方波脉冲电压频率对变频牵引电机绞线对绝缘特性的影响

Effect of Square Impulse Voltage Frequency on Insulating Characteristics of Inverter-Fed Traction Motor Twisted Pair

测试了不同频率方波脉冲电压下牵引电机绞线对的电热联合老化寿命、介质损耗因数(tanδ)及局部放电平均放电量,测试结果表明:方波脉冲电压频率升高,使局部放电平均放电量增大,局部放电对绞线对绝缘的破坏作用加强,使绞线对的老化寿命缩短;方波脉冲电压频率升高,使绞线对老化程度加深,陷阱密度增大,降低了自由载流子浓度,使局部放电起始放电电压(PDIV)增大,从而使介质损耗因数曲线转折点电压升高。

Electrical and thermal aging lifetime, dielectric loss factor （tan） and average discharge amount of partialdischarge of traction motor twisted pair under different frequency of square impulse voltage are investigated. The resultsshow that as the frequency of square impulse voltage increases, the average discharge amount of partial discharge increa-ses, the damage to the insulation of the twisted pair strengthens, making the lifetime of the twisted pair shortened. The fre-quency of the square impulse voltage increases, the aging of the twisted pair deepens, making the trap density increasesand the density of the free carriers reduces,leading to the partial discharge inception voltage （PDIV） increases and final-ly making the turning point voltage of the tans curve increases.