1.Research Center of Smart Energy Technology, School of Electrical Power, South China University of Technology;2.Guangzhou Power Electrical Engineering Technology Co., Ltd.
Aiming at the analysis of operation risk of the distribution network caused by electric vehicle to grid, the indicator of loss severity with amplification factor is proposed, and the distribution entropy is used to measure the risk caused by the uncertainty of the distribution of the state variables of the distribution network. Weighting the distribution entropy using loss severity, the weighted distribution entropy (WDE) is established, based on which the voltage risk index and the load-flow risk index are established. The weighted sum of WDE is calculated according to the component importance, so as to evaluate the voltage risk and the load-flow risk of the network. Taking into account both types of risks, a comprehensive set of indexes is constructed to evaluate the operation risk of distribution networks. Finally, simulation studies are conducted on an improved IEEE 33-node distribution system with wind power and photovoltaic accessed, and the superiority of WDE over traditional risk indicators and the rationality of the comprehensive index are analyzed by dynamic probabilistic power flow simulation. In addition, the variation of the operational risk with the access location and capacity of electric vehicle load are studied. By the simulation studies, the effectiveness of the indicators and models proposed in this paper is verified.