发电机定子绕组绝缘缺陷及老化的声学检测

Acoustic detection of defects and aging of stator winding insulation in generator

利用自行开发的声学检测系统 ,研究了大电机主绝缘在电、热和机械应力作用下的老化特征。通过时 频分析和四个尺度的小波变换分析 ,证实电老化和机械应力老化导致绝缘的体密度降低 ,而热老化则对环氧

An acoustic detecting system developed by our research group is used to study defects and aging of stator winding insulation of generator,which is subjected to electrical,thermal and mechanical stresses for 1000 hours.The analysis of acoustic signal in time domain,frequency domain and wavelet transform in four scales has been carried out.It is found that electrical and mechanical stress aging leads to decrease in block density of expoxy/mica insulation and thermal aging has strong effect on delamination of the insulation.This acoustic detecting system is effective of finding defects in stator winding insulation of generator.