Optimization Method for Protection of Distribution Network with MW-PV Based on Multi-level Cooperative Protection Strategy

Multi-level cooperative protection strategy provides a new optimization method for distribution network protection of megawatt photovoltaic power plants(MW-PV). This research discusses the influence to relay protection after MW PV is connected to distribution network. Aiming at improving reliability and sensitivity of current differential protection, A Integration and Difference phasor algorithm is proposed for the a periodic attenuation component after fault. Dividing Distribution network with MW PV power station into central layer, regional layer and system layer, the research studies inverse-time protection architecture of Multilayer protection .A multi-level cooperative protection strategy is established to remove fault accurately and intelligently, The calculation results of the cases confirm the effectiveness and objectivity of the proposed method.