感应脉冲电压下电机绕组局部放电近场测量技术及应用

Near-field Partial Discharge Measurement Technology and Application in Rotating Machine Winding Under External Induced Impulse Voltage

为了检测和诊断旋转电机成型绕组内部的绝缘缺陷,尤其是匝间缺陷,文中提出一种外部感应脉冲电压下局部放电测量的方法。首先基于阻抗谱分析方法对一种典型的电机绕组进行了宽频等效建模,进而结合传输线理论推导出该电机绕组主绝缘或匝绝缘中发生局部放电后,脉冲信号沿绕组传播的特性。详细阐述并论证了只有采取近场测量的方式,才可能在感应脉冲电压下捕捉相对完整的局部放电信号。同时,为基于近场电磁感应原理研制合适的新型高频电流传感器提供了设计依据。最后,介绍了基于感应脉冲电压法局部放电测量系统的整体设计与典型电机的测试案例。

In order to detect the insulation defects, especially inter-turn defects, in form-wound coils or windings for rotating machines, a method based on partial discharge（PD） measurement under induced impulse voltage has been proposed in previous researches. In this paper, the wideband modeling and analysis of rotating machine winding based on its impedance spectrum was carried out. Furthermore, combined with transmission line theory, the propagation and attenuation characteristics of PD pulse signals originated from the insulation defect along the winding were derived. It has been proved that, the technically feasible option to achieve fully capture of the PD signals under induced impulse voltage is near-field measurement. The research also provided the guidance for developing a new high-frequency current sensor based on the near-field electromagnetic induction. Finally, the general design of impulse induction and PD testing unit was introduced, and a typical actual case of this PD detection was presented.