Best antenna arrangements for partial discharge detection in medium voltage switchgear

Partial discharge (PD) is known as small electrical discharge that occur within insulation of medium and high voltage electrical instruments. PD that occurs within gaps in medium voltage (MV) switchgear can wear off the insulation of equipment which leads to failure of the switchgear. The electrical and mechanical stresses can cause damage of components within switchgear, including the bus bar arm, cable compartment and the insulation within switchgear housing. Therefore, a precise method to determine the PD location within electrical equipment is important for the maintenance of the equipment and rectification of the PD source. The current available method is able to determine the location of PD within the 3-D space of MV switchgear without the need to disrupt power during detection. This method uses several radiometric signal detection antennas to detect PD signal and Time Difference of Arrival (TDOA) based algorithm combined with trilateration method to determine the PD location. This paper focuses on the determination of the best possible antenna arrangements for PD location to improve the accuracy of the method from 60cm to 30 cm. PD location detection methods were performed in 1-D and 2-D space of MV switchgear. The results obtained clearly show the best antennas arrangement and the accuracy of the location in laboratory condition.