一种高精度的电力系统相量测量方法

A high-precision algorithm for phasor measurement of power systems

在传统的离散傅里叶算法的基础上提出了一种新的相量测量算法,首先,对纯基波信号,该算法利用2个数据窗的DFT变换数据推导出了一个关于频率偏移的方程,解此方程后可以求出基波信号的频率、幅值及相位的精确解,在推导过程中无任何近似误差,有效减小计算量的同时提高了测量的精确性。接着,为了提高谐波情况下测量的精度,利用迭代法对原采样序列进行修正,然后在最终的修正序列上用前面的算法进行相量测量。最后,分别对存在谐波和噪声的情况进行了仿真,结果表明,该算法在各种情况下具有测量精度高的优点。

A new phasor measurement approach which is based on conventional DFT algorithm is proposed. Firstly, with the fundamental signal, the equation of frequency deviation can be obtained by use of data derived from DFT of two data windows in the proposed approach, hence, the accurate frequency, amplitude and phase of fundamental signal can be obtained after solving this equation, and there is no any approximate error in the process of derivation of the proposed approach in which the operation amount can be effectively reduced and the measurement accuracy is improved. Then, to improve the measurement accuracy with harmonics, iteration method is applied to modify the original sampled sequence, and the same algorithm is proposed to measure phasor on the last modified sequence. Finally, signals with harmonics and noises are simulated respectively, and the results show the high accuracy of this algorithm in all these situations.