牵引电机定子绝缘局部放电试验和可靠性评估

Stator Insulation Partial Discharge Test and Reliability Evaluation of Traction Motor

针对牵引电机定子绝缘局部缺陷问题,基于局部放电脉冲电流法,提出了一种可用于评估牵引电机定子绝缘可靠性的方案。根据电机定子绝缘的4种放电类型建立了放电模型,通过放电模型的局部放电试验获取了不同放电类型的相位谱图和放电脉冲,对典型放电相位谱图和脉冲特征进行了分析;提取了相位谱图的特征序列,采用BP神经网络对放电类型进行分类,并根据放电幅值的大小划分定子绝缘安全等级,提出定子绝缘评估方案;搭建了局部放电试验平台,对牵引电机试验样机的定子绝缘性能进行了局部放电测试。文章提出的定子绝缘可靠性评估方案可有效评估电机定子绝缘的局部放电缺陷类型和放电强度,对分析电机的绝缘状况具有一定的通用性和指导意义。

Aiming at the local defects of traction motor stator insulation, based on the partial discharge pulse current method, a scheme for evaluating the reliability of traction motor stator insulation was proposed. First, discharge models were established based on the four types of electrical discharges in the stator insulation of the motor. The phase spectra and discharge pulses of different types of discharge were obtained through the partial discharge test of the discharge model, and the typical discharge phase spectra and pulse characteristics were analyzed. Then the characteristic sequence of the phase spectrogram was extracted, the BP neural network was used to classify the discharge types, and the stator insulation safety level was divided according to the magnitude of the discharge amplitude, and then the stator insulation evaluation plan was proposed. Finally, a partial discharge test platform was built, and the partial discharge test was carried out on the stator insulation of the traction motor test prototype. The stator insulation reliability evaluation program proposed in the article can effectively evaluate the partial discharge defect type and discharge intensity of the stator insulation of the motor, and has a certain versatility and guiding significance for the analysis of the insulation status of the motor.