformer service will not take and it should be repair for further use. Actually these values are ideally but they are approximately same. 12. Isolator Isolator is the devices used to protect the S/S from any fault on the incoming feeder. When any fault occur then operating handle will make open so the contact of isolator will open and this way we can protect the transformer from any damage. 13. Grounding System A connection made with a conductor, whether intentional or accidental, by which an electric circuit or equipment is connected to earth, or to some conducting body of relatively large extent, which serves in place of the earth. For mankind nature has provided EARTH as the single largest grounding conductor. shubham sachan 17 Grounding Systems Serve Four Main Functions Equipment or Safety Grounding. System Grounding. Lightning Protection System Grounding. Neutral Grounding 13.1. System Grounding The process of connecting some electrical part of the system to earth is called System Grounding. 13.2. Neutral Grounding The process of connecting neutral point of 3-phase system to earth either directly or through some circuit element is called neutral grounding. 14. Method of Neutral Grounding 14.1. Solid Grounding When the neutral point of 3-phase system is directly connected to the earth through a negligible resistance or reactance is known as solid grounding. Advantage The neutral is effectively held at earth potential. It becomes easier to protect the system from earth fault. shubham sachan 18 When there is an earth fault on any phase of the system the phase to earth voltage of the faulty phase becomes zero. * This type of system grounding is used for voltage up to 33KV. 14.2. Resistance Grounding When neutral point of the system is connected to the ground to earth through Resistance is called Resistance Grounding. It improves the stability of the system. The earth fault is small due to the presence of earthing resistance. * It is used on a system operating at voltage between 2.2KV and 33KV. 14.3. Reactance Grounding In this system a reactance is inserted between the neutral and ground. The purpose of reactance is to limit the earth fault. 14.4. Resonant Grounding When the value of L of arc suppression coil is such that the fault current If exactly balance the capacitive current Ic, It is called resonant grounding. This type of grounding is called Peterson Coil Grounding. The Peterson Coil is completely effectively in preventing any damage by an arcing ground. The Peterson Coil has the advantage of ungrounded neutral system. 15. Capacitor Bank The load on the power system is varying being high during morning and evening which increases the magnetization current. This results in the decreased power factor. The low power factor is mainly due to the fact most of the power loads are inductive and therefore taking lagging current. The low power factor is highly undesirable as it causes increases the current, resulting in additional losses. In order to improve the power factor come devices taking leading power should be connected in shubham sachan 19 parallel with load. One of such devices can de capacitor bank. The capacitor draws a leading current and partly or completely neutralizes the lagging reactive component of load current. 16. Lightning Arresters Lightening arrestors are the instrument that are used in the incoming feeders so that to prevent the high voltage entering the main station. This high voltage is very dangerous to the instruments used in the S/S. Even the instruments are very costly, so to prevent any damage lightening arrestors are used. The lightening arrestors do not let the lightening to fall on the station. If some lightening occurs the arrestors pull the lightening and ground it to the earth. In any S/S the main important is of protection which is firstly done by these lightening arrestors. The lightening arrestors are grounded to the earth so that it can pull the lightening to the ground. The lightening arrestor works with an angle of 30 to 45 making a cone. 17. Main Bus-Bars The bus is a line in which the incoming feeders come into and get into the instruments for further step up or step down. The first bus is used for putting the incoming feeders in la single line. There may be double line in the bus so that if any fault occurs in the one the other can still have the current and the supply will not stop. The two lines in the bus shubham sachan 20 are separated by a little distance by a conductor having a connector between them. This is so that one can work at a time and the other works only if the first is having any fault. A bus bar in electrical power distribution refers to thick strips of copper or aluminium that conduct electricity within a switchboard, distribution board, S/S, or other electrical apparatus. The size of the bus bar is important in determining the maximum amount of current that can be safely carried. Bus bars are typically either flat strips or hollow tubes as these shapes allow heat to dissipate more efficiently due to their high surface area to cross sectional area ratio. The skin effect makes 50-60 Hz AC bus bars more than about 8 mm (1/3 in) thick inefficient, so hollow or flat shapes are prevalent in higher current Applications. A hollow section has higher stiffness than a solid rod of equivalent current carrying capacity, which allows a greater span between bus bar supports in outdoor switchyards. A bus bar may either be supported on insulators or else insulation may completely surround it. Bus bars are protected from accidental contact either by a metal enclosure or by elevation out of normal reach. 17.1. Over Head Line Transmission Voltage Level Minimum Ground Clearance Less than 11KV 6.1m 11KV-20KV 6.4m 20KV-30KV 6.7m Greater than 30KV 7.0m shubham sachan 21 18. Wave Trap Reliable & fast communication is necessary for safe efficient & economical power supply. To reduce the power failure in extent & time, to maintain the interconnected grid system in optimum working condition to coordinate the operation of various generating unit communication network is indispensable for state electricity board. Wave trap is an instrument using for tripping of the wave. The function of this trap is that it traps the unwanted waves. Its function is of trapping wave. Its shape is like a drum. It is connected to the main incoming feeder so that it can trap the waves which may be dangerous to the instruments here in the S/S. 19. Switchgear In an electric power system, switchgear is the combinations of electrical disconnect switches; fuses or C.Bs used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be done and to clear faults downstream. This type of equipment is directly linked to the reliability of the electricity supply. shubham sachan 22 20. Batteries DC Battery and Charger All but the smallest S/S include auxiliary power supplies. AC power is required for S/S building small power, lighting, heating and ventilation, some communications equipment, switchgear operating mechanisms, anti-condensation heaters and motors. DC power is used to feed essential services such as C.B trip coils and associated relays, supervisory control and data acquisition (SCADA) and communications equipment. This describes how these auxiliary supplies are derived and explains how to specify such equipment. It has Single 100% battery and 100% charger, Low capital cost, No standby DC System outage for maintenance. Need to isolate battery/charger combination from load under boost charge conditions in order to prevent high boost voltages. 21. Fuse A fuse is a short piece of wire or thin strip which melts when excessive current through it for sufficient time. It is inserted in series with the circuit under normal operating condition; the fuse element is at a nature below its melting point. Therefore it carries the normal load current overheating. It is worthwhile to note that a fuse performs both detection and interruption functions. 22. Circuit Breaker A circuit breaker can make or break a circuit either manually or automatically under no load, full load or short circuit conditions. Circuit Breaker is of types 22.1. Oil Circuit Breaker A high-voltage C.B in which the arc is drawn in oil to dissipated the heat and extinguished the arc; the intense heat of the arc decomposes the oil, generating a gas whose high pressure produces a flow of fresh fluid through the arc furnishes the necessary insulation to prevent a restrike of the arc. shubham sachan 23 22.2. Vacuum Circuit Breaker In Vacuum C.B the production of arc is produced between the contacts by the ionisation of metal vapour of contact, however the arc is quickly extinguished because the metallic vapour, electrons and ions produced during arc rapidly condense on the surface of the C.B contacts, resulting in quick recovery of dielectric strength. As soon as the arc is produced in vacuum, it is quickly extinguished due to the fast rate of recovery of dielectric strength in vacuum. 22.3. SF6 Circuit Breaker Air In this hexafluoride gas is used as arc quenching medium. The SF6 is an electro-negative gas and has a strong tendency to absorb free electrons. shubham sachan 24 Internal Structure of SF6 C.B Pressure of this C.B is placed at 6, below this pressure this C.B will not work, Red light indicate that this C.B is working and green show it is not in use. 22.4. Air Blast Circuit Breaker Air is used as an arc quenching medium. This is multi break constructions, simple assembly, modest maintenance are some of the main features of air blast C.B. Compressors are necessary to maintain high air pressure in the air receiver. The air blast C.B is basically used in railways and arc furnaces, where breaker operates repeatedly. shubham sachan shubham sachan shubham sachan shubham sachan 25 23. Motivation As we know electricity is our basic need without electricity nothing can be happened in todays life, also know about how generation is happened and what the basic requirements of electricity. My trainings most interesting part is my 132/33KV S/S visit where I learnt about latest technology this S/S is fully automatic and it use all latest equipment like C.B like SF6 and Vacuum C.Bs and how the protect the equipments installed in the S/S. In the field of generation there is huge scope for carrier point of view as solar energy is an another source through this generation can be happened. I am highly obliged to J.E, SSOs of substation as they guided me very well, as what I learned through my text books to implement in real life is quite different and it is very interesting. Practical knowledge is very important, through this training I can now able to describe my theoretical more precisely and with great innovation. J.E of my S/S also guided me related to my future as he motivates me about my knowledge and also he encourages me to learn new things. Most important, after doing work in this it rise my interest to doing work in this field. At last I am highly thankful to my Teachers, J.E, SSOs the guide me very well and they help to make my training successful. shubham sachan 26 24. Learning Outcomes Now from this report I can learn understand that electricity plays an important role in our daily life. We are made aware of how the transmission of electricity is to be done not only transmission but also distribution, and also learn about various part of the substation. In additional, I gained a good experience in term of self-confidence, real life working situation, interactions among people in the same field. I had an interest in understanding basic engineering work, it is a small S/S but I think nothing is small or big, S/S is act as a mediator between generation and consumer, I also learn how to interact with local people with their problems regard electricity supply and connections. To work with big industry first we should start with the very beginning related to that field, it give us knowledge as well as experience, it help us to know and resolve the problem more effectively and gently. This training experience will help me in future while doing job in the related field. TT Nagar S/S is look like: shubham sachan Tatya Tope Nagar Sub-Sation 27 Visit of 132/33KV substation give me more knowledge about distribution how distribution is happen, this is done by me under guidance of J.E of T.T Nagar substation as he tell me about 132KV substation. As 132/33KV Armapur S/S is come under Uttar Pradesh Power Transmission Corporation Ltd. This S/S is only for giving the supply to the Kanpur Ordinance Factory. In this S/S 132KV is step down to the 33KV and then give it to the OFC. Here two 132KV main lines are taken as I/P from Panki Thermal power plant than with this line LA is attached after two PTs are attached in parallel, after PTs two CTs are attached in series here in this S/S two PTs & CTs are use because first PT is of KESCO department and second PT is of OFC Armapur S/S same as concept is used is CTs also. After this bus bar is used again LA is connected on further connections after this SF6 circuit breaker is used, this is done with both the lines, after this insulators are connected now this 132KV is then give to PT of rating 20MVA and converted to 33KV, in this PT oil circuit breaker are used with buchholz relay is used for this transformer protection. Then again insulators, PTs, CTs and bus bar are used for further supply before this 33KV is given to the OFC Vacuum circuit breaker is also used. This S/S is fully automatic and these all equipment are also controlled through control room. So before doing any kind of maintenance it is close it from the control room then also through isolators and if any maintenance in doing on C.Bs then there is an special feature to close it from there also. On the last day of my training. I get this opportunity to see the 132/33KV Armapur S/S. This S/S is installed in 2006 and give its service from 2007 this is Kanpurs first S/S with latest all technology. All the equipment which is used in this S/S are well grounded and fully protected. Future Scope: Two main drivers for Vattenfall are customer satisfaction and environment protection. High availability in power supply and good power quality are required for future satisfaction of the customers. It will be essential to understand the customer needs and to increase the reliability. Lack of land will demand an effective land usage. Therefore a modular compact structure of the substation is necessary. In urban or in environmentally bad shubham sachan 28 affected areas the future substation will be installed indoor or underground. A solid-state substation may consist of equipment placed in containers. Indoor installations increase the reliability and provide better working facilities. In the future it can be difficult to find the right competences of operating and maintenance staff, hence the simplicity of the station will be very important. The used technique must also be safe and simple to handle and be well documented. Cables will be more common for connection between substations. Also position of the substation is simplified with cable connection. Cable connections are therefore generally foreseen. Real-time estimation and adaption in control and protection systems will be possible. The change in load and load patterns will require a flexible substation. It must be able to take care of distributed generation and reversed transfer of power. The future substation must have low environmental impact. A compact design is recommended. It shall produce as low noise as possible, and also be environmental friendly in terms of chemical aspects. Chemicals, oil and gases, shall be avoided. Economically: The price on distribution and transmission must be as low as possible, resulting in a demand for a cost effective substation. The need and costs for maintenance are predicted to decrease, as well as the total investment costs. This can be achieved by adapting simple solutions, which make it easy to install and maintain the substation. The maintenance shall be as low as possible i.e. the installation shall be maintenance free. In order to reduce costs, alternatives to metal should be considered. Composite may be an alternative. The used material must have a reasonable cost impact. Protection: The future substation with its more sophisticated and common functions needs facilities for better control and analysis. There will be an increased demand on fast detection and disconnection of faults. Faults should be attended to before outage occur. This can be done by redundancy. Connection between substations via fibre optic makes analytical redundancy in protection system possible. S/S should be: Simple, safe and reliable. With low environmental impact, compact and flexible. Intelligent, maintenance-free and self-reparatory. Cost effective. shubham sachan 29 25. Gantt chart My training was started on 25th of June 2014 On first day I introduce about myself, about my collage. And also they ask me about my interest related to the field of transmission and distribution. They ask me some question related to substation, as they try to know about what I am know about substation or related to this field. After they show me the substation and tell me about the substation, purpose of substation. From where this substation get input supply. He also tells me about his professional life, related to his job and from how long he work in KESCO. He also tells me about experience of his job under KESCO. First weak- In first weak he firstly show me Barra-8 substation, with the Assistant Engineer N.N Pandey (AE) and tell me about substation because through Barra-8 substation Tatya Tope nagar get the supply of 33KV. And from this substation another line of 33 KV is given to the Meharbaan Singh Ka Purvas substation. Second Weak- Now he show me Tatya Tope nagar substation, and told me about connections how these connections are done. Because it is distribution substation so it is small so there is only single Power transformer through this transformer 33KV is step down to 11KV, and then it is supplied to different areas, this substation is connected with 16 villages, Tatya Tope nagar, Ambedkar nagar, and Meharbaan Singh Ka Purva also. Third weak- On third weak learn about Power transformer and buckles relay and he tell me about transformer cooling, windings, and how buchholz relay operate, he asked me about circuit breakers what are the types, he also shown me how the transformer is installed in particular area as I see installation of transformer at Ambedkar nagar, area sector-D. but for grounding they use coal and salt as grounding material, an iron rod is connected to transformer body and it is placed inside the earth area is dig about 10-12 feet and is filled by shubham sachan 30 coal and salt and road is placed in between them. He tell that this is used as coal and salt are the good absorber of negative charges. Fourth weak- In fifth weak he tells me about how transformers are controlled through control room. As there is an incomer chamber where 11KV supply is given as input in this incoming chamber there is an trolley which is to be pull up through a rod it is an channel type while it is fully up the supply from incomer is passed to next chamber through this chamber different- different areas of transformer are connected, this is also used as for the purpose when roasting Are to done or repairing the fault, when any fault is happened then the tripping switch is kept open so the power is not given to that area and fault can be easily repaired. In substation there is an battery room, this DC supply is used to give supply to the substation and equipments of substation like lights, computer, communication devices and also for cooling of transformer etc. Fifth weak- On last week he took me to the 132/33KV Armapur substation this substation is come under ordinance factory and it give supply only this factory, here he shown me and tell me how this large substation is operated. Armapur substation is get an 132KV input power from Panki power house, where electricity is made through coal, here coal is burned and the heat of this coal is firstly highly compressed and then it is through with high pressure on the turbine and then 132KV electricity is generated. He tell me the working of 132/33KV Armapur substation, as 132/33KV Armapur S/S is come under Uttar Pradesh Power Transmission Corporation Ltd. This S/S is only for giving the supply to the Kanpur Ordinance Factory. In this S/S 132KV is step down to the 33KV and then give it to the OFC. Here two 132KV main lines are taken as I/P from Panki Thermal power plant than with this line LA is attached after two PTs are attached in parallel, after PTs two CTs are attached in series here in this S/S two PTs & CTs are use because first PT is of KESCO department and second PT is of OFC Armapur S/S same as concept is used is CTs also. After this bus bar is used again LA is connected on further connections after this SF6 circuit breaker is used, this shubham sachan 31 is done with both the lines, after this insulators are connected now this 132KV is then give to PT of rating 20MVA and converted to 33KV, in this PT oil circuit breaker are used with buchholz relay is used for this transformer protection. Then again insulators, PTs, CTs and bus bar are used for further supply before this 33KV is given to the OFC Vacuum circuit breaker is also used. This S/S is fully automatic and these all equipment are also controlled through control room. So before doing any kind of maintenance it is close it from the control room then also through isolators and if any maintenance in doing on C.Bs then there is an special feature to close it from there also, for more protection. Sixth weak- As my 1 month training is completed on 24th of June, at the last he tell me how local connection are provided to consumers. 1. You have to write an application for electricity connection. And also tell how much load you want to take these are as 1 KW, 2KW, 5KW etc. 2. Then you have to give quotation fees or processing fees, meter charge, house registry papers and your voter id card. 3. Then when all these processing is completely done within 1 weak meter and connection will be given to you. In this same weak all the work of training certificate is done by me. Signed by all the respected engineers, and finally I got my training certificate on 28th of June. shubham sachan 32 26. Reference 1. VK Mehta book 2. http://www.kesco.co.in/ 3. http://www.kesco.co.in/docs/grid_code.htm#1 4. http://en.wikipedia.org/wiki/Kesco 5. www.yahooanswers.com 6. www.britannica.com 7. www.webopedia.com 8. www.encyclopedia.com 9. www.worldbook.com 10.http://www.slideshare.net 11.http://www.csanyigroup.com/ 12.http://www.electrical4u.com/ 13.www.wekipedia.com 14.www.33/11KVsubstation.com 15.http://www.science.smith.edu/ 16.http://www.electrical4u.com/protection-system-in-power- system/ 17.http://goodnews11.hubpages.com/hub/Parts-of-a-power- transformer 18.http://en.wikipedia.org/wiki/Aerial_bundled_cable shubham sachan 33 27. Abbreviation 1. KESCO Kanpur Electricity Supply Authority 2. S/S Sub-Station 3. T&D Transmission & Distribution 4. O.F.C Ordinance Factory 5. C.B Circuit Breaker 6. O.C.B Oil Circuit Breaker 7. SF6 Sulphur Hexa Fluoride Gas 8. KV Kilo Volt 9. LA Lightning Arrester 10. CT Current Transformer 11. PT Power Transformer 12. R Red Wire 13. Y Yellow Wire 14. B Black Wire 15. N Neutral Wire 16. T.T Tatya Tope 17. J.E Junior Engineer 18. O/P Out Put shubham sachan This training report is based on Sub-station. fro any mistake please remind me. Thank you.
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