基于UHF和HF的局部放电降噪方法的研究

采用基于阿基米德螺旋天线的特高频法与基于电流传感器的高频法对比测量的方法 ,发展了一种新型的降噪方法。其基本原理是 :高频法测得的脉冲信号中包括了油中放电信号和空气中电晕造成的脉冲干扰信号 ;特高频法测得的只有油中放电信号 ;故对高频法获得的信号 ,在仅对应于特高频法获得的信号处开窗时 ,可剔除脉冲干扰而获得油中放电信号。模拟实验以及现场变压器的实测结果证明这种降噪方法可有效抑制各种干扰特别是脉冲型干扰。

Study on a Noise Rejection Method Based on UHF for Partial Discharge Monitoring

During partial discharge(PD)on-line monitoring, various effective methods are be used to reduce all kinds of electrical noises, especially the pulse-shaped interference including periodical and non-periodical type. A comparative measurement including the ultra high frequency (UHF)detection method based on Archimedean spiral antenna and HF detection method is presented in this paper. A new noise rejection method has been developed Among the measured pulse-shaped signals based on HF method, the discharge signals in oil and pulse-shaped interference caused by corona discharge in air are included. But for measured signals of discharge in oil, pulse-shaped interference is depressed and signals of discharge in oil are obtained when windows are open in moments of measured pulses based on UHF method. It is proved that it is useful for rejecting various noises especially pulse shaped interference by the simulated experiment and on-site measurement for a transformer.