Comprehensive detection and analysis of partial discharge in switchgear

Partial discharge (PD) measurement is a promising method for condition assessment of insulation systems in high voltage equipments. Conventional PD measuring systems have some difficulties in the measurements especially in online conditions and noisy environments. There is a growing tendency to use new measuring systems for separation of PD pulses from different sources and rejection of external noises. In this investigation a new online multifunctional PD measuring system and relevant methodology are discussed. The proposed system uses an efficient detection method in identification and localization of PD pulses and reduction of interferences based on the transient earth voltage (TEV). Meanwhile, a wavelet multi-resolution analysis is applied to reduce background and communication noise level. In this paper some new and modified features for pulse classification procedure have been proposed. The proposed system, methodology and features have been implemented on a high voltage switchgear. Finally performance of the system is discussed.