Determination of Critical Cavity Size on Stator Bar Insulation System Using a Finite Element Method Model
Keywords: partial discharge modelling, electric field, insulation system, finite element method, simulation
AbstractPartial discharge (PD) inside cavities causes aging of a stator bar groundwall insulation system that can generates a breakdown leading to equipment failures. One of the conditions to a PD occurrence is that the electric field (EF) within the cavity must exceed an inception field that mainly depends on the cavity size and pressure. A stator bar model has been simulated using Finite Element Method (FEM) in order to study the presence of a spherical cavity within the insulation. Simulation results and inception field calculation were used to determinate critical cavity size.