改进小波包与EMD的微电网谐波检测研究  

Harmonic Detection Method Based on Improved Wavelet Packet and EMD

作　　者：季青川 刘鸣 毕伟 黄一鸣 JI Qing-chuan;LIU Ming;BI Wei;HUANG Yi-ming(State Grid Hubei Integrated Energy Services Co.,Ltd.,Wuhan 430070,China)

机构地区：[1]国网湖北综合能源服务有限公司,湖北武汉430070 [2]武汉理工大学,机电工程学院,湖北武汉430070

出　　处：《电力电子技术》2020年第12期89-92,共4页Power Electronics

基　　金：国家重点研发计划(2018YFB2000103)。

摘　　要：针对传统小波包与经验模态分解(EMD)算法难以检测微电网高次低幅值谐波,且检测结果容易产生频率混叠的问题,提出一种基于改进小波包与EMD的微电网谐波检测方法。该方法首先将原始微电网谐波信号进行小波包分解得到信号的近似系数与细节系数,通过多次选取细节系数进行分解,从而尽可能多地获得信号有效谐波成分。仿真结果表明,该算法能够有效地改善频率混叠现象,检测出信号50 Hz的基波成分及频率分别为150 Hz,250 Hz,350 Hz,650 Hz的3,5,7,13次谐波成分。通过实验分析且与传统的小波包与EMD算法对比,在分布式并网系统模式下可对并网电流谐波进行检测。Aiming at the problem that the traditional wavelet packet and empirical mode decomposition(EMD)algorithm are difficult to detect the high-order and low-amplitude harmonics of micro-grid and the detection result is easy to generate frequency aliasing,a method for harmonic detection of micro-grid based on improved wavelet packet and EMD is proposed.The approximate coefficient and the detail coefficient of the signal are obtained by the wavelet packet decomposition of the original harmonic signal of the micro-grid.The simulation results show that the algorithm can effectively improve the frequency aliasing phenomenon,and can detect the 50 Hz fundamental wave component of the signal,as well as the 3,5,7,13 harmonic components with frequencies of 150 Hz,250 Hz,350 Hz,650 Hz respectively,which proves the feasibility of the method.Adopting the experimental analysis and comparison with the traditional wavelet packet and EMD algorithm,the superiority of the proposed algorithm to the harmonic detection of grid-connected current in distributed grid-connected system is verified.

关 键 词：微电网 谐波检测 小波包 频率混叠 

分 类 号：TN819.1[电子电信—信息与通信工程]