用小波变换和希尔伯特变换测量无功功率

Reactive Power Measurement by Wavelet Transform and Hilbert Transform

介绍用小波变换和希尔伯特变换求基于Budeanu定义的无功功率的新方法。希尔伯特变换能将各次谐波电压分别平移90,不受频带宽度的限制,移相精度高。用小波变换可在时间域高效准确地求电压电流有效值、有功和无功。将电压、电流和各次谐波分别移90的电压正交小波分解,用分解系数可求出电压及电流有效值、有功和无功,还可以求出各子带上的有功及无功。最后对新方法进行了仿真研究。

A new method is presented using Wavelet transform and Hilbert transform to calculate reactive power based on Budeanu's definition. Hilbert Transform can shift 90° for every harmonics. 90° shift isn't limited by frequency range and phase-shift precision is high. RMS, reactive power and active power are calculated most efficiently and most accurately using wavelet transform in time domain. The voltage signal, the current signal and the voltage signal shifted 90° are decomposed using orthonormal wavelet. RMS, reactive power and power can be calculated using coefficients, and reactive power and power in each subband can also be calculated. Simulation using the new method is carried out.