一种基于小波包变换的电力系统谐波检测方法  

A harmonic detection method for power system based on wavelet packet transform

作　　者：肖厦颖 李开成[1] 王凌云 孟庆旭[1] 蔡得龙 罗奕[1] Xiao Xiaying;Li Kaicheng;Wang Lingyun;Meng Qingxu;Cai Delong;Luo Yi(State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074, Chin)

机构地区：[1]华中科技大学强电磁工程与新技术国家重点实验室,武汉430074

出　　处：《电测与仪表》2017年第24期1-6,16,共7页Electrical Measurement & Instrumentation

基　　金：国家自然科学基金资助项目(51277080)

摘　　要：非线性设备的大量使用和分布式电源的投入使得谐波污染愈加严重,文中提出了一种基于小波包变换的谐波检测方法,能对电能质量进行有效的分析。该方法在五层db40小波包变换的基础上,利用希尔伯特变换做移频运算,避免了中间频段小波混叠对检测精度造成的不利影响,并将各次谐波分量转移到精度较高的边频带进行小波包分解并重构信号,实现了各次谐波的高精度检测,同时通过Matlab工具对不同算法的仿真进行了比较和误差分析。仿真表明,相比于传统傅里叶变换,该算法具有高分辨率时频分析能力,能有效定位暂态干扰;与经典小波包变换相比,测量精度也有了较为明显的提高,实验结果一致显示了该算法的可行性和优越性。As the widely use of the non-linear equipment and distribution generation, the harmonic pollution is becoming increasingly severe. Harmonic detection is a major topic in power quality（PQ） analysis. In this paper, a harmonic detection method based on wavelet packet transform is proposed. This algorithm is based on the five-layer db40 wavelet packet transform（WPT）. In order to reduce wavelet aliasing in the middle band, and the Hilbert transform （HT） is used for frequency shift so that the harmonic components are transfe^ed to the marginal band with a better accuracy. Then, the shifted signal is decomposed and reconstructed by the WPT for high-accuracy detection of the harmonics. Simulation of different algorithms and error analysis are also given in this paper. The simulation results show that this algorithm has a better ability of high-resolution time-frequency analysis and can detect the transient disturbance more effectively. Compared with the traditional proved, which is more accurate than WPT, and the test method. Fourier transform, the measurement accuracy is also imresults verify the feasibility and advantages of the proposed

关 键 词：小波包变换 希尔伯特变换 谐波 电能质量 

分 类 号：TM935[电气工程—电力电子与电力传动]