A modified method of suppressing narrow-band interference using FFT power spectrum

Suppressing narrow-band interference is one of the key techniques of partial discharge (PD) on-line monitoring. Based on the characteristics analysis of FFT power spectrum of PD signals with and without the narrow-band interference, the partial peaks and partial energy ratio is defined. Thus, a method of suppressing narrow-band interference using partial energy ratio pretreatment is proposed, and the steps are also detailed. Besides, the magnitude of partial energy ratio is fuzzified and the adaptive fuzzy C-mean threshold algorithm is proposed to extract the threshold of partial energy ratio. The denoising results show that the proposed method could pick narrow-band interference from the real PD signal.