三种基于WVH变换的间谐波测试算法的分析和比较

摘要

间谐波除了造成与谐波相同的危害外还体现出时变性,基于时频分布思想下的维格纳-威尔分布(WVD)、伪维格纳-威尔分布(PWVD)、平滑的伪维格纳-威尔分布(SPWVD),虽然能够很好地解决电力系统中间谐波时域和频域的对应关系问题,但有不可避免的交叉项,在采用霍夫变换以后间谐波信号能够被清晰地提取；经过对三种方法的比较可以得到基于平滑的伪准格纳-威尔分布的霍夫变换(SPWVH)为比较理想的间谐波提取和测试方法.%Inter -harmonic and harmonic have the same harms; and inter -harmonic reflects time -varying characteristic. Wigner-Ville Distribution (WVD); Pseudo Wigner-Ville Distribution (PWVD); Smoothed Pseudo Wigner-Ville Distribution (SPWVD) based on time-frequency distribution can reflects time-frequency characteristic of inter-harmonic in the electric power system; but cross-items can't be averted. By the Hough transformation; inter-harmonic signals can be extracted. Comparison of three testing methods concludes that SPWVH is the best algorithm for testing and extracting inter-harmonic from the electric power system.