火力发电厂一次风机频繁雷击跳闸故障原因分析

Analysis on the Fan Frequent Lightning Trip in a Thermal Power Plant

针对某大型火力发电厂一次风机频繁雷击跳闸的故障,通过现场的试验分析,发现一次风机附近的烟囱将雷电流引入到主接地网,使附近地电位抬升,造成一次风机进线电缆接头多次发生反击闪络,并最终导致绝缘击穿,引发设备事故,据此,提出了整改措施,并建议烟囱避雷设施的接地网应与主接地网分开。

The fan in a large thermal power plant experienced frequent lightning trips. Analysis by field test found the chimney near the fan will be introduced the lightning current to the main ground network, so near the chimney ground potential rises,resulting in cable connector into the line of fans occurred back flashover and eventually led to insula- tion breakdown, triggering equipment accident. According to this, we proposed corrective measures, and suggested that the chimney lightning ground network facilities should be separated from the main ground network.