脉冲电应力下电气绝缘劣化程度在线检测方法初探

摘要

In order to meet the needs of online evaluation of the electrical insulating materials’ deterioration degree and remaining life under the pulse electrical stress, the leakage current and its change rule of the insulating materials under different deterioration degrees are researched.At first, the average life and lowest life of insulating film samples under the condition of corresponding accelerated stresses are determined through the accelerated aging experiments by using the pulse electrical stress accelerated aging experimental device.Then, a batch of pre-aging samples are created based on the aging model and the deterioration speed of the pre-aging samples is delayed by decreasing the pulse am-plitude and keeping the frequency of accelerated factors invariant.The results of experiment show that the deviation degree between leakage current’ s centroid and initial leakage current, the dispersion of leakage current and centroid of observation interval and the slope of leakage current are all related with the deterioration in the observation interval. The insulating deterioration which is defined by these three parameters can describe the deterioration degree of insula-ting property.%为满足PWM调速等脉冲电应力下电气绝缘材料劣化程度和剩余寿命在线评估需要，研究不同劣化程度下绝缘材料漏电流及其变化规律。首先利用脉冲电应力加速老化实验装置通过加速老化寿命实验测试绝缘薄膜试样在该加速应力条件下的平均寿命和最低寿命，然后依据寿命模型制作一批经过预老化的试样，通过降低脉冲幅值和保持加速因子频率不变的方法适当延缓预老化试样劣化速度，实验表明在观察区间内漏电流质心与初始漏电流的偏离度、漏电流与观察区间质心的离散度、漏电流的变化斜率都与劣化相关联，以这三个参数定义的绝缘劣化度可以较好的描述绝缘性能的劣化程度。