Measurement and Denoising of Partial Discharge Signal in High Voltage Cables using Wavelet Transform

Abstract

A huge amount of exploration propagated over the past decade investigates the characterization of Partial Discharge (PD) inception in cable ideology. Underground cables are passed down as surrogate for over hauling in congested areas. The intention of this research is to examine the feasibility of exploring insulation defects present in High Voltage (HV) Cable setup by employing PD disclosure under alternating current (AC) Voltage. Study of PD characteristics has a congregate of predictable distinguished contraption to prove the probity and the affirmation of electrical insulation of Power System. In this work, the cable is exposed into the measurement of PD signal under artificially conceived defects. PD signal parameters are mainly depends on the size of void and applied voltage. In general, the measured PD signal is depraved with interferences. To identify the exact characteristics of PD distinctive and its severity, the PD signal is subjected to Wavelet Transform (WT) for denoising. Different types of WT families with various level is used for de-noising. To identify the effectiveness of the WT for de-noising guidelines like Signal to Reconstruction Error Ratio (SRER) and Reduction in Noise Level (RNL) are used.

Evaluation Study on Wavelet Denoising of Antenna-Based PD Measurements in Strong Interference Environments Considering a New Reliability Score of Pulse Detection

“…Several studies on the wavelet selection are available. The Daubechies Wavelet (db), designed around 1990 by Ingrid Daubechies, as well as the Coiflet Wavelet (coif), also designed by her, and a modified form of the Daubechies Wavelet, the Symmlet Wavelet (sym), are already subject of research on interference suppression of PD measurement signals [8] [9] [10] [11] [12]. These wavelet families mentioned are orthogonal wavelets.…”

“…This is associated with differences in the interference level and, correspondingly, the SNR of the data to which wavelet denoising is applied. Conventional measuring circuits with coupling capacitor and measuring impedance are used in [9], [10] and [13] to decouple the PD signal. This results in PD signals with an SNR of 69 dB [10] and −16 dB [13].…”

“…Common to all studies is the use of quantitative evaluation criteria. For evaluation of interference suppression processes, besides the already mentioned signal to noise ratio (SNR), parameters such as the noise reduction level (RNL) [9] [17] or noise reduction ratio (NRR) [15] [19] are commonly used. Parameters such as the root mean square error (RMSE) [15] [17] [18] or mean square error (MSE) [10] and the correlation coefficient (Corr) [8] [15] [19] are used to evaluate the influence of the interference suppression process on the input useful signal.…”