GIS局部放电检测的有源外置UHF传感器设计

Design of active outer sensor for GIS partial discharge detection

针对传统无源外置局部放电超高频(UHF)传感器频带窄、增益低、容易引入噪声的问题,研究并设计了基于有源集成天线(AIA)技术的有源外置传感器。传感器通过宽频带天线接收局部放电产生的电磁波信号,在天线介质板上直接由有源对数检波器放大信号进行包络检波,省去了传统设计中的平衡不平衡转换与射频传输线,降低天线前端的匹配损耗,改善传感器的频带、噪声和增益。测试结果表明:传感器中心频率为900MHz,驻波比小于2的频带为730MHz^1.05GHz,传感器输出信号峰值为5V,频率为2~10MHz。该传感器抗干扰能力强,增益高,适合GIS局部放电的检测。

Aiming at problem that traditional passive outer UHF partial discharge sensor has narrow band,low gain and easy to introduce noise,so an active outer sensor is designed based on active integrated antenna（ AIA）technology. Sensor receives electromagnetic wave signals by wideband antenna,amplify signal directly by active logarithmic detector on a dielectric plate. Omitting the balun and RF transmission line in traditional design,and loss of antenna is reduced,band,signal to noise ratio and gain are improved. Test results shows that the sensor has 900MHz center frequency,the band is 760MHz ~ 1. 05GHz when VSWR is less than 2,peak value of sensor output signal is 5V with frequency of 2 ~ 10MHz. The sensor has strong antijamming capability and high gain,which is suitable for GIS partial discharge detection.