摘要
Abstract
To address the abnormal hidden temperature rise of the motor stator winding that cannot be detected by conventional electrical tests after a full rewind major overhaul of the high-voltage motor stator winding,a 560 kW/10 kV high-voltage motor was taken as a case study.Through theoretical analysis,on-site data monitoring,infrared thermography inspection,and re-view of the overhaul process,the fault mechanism was systematically analyzed.The research results indicate that the non-standard implementation of the vacuum pressure impregnation(VPI)process for the motor stator winding leads to the formation of a large number of closed air gaps between the stator winding and the stator core slot wall,which is the root cause of the sharp increase in contact thermal resistance and the blockage of the heat dissipation path.The loosening of the stator slot wedges and the blockage of the air ducts further aggravate the heat accumulation.Based on this,a comprehensive remediation scheme of"secondary impregnation+standardized fastening of the stator slot wedges+thorough cleaning of the motor air ducts"was proposed.After implementation,the tem-perature difference between the motor stator winding and the motor frame dropped from 55.9℃to 23.8℃,and the operating temperature rise fully met the specification requirements.关键词
高压异步电动机/定子绕组/隐性温升/VPI/接触热阻/红外热成像Key words
high-voltage asynchronous motor/stator winding/hidden temperature rise/VPI/contact thermal resistance/infrared thermography分类
信息技术与安全科学
