含分布式电源的配电网继电保护配置改进

Improvement on Relay Protection of Distribution Network with Distributed Generation

分布式电源(distributed generation,DG)的接入将会使配电网由单侧电源辐射状网络变成多端电源网络,使得配电网的潮流分布发生改变,进而导致配电网原有的继电保护不再具备可靠性。分析了DG的接入对配电网原有继电保护的影响,提出了方向纵联保护结合定时限过电流保护的方案来完成对故障的隔离与恢复供电,此方案可以解决DG的接入给配电网保护带来的影响,也使得DG的利用率得到提高。最后利用电力系统仿真软件PSCAD/EMTDC对10kV配电网进行了建模仿真,验证了保护方案的有效性。

The connection of distributed generation（DG） will change distribution network form single-source radial network to multi-source network,as well as the distribution of power flow leading to unreliability of the relay protection.According to the impact of DG connection on the relay protection of distribution network,a method was proposed for fault isolation and service restoration using directional pilot protection and over-current protection.This method can solve DG connection problems and improve the efficiency of DG utilization.Power system simulation software PSCAD/EMTDC was used for the simulation of 10 kV distribution network,whose results proved the method＇s effectiveness and correctness.