一起110 kV GIS设备自由金属颗粒放电缺陷及解体分析案例

Discharge Defect of Free Metal Particle of 110 kV GIS Equipment and Its Disassembly Analysis

介绍了一起110 kV GIS设备母线PT开关气室超声波信号异常的分析处理案例。通过幅值定位、时延定位和改变设备运行状态,判断缺陷来自于开关气室内部。对局放超声波信号进行多种测试图谱分析,认为该气室底部自由金属颗粒放电是产生异常超声波信号的主要原因。经开罐检查,发现开关静触头均压罩上存在明显刮痕,气室底部存在较多黑色固体碎屑,开关安装工艺不良导致金属碎屑掉落在气室底部,产生局部放电引起超声波信号异常。该起PT开关气室放电是一起较为典型的自由金属颗粒放电案例,为今后类似异常情况的分析处理提供了借鉴与参考。

The analysis and treatment of abnormal ultrasonic wave in the disconnecting switch(DS)compartment of PT of 110 kV GIS is introduced.It is judged through amplitude location,time delay location and the change of equip-ment operation state that the defect is from the inside of the DS compartment.Multiple kinds of spectrum analysis on the partial discharge ultrasonic signal are performed,thinking that the free metal particle at the bottom the compart-ment is the main reason which causes abnormal ultra sonic wave signal.It is found by opening the enclosure that the grading cover of the stationary contact of the blade has obvious scratches and many black solid debris are at the bot-tom of the gas compartment.The weak installation process of the blade causes the metal debris to drop at the bottom of the gas compartment,generating partial discharge and causing the ultrasonic wave signal abnormal.The discharge of disconnecting switch of PT is a typical metal particle discharge case,which has provided experience and reference for the analysis of the similar abnormal situation in the future.