Design of a three-phase AC/DC converter with paralleled SiC MOSFETs

Abstract

This paper describes a design procedure of a three-phase AC/DC converter with special focus on semiconductors: paralleled SiC MOSFETs and SiC Schottky diodes. The converter is aimed to operate as a 14kVA Support Converter (SC) for the 55kVA AC drive system. The SC acts as active parallel filter during normal operation of the drive and is also capable to return part of the regenerative breaking energy to the supply grid. Initial calculations of power losses conducted with Matlab are verified by simulations in SABER software. Laboratory model designed on the base of calculations and simulations was tested with special attention to power losses measurements. Total efficiency of the AC/DC converter (including LC filter and gate drivers) measured during inverter operation is on the level of 98.8% at switching frequency of 40kHz.