【摘要】 虽然许多文献表明基于小波的谐波检测方法优于传统的谐波检测技术,但因混叠现象的普遍存在,导致其精度低、鲁棒性差,需要寻求新的解决方法。该文研究了小波变换的混叠现象,提出了一种电力系统谐波检测的抗混叠小波分析方法。离散小波变换混叠补偿方法,通过该方法将谐波信号分解成不同频带的子频带信号,再利用连续小波变换对非零子频带信号进行分析,提取谐波分量特征。仿真试验和几种方法的计算结果表明,文中所提出的谐波分析方法能够有效地消除小波混叠,并能精确地提取谐波分量特征,从而为电力系统谐波精确检测提供了一种有效的手段。更多还原

【Abstract】 Although it was shown the wavelet-based methods proposed in many literatures are superior to the traditional harmonic detection techniques, because aliasing in wavelet transform (WT) often cause measurement error, so there still remains a need to investigate new wavelet-based methods for more accurate and robust detection. Through analysis of aliasing phenomenon in WT, this paper developed an aliasing compensation method to reduce aliasing in discrete wavelet transform (DWT) for power system harmonic detection. Through DWT with aliasing compensation, it decomposes the power system harmonics into sub-band frequency signals with different frequency-bands, then the continuous wavelet transform (CWT) is applied to analyze the nonzero sub-band signals, so harmonic characters such as frequency, amplitude and phase were detected. Simulation and comparative results reveal that the proposed method can effectively eliminate aliasing, can precisely extract harmonic information, so it provides a vigorous means for power system harmonic analysis.更多还原