GIS局部放电特高频在线监测系统传感器配置方案研究

笔者通过在一个220 kV GIS线变间隔断路器气室、母线气室和进线气室安装尖刺故障模型,在盆式绝缘子和绝缘衬垫上进行检测,验证了特高频传感器的灵敏度及衰减特性。结果表明:在外加电压7 kV、视在放电量为5 pC的试验条件下,UHF传感器就可以准确地检测放电信号,并准确判断放电类型及故障位置。试验发现局部放电产生的电磁波经过L型、T型、断路器仓、CT等结构,发生了明显衰减。不带金属屏蔽环的盆式绝缘子和绝缘衬垫,更有利于检测放电产生的电磁波信号。根据测试结果提出了合理的GIS局部放电特高频在线监测系统传感器配置方案。

Transducers Arrangement of the UHF-PD Online Monitoring System for GIS

The ultra-high frequency(UHF) method is widely used for partial discharge(PD) detection in gas insulated switchgear(GIS).In this study,the metal spikes for producing PD signal were laid in the gas cells of circuit breaker,bus and incoming wire,and the sensitivity and attenuation characteristic of the UHF transducer were investigated by detecting the PD signal from basin-type insulator.The results showed that: the UHF transducer could detect the PD signal,and judge the discharge type and position in the condition of 7 kV in voltage and 5 pC in discharge capacity;the PD signal diminished through the L-,T-or CT-type structure;and the metal shielding ring of basin-type insulator interfered in the detection.Consequently,transducers arrangement of the UHF-PD online monitoring system for GIS is suggested based on the tests.