Electric vehicle charging strategy in metropolises in China

Electric vehicle (EV) charging will impose massive charging power on current power system, which may lead to power shortage and weakened stability of power grid, therefore orderly charging is required for large amount of EVs charging. This paper presented orderly charging scenarios in three metropolises in China, Beijing, Wuhan and Chongqing, which aimed not to form higher load peak with 500 thousands EV charging. Considering the randomness of time and site of EV charging, probability distribution functions of SOC and start time were built firstly, and statistical method based on Monte Carlo simulation was applied to forecast EV free charging power. In order to eliminate the higher load peak in free charging, orderly charging scenarios were designed then. New load curves with charging power and longest waiting time for charging in these cities were obtained. Comparison among results of these three cities showed that strategies for EV charging management should vary with the status of regional basic loads.