摘要
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,利用采样起点间隔半个信号周期的DFT变换数据进行谱泄漏抵消;然后用前面的方法进行相量测量,通过跟踪采样频率,进而再次测量;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 based on conventional DFT algorithm has been proposed. Firstly,with the fundamental signal, the equation of frequency deviation can be obtained by using 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, in order to improve the measurement accuracy with harmonics, it is applied by counteracting the spectrum leakage of data derived from DFT of two data windows which stagger about half period of signal, the same algorithm of measure phasor, tracking of sampling frequency, and measuring again. Finally, signals with harmonics and noises are simulated respectively, and the results show high accuracy of this algorithm in all these situations.
出处
《电测与仪表》
北大核心
2009年第6期13-16,20,共5页
Electrical Measurement & Instrumentation
关键词
相量测量
DFT变换
谱泄漏
phasor measurement, discrete Fourier transform, spectrum leakage
