提出一种具有高准确度的电网正弦信号相位差测量方法。在非同步采样条件下，对离散傅里叶变换(discrete Fourier transform，DFT)的原理进行分析，得到短范围频谱泄漏效应和负频点频谱泄漏效应的解析表达式，据此提出利用信号离散频谱中具有最大和次最大幅值的2根谱线的位置以及实部和虚部的大小，构造一种新的插值方案，用以同时消除短范围和负频点频谱泄漏效应。仿真实验和实际测量结果表明，与已有的插值修正算法相比，所提出的插值方法能够有效地减小频谱泄漏效应，特别是负频点频谱泄漏效应，可应用于微小相位的高准确度测量。

A new accurate measurement method on phase difference between two sinusoidal signals in power system was presented. For asynchronized sampling, the principle of discrete Fourier transform was analyzed and the expressions of short-range spectrum leakage and negative frequency spectrum leakage effects were obtained. Then a new interpolation method was presented using the positions, the real parts and the imaginary parts of two spectral lines with the largest and larger magnitudes in discrete spectrum of the sampled signals. The method could eliminate the short-range and the negative frequency spectrum leakages at one time. The results of simulations and practical measurements show the presented interpolation algorithm can reduce apparently the spectrum leakages, especially the negative frequency spectrum leakage and can be applied in measuring the smaller phase with higher accuracy.

电力系统及发电设备安全控制和仿真国家重点实验室开放课题基金项目(SKLD09KM06)。