Compact Three-Phase SiC Inverter for the IST Formula Student Prototype

Pedro Miguel Batista de Sousa Correia da Costa

Key information

Authors:

Pedro Miguel Batista de Sousa Correia da Costa (Pedro Miguel Batista de Sousa Correia da Costa)

Supervisors:

José Fernando Alves da Silva (José Fernando Alves da Silva)

Published in

11/23/2018

Abstract

This thesis has as primary objective the development of a prototype for a three-phase inverter, driving circuits and instrumentation, using new semiconductor technologies available in the market, to be implemented in a competition electric vehicle of the IST Formula Student team. Furthermore, a theoretical basis and a set of experimental procedures was proposed in order to estimate the semiconductor losses in inverter operation. In a preliminary analysis the state of the art on the development of wide bandgap semiconductors for use in power converters is depicted. Two promising devices, Silicon Carbide MOSFET and Gallium Nitride HEMT, were chosen from two leading manufacturers in the production of these devices, and for each several experimental tests were performed. At the light of the test results the MOSFETs and Silicon Carbide Schottky Diodes were selected as the most suited technology to be used in inverters for motorization of racing vehicles. The switching and conduction losses for both chosen devices were characterized in an inverter configuration. The obtained experimental results were compared with values obtained by simulations using SPICE models available by the manufacturers. In addition, the experimental data was used to formulate new models that allow the determination of losses in dynamic conditions, thus meeting the real needs of the Formula Student prototype. During the execution of the thesis the operation of the inverter prototype was tested using an inductive load and a three-phase motor, showing prominent results both in power density as in efficiency.