Reliability evaluation of electrical distribution system considering the random energy output of wind power generators

A novel network model and a fast algorithm for electrical distribution system (EDS) reliability evaluation considering the random energy output of wind power generators (WPG) are presented in this paper. Firstly, a Switch-Section network model is proposed according to the failure isolation characteristics of switches, and then the Switch-Section network is divided into two kinds of parts, main-network and branch-network, based on the property of the power flow direction when WPG are unavailable. Secondly, the concept of energy influence domain (EID) is proposed in order to consider the random wind energy impact on the power supply range of WPG. Based on this concept, we construct the power supply order which successfully implemented the mapping between the random output of WPG and the supply probability to the sections in the EID. Finally, the reliability indices of the main-network and branch-network are calculated by using properties of elements in upstream and downstream fault propagation. Meanwhile, the impacts of WPG on the sections of its EID are considered when computing the nodal downstream reliability indices. The application of the proposed method to the RBTS-BUS6 demonstrates its validity. And the impacts of the position, load demand characteristics, rated capacity of WPG and wind speed on system reliability are also discussed in detail in this paper which will provide some constructive suggestions to WPG installation.