贵—广Ⅱ宝安站极2Y3阀因无回报信号导致极2跳闸的故障分析及相关反措的建议

中国贵—广Ⅱ±500 kV高压直流输电工程中均采用激光脉冲直接触发晶闸管的直接光控晶闸管换流阀(以下简称LTT阀)。为了确保换流阀的安全可靠运行,对换流阀中的每个晶闸管用晶闸管电压监测电子线路(thyristor voltage mornitoring,TVM)进行在线监测。TVM实时用回报信号将监测的结果通过光缆送往阀底部电子设备柜(VBE)中。VBE中的单片机监测系统根据回报信号分析判定晶闸管的故障,当阀内故障晶闸管数超过设计允许的冗余数,产生相应的跳闸信号。笔者就2009年3月12日和2010年5月29日贵—广Ⅱ宝安站极2 Y3阀因无回报信号导致极2跳闸的故障进行了分析,得出:跳闸故障并非由阀或VBE故障引起,而是由阀侧电压不稳定或扰动引起的结论,并提出相关反措的建议。

Analysis and Suggestions on Pole 2 Strip Caused by No Check Back Signal from Y3 Valve of GGII Baoan Station

The light triggered thyristor valves,which are directly triggered by laser,are used in Guizhou-Guangdong ±500 kV HVDC II power transmission lines.To ensure safe and reliable operation,thyristor voltage mornitors(TVM) are used to have on-line mornitoring on each thyristor.By light cables,TVM sends real-time feedback signal to VBE,whose single-chip can judge the default of thyristor valves by reading such check back signals.When the number of default thyristors exceeds the number of thyristor redundancy,trip signal is sent.The author analyzes the default and provides the related suggestions on Pole 2 trip caused by no check back signal from Y3 valve of GGII Baoan station,12th March,2009 and 29 th May 2010.