Time-Frequency Analysis of Partial Discharge Phenomena in SF₆ gas using Wavelet Transform

Abstract

Recently, diagnostic techniques have been investigated to detect a partial discharge (PD) associated with a dielectric material defect in a high-voltage electrical apparatus. However, the properties of PD aren't completely understood because the physical process of PD is complicated. For improvement of detection techniques of PD, it is important to make clear the fundamental physical process of PD.
Therefore, this paper analyzes the process of PD using Wavelet transform. Wavelet transform provides a direct quantitative measure of spectral content ( Dynamic spectrum ) in the time-frequency domain. As it is important to develop a non-contact method for detecting the insulation fault, this paper analyzes the electromagnetic waves emitted from PD using Wavelet transform.
This paper experimentally shows the process of PD as a two-dimensional distribution “Dynamic spectrum” in the time-frequency domain. This method is shown to be useful for detecting prediction of insulation fault.