Study Of Interharmonics Analysis And Detection In Power System

Interharmonics in power system is a kind of the harmonics which are not an integer of the fundamental frequency component. The interharmonics make the induction motor noisy and vibrative, cause voltage flicker and worsen the power quality, so it is important to measure interharmonics accurately. Interharmonic parameters cannot be obtained accurately by using Fast Fourier Transform (FFT) for an unsynchronized sample sequence analysis because of large errors in such cases. A novel method to detect interharmonics based on CWPT is proposed in this paper by research on many methods such as continuous wavelet transform (CWT) and wavelet packet transform (WPT). A method which functions through the continuous wavelet transform is discovered to precisely detect the parameters of the non-zero frequency band after wavelet packet transform. Simulation and comparative results reveal that the proposed method can precisely extract interharmonics information, so it provides a vigorous means for power system interharmonics analysis.