基于最优小波包基的电能质量扰动数据的压缩

Compression of power quality disturbance data based on optimum wavelet packet base

针对电能质量扰动信号的频率变化十分广泛(最高达到MHz)的特点,在小波压缩的基础上,提出将基于最佳小波包基的数据分析方法应用于电能质量数据压缩,利用最佳小波包基的快速搜寻算法对高,低频分量同时进行分解,再对扰动数据进行压缩重构,并将其与基于小波变换的数据压缩方法进行仿真比较。结果表示,对于暂态信号,在压缩比大致相同的情况下,基于最佳小波包基的数据压缩效果比基于传统小波的数据压缩效果好,而对于稳态信号,基于两种方法的压缩效果相当。

According to characteristic of the disturbance signal of power quality whose frequency varies widely, this paper puts forward a method based on optimum wavelet packet base for the compression of disturbance data of power quality . Then the fast search algorithm of optimum wavelet packet base is used to decompose the parts of high frequency and the parts of low frequency at the same time, and subsequently the signal is compressed and reconstructed. Finally, by comparing with the method based on the wavelet, the conclusion can be drawn that for the transient disturbance signal the distortion rate of the former is lower when the compression rates of the both methods are approximately same, while for the static signal the effects of the compression based on the two methods are equivalent.