一起同塔四回线路三相不平衡引起的母联断路器零序保护告警事件分析

摘要

剖析同塔四回输电线路三相电流不平衡产生的机理，指出不对称叠加感应电势和低阻回路是导致同塔四回架设输电线路三相电流严重不平衡的主要原因。基于理论研究成果，结合现场试验录波数据分析万江变电站220 kV母联断路器2012零序电流保护告警事件，找出事件的关键诱因，并针对此提出了调整运行方式和优化相序两种解决方案。%This paper analyzes producing mechanism of three-phase imbalance of quadruple-circuit transmission line on the same tower and points out the main reasons for serious three-phase current imbalance are superposition induced potential and low resistance circuit.On the basis of theoretical research achievement and combining experimental recording data,an alarm event of 2012 zero-sequence current protection of 220 kV bus coupler breaker in Wanjiang substation was analyzed and the key inducement was found out.Aiming at the above reasons,solutions to regulate running mode and optimize phase sequence were proposed.