开关柜局部放电检测技术应用

文中分析了一起典型的某变电站高压室内开关柜局部放电缺陷案例。通过暂态对地电压(TEV)、超声波测试数据较往年数据突增判定该高压室存在异常局部放电信号。为实现故障位置的精准定位,综合采取了暂态对地电压(TEV)定位法、超高频(UHF)局部放电检测与定位方法;结合该型号开关柜的内部结构给出了故障位置范围,并通过停电检查确认了缺陷诊断分析的正确性。测试表明:对于内部缺陷TEV检测较超声波检测灵敏;随着检测距离增大,UHF信号及TEV信号幅值均减小,可通过该原理进行局放源定位;随着检测距离增大,UHF信号及TEV信号到达时间变长。给同类案例的处理积累了经验。

Application of Partial Discharge Detection Technology in Switchgear

This paper analyzes a typical partial discharge defect case of a high voltage indoor switchgear in a substation.The abnormal partial discharge signal in the high voltage chamber is determined by transient earth voltage(TEV)and ultrasonic test data.In order to realize the precise location of the fault location,the method of TEV location,UHF local discharge detection and location is adopted.The fault location range is given by the above method combined with the internal structure of the type switchgear,and the correctness of the defect diagnosis analysis is confirmed by the blackout check.The test shows that the internal defect TEV detection is more sensitive than the ultrasonic detection.As the detection distance increases,the amplitude of the UHF signal and the TEV signal can be reduced,and the location of the local source can be located through this principle.As the detection distance increases,the arrival time of the UHF signal and the TEV signal becomes longer.Experience has been accumulated for the treatment of similar cases.