Boost Converter With SiC JFETs: Comparison With CoolMOS and Tests at Elevated Case Temperature

The emergence of hybrid electric vehicles (HEVs) has driven an increasing demand for high power densities in power converters. Silicon carbide (SiC) is a candidate of choice to meet this demand, and it has, therefore, been the object of a growing interest over the past decade. The boost converter (step-up converter) is an essential part of the typical powertrain of an HEV. This paper presents a scaled experiment in which a boost converter with a SiCjunction field-effect transistor is compared to the same converter with a silicon (Si) superjunction metal oxide semiconductor field-effect transistor (MOSFET). In a first part, classic heatsinks are used; in a second part, the case of the transistors is maintained at 105 $^{\circ}$ C to mimic a cooling by radiator water. In both cases, results show a clear advantage for SiC.