基于ETAP的光伏接入10kV配电网对继电保护的影响

Effect of photovoltaic generation on relay protection of 10kV distributed system

阶段式电流保护常用于配电网继电保护中,然而分布式电源接入配电网后,会改变其短路电流大小、方向,导致保护误动、拒动等。本文以ETAP软件为平台,搭建了含光伏电源的10kV配电网模型,重点研究了一定容量的光伏电源接入后,不同线路上发生三相短路故障时,对短路电流产生的助增、汲流作用,导致保护范围扩大、保护灵敏度降低等影响。基于保护动作的时间电流曲线分析了光伏电源接入对传统电流速断保护及反时限过电流保护动作配合的影响。在不改变原有保护方案的基础上,仿真并验证了限制光伏电源接入容量的保护策略。

Stage current protection is commonly used in relay protection of distribution network.However,it will change the short circuit current size and direction,and consequently,lead to mis-operation and malfunction of protective relays,etc.Using the ETAP software as platform,the 10 kV distribution network model of photovoltaic generation（PVA）was set up for studying the impact of PVA on the protection.The short circuit fault occurs at different positions of the transmission line,leading to the impacts including flow increase,protection scope enlargement,sensitivity decrease,etc.Based on the time current characteristic（TCC）curve of protecting action,the impacts on the cooperation and operation behavior of the current instantaneous fault protection and the inverse over-current protection were analyzed.Protection strategy of limiting access to the photovoltaic power supply capacity was demonstrated through the simulation and verification without changing the original protection scheme.