Electrical stress mapping in a Type II machine supplied by inverters using Si and SiC‐based components

Abstract

The introduction of Silicon Carbide (SiC) based components in the electromechanical chain presents numerous advantages but has consequences on the reliability of the insulation systems in the machine. It is, therefore, necessary to determine whether, under normal operating conditions, phenomena that did not previously exist or were not completely apprehended will appear with the transition to SiC-based inverters. One of these phenomena is partial discharge (PD) and its development in machines, and more precisely in the turn-to-turn, turn-to-ground, and phase-to-phase insulation systems. The present study reports the investigations carried out on a high voltage machine fed by inverters using Silicon (Si) and SiC-based components. It forms part of a general study in which the primary objective is to determine the electrical stress to which the machine is subject, in order to systematically determine the conditions of occurrence of PDs and their consequences on the insulation system lifetime. The following work, which is the first part of the investigation, seeks to perform a thorough electrical stress mapping depending on both geometric and electrical parameters. An analysis of the results will also be presented, as well as thoughts concerning future work, especially regarding the link between electrical constraints and PD activity.