Estudo de descargas parciais em isolamento de máquinas elétricas usando o método dos elementos finitos

Abstract

Partial discharges are internal discharges in the insulation system caused by imperfections during the manufacturing process or by regular insulation deterioration. The repetition of partial discharges can deteriorate the insulation that can lead it to fail. In stator coils of medium voltage machines, monitoring partial discharge is a great tool for monitoring the condition of the insulation of motors and generators as a way to try to predict whether the insulation is close or not to fail. The good understanding of partial discharge phenomenon is an important first step to increase the assertive diagnosis in monitoring the life of the insulation system in electric machines. In this context, this work aims to study the phenomenon of partial discharges using a model via finite elements, which was presented previously, in the insulation of a stator coil of 13.8 kV with an internal cavity in the main insulation. The main goal of this work is to check the influence of certain parameters in the results. Thus, simulations were carried out considering variations of parameters such as size, position and geometry of the cavity, amplitude of the applied voltage, thickness of main insulation of the coil and initial temperature of the geometry.