三种基于WVH变换的间谐波测试算法的分析和比较

Analysis and Comparison of Inter-harmonic Testing Method Based on Three Algorithms of WVH

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。

Interharmonic and harmonic have the same harms, and interharmonic reflects timevarying characteristic. WignerVille Distribution （WVD）, Pseudo WignerVille Distribution （PWVD）, Smoothed Pseudo WignerVille Distribution （SPWVD） based on timefrequency distribution can reflects timefrequency characteristic of interharmonic in the electric power system, but crossitems can＇t be averted. By the Hough transformation, interharmonic signals can be extracted. Comparison ＂of three testing methods concludes that SPWVH is the best algorithm for testing and extracting interharmonic from the electric power system.