Development of a UHF PD detection system to estimate the dielectric condition of a Medium Voltage Switchgear

Defects in the SF₆ medium voltage (MV) switchgear can result in failure. Therefore it is important to detect defects, such as protrusion and particle, in time and to determine their risk for a possible breakdown. For high voltage apparatus, the ultra high frequency (UHF) partial discharge (PD) detection technology has proven to be a useful method. This paper describes the development of a UHF PD detection system for the MV switchgear and its practical application. Experimental studies show that the PD detection of the MV switchgear defects is possible. The practical experiences related to this study provide further insight for applying the UHF PD monitoring technique to MV switchgears.