Wavelet-based de-noising of partial discharge signals in MV covered-conductor networks
G.Murtaza Hashmi, Matti Lehtonen, Rana A. Jabbar, Suhail Aftab Qureshi · 2006
Partial discharge (PD) measurements conducted in the high voltage (HV) laboratory are less affected by electromagnetic disturbances (EMD). However, on the other hand, online/on-site PD measurements are often affected by several EMD sources. Extracting low level PD signal from noisy background is a major challenge for on-line condition monitoring. The PD signals are captured in the laboratory environment and on-site measurements are simulated in MATLAB. In this paper, wavelet transform (WT) technique is proposed as a powerful tool to de-noise PD signals in medium voltage (MV) covered-conductor (CC) overhead lines. The principle of de-noising based on multi-resolution signal decomposition (MSD) is implemented. The proposed method would be implemented in a real system environment to get more stable and reliable online/onsite PD detection results for the monitoring of fallen trees on the CC distribution lines.