基于改进的小波变换电力系统谐波分析  

Improved wavelet transform based harmonics analysis of power system

作　　者：康家玉[1] 曹志威[1] 王旭[1] 刘甲琛 KANG Jiayu;CAO Zhiwei;WANG Xu;LIU Jiachen(College of Electrical&Information Engineering,Shaanxi University of Science&Technology,Xi’an 710021,China)

机构地区：[1]陕西科技大学电气与信息工程学院,陕西西安710021

出　　处：《现代电子技术》2018年第19期49-53,共5页Modern Electronics Technique

基　　金：陕西省科技厅工业攻关项目(2015GY038)~~

摘　　要：小波变换(WT)具有可变的时-频窗口,能够聚焦信号的任意细节,适用于非稳态及瞬变信号的分析和处理,但因存在小波混叠现象,导致其分析的精度低、鲁棒性差。针对db20小波消失矩阶数大的特性和良好的频带划分效果,同时为满足电力系统谐波有效分析的要求,提出基于db20小波变换抗混叠的谐波分析方法。该方法首先将信号按频带分解成子频带信号,再利用连续小波变换分析子频带信号,获取谐波信息。经Matlab仿真表明,所提方法能够有效地分析电力系统谐波信号。Wavelet transform(WT)with variable time-frequency window can focus on any details of the signal and is suitable for the research and analysis on non-steady state and transient signals,but the presence of wavelet aliasing phenomenon leads to the low accuracy and poor robustness for harmonic analysis.Since the db20 wavelet has the characteristics of high-order vanishing moments and perfect effect for frequency band division,the harmonic analysis method based on db20 anti-aliasing wavelet transform is proposed to meet the requirement of power system for effective harmonic analysis.The method is used to decompose the signal into sub-band signals according to the frequency bands,and then the continuous wavelet transform is used to analyze the sub-band signals to acquire the harmonic information.The simulation results of Matlab show that the proposed method can analyze the harmonic signal of power system effectively.

关 键 词：小波变换 db20小波 小波混叠 子频带信号 抗混叠 电力系统谐波 

分 类 号：TN915-34[电子电信—通信与信息系统] TM711[电子电信—信息与通信工程]