分布式电源并网对配电网电流保护影响的研究

摘要

The paper analyzed influence of grid connection of distributed generation on traditional current protection of distribution network, used Matlab/Simulink simulation software to prove influence of different capacities and grid connected positions of distributed generation on each section of current protection of distribution network, and proposed an improved scheme which can meet with protection requirement of distribution network after grid connection of distributed generation. The implementing principle of the scheme is as follows: for downstream protection of distributed generation, taking power supply of power system and distributed generation as a whole, resetting set values of each section of current protection; for upstream protection of distributed generation, installing a direction relay based on fault current component on each protector, so as to ensure reliable action of protection when over-current relay and direction relay start simultaneously.%分析了分布式电源并网对传统的配电网电流保护的影响,采用Matlab/Simulink仿真软件验证了分布式电源容量不同、并网位置不同对配电网各段电流保护的影响,提出了一种能够满足分布式电源并网后配电网保护要求的改进方案.该改进方案实现原理:对于分布式电源下游的保护,将供电系统电源和分布式电源作为一个整体,重新整定各段电流保护的整定值；对于分布式电源上游的保护,需在各保护装置上安装一个基于故障电流分量的方向元件,只有当保护中的过流元件和方向元件同时启动时,保护才能够可靠动作.