含大量DPVS的配电网反时限电流保护研究

STUDY ON INVERSE TIME CURRENT PROTECTION FOR DISTRIBUTION FEEDERS WITH HIGH PENETRATION OF DPVS

随着大量分布式光伏发电系统(DPVS)的接入,配电网线路故障电流分布将产生很大变化,这对装有反时限电流保护的配电网线路产生较大影响。对DPVS提供的故障电流特性及DPVS不同时被切除进行分析,结合大量DPVS接入对配电网反时限电流保护时间配合影响研究,提出新的反时限电流保护方法,该方法通过对变化电流进行微分求和,比较前后获得的相关数据最终确定最短跳闸时间,以增强配电网对大量DPVS接入的适应性。最后基于PSCAD/EMTDC平台进行仿真。

Distribution network with high penetration of DPVS greatly changes the fault current profile, and brings great effect on inverse time current protection. Based on the fault characteristic of DPVS and the process to disconnect DPVS at different time, a new method of inverse time current protection is proposed because the current changes after fault. This method is aimed to get the shortest trip time due to differential summation and different trip time comparison, and it increases the adaptability of new inverse time current protection. Lastly, a 10 kV radial distribution network case is built in PSCAD/EMTDC, and the result indicates the effect of high penetration of DPVS and the validity of proposed method.