水电站易忽视的接地不良引发的反击事故分析

Analysis on back striking caused by poor grounding of hydropower station

分析了水电站油罐金属管道在周边短路电流条件下可能产生的电位升高,从而使金属管道法兰间的油膜被击穿导致的火花事故。阐述了金属管道的跨接导线不仅只有防止静电的作用,更重要的是防止接地反击事故。同时还分析了主变压器接地引下线在出现问题后对附近二次设备的反击现象。最后提出相应的对策措施,为水电站的安全运行提供技术支撑。

The authors analyze the potential rise when the metal pipe of oil tank of hydropower station is in the condition of short-circuit current,which would cause the spark accident due to the breakdown of oil film between pipe flanges.And,the jumper wire of the metal pipe not only prevents electrostatic,but also prevents the grounding back striking accident.At the same time,the authors analyze the back strik ing phenomenon of the grounding down lead of main transformer to nearby secondary equipments after problem occurs.Finally,the relevant countermeasures are put forward to provide technical support for the safe operation of hydropower station.