断路器本体三相不一致保护系统二次回路优化

The Optimization for the Secondary Loop of Breaker Three-phase Inconsistent Protection System

针对目前断路器本体三相不一致二次回路抗干扰能力不足、尤其在直流系统接地故障下不能可靠防止误动作的问题,提出了一种基于电网安全运行可靠性的断路器本体三相不一致二次回路优化的新方案。分析了两起断路器误动作跳闸事故原因,利用实测参数建立准确的控制回路系统仿真模型,模拟直流系统接地故障工况引发断路器跳闸的情形,理论上阐释了直流系统接地对保护及二次回路的危害因素。试验结果和设备运行实践验证了该技术方案的先进性和实用性。

A novel scheme for grid safety-operation based optimization for the secondary loop of breaker three-phase inconsistent protection is proposed, considering the incapability for anti-interference of the current secondary loop of breaker three-phase inconsistent protection, especially the unreliability for preventing misoperation when DC system grounding fault happened.This paper analyzed two accidents for breaker misoperation, established simula-tion mode accurately for the breaker controlling loop system by using the measured parameters, simulated the cir-cumstance that breaker tripping caused by DC system grounding fault, and theoretically explained the risk factors for the relay protection and the secondary circuit when DC system grounding fault happened.The experimental re-sults and practical equipment-operation proved the advantage and practicability of the scheme.