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Accepted Manuscript

Power Quality Impacts of High-Penetration Electric Vehicle Stations and Re

newable Energy-based Generators on Power Distribution Systems

Masoud Farhoodnea, Azah Mohamed, Hussain Shareef, Hadi Zayandehroodi

PII: S0263-2241(13)00143-7

DOI: http://dx.doi.org/10.1016/j.measurement.2013.04.032

Reference: MEASUR 2246

To appear in: Measurement

Received Date: 12 January 2013

Revised Date: 23 March 2013Accepted Date: 17 April 2013

Please cite this article as: M. Farhoodnea, A. Mohamed, H. Shareef, H. Zayandehroodi, Power Quality Impacts of

High-Penetration Electric Vehicle Stations and Renewable Energy-based Generators on Power Distribution

Systems, Measurement (2013), doi: http://dx.doi.org/10.1016/j.measurement.2013.04.032

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Power Quality Impacts of High-Penetration Electric Vehicle Stations and Renewable1Energy-based Generators on Power Distribution Systems2

3Masoud Farhoodnea (Corresponding author)

4Department of Electrical, Electronic, and Systems Engineering, University Kebangsaan5Malaysia, Bangi, Selangor, Malaysia6Phone No.: 006011128004037E-mail address: [email protected]

9Azah Mohamed10Department of Electrical, Electronic and Systems Engineering, University Kebangsaan Malaysia,11Bangi, Selangor, Malaysia12E-mail: [email protected]

14Hussain Shareef

15Department of Electrical, Electronic and Systems Engineering, University Kebangsaan Malaysia,16Bangi, Selangor, Malaysia17E-mail: [email protected]

19Hadi Zayandehroodi20Department of Electrical, Electronic and Systems Engineering, University Kebangsaan Malaysia,21Bangi, Selangor, Malaysia22E-mail: [email protected]

24

Abstract25

High-penetration renewable energy-based generators (REGs) in distribution systems have26increased the importance of impact assessment involving these systems. This assessment focuses27on power quality (PQ) and compatibility between REGs and existing system components.28Electric vehicle (EV) technology has also recently achieved a substantial market share. This29technology requires the development of charging stations similar to current petroleum fuelling30stations in the near future. Thus, the effect of EV stations on PQ must also be considered. This31study presents a PQ analysis on the effects of high-penetration EV and REG systems, including32wind turbines, grid-connected photovoltaics (PVs), and fuel cell (FC) power generation units on33a modified 16-bus distribution system under different loading and weather conditions. All data34


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on EV, wind farm, PV, and FC units as well as weather conditions presented in this paper were1collected from different power companies and the Malaysian Meteorological Department. The2system is modelled and simulated using the MATLAB/Simulink software to study the effects of3these technologies on system performances at various penetration levels. Simulation results4indicated that the presence of high-penetration EVs and REGs can cause severe PQ problems5such as frequency and voltage fluctuations, voltage drop, harmonic distortion and power factor6reduction.7

8

Keywords: electric vehicle stations; fuel cell; photovoltaic; power quality; renewable energy;9

renewable energy generator; wind farm1011

1. INTRODUCTION12Power systems have been conventionally designed for unidirectional power flows from the main13source, distributed downstream at lower voltage levels. The increasing number of customers14willing to install distributed generation (DG) to provide part of their power consumption15indicates that DG has gained more interest in the electricity market. Considering the16environmental issues related to conventional power plants, especially CO2 emission, utilities and17customers have widely accepted the use of pollution-free renewable energy-based generators18(REGs), including photovoltaic (PV) system, wind turbine (WT) and fuel cells (FC), among19others, as alternative sources of electricity [1]. Utility-scale hybrid REGs consisting of two or20more energy conversion mechanisms are widely developed to overcome the limitations and21improve the security and reliability levels of REGs as well as their interconnected networks. The22power plant in Zhangbei, China is an example of a utility-scale hybrid REG with a 100 MW23


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wind turbine, a 40 MW PV, and 20 MW to 36 MW battery storage. The Les Borges Blanques1Power Plant, Spain is another example of a utility-scale hybrid REG based power plant. The2system is composed of 36 MW biomass and 22.5 MW solar CSP power generation, and is able to3produce 101.6 GWh of electricity per year [2].4

Economic and operational advantages provided by REGs for distribution systems include5the following: power balance during peak demand, decreased occurrence of power interruptions6and system outages, reduction in investment and operational costs due to flexible capacity and7location or installation, as well as decreased dependence on imported fossil fuel [3]. Despite8

these advantages, the increasing use of scattered and time-varying hybrid REGs can result in a9

bidirectional power flow, which may either improve or worsen power quality (PQ)-related10problems, protection, and stability [4]. These effects (especially at high-penetration levels of11REGs) heavily rely on the characteristics of each installation and specifications of the12distribution system. Therefore, an entire system must be continually monitored for satisfactory13levels of REGPQ system compatibility [5].14

Electric vehicle (EV) technology and electric vehicle stations (EVS) are rapidly15developing to reduce oil dependence and minimize greenhouse gas emissions [6]. The influence16of EV and future EVS on system performance highly depends on the charging scenario and the17resulting ability of utilities to deliver the required power to EVS regardless of loading conditions.18This dependence is due to the time variability of electricity use by EVs. Thus, an investigation19must be conducted [7]. Accurate assessment of the possible impacts of large grid-connected20REGs and EVSs on network performance before installation is crucial. Performing such analysis21is important and allows utilities to become efficiently equipped to solve potential operational22issues that REGs and EVSs can cause other system components. Numerous studies have focused23


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on steady-state modelling as well as the analysis of a single REG and its impacts on the system1[8, 9]. However, studies on the effects of high-penetration hybrid systems on dynamic operation2and control of the system before real-time implementation have been scarcely reported.3

The present study aims to analyse accurately the dynamic effects of high-penetration4hybrid REGs and EVSs on the PQ performance of distribution systems. To address the practical5aspects, the required data on weather conditions, EVS loading conditions, and REG modelling6were obtained from the Malaysian Meteorological Department (MMD) [10] in the absence of7field measurements. Other data were also obtained from various power system manufacturers8

such as SunPower, Sanyo, General Electric, and FuelCell Energy. Simulation using9

MATLAB/Simulink software was conducted on a modified radial 16-bus test system with10distributed EVS, WT, PV, and FC units to study the effects of hybrid REGs and EVSs on system11performance under various weather and loading conditions.12

132. REG AND EVS SYSTEM MODELING142.1 Wind Turbine System Model15In the last several years, WT generators have rapidly developed worldwide as a competitive and16effective type of DG at various kW to MW ratings. The following models are often used to17operate WTs: fixed-speed wind turbines, variable-slip wind turbines, doubly fed induction18generator (DFIG) wind turbines, and full-converter wind turbines. Among the four models,19DFIG wind turbines have gained more interest for new installations. This type of WTs supports20power system stability and reliability during peak load or disturbance conditions. This model21also performs more efficiently to control active and reactive power independently by using low-22power electronic devices [11]. In the DFIG controller, the rotor-side converter must inject23


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variable rotor currents into the rotor circuit to attain decoupled active and reactive power control.1The measured active power (Pmeas) is compared with the reference active power (Pref), which is2determined by wind speed. The estimated error then passes through a proportionalintegral (PI)3controller to determine the reference value of the q-axis rotor current Iq-ref. The reference d-axis4rotor currentId-ref can be calculated using the same procedure. The obtained values forIq-ref and5Id-ref are then converted into the abc frame to achieve the required value of the rotor reference6currentsIabc-ref. The gating signals of the rotor-side converter can be generated by comparing the7reference and measured currents of the rotor and using a hysteresis controller. Figure 1 shows the8

schematic of the rotor-side converter [12].910

Figure 1. Block diagram of a rotor-side converter control1112

The main task of the grid-side converter is to balance the power injected into the DC-link13capacitor and maintain its constant voltage. The DC-link voltage is measured and compared with14the reference value to control the grid-side converter. The obtained error is then passed through a15PI controller to estimate the d-axis stator reference current Id-ref. The reference terminal voltage16can be computed by comparing the measured value ofId-meas with that ofId-ref and using a PI17controller. The obtained reference terminal voltage is then compared with the measured d-axis18terminal voltage to generate the reference d-axis terminal voltage Vd-ref. The same procedure can19be applied to obtain the reference q-axis terminal voltage Vq-ref by using the measured reactive20power, as shown in Figure 2. Vd-ref and Vq-ref are transformed into the abc frame, which is then21compared with the terminal voltage. Consequently, the gating signals of the grid-side converter22are generated using a hysteresis controller [12].23


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1Figure 2. Block diagram of a grid-side converter control2

32.2 PV System Model4The main components of a grid-connected PV system include a series/parallel combination of5PV arrays and a power-conditioning unit. The first component directly converts sunlight to DC6power, whereas the second converts DC power to AC power and maintains the maximum7efficiency of the PV operation [13]. Certain conditions such as phase sequence, frequency, and8

voltage level matching must be satisfied to provide a proper interface between the grid-9

connected PV systems and the utility grid. Providing these conditions strongly depends on the10applied controller and the power electronics technology of PV inverters. The applied control11strategy of the PV system in this study is based on a PI controller and pulse-width modulation12(PWM), as shown in Figure 3 [14]. In the figure, the PV panel block generates the reference13voltage as a function of injected current, solar irradiance, and panel temperature. The obtained14reference voltage is then compared with the measured terminal voltage. The generated error is15passed through a PI controller to obtain the appropriate PWM duty cycle and generate the16switching signal of the DC/DC converter (Booster) using IGBT switches. The IGBT based boost17converter is used as switching mode regulators to convert an unregulated dc voltage to a18regulated dc output voltage. In addition, an MPPT technique is used in the boost converter to19efficiently control the produced power of PV arrays. A three-phase, three-level voltage source20converter can also be used to convert the produced DC power into AC power. The power is then21injected into the system by using a coupling transformer at the desired voltage level [15].22

23


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Growing concern about global warming and energy security aspects associated with road1transport systems has directed more public interest to EVs. The main difference between EVs2and conventional vehicles is that the required torque in EVs is supplied through an electric3motor, powered either solely by a battery or in combination with an internal combustion engine4referred to as hybrid electric vehicle. The impact of EVs on system performance depends on the5charging scenario [18]. To investigate the effects of high-penetration EVs in this study, charging6is assumed at remote spots called charging stations (similar to petrol filling stations) under a fast-7charging mode [19]. The important factors in modelling EVs include charging time and charging8

power level. In this study, each EV is assumed to consume 10 kW of electricity on average, and9

each can reach full-charge levels within 10 min to 15 min through a 330 V DC fast-charging10board in the EVS [20]. Figure 5 shows the demand curve for a 2.3 MW EVS at peak and off-11peak times. The described EVS can be modelled as a dynamic DC load connected to the grid12through a AC/DC power converter, which includes a phase-shifting power transformer, a set of13rectifier and one set of DC-DC full-bridge converter to provide the predetermined DC voltage14level, as shown in Figure 6 [18]. The main importance of the phase-shifting power transformer is15to mitigate current harmonic and increase the system power factor, and the rectifier and DC-DC16converter are fed through the secondary winding of transformer.17

18Figure 5. Typical EVS load profile19

20Figure 6. Block diagram of the EVS21

2223


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3. POSSIBLE POWER QUALITY PROBLEMS1REGs have recently been considered efficient sources of power that can provide sustainable and2clean energy. Despite the efficiency of these generators, the connection of large hybrid REG3systems to utility grids can cause several operational problems for distribution networks. The4severity of these problems directly depends on the applied REG technology, penetration level,5and geography of the installation. The negative effects of EVS as a vital part of future6transportation systems must also be considered. Hence, studying the possible impacts of large7hybrid REGs and EVSs on the performance of a distribution network and its components can8

provide feasible solutions to meet engineering requirements for voltage, frequency, waveform9

purity, and others prior to implementation. This section aims to introduce possible technical10problems that high-penetration hybrid REGs and EVSs present to distribution systems.113.1 Inrush Current12The small inevitable difference between REG systems and grid voltages can produce a13unidirectional transient inrush current that flows between the REGs and the utility system at the14time of connection and decays to zero at an exponential rate. Inrush current can cause a15temporary voltage sag at the neighbouring buses, thermal stress of the power components, or16nuisance trips of the protection systems. The severity and duration of the produced inrush current17depends on the system impedance, magnitude and sign of the flux linkage of the coupling18transformer, and nonlinear magnetic saturation characteristic of the coupling transformer [21].193.2 Protection20Protection problems in REGs can occur at the time of fault and unintended islanding in specific21parts of utility grids. Under this condition, REGs may feed the loads or a part of the system even22


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after the network has been disconnected from the utility grid. The installed REGs can also1increase fault levels and problems related to protection coordination and isolation [22].23.3 Undervoltage/Overvoltage3Some REGs such as PV systems are usually intended to operate near unity power factor to4optimize solar energy use. Therefore, these systems only inject active power into the utility side5of the grid, which may change the rate of reactive power flow in the system, and the nearby6buses may experience under/overvoltage problems because of the lack of reactive power [23].73.4 Output Power Fluctuation8

Output power fluctuations of REGs can present severe operational problems. Power fluctuations9

mostly occur in the interconnected WT and PV systems because of minute-to-minute variations10in wind speed or solar irradiance. The severity of such phenomenon depends on weather11conditions, installation geography, and topology of the system. Power fluctuations can increase12overloading or underloading, unacceptable voltage fluctuations, and voltage flickers [24].133.5 Harmonic Distortion14Harmonic distortion, which is known as a critical PQ issue, can occur because of the use of15power inverters in REG systems without the application of a proper filtering system. Harmonic16distortion can increase the risk of parallel and series resonances, overheating in capacitor banks17and transformers, neutral overcurrent, and false operation of protective devices [25].183.6 Frequency Fluctuation19Frequency fluctuation is one of the more important factors influencing PQ. Any imbalance20between power production and the power consumption can result in frequency fluctuation. Small21REG systems cause negligible frequency fluctuations compared with large REG-based resources.22


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However, at increased penetration levels, REG systems can increase the severity of this problem.1Frequency fluctuations can change electromotor winding speed and damage generators [26].2

34. SIMULATION RESULTS4A modified IEEE 16-bus test system shown in Figure 7 [27] is modelled using the5MATLAB/Simulink software to investigate the various effects of hybrid REGs and EVSs on6distribution systems. The system is fed through 380 and 230 kV utility grids. It also consists of 97loads with a total power of 10 MVA, a power factor between 0.65 and 0.8, 3 inter-tie circuit8

breakers, and 2 capacitor banks to improve the power factor on buses 5 and 6. An 8 MW wind9

farm, a 1.4 MW FC, and a 2.4 MW grid-connected PV system are placed on buses 4, 7, and 11,10respectively, to supply the required power for local loads and exchange the rest with the system.11A 2.3 MW EVS with 23 chargers, which the power of every single charger is 100 kW, was also12placed on bus 9.13

14Figure 7. Single-line diagram of the IEEE 16-bus test system15

16The commercial specifications of the PV arrays, WT, and FC were collected from17

SunPower SPR-305 [28], Sanyo HIP-225 [29], General Electric 2.5-100 WT [30], and FuelCell18Energy DFC3000 [31]. The required data related to solar irradiance and wind speed under19different weather conditions within a year were collected from the MMD [10]. The data were20combined to create different patterns for slow and fast weather variations, as shown in Figure 8.21The per-minute load demand of EVSs shown in Figure 5 was also used during the simulation22[32].23


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1Figure 8. Solar irradiance and wind speed pattern2

3The REGs and EVSs in the system are designed to operate at three penetration levels. At4

the first penetration level, all REGs operate at 33.3% of their nominal power (EVS also operates5at 33.3% of its charging capacity). The penetration level escalates to the second and third levels6when the REGs operate at 66.6% and 99.9% of their nominal powers, respectively. Figures 9 to712 reveal the EVSs power consumption and REG-injected power at three penetration levels.8

From Figures 11 and 12, the active power fluctuations are visible at the PV and WT terminals9

because of solar irradiance and wind speed variation, as shown in Figure 8.1011

Figure 9. EVS power consumption12Figure 10. FC-injected power13Figure 11. PV-injected power14Figure 12. WT-injected power15

16The measured frequency on buses 1 and 2 are shown in Figure 13 to show the effects of17

REGs and EVS on the system frequency at different penetration levels. These variations escalate18and exceed the limits (1%) [33] at higher penetration levels because of the active power19fluctuations at the PV and WT terminals under different weather conditions. Fluctuations also20occur more frequently on bus 2, which is closer to PV and WT buses.21

22Figure 13. Measured frequencies (A) Bus 1 and (B) Bus 223


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1In addition to frequency issues, the sudden active power absorption caused by EVSs and2

the unmanaged power produced by FCs can interrupt the active and reactive power equilibrium3of the system. Such absorption also causes a voltage drop, as shown in Figure 14 for buses 6 and48. The figure indicates that bus 8 experiences a deeper voltage drop because of its proximity to5EVS compared with bus 6. Voltage fluctuations caused by different weather conditions are6observed on both buses. Table 1 presents the maximum and minimum values of the voltage7profile of all system buses at three penetration levels. As indicated in Table 1, the buses placed8

within the vicinity of EVSs experience exceeded-standard voltage drop (values in bold) [33].9

Voltage sag is likely to occur on some buses such as buses 8, 12, and 13 at penetration levels 210and 3.11

12Figure 14. Voltage profile (A) Bus 8 and (B) Bus 613

14Table 1 Maximum and minimum voltage variations of the system15

16Power exchanges between REGs and EVSs with the utility system influence the amount17

of utility-injected active and reactive powers. These power exchanges can negatively influence18the predesigned power factor of the system, as shown in Figures 15 and 16. The figures indicate19that variations in WT power generation and EVS power consumption cause power factor20variations on buses 5 and 6 and that the installed capacitor banks on these buses cannot maintain21the power factor at the desired level.22

23


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12

Figure 15. Injected active and reactive powers. (A) Active power on bus 1; (B) Reactive power3on bus 1; (C) Active power on bus 2; and (D) Reactive power on bus 24

5Figure 16. Measured power factor (A) Bus 5 and (B) Bus 66

7The voltage and current total harmonic distortion (THD) of the system buses were8

measured to assess the harmonics generated by the REG and EVS inverters. The measurements9

are presented in Table 2. As indicated, the current THD values exceed the IEEE Std. 519 limits10(12%) at second and third penetration levels; the values also affect most of the system.11Meanwhile, the voltage THD values exceed the limits (5%) at third penetration level [34]12because of the absence of a proper harmonic filter in the inverters or connection points.13

14Table 2 Voltage and current THD15

16The impedance vs. frequency curve is plotted to show the effects of produced current17

harmonics on system resonance, as shown in Figure 17. The figure indicates that the parallel18resonance in the test system has a very high probability of occurrence within the vicinity of the193

rd, 5

th, and 11

thharmonic orders. The figure also reveals that the severity of parallel resonance20

incident in the systems is increased at higher penetration levels because of the enlargement of the21required WT capacitor bank.22

23


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Figure 17. Impedance vs. frequency curve12

Simulation results indicate that frequency and voltage fluctuations are the most critical3effects of PV and WT systems. These fluctuations occur because of solar irradiance and wind4speed variations as well as excessive real power produced by the PV unit, which can severely5harm system components. EVSs and FCs can also result in a severe voltage drop for the6neighbouring buses because of high power consumption and unmanaged power production,7respectively. The power production and consumption of the installed REGs and EVSs reduce the8

system power factor, as well as increase the voltage and current THD on most system buses;9

these problems are aggravated at a higher penetration level. Therefore, adjustable capacitor10banks or active power conditioning devices in close electrical proximity with REG and EVS11units must be used to manage the exchanged powers and the control voltage magnitude of the12system. Proper harmonic filters in the inverter terminals of REG and EVS systems also reduce13the voltage, current THD, and resonance probabilities especially in distribution systems with low14X/R ratio.15

165 CONCLUSION17This study investigates the possible effects of high-penetration REG and EVS systems on PQ in18distribution systems under varying weather and loading conditions. All information related to19modelling of EVS, WF, PV, and FC systems as well as weather conditions were obtained from20different power companies and the Malaysian Meteorological Department (MMD), respectively.21A radial 16-bus test system with distributed EVS, WF, PV, and FC units was simulated using22MATLAB/Simulink software under various weather conditions. The results indicated that the23


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installed hybrid REG and EVS systems cause frequency and voltage variations, voltage drop,1power factor reduction and harmonic distortion, thus creating severe PQ problems in the system2components.3

45

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[27] A.F. Abdul Kadir, A. Mohamed, H. Shareef, Harmonic Impact of Different Distributed Generation1Units on Low Voltage Distribution System, IEEE International Electric Machines and Drives, 2011, pp.2120-125.3[28] SunPower. Online: http://us.sunpowercorp.com.4[29] SANYO North America Corporation. Online: http://us.sanyo.com.5[30] General Electric, Onilne: http://www.ge-energy.com.6[31] FuelCell Energy Inc., Online: http://www.fuelcellenergy.com.7[32] ABB Internal Report, PHEV Impact Task Force.8[33] NERC, NERC Standard FAC-001-0 Facility Connection Requirements, February 8, 2005.9[34] S.M. Halpin, Revisions to IEEE Standard 519-1992, IEEE PES Transmission and Distribution10Conference and Exhibition, , 2006, pp. 1149-1151.11

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1

2Figure 1. Block diagram of a rotor-side converter control3

4

5Figure 2. Block diagram of a grid-side converter control6

7


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1Figure 3. Block diagram of the PV system2

3

4Figure 4. Fuel cell system (A) FC configuration and (B) constant utilization control5

67


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1Figure 5. Typical EVS load profile2

345

6Figure 6. Block diagram of the EVS7

89


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1Figure 7. Single-line diagram of the IEEE 16-bus test system2

3

4Figure 8. Solar irradiance and wind speed pattern5


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1Figure 9. EVS power consumption2

34

5Figure 10. FC-injected power6

7


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1Figure 11. PV-injected power2

34

5Figure 12. WT-injected power6

78


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1Figure 13. Measured frequencies (A) Bus 1 and (B) Bus 22

3

4Figure 14. Voltage profile (A) Bus 8 and (B) Bus 65

67


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1Figure 15. Injected active and reactive powers. (A) Active power on bus 1; (B) Reactive power2

on bus 1; (C) Active power on bus 2; and (D) Reactive power on bus 234

5Figure 16. Measured power factor (A) Bus 5 and (B) Bus 66

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1Figure 17. Impedance vs. frequency curve2

34567


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Table 1 Maximum and minimum voltage variations of the system

Penetration

level

No

REGs

and

EVS

Level 1 Level 2 Level 3

Bus V [pu]Min[pu]

Max[pu]

Min[pu]

Max[pu]

Min[pu]

Max[pu]

1 1.0 0.98 1.0 0.97 1.0 0.96 0.99

2 1.0 0.98 1.0 0.97 1.0 0.96 0.99

3 1.0 0.97 1.0 0.96 1.0 0.95 0.98

4 0.97 0.96 0.97 0.96 0.98 0.95 0.98

5 0.99 0.97 0.99 0.95 0.99 0.93 0.98

6 0.97 0.96 0.98 0.96 0.98 0.95 0.98

7 0.99 0.96 0.99 0.94 0.98 0.92 0.99

8 0.98 0.95 0.97 0.92 0.97 0.87 0.98

9 0.96 0.96 0.96 0.96 0.97 0.95 0.9810 0.97 0.96 0.98 0.96 0.98 0.95 0.98

11 0.97 0.96 0.98 0.96 0.98 0.95 0.98

12 0.98 0.95 0.97 0.92 0.97 0.87 0.98

13 0.98 0.95 0.97 0.92 0.97 0.87 0.98

14 0.96 0.96 0.96 0.95 0.97 0.95 0.98

15 0.95 0.95 0.95 0.95 0.96 0.94 0.96

16 0.95 0.95 0.95 0.95 0.95 0.94 0.96

le(s)


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Table 2 Voltage and current THD

Penetration

levelLevel 1 Level 2 Level 3

BusTHDV

[%]

THDI

[%]

THDV

[%]

THDI

[%]

THDV

[%]

THDI

[%]1 1.11 3.17 1.56 4.76 2.39 6.20

2 0.98 3.40 1.37 5.23 1.97 8.70

3 0.87 8.97 1.43 9.94 2.19 10.59

4 1.21 3.33 2.84 5.17 3.91 8.44

5 1.19 11.28 3.55 17.36 5.04 24.32

6 1.60 11.17 3.87 15.22 5.20 18.12

7 1.32 8.97 3.89 12.46 5.12 16.32

8 2.30 10.98 4.01 13.55 5.17 17.46

9 2.12 12.34 4.32 16.12 6.56 19.09

10 0.98 11.12 1.23 15.16 3.70 17.99

11 1.12 10.33 1.60 14.34 2.79 18.0312 3.13 11.23 4.77 14.89 6.83 17.88

13 2.62 11.15 4.15 13.77 5.48 17.42

14 0.76 11.10 1.08 14.87 2.68 17.72

15 1.03 10.30 1.13 14.31 1.90 17.93

16 0.80 10.31 1.21 14.27 2.33 17.95


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Power quality impacts of renewable energy-based generators on power distribution systems are

investigated.

The effects of electric vehicle stations are also considered.

The measurements are done in low and high-penetration levels.

power quality impacts of high-penetration electric vehicle stations and re‐newable energy-based...

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