一次特别的系统故障分析

多数的系统故障引起保护非正常动作时,都是由二次系统的干扰引起的,于是本文从电压互感器二次绕组放电间隙或氧化锌阀片击穿和电压互感器二次直接两点接地、以及电压互感器二次与三次绕组N线未分开等二次整定及二次接线错误入手分析,得出非二次干扰引起保护动作行为变化的结论,该文的目的除了提醒现场的运行维护单位重视起地网检查的重要性外,还纠正了继电保护人员分析问题只注重二次回路,而忽视一次系统对二次保护的影响的惯病。

Analysis of an unusual system fault

Since most of maloperation of protection equipment in the power system are caused by the disturbance of the secondary circuit system, the paper analyses the wrong setting and wiring of the secondary circuit including arc discharge gap or zinc oxide valve of the VT secondary winding, direct two-point earthing of the PT secondary winding and the disconnection failure of N lines of secondary and third winding of PT. A conclusion is reached that the disturbance of secondary circuit does not cause the operation change of protection equipments. To remind the site operation and maintenance organization of attaching importance to inspection of the earthing system, it also points out that relay protection engineers only pay attention to secondary circuit but ignore the effect of the primary circuit on protection equipments.