SPWM变频调速电动机线圈局部放电的测量

Measurement of Partial Discharge of Winding in SPWM Inverter-Fed Induction Motors

讨论了脉冲波在电缆中的传播过程以及电缆长度对线圈端的过电压和脉冲上升时间的影响。由于线圈电压的升高和电压分布极不均匀,在线圈中产生了局部放电,导致绝缘老化严重时会使绝缘击穿。为了有效提取局部放电信号,设计了一个高频脉冲电流传感器,构建了一套类似于电桥的专门用于SPWM变频电动机线圈局部放电测试电路,测试结果表明该局部放电测试系统可以在强干扰下(SPWM)检出局部放电信号。

The propagation process of pulse wave in the cable and influence of cable length on overvoltage and wavefront time of winding are discussed in this paper. The partial discharge（PD） of motor winding can produce due to voltage increasing and distorted distribution of electric field. PD will cause insulation aging, and even leads to breakdown of motor winding. Therefore it is necessary to set up PD detecting system for SPWM motor. In this paper, the current transducer （CT） of high frequency has been developed and circuit similar to bridge for measuring PD has been designed. The experimental results show it is possible to detect and record PD in the high disturbance environment.