楚穗直流输电系统双阀组闭锁事件及保护动作行为分析

基于±800 kV楚穗直流输电系统2012年12月15日单极双阀组相继闭锁事件，通过对现场设备的检查，相关录波和保护动作情况的分析，查明了故障原因是极1双阀组的不对称运行导致极1双阀组闭锁，同时由于接地极线路与中性母线绝缘水平不匹配，造成接地极线路闪络从而导致接地极线路不平衡保护动作。针对事件暴露的问题提出了合理的改进措施。

Double Valve Group Blocking Fault and Protection Action Analysis of Chusui UHVDC Power Transmission System

Based on the blocking fault of monopole double valve group in ± 800 kV Chusui UHVDC transmission system happened on Dec. 15,2012,the analysis of on-site equipment checking,relevant recorded wave and protection actions were carried out. It points out that Pole 1 blocking was caused by the asymmetric operation of two groups of Pole 1. Moreover,the mismatch of the grounding lines and the insulation level of the neutral bus resulted in the flashover and imbalance protection action of grounding lines. Finally,this paper also suggests reasonable improvement measures for the exposed problems.