GIS局部放电特高频传感器有效高度的比对测试

为提高气体绝缘金属封闭式开关设备(GIS)局部放电特高频(UHF)检测技术现场应用的有效性,有必要对UHF传感器耦合性能进行校核。为此,建立了基于吉赫兹横电磁波(GTEM)小室的UHF传感器有效高度测试平台,采用0.3~1.5 GHz频段内的平均有效高度和该频段内有效高度大于等于2 mm的百分比表征UHF传感器的耦合性能。基于GTEM750小室,采用时域脉冲和扫频参考法对UHF传感器的有效高度进行了比对测试,并与GTEM1500小室的测试结果进行了比较;基于GTEM750小室的时域脉冲参考法,讨论了UHF传感器类型、工装、安装角度对有效高度测试结果的影响。研究结果表明,不同方法和平台对UHF传感器在0.3~1.5 GHz频段内的平均有效高度测试结果的偏差在±1 mm以内;UHF传感器类型、工装、安装角度对有效高度有显著的影响。

Comparative test of effective height of UHF sensor for partial discharge in GIS

The coupling performance of UHF(Ultra-High Frequency) sensor has to be checked to improve the site application effectiveness of UHF detection technology for partial discharge in GIS(Gas Insulated Switchgear). A test platform based on the GTEM(Gigahertz Transverse ElectroMagnetic) cell is built to test the effective height of UHF sensor. The average effective height within 0.3~1.5 GHz and the percentage of effective height above 2 mm are adopted to characterize the coupling performance of UHF sensor. Based on the GTEM750 cell, the time-domain pulse method and sweep-frequency reference method are applied to comparatively test the effective height of UHF sensor. The test results are compared between GTEM750 cell and GTEM1500 cell. Based on the GTEM750 cell and the time-domain pulse reference method, the influences of sensor type, installation mode and installation angle on the tested effective height of UHF sensor are discussed. Research results show that, the deviation of average effective height within 0.3~1.5 GHz between different platforms or methods is within ±1 mm; the sensor type, installation mode and installation angle have obvious influences on the average effective height.