基于小波包的功率测量及其频率灵敏性分析

For Measuring Fundamental Powers and its Analysis of Frequency Sensitivity Based Wavelet Packet Transform

功率测量和谐波分析是电力系统极其重要的课题,它们通常是基于傅里叶变换法来完成的。本文提出了一种基于小波包变换法实现单相基波有功、无功、视在功率及位移功率因素测量/计算的新方法,并对它们的精确度进行了分析。通过使用MATLAB中的GUI(Graphical user interfaces)针对不同的方法进行了比较仿真和实验分析,结果一致显示了该方法的可行性和有效性。此外,对使用傅里叶变换法和小波包变换法对频率变化的灵敏性进行了对比研究,结果表明小波包变换法对频率变化的敏感性更小,小波包变换法比传统傅里叶变换具有绝对的优势。

Power measurement and harmonic analysis are the vital issues of power systems. The analysis usually is based On FFT method. In this study, the accuracy of proposed method using WPT for fundamental active-reactive- apparent powers, displacement power factor are pointed out with computer MATLAB simulations and experimental analysis. The MATLAB simulations by computer and experimental results show consistent evidence of the feasibility and effectiveness of proposed method. Furthermore, frequencY sensitivity of the wavelet packet based power analysis is carried out in comparative simulation with the classic Fourier based analysis and the results show the supremacy Of the proposed wavelet packet-based approach over the Fourier-based approach when the frequency variation is concerned.