应对线路差动主保护丢失的后备保护应急方案

Emergency plan for backup protection against loss of line differential main protection

超高压输电系统中,存在单间隔或多间隔线路差动主保护丢失后后备保护在线路区内故障时可能存在动作延时长、失配导致的误动或拒动风险。针对单间隔或多间隔线路保护装置闭锁、通信设备异常、通信通道故障导致的线路差动主保护丢失工况,分析了后备保护的适应性,提出了基于站域开关量信息采集来判断不同工况导致主保护丢失的识别逻辑。并制定了基于站域共享信息的后备保护主动和被动加速自调整应急优化方案,缩短后备保护的动作时间和自适应调整后备保护的动作范围,并通过仿真验证。仿真表明,优化后的应急后备保护实现线路差动主保护丢失后由距离保护和零序保护快速有序切除故障。

In a UHV transmission system,there is an abnormal working condition in which the single or multiple interval line differential main protections are lost.If the fault protection in the line area after the main protection is lost,there may be a long action delay,mismatch or mis-operation risk caused by mismatch.The adaptability of back-up protection is analyzed in view of the loss of line differential main protection caused by single or multiple line protection device blocking,communication equipment abnormalities and communication channel failure.An identification logic,for judging the loss of main protection caused by different operating conditions,based on the collection of switch information in the substation domain is proposed.An emergency optimization plan for active and passive acceleration self-adjustment of backup protection based on the shared information of the station domain is formulated to shorten the operation time of the backup protection and adaptively adjust the range of the backup protection.This is verified by simulation.The simulation shows that the optimized emergency backup protection shows that distance protection and zero sequence protection can quickly and,in an orderly fashion,remove the faults after line differential main protection is lost.