随机环境下电力系统谐波分析算法

离散傅里叶变换（DFT）是电力系统谐波分析常用的算法。研究随机环境下DFT算法在同步采样和非同步采样2种情况下的统计特性，DFT算法包括普通DFT算法和加窗DFT算法，统计特性包括均值、方差和相关性等。导出了用加窗DFT算法实现谐波幅值和相位无偏估计的条件，并由此提出了一种新的时变加权DFT算法。基于MATLAB软件的仿真结果证实了结论的正确性。

Algorithms for Harmonic Analysis of Power Systems Under Stochastic Condition

Discrete Fourier transform (DFT) is popular in harmonic analysis of power systems. The statistical characteristics of DFT algorithms for synchronous sampling and asynchronous sampling under stochastic condition are studied. DFT algorithms contain normal DFT algorithm and windowing DFT algorithm. The statistical characteristics contain the mean value, the variance and the correlation for every order of harmonic and so on. A non-deviation estimation approach for harmonic amplitudes and phase angles with windowing DFT algorithm is deduced. A novel time-invariant windowing DFT algorithm is proposed based on the condition deduced. Simulation results based on MATLAB show the correctness of the conclusions given.