基于脉冲源的高频电流传感器传输阻抗测量新方法

针对目前点频法在测量局部放电高频电流传感器(HFCT)传输阻抗上的不足,提出一种基于脉冲源的新方法。该方法使用脉冲作为激励信号注入,仅需1次测量即可获得检测频段内的传输阻抗曲线,极大地缩短了测试时间,提高了测试效率,具有操作简便、分辨率高等优点。搭建实验平台测量了多种型号HFCT的传输阻抗,分析了脉冲激励对测量结果的影响,并且将脉冲注入法和点频法进行了对比。实验结果表明:脉冲注入法宜使用上升时间小于10 ns的高斯脉冲作为激励信号,其测量结果与点频法高度一致,两者得到的传输阻抗曲线均值差不超过0.1 V/A,均方根误差小于0.25 V/A,相关系数大于0.85。

A novel pulse-source-based method for measuring transfer impedance of high frequency current sensor

Aiming at the shortcomings of the existing single-point frequency method in measuring the transfer impedance of HFCT(High Frequency Current Transformer) with partial discharge, a novel method based on pulse source is proposed. The proposed method adopts a pulse signal as the injecting source and can obtain the transfer impedance curve within the detection band by measuring only once, it greatly reduces the test time, improves the test efficiency, and has the advantages of simple operation and high resolution. An experimental platform is built, and the transfer impedances of various types of HFCTs are measured. Moreover, the influences of pulse signal source on the measurement results are analyzed. Finally, the pulse injection method and the single-point frequency method have been compared. The results show that Gaussian pulse with a rise time shorter than 10 ns should be used as the signal source. The measured transfer impedance curves of the pulse injection method and the single-point frequency method are highly consistent. The mean difference of the transfer impedance curves obtained by the two methods is at most 0.1 V/A, the root mean square error is less than 0.25 V/A, and the correlation coefficient is larger than 0.85.