6.5kV enhancement mode SiC JFET based power module

Abstract

United Silicon Carbide, Inc. (USCi) has developed a novel low-loss 6.5kV enhancement-mode SiC JFET chipset to address transformerless grid-tie, variable frequency drives (VFD) for industrial motors, heavy vehicle motor traction and other high DC-link voltage applications. The JFET devices demonstrate excellent switching losses, approximately ~20X less than 6.5kV Si-IGBTs. The new JFET devices were packaged along with 6.5kV rated SiC JBS diodes in a half-bridge configuration to form an all-SiC high temperature power module rated at 60A. The module performance parameters vs. temperature were evaluated and are presented. Turn-on and turn-off behavior of the module and the nature of paralleling enhancement-mode JFETs are presented. The power modules were tested in a buck converter where switching a bus voltage of 3.3kV at 10kHz and 15kHz was achieved and module power losses estimated. The fast-switching medium voltage SiC module can have a large impact on reducing system components and targets next generation power conversion systems seeking higher power densities.