Evaluation of Voltage Sag and Unbalance due to the System Connection of Electric Vehicles on Distribution System

Lee, Soon-Jeong;Kim, Jun-Hyeok;Kim, Doo-Ung;Go, Hyo-Sang;Kim, Chul-Hwan;Kim, Eung-Sang;Kim, Seul-Ki

  • Received : 2013.06.16
  • Accepted : 2013.11.13
  • Published : 2014.03.01


Due to increased concerns for rising oil prices and environmental problems, various solutions have been proposed for solving energy problems through tightening environmental regulations such as those regarding $CO_2$ reduction. Among them, Electrical Vehicles (EVs) are evaluated to be the most realistic and effective approach. Accordingly, research and development on EVs and charging infrastructures are mainly proceeding in developed countries. Since EVs operate using electric energy form a battery, they must be connected to the power system to charge the battery. If many EVs are connected during a short time, power quality problems can occur such as voltage sag, voltage unbalance and harmonics which are generated from power electronics devices. Therefore, when EVs are charged, it is necessary to analyze the effect of power quality on the distribution system, because EVs will gradually replace gasoline vehicles, and the number of EVs will be increased. In this paper, a battery for EVs and a PWM converter are modeled using an ElectroMagnetic Transient Program (EMTP). The voltage sag and unbalance are evaluated when EVs are connected to the distribution system of the Korea Electric Power Corporation (KEPCO). The simulation results are compared with IEEE standards.


Electric vehicle;Voltage sag;Voltage unbalance;System connection;Penetration level


  1. Korea Smart Grid Institute, "A Research of Charging Infrastructure for Electric Vehicle," 2010
  2. P. T. Staats, W. M. Grady, A. Arapostathis, R. S. Thallam, "A Statistical Analysis of the Effect of Electric Vehicle Battery Charging on Distribution System Harmonic Voltages," IEEE Transactions on Power Delivery, Vol. 13, No. 2, April 1998
  3. L. Kelly, A. Rowe, P. Wild, "Analyzing the Impacts of Plug-in Electric Vehicles on Distribution Networks in British Columbia," Electrical Power & Energy Conference, Otc, 2009
  4. J. Taylor, A. Maitra, M. Alexander, D. Brooks, M. Duvall, "Evaluation of the Impact of Plug-in Electric Vehicle Loading on Distribution System Operations," Power & Energy Society General Meeting, July, 2009
  5. J. Carlos Gomez, Medhat M. Mocrcos, "Impact of EV Battery Chargers on the Power Quality of Distribution Systems," IEEE Transactions on Power Delivery, Vol. 18, No. 3 July, 2003
  6. Shengnan Shao, Manisa Pipattanasomporn, Saifur Rahman, "Grid Integration of Electric Vehicles and Demand Response With Customer Choice," IEEE Transactions on Smart Grid, Vol. 3, No. 1, March, 2012
  7. Arindam Maitra, Jason Taylor, Daniel Brooks, Mark Alexander, Mark Duvall, "Intergrating Plug-in-Electric Vehicles with the Distribution System," International Conference on Electricity Distribution, June, 2009
  8. Martin Geske, Martin Stotzer, "Modeling and Simulation of Electric Car Penetration in the Distribution Power System-Case Study," Modern Electric Power Systems, 2010
  9. Kejun Qian, Chengke Zhou, Malcolm Allan, Yue Yuan, "Modeling of Load Demand Due to EV Battery Charging in Distribution Systems," IEEE Transactions on Power Systems, Vol. 26, No. 2, May, 2011
  10. Jason Taylor, Arindam Maitra, Mark Alexander, Daniel Brooks, Mark Duvall, "Evaluations of Plug-in Electric Vehicle Distribution System Impacts," Power and Energy Society General Meeting, July, 2010
  11. Kristien Clement, Edwin Haesen, Johan Driesen, "Stochastic Analysis of the Impact of Plug-In Hybrid Electric Vehicles on the Distribution Grid," International Conference on Electricity Distribution, June, 2009
  12. Kristien Clement-Nyns, Edwin Haesen, Johan Driesen, "The Impact of Charging Plug-In Hybrid Electric Vehicles on a Residential Distribution Grid," IEEE Transactions on Power Systems, Vol. 25, No. 1, Feb, 2010
  13. Koichiro Shimizu, Taisuke Masuta, Yuyaka Ota, Akihiko Yokoyama, "Load Frequency Control in Power System Using Vehicle-to-Grid System Considering the Customer Convenience of Electric Vehicles," International Conference on Power System Technology, 2010
  14. P. Papadopoulos, L. M. Cipcigan, N. Jenkins, I. Grau, "Distribution Networks with Electric, Electric Vehicles Chargers Characterization: Load Demand and Harmonic Distortion," Electrical Power Quality and Utilisation, 2011
  15. Joao P. Trovao, Paulo G. Pereirinha, Leonor Trovao, Humberto M. Jorge, "Electric Vehicles Chargers Characterization: Load Demand and Harmonic Distortion," Electrical Power Quality and Utilisation, 2011
  16. Keon-Woo Park, Hun-Chul Seo, Chul-Hwan Kim, Chang-soo Jung, Yeon-Pyo Yoo, Yong-Hoon Lim, "Analysis of the Neutral Current for Two-Step-Type Poles in Distribution Lines," IEEE Transactions on Power Delivery, Vol. 24, pp1483-1489, 2009
  17. Statics Korea, ""
  18. Korea Transport Database, ""
  19. Doo-Ung Kim, Jun-Hyeok Kim, Hyo-Sang Go, Hun- Chul Seo, Chul-Hwan Kim, Eung-sang Kim, "Modeling of Single Phase PWM AC/DC Converter for EV using EMTP/MODELS," KIEE Summer Conference & General Meeting, July, 2012
  20. Jun-Hyeok Kim, Hyo-Sang Go, Doo-Ung Kim, Hun- Chul Seo, Chul-Hwan Kim, Eung-Sang Kim, "Modeling of Battery for Electric Vehicle Using EMTP/ MODELS," IEEE Vehicle Power and Propulsion Conference, Oct, 2012.
  21. IEEE Power & Energy Society, "IEEE Recommended Practice for Monitoring Electric Power Quality," 2009
  22. Jan Meyer, Stephan Hahle, Peter Schegner, Carsten Wald, "Impact of electrical car charging on unbalance in public low voltage grids," Electrical Power Quality and Utilization conference, 2011

Cited by

  1. Mitigation of voltage unbalance by using static load transfer switch in bipolar low voltage DC distribution system vol.90, 2017,
  2. Analysis for Evaluating the Impact of PEVs on New-Town Distribution System in Korea vol.10, pp.3, 2015,
  3. A review of the stage-of-the-art charging technologies, placement methodologies, and impacts of electric vehicles vol.64, 2016,
  4. A Comprehensive Study of Key Electric Vehicle (EV) Components, Technologies, Challenges, Impacts, and Future Direction of Development vol.10, pp.8, 2017,