Abstract:  ABSTRACT： With the increasing of electric vehicles, the impact of charging load on the distribution network cannot be ignored. As deferrable loads, electric vehicles have great potential for demand response （DR）. Rational control on them can assist the safe and economic operation of distribution network. This paper establishes the hysteresis charging load model of a single electric vehicle. Based on the hierarchical control structure of distribution network, the paper introduces the optimal energy status regulation control strategy （OESRCS） for the participation of cluster electric vehicles in demand response, which can realize the real-time control of the charging process of the cluster electric vehicles by applying the optimal adjustment amount to the energy state set point of electric vehicle. On this basis, two indicators named percentage of distribution-voltage change and percentage of network losses are formulated to evaluate the effect of demand response. Simulation results show that by using OESRCS strategy, the electric vehicles can accurately track the target power, and the voltage fluctuation and network loss of the distribution network are reduced at the same time. 

Key words:  KEYWORDS： electric vehicles, cluster demand response, hysteresis model, optimal energy status regulation control strategy （OESRCS）, distribution network