Simulation of HFCT PD Detection in MV Bus Bar Chamber

A simulation investigation is conducted for high frequency current transformers (HFCT) partial discharge (PD) detection on a grounding conductor in a medium voltage (MV) switchgear compartment. A three-dimensional (3-D) bus bar chamber of an air insulated MV metal clad switchgear including PD sources and grounding position is developed using Comsol Multiphysics. The PD sources are placed at different locations in the chamber and the sensitivity of the HFCT signal is investigated depending of different position of the bus bar chamber grounding. The current induced by PD in the grounding conductor is provided as input to the HFCT sensor. Throughout the simulation it can be seen that there is an influence on the sensitivity of the HFCT signal depending on the grounding position. The analysis helps also to inform the nature of HFCT signals related to different PD locations and grounding wire positions which will help to refine and understand better HFCT measurements for condition monitoring within such systems.