高压方波脉冲下局部放电的相位分布特征

针对局部放电可导致变频电机绝缘过早损坏这一问题,笔者分别在方波脉冲下和工频下,对匝间绝缘电磁线进行了老化试验和局部放电测量,主要对脉冲电压下局部放电的相位分布特征进行分析,并与工频下进行了对比。结果表明:脉冲条件下,随老化时间的增长,放电相位呈展宽趋势且出现明显的离散特征;高相位放电的出现是部分缺陷迅速发展的标志,是绝缘失效的先兆。

Phase Distribution Characteristic of Partial Discharge under Square Pulse Voltage

The pulse voltage engendered by pulse width modulated(PWM) power may lead to premature failure of inverter-fed motors.Partial discharge under a sequence of high-frequency impulse is one of the key factors which lead to premature failure of inverter-fed motors.In this paper,aging experiment on magnetic wires for turn to turn insulation was conducted and partial discharge was measured.Phase distribution of partial discharge under pulse voltage was analyzed.The results show that with the increasing of aging time,the discharge phase become broader and appears scattering property;The appearance of the discharge between high phases is the symbol of some faults expanding rapidly,which means an early failure of insulation.