分布式电源接入对继电保护的影响及改进措施探讨

分析了分布式电源接入对短路电流的影响;讨论了其在不同位置接入时对配电网继电保护配合的影响;阐述了短路限制器对配电网继电保护的作用,引入电力电子开关使其仅在故障时限流,使保护装置正确动作;同时分析了重合闸的改进措施,通过改变原有配电网继电保护与重合闸的配合方式,采用前加速与后加速相结合的配合方式使分布式电源在故障发生时可以快速解列,并在分布式电源侧配置检同期重合闸以保证分布式电源正常的并网运行。

Improvement Scheme Discussion of Protection in Distribution Network of Installing Distributed Generation

This paper studies the effect of DG on short-circuit current,then discusses the effects on the co-ordination of distribution network relay when installing DG in different position.It also explains the benefit of short-circuit limiter for the distribution network relay.Power electronic switch is introduced to make the limiter only operate when the fault occurs.Meanwhile,it is proposed to change the original co-ordination behavior of protection with reclosing into the way of combine of instant accelerated protection trip and delayed accelerated protection trip.Configuring synchronous reclosing at DG side make sure DG paralleling in the grid safely.