输电线路雷电流测量用Rogowski线圈低频失真校正技术

Low-frequency Distortion Correction Technology of Rogowski Coil Applied to Lightning Current Measurement on Transmission Lines

自积分式Rogowski线圈用于输电线路雷电流测量时,由于雷电流含有丰富的低频成分,往往导致测量得到的雷电流波形出现低频失真现象,影响雷电流参数的精确测量。为此,经过对自积分式Rogowski线圈低频失真现象产生机理的理论分析及雷电流频谱分析,提出了一种基于新型模拟积分补偿电路的低频失真校正方法,用以对被测电流逆向还原,分析了电路的工作原理并根据Rogowski线圈的电磁参数计算出电路各元件的参数值,此外,电路中的二阶高通滤波电路可以滤除工频负荷电流对Rogowski线圈的电磁干扰。实验结果表明:该方法简单可行,提高了自积分式Rogowski线圈的低频响应性能,解决了Rogowski线圈雷电流测量中的低频失真问题;在已投入的输电线路雷击故障定位系统实际应用中,有效提高了故障行波电流测量的精度和可靠性。

When self-integrator Rogowski coil is used for measuring lightning current on transmission lines, because of the rich low-frequency component contained, the lightning current waveform measured often tends to be in low-frequency distortion, affecting the accurate measurement of lightning current parameters. Therefore, according to a theoretical analysis of the low- frequency distortion mechanism of self-integrator Rogowski coil and an analysis of lightning current spectrum, a low-frequency distortion correction method based on a new integral compensation circuit is put forward for restoring the original measured current retroactively. The working principle of the circuit is also dealt with, and the circuit parameter value of each element is calculated based on electromagnetic parameters of Rogowski coil. Furthermore, the second-order high-pass filter circuit can be used to filter out the electromagnetic interference in Rogowski coil caused by the power frequency current. Experimental results show that the method is simple and feasible, the low-frequency response performance of self-integrator Rogowski coil is improved, the problem of low-frequency distortion of Rogowski coil used for measuring lightning current is solved. Adoption of the method for a transmission line lightning fault location system has effectively improved the measurement precision and reliability of the fault traveling wave current.