Multidimensional Switching Loss Analysis of Various 1200 V SiC - Power MOSFET Technologies

Abstract:
The precise knowledge of losses occurring in hard-switching applications is required for virtual prototyping, digital twins, and hardware-in-the-loop optimization of power converters. For conduction losses, accurate models exist including multiple dependencies such as gate-source voltage, drain-source voltage, and temperature. These multidimensional dependencies are mostly lacking for switching losses. For hard-switching losses, the double pulse test has been established as an industrial standard, but the coupling between multidimensional parameters such as gate-source voltage and junction temperature usually is neglected since they require dedicated circuitry for variable gate-source voltage. This paper presents a multidimensional switching loss analysis and comparison of various 1200 V SiC MOSFET transistor technologies for hard-switching losses. It is shown that for different technologies different temperature behavior can occur. Furthermore, it is shown that the temperature has only a minor influence on the hard-switching losses, while the gate-source voltage can vary the switching losses significantly. An in-depth analysis of the gate-source voltage dependency of the turn-on and turn-off losses is conducted. While the positive gate-source voltage influences solely the turn-on losses, the negative gate-source voltage influences the turn-off losses and at elevated temperatures also the turn-on losses.