500 kV开关弹簧机构支架螺栓断裂的原因分析及处理

Cause Analysis and Treatments of Spring Bracket Bolt Fracture of 500 kV Switch

HPL500B2型弹簧机构支架(BA)螺栓断裂可能导致开关分合闸失败,对其原因进行分析,发现BA螺栓由于预紧固力矩过大,接近其扭断力矩,使得作用在BA螺栓上的力偏高,BA螺栓安全系数仅为12%,安全系数较低。列出BA螺栓更换步骤及注意事项,并详细介绍分闸、合闸弹簧调整步骤,为类似事件的处理提供参考。

The fracture of the BA bolt of HPL500B2 spring mechanism may lead to the on-off failure of the switch.Through the analysis of the potential cause of the fracture,it is found that the force acting on the BA bolt is near the breaking point of the bolt during pre-tightening which is high enough to cause fracture in the long term service.Also,the safety coefficient of the BA bolt is only 12% which is not considered high.A check list of the standard replacement operations is issued in this paper.The adjustment steps of the opening and closing spring are introduced in detail to provide reference for handling similar events.