基于Rogowski线圈和压频变换的电流测量方法

Accurate current measurement method for large currents

将 Rogowski线圈和压频变换 ( VFC)有机地结合 ,实现了在大电流范围内进行高准确度的数据测量。利用 Ro-gowski线圈的输出电压和输入电流的导数成正比 ,而 VFC的转换结果和输入信号的积分成正比的原理 ,使整个数据采集系统节省了非线性的积分环节。还论述了只要适当地选取VFC的积分周期就可以滤除主要噪声 ,而保留感兴趣的谐波分量 ,从而提高了抗干扰能力。在实际应用中 ,基于这种测量方法的光电式电流互感器 ( OECT)可期望实现 10 A～5 k A范围电流的高准确度测量。

A new current measurement method combines Rogowski wiring with a voltage frequency convector (VFC) was discussed to offer a very accurate current measurement for large currents. Since the output voltage of Rogowski wiring is proportion to the differential of the input current and the VFC result is proportion to the integral of the input voltage, a nonlinear integral circuit is not needed. The paper shows that for the proper integral interval, the harmonics in concern can be reserved and some noise can be filtered. A very accurate optical electric current transformer (OECT) was developed using this method in the 10A～5kA current scale.