基于超声波检测技术的GIS内部自由颗粒缺陷分析

Analysis of Free Particle Defect in GIS Based on Ultrasonic Detection Technology

超声波检测技术作为一种有效的局部放电检测技术,目前已在气体绝缘全封闭组合电器(Gas Insulated Switchgear,GIS)设备缺陷分析中广泛应用。对投运前的变电站设备施加1.1倍额定相对地电压进行局部放电检测,发现一处220 kV GIS开关气室存在超声波异常信号,通过缺陷分析确定为自由颗粒放电。对异常气室进行开仓检查,发现开关气室下部盆式绝缘子上存在一个白色树脂环状异物,系设备在厂内装配时遗留。检测结果说明超声波局部放电检测对GIS内非金属异物也具有一定敏感性,可以为后续类似异常的分析提供一定参考。

Ultrasonic detection technology is an effective partial discharge detection technology,which has been widely used in GIS equipment defect analysis.Partial discharge detection was carried out by applying 1.1 times of rated phase to ground voltage to the substation equipment before putting into operation,and an abnormal ultrasonic signal in 220 kV GIS knife switch gas cham⁃ber was found,which was determined as free particle discharge through defect analysis.The abnormal gas chamber was opened for inspection,and it was found that there was a white resin ring on the basin insulator at the lower part of the gas chamber that was left by the equipment assembly in the factory.The detection results show that ultrasonic partial discharge detection is also sensi⁃tive to non-metallic foreign bodies in GIS,which can provide certain reference for the analysis of similar anomalies.