变频牵引电机线圈绝缘电老化规律的研究

Electrical Aging Law of Winding Insulation for Pulse Width Modulation Inverter-Fed Traction Motor

为了解决大量变频电机线圈绝缘过早损坏的问题,采用变频牵引电机线圈作为试样,施加高压脉冲方波电压进行电老化试验,研究脉冲电源的电压幅值、脉冲频率、温度对变频牵引电机线圈试样寿命的影响规律.试验结果表明:电机线圈寿命随电压幅值和温度的增加成指数性衰减,而在13～20kHz范围内,试样寿命与频率成负线性关系;在老化条件相同时,同批次试样的寿命差距较大;试样击穿点几乎都发生在电磁线的弯曲部分和铜线棱角处.

Aiming at a large number of premature failures of wingding insulation of PWM inverter-fed AC traction motor,the inverter-fed AC traction motor wingding is taken as a sample,and square-wave high-voltage pulse is imposed to carry out electric aging test.The influences of pulse supply voltage,pulse frequency,and temperature on the life of traction motor wingding sample are investigated.It is shown that the wingding life decays exponentially with the increasing voltage and temperature.Within frequency range form 13 kHz to 20 kHz,the relation between winding life and frequency gets negatively linear.Under the same aging conditions,the winding life in the same batch can be quite different.The almost all winding sample breakdowns occur in the electromagnetic wire＇s bent portion and copper corner.