高海拔500kV交流滤波断路器外绝缘特性

The Outer Insulation Characteristics of ac 500 kV Filter Circuit Breaker at High Altitude

地处高海拔地区的500kV贵广I回直流输电系统高坡换流站中多次出现交流滤波断路器外绝缘闪络事故。分析了断路器外绝缘闪络的机理，通过人工污秽试验确定了闪络电压变化情况，确认故障是高海拔地区恶劣天气条件下污秽断路器灭弧室外绝缘降低所致，基于试验结果提出了防止断路器污秽闪络的措施。

Flash faults of ac filters at Gaopo substation of Guizhou-Guangdong 500 kV HVDC transmission system have heppened many times. The mechanism of the flash is analyzed in this paper, and through artificial contamination tests for displaying the voltage change of flash the cause of these flash faults is discovered as follows： The outer insulation of filthy circuit breaker＇s arc-chute lowered by the inclement weather condition in the high altitude area. Furthermore, countermeasures against the flash of filthy circuit breaker are proposed based on the experimental results.