基于Rogowski线圈的电子式电流互感器复合误差计算方法

Calculation Method of Composite Error for Electronic Current Transformers Based on Rowgowski Coil

电子式电流互感器复合误差的计算与分析是提高获取电力系统运行信息精度的重要内容。为了准确测量电子式互感器的复合误差,介绍了电子式电流互感器的误差校验方法,分析了基于Rogowski线圈的电子式电流互感器基本工作原理,从而提出了多种基于Rogowski线圈的电子式电流互感器的复合误差计算方法。在此基础上对各种复合误差计算方法进行比较与分析,提出了基于Hilbert变换的复合误差计算方法。结果表明:Hilbert变换在信号为标准正弦信号时,计算结果不受采样频率的影响,当信号频率在常见范围内波动时,计算结果都能满足误差限值要求,即使信号出现一定谐波含量,也能达到准确度要求,因此选择Hilbert变换作为基于Rogowski线圈的电子式互感器复合误差计算的积分算法。实际检测证明基于Hilbert变换的Rogowski线圈复合误差计算方法是可行的。

The calculation and analysis of composite error for electronic current transformer is important to the precision of power operational factors. We introduced the error calibration method of electronic current transformer, analyzed the fundamental principle of electronic current transformer on the basis of Rogowski coil, and proposed several composite error calibration methods of electronic current transformer on the basis of Rogowski coil in order to test composite error accurately. Then we proposed a composite error calibration method based on Hilbert transform according to the comparison and analysis of several composite error calibration methods. The results show that, when using Hilbert transform, the calculation result is not affected by sampling frequency and can satisfy the demands of error limiting value when signal frequency fluctuate in common range if the signal is of standard sine wave. The calculation result can satisfy the accuracy requirements even the signal contains some harmonic content. Therefore, the Hilbert transform can be chosen to be a calculation method of composite error for electronic current transformers based on Rowgowski coil. This method is proved practicable by practical test.