改进型小波包变换的谐波检测研究

摘要

For the signal aliasing problems existing in the current extracting using wavelet packet transform algorithm unstable DC elevator,a modified wavelet packet transform algorithm is proposed.This improved algorithm separates the initial mixing of the fundamental, and then the characteristic information of non-stationary signals can be accurately extracted.lt is a good solution for aliasing.Simulation results show that 0.04 s signal after the reconstruction of coincidence and the fundamental signal accord within 1% accuracy .The experimental results show unproved wavelet packet transform algorithm has high accuracy and meets the active power filter for harmonic detection.%针对当前利用小波包变换算法提取直流提升机中非稳定型信号时存在的信号混叠问题,提出一种改进型小波包变换算法,该改进型算法在起始时对引起混叠的基波进行分离,从而消除引起的影响,进而能准确地提取出非平稳信号的特征信息.仿真实验表明,0.04s后重构的信号与基波信号的重合精度在1％以内,并通过设计硬件检测系统进行现场实验.实验结果证明改进型小波包变换算法有较高的精度,能够很好地满足有源滤波器对谐波检测的要求.