Research on reconfiguration of distribution system base on snop integrated with orderly electric vehicle charging strategy

Abstract

The disorderly access of large-scale electric vehicle(EV) charging load to the distribution network will affect the economic operation and bring pressure to the upgrading of distribution network facilities. This paper takes measures from three aspects: the orderly charging strategy of EVs, the reconstruction of distribution network and the application of soft normally open point (SNOP), trying to analyze the impact on the planning and operation of distribution network. The basic model framework of optimal dynamic power flow of distribution network based on second-order cone relaxation is constructed. Combined with the linearization model of SNOP and the necessary conditions of radial topology, the reconfigurable active distribution network optimization model with SNOP is obtained. Based on the American household traffic questionnaire survey data, the disordered charging load of EVs is extracted and superimposed on the original load curve. The charging strategies of “delay” and “improved delay” for orderly charging of EVs are proposed, and the delay time is optimized in the distribution network reconfiguration model at the same time. The orderly charging strategy of EVs, the application of SNOP and the reconstruction of distribution network also reduce the requirements for the transformer capacity of distribution network and delay the pace of investment in power equipment. Based on the simulation of 94 node distribution system, the effects of orderly charging strategy of EV, reconfiguration of distribution network and the effectiveness of SNOP on the transformer capacity margin of distribution network are analyzed and verified.