Edinburgh Napier University

  The underlying cause of the cessation in high voltage machineries can be rooted from the failure in the insulation system due to cavity's discharges originating from the presence of cavities. This paper caters to the study of the electric field distribution inside stator bar insulation system with different arrangement of cavities, in either single or multiple cavities of different alignment to aid the investigation of electric field stresses inside the cavities and the tendency of electrical breakdown in the stator bar insulation system. Simulation using Finite Element Method (FEM) with the assistance of COMSOL software is being carried out for this 2-Dimensional stator bar insulation modelling. A 10kV stator bar insulation system is modelled in 2 dimensions to analyse the electric field distribution under different arrangements of cavities. The simulation results show that the randomly distributed cavities aligned in vertical direction constitutes a greatest upsurge of electric field stress by 85% while horizontally aligned cavities that are 0.7mm apart instigates only 46.2% increase in electric field stress within the cavity. This affirms that the arrangement of cavities poses an influence over the electric field distribution inside stator bar insulation system.