Research on the Influence of Photovoltaic Grid-connected on the Relay Protection of Distribution Network

First of all, this paper makes a theoretical analysis of three-section current protection of the traditional distribution station, and uses the software to build a simulation model of the distribution network. The situation of relay protection in the case of three-phase fault in the distribution network is studied, and it can be found that the three-section current protection can remove the fault well before the photovoltaic is connected; Then a photovoltaic distribution grid model is built to study the operation of protection components when three ground faults occur at different locations when photovoltaic generation of different capacities are connected to the midstream and down-stream of the distribution system, which leads to the impact of faults on the distribution network relay protection after grid connection of photovoltaic systems.