Simulation of PD RF EM wave propagation in different MV bus bar compartment configurations

Monitoring of partial discharge (PD) in air-insulated medium voltage (MV) switchgear can reveal potential insulation failure. There is still clarification needed to understand the most effective placement of RF probes, especially along extended MV switchgear line-up structures. In this work a simulation study was performed to investigate the differences between the PD propagation characteristics of electromagnetic (EM) waves in one single bus bar and a triple line-up of bus bar compartments. A finite element method (FEM) bus bar compartment model is created and simulations are performed in Comsol Multiphysics. By applying PD sources at specific locations on particular phases, RF signals are recorded along the compartment surfaces. Based on created signal energy interpolation maps, the potential best sensor position placement areas of RF sensors is revealed for each PD case for the different compartment structures. The investigation reveals that for the sake of PD signal propagation studies PD within a single compartment model may produce similar PD sensor positions patterns to PD of a central bus bar chamber within a triple compartment.