光伏电源接入对电网突变量方向元件的影响分析

Analysis of the Impact of Direction Relay of Power Systems with Potovoltaic Generation

方向元件是电网继电保护系统的重要组成部分,然而光伏电源异于传统同步发电机的故障电流特性,对电网方向元件产生了新的影响。文章首先考虑光伏电源低电压穿越运行的影响,分析了光伏电源的故障电流特征。在此基础上,分析光伏电源接入对突变量方向元件的影响,研究结果表明正序和负序突变量方向元件均难以满足电网故障方向判断的要求。最后,通过仿真验证了分析结论的正确性。研究结果对光伏电源接入后的电网继电保护配置具有重要的指导意义。

Direction relay is the key part of relay protection in power system. The complicated fault current characteristics of the photovoltaic（PV）system make the performance of the direction relay deteriorate greatly. Based on this,the fault current characteristics of the photovoltaic generation are studied considering low-voltage ride-through control. Then,the impact mechanism of PV on direction relays based on fault components is analyzed. It is pointed out that the direction relay based on fault components cannot meet the requirements of the power distribution network with PV. Finally,the analysis results is verified by the simulation cases in PSCAD/EMTDC. The research results are helpful to the configuration of relay protection in power system with PV.