摘要
变频电机匝间绝缘承受来自逆变器的连续高压脉冲方波的作用,为探讨工频正弦电压作用下具有很大差异的老化机理,通过采用工频正弦和高压脉冲方波两种电压源对模拟变频电机匝间绝缘的绞线对试样进行了电热联合老化对比试验,测量损耗角正切tanδ随老化时间的变化趋势,并结合热刺激电流测量结果,分析了电压形式对匝间绝缘介质损耗产生和发展的作用机理。试验结果表明:绝缘内部有放电发生时,放电与空间电荷协同作用使绝缘缺陷迅速增多;无放电时空间电荷反复注入和抽出造成绝缘损伤。两者都导致高压方波脉冲老化下绝缘材料的tanδ高于工频正弦老化下的tanδ;高压方波脉冲下空间电荷可能是导致绝缘材料最后击穿的原因。
Contrast aging tests are carried out on twisted pairs simulating inter-turn insulation of inverter-fed traction motor under AC and square wave pulse conditions. The variety of tan 8 subjected to various aging factors with aging time and measuring voltage are investigated. The differences of dielectric loss between AC aging and square wave pulse aging are studied based on change curves of tan 8 combining the results of thermally stimulated current （TSC）. When measuring voltage is Un, the PD and space charge result in a sharp increase of insulation defects. When measuring voltage is 0.2Un, the eject and inject of space charge result in a damage of insulation. Both of them cause that tan 8 under square wave pulse aging is bigger than that under AC aging. Space charge is likely to be the key factor resulting in breakdown of insulation materials under continuous imPulses.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2007年第8期165-168,共4页
High Voltage Engineering
基金
国家自然科学基金(50377035)
霍英东教育基金(91060)
教育部博士点基金(20050613008)。~~
关键词
变频电机
匝间绝缘
老化
介质损耗
热刺激电流
空间电荷
inverter-fed traction motor
inter-turn insulation
aging
dielectric loss
TSC
space charge
