一种基于小波包和apFFT的间谐波检测方法

A method to detect inter-harmonics based on wavelet packet and apFFT

针对现有的间谐波检测精度不高以及暂态间谐波信号定位困难等问题,探讨了一种新的间谐波检测方法。首先,将信号进行小波包和FFT变换,计算相对小波包能量。然后应用频谱特征量和相对小波包能量确定信号所含分量。最后利用小波包重构与apFFT算法检测和定位信号,计算间谐波幅值和频率。分别采用含稳态及暂态的间谐波信号模型对该检测方法进行了仿真研究,并将仿真结果与文献的结果进行了比较。仿真结果表明:该检测方法能够有效地检测间谐波,并具有较高的检测精度。

For the low accuracy and positioning difficulty to detect inter-harmonics, a new method is discussed in this paper. It calculates the relative wavelet packet energy based on wavelet packet. The spectral features are obtained by using FFT algorithm. According to its relative wavelet packet energy and its spectral features, it can determine the frequency components of the detected power signal. The transformed signal is reconstructed using wavelet packets. The amplitudes and its frequencies of inter-harmonics of the reconstructed signal are calculated using apFFT algorithm. The proposed algorithm is simulated. The simulation results are compared with those of literatures. It can be seen that the proposed algorithm is verified, and the proposed algorithm can detect inter-harmonics of a given signal much more accurately.