On-site Portable Partial Discharge Detection Applied to Power Cables Using HFCT and UHF methods

Partial discharge (PD) events happen inside the power cables and cable terminations with the insulation degradation. The PD detection can effectively supply the information of cable status. According to the electrical and electromagnetic emission of PD activities, high-frequency transformer (HFCT) and ultrahigh-frequency (UHF) methods are employed to detect the PD signals. Besides, a portable PD monitoring device is developed for on-site PD testing. The device consists of signal conditioning, high-speed data acquisition system and data processing unit. The comparison between HFCT and UHF results discriminates the real PD signals from interference remarkably, and contributes to PD source location. Additionally, advanced phase-resolved PD analysis is used to recognize the defect pattern. The on-site experiments show that the combination of HFCT and UHF methods is successful and abstractive in the power cables condition diagnosis. Key-Words: Partial discharge, HFCT, UHF, Potable PD monitoring device, High-speed data acquisition, Interference discrimination, Pattern recognition