应用于电力系统谐波分析的采样周期自适应方法

摘要:

提出了一种谐波检测时，基于序列相关计算的采样周期自适应方法。该方法首先计算两组相邻采样信号序 列的相关系数，根据相关系数和二次修正方程修正采样周期，不断迭代直至采样序列满足同步化收敛条件; 最后对最 新同步序列进行 FFT 计算得到各次谐波参数值。该方法无需知道信号的实际频率，在迭代过程中采样点数保持不 变，克服了基于相关计算的采样窗口同步化方法中由于采样周期固定所引起的长序列 DFT 计算。数字仿真计算表明 在系统信号频偏较大的情况下该方法收敛速度快，计算量小，计算精度高。

Abstract:

A method for exact calculation of static harmonic using adaptive sampling period based on correlation calculation is presented． It is an iterative optimization procedure which searches for the most suitable sampling period according to the correlation coefficient of two adjacent sections and the quadric modified equation． The harmonic parameters are finally presented by the FFT calculation of the latest synchronous sequence． The algorithm does not require any knowledge about the system frequency，and the long sequence DFT computation can be avoid because of the constant sampling window． Various case studies using simulation data show that the proposed algorithm has fast convergent speed and high detection precision even if the system frequency deviation is large．