基于MRA的三相不对称系统谐波监测的研究  

Study of Three-Phase Dissymmetrical System Harmonic Monitoring Based on Multi-Resolutional Analysis

作　　者：郑明辉[1] 

机构地区：[1]江苏科技大学电子信息学院,江苏镇江212003

出　　处：《实验室研究与探索》2008年第11期24-27,共4页Research and Exploration In Laboratory

摘　　要：首先论述了基于小波变换的谐波检测的原理,根据目前小波变换在三相不对称系统谐波检测中存在的无法分离基波信号之不足,介绍了一种用于三相不对称系统的基于周期交错的测量方法。针对MRA算法既不能直接可靠地估算三相交流信号的基波成分(50 Hz),也不能精确地提取信号的谐波分量的缺点,探讨了将快速傅立叶变换和小波变换相结合的方法,利用小波变换的奇异信号检测能力和较好的时域分辨率,结合傅立叶变换准确的频域分辨能力对电网谐波信号模型进行了分析。文中归纳出基于小波变换的谐波监测方法。该方法的技术优势是可以实时跟踪谐波信号的变化。仿真实验结果表明了该方案能够满足电力系统中谐波检测的实时性要求。The principle of harmonic wave detection which is based on wavelet transform was expatiated. It introduced a new approach of harmonic measurement based on period-interleaving of arithmetic for dissymmetrical system. As multi- resolution analysis algorithm can＇ t reliably estimate fundamental frequency （50Hz） , also can＇ t precisely pickup harmonic frequency, a method which combines Fourier and wavelet comprehensive detecting algorithm was discussed. Using the special effect on detecting singularity point and high resolving degree in time domain of wavelet, combining with the exact frequency resolving ability of fast Fourier transform, it can analyze all kinds of harmonic. The simulative results shouw that the scheme is better than traditional harmonic analysis method. The advantage of the method is that it can track the change of harmonic frequency on real time. It can meet the requirements in real time monitoring of harmonic frequency in power system.

关 键 词：谐波 小波变换 周期变换法 电力系统 

分 类 号：TM769[电气工程—电力系统及自动化]