基于声光联合法发现的GIS内部绝缘子裂纹引起的局部放电缺陷

A Partial Discharge Defect Caused by Cracks in GIS Internal Insulator Based on Acoustic and Optic Joint

首先阐述气体绝缘金属封闭开关设备(gas-insulated switchgear,GIS)局部放电带电检测的现状,然后介绍一起应用超声波、特高频等带电检测技术发现的GIS内部支撑绝缘子裂纹引起的局部放电缺陷案例。综合分析该缺陷的超声波、特高频信号特征以及SF 6分解物测试结果,对缺陷进行精确定位。经解体检查以及绝缘件返厂完成局部放电和X光探测检查,发现异常局部放电信号是GIS内部某绝缘件上的微小裂纹引起的。最后结合该案例,对GIS局部放电带电检测技术提出相关建议。

This paper firstly describes current situations of partial discharge(PD)electrification detection in the gas insulated switchgears(GISs)and then introduces a PD defect caused by small cracks in the internal support insulator in the GIS,which is detected by the application of ultrasonic,ultra-high frequency(UHF)techniques,and other live detection methods.The paper comprehensively analyzes ultrasonic and UHF signal characteristics of the defect and the test results of SF 6 decomposed product,and then locates the defect preciously.Through disassembly inspection,PD detection,and X-ray inspection,it discovers the abnormal PD signal is caused by small cracks on an insulating part inside the GIS.Finally,the paper proposes suggestions for PD detection technology of GIS.