电压互感器柜内过电压保护器烧损事故分析及反措建议

Accident Analysis and Countermeasures Suggestion for Over Voltage Protector Overburning in Voltage Transformer Cabinet

对广东电网公司揭阳供电局220 kV铁山变电站2号主变压器低压绕组电压互感器柜内过电压保护器烧损事故进行分析,指出雷电波经10 kV馈线侵入10 kV高压室是事故的诱因,而电压互感器柜内组合式过电压保护器结构设计缺陷引发相间短路则是造成事故扩大的主要原因,变电站出线电缆终端避雷器和终端塔地网的不可靠也是导致事故发生的原因之一。针对该典型事故折射出10 kV配电网防雷和过电压管理上存在的问题,提出具体的反措建议。

This paper analyzes overburning accident of over voltage protector in low voltage winding voltage transformer cab- inet of No. 2 main transformer in 220 kV Tieshan substation of Jieyang power supply bureau of Guangdong power grid cor- poration and points out the incentive of the accident is intrusion into 10 kV high voltage chamber of thunder and lightning through 10 kV feeder which the main reason for expansion of the accident is phase fault caused by design defects of com- bined type over voltage protector in voltage transformer cabinet. Meanwhile, unreliability of terminal arrester and tower counterpoise of substation outlet cable is another reason for the accident. Aiming at existing problems in lightning protection of 10 kV distribution network and over voltage management, it proposes specified countermeasures.