Research of Impacts on Power Systems by Electric Vehicle Charging in China

Battery Electric vehicle (BEV) has been set as one of the most prominent sectors of automobile industry in China in the future due to its significant contribution to energy safety, low carbon emission and leading technology status in vehicle driven by new energy. High penetration of BEV will have obvious impacts on power systems, and its load characteristics are quite different from those traditional loads. Therefore with an eye on the safe, stable and economic operation of power system, this paper studied the impacts of EV on power systems from four aspects: total electricity demand, power rush in short period, power quality and vehicle to grid (V2G) technology. Total electricity demand by BEV charging in 2020 in China was firstly estimated in the paper, and it is sure that power system has the capability to meet this demand. However uncontrolled massive BEV charging will probably results in higher peak load and upgrading requirement of power systems, so orderly charging is required. EV battery is charged through rectifier, which will decrease power quality by harmonic current, therefore power electronic equipment is required to ensure power quality. Finally possibility of scheme of vehicle to grid (V2G) application is discussed when the scale of BEV is large enough and performance of EV battery is greatly improved.