197 / 2018-09-09 10:37:57

Digital Filter Based on Chaos Theory Used for Removing Narrow-Frequency-Band Noise in PD Signals

partial discharge,on-line monitoring,narrow-frequency-band,chaotic oscillator

Partial discharge (PD) on-line monitoring is an effective approach to inspect insulation defects and identify potential faults in high voltage equipment. However, electromagnetic noises such as narrow-frequency-band (NFB) noise make it difficult to measure PD signals in the field accurately. Some digital filters such as IIR, FIR filter are effective in rejection of the NFB noise. However, it is non-effective while the frequency of the NFB noise is coincident with the frequency of the PD signal. This paper proposed an approach which can remove the NFB interference in the PD signals by the chaos theory. The basic principles of chaotic oscillator interference filter in suppressing PD signal narrow-band was researched. The method based on the characteristic that the moving state of chaotic oscillators which was determined based on the chaotic phase diagram and Lyapunov exponent, and put forward chaos oscillator filter to inhibition the narrow-band interference in PD detections. The de-nosing results show that: the chaotic oscillator filter denoising effect is better than the two order IIR-rated filter.