光伏电源接入配电网对馈线继电保护的影响

Influence of photovoltaic power supply connected to distribution network on feeder protection

光伏电源作为分布式电源的一种,逐渐成为重要的电力电源形式。大规模的光伏并网电站(Photovoltaic或PV)接入配电网后,单端供电配电网络变成双端甚至多端网络,使得配电网中的潮流分布发生根本变化,从而发生短路故障时可能引起保护误动或拒动。本文以PV电源通过10kV馈线接入配电网为例,利用短路电流计算公式计算短路电流大小,分析了对馈线电流保护以及重合闸等继电保护所带来的影响。指出对馈线继电保护的影响程度与PV电源容量大小和位置等相关。

As a kind of distributed generation,photovoltaic power supply gradually becomes an important source.Since large scale grid-connected PV power parallel in distributed network,distribution network supplied by single-ended power gradually has two port source or multi-port source,which results in fundamental changes to distribution network loadflow,and failure to work correctly when short circuit happens.With an example of PV paralleled into distribution network by 10 kV feeder line,the paper calculates the magnitude of short circuit current by formula,and analyses the effect of feeder line current protection and reclosing.The result shows that the influence to feeder line protection relates to capability and position of PV.