Assessment of the reverse operational characteristics of SiC JFETs in a diode-less inverter

In this paper, a thorough analysis of the reverse conduction characteristics of vertical trench (VT) Silicon Carbide (SiC) junction field effect transistors (JFETs) is performed. While these power devices do not encompass a body diode, traditionally present in conventional Silicon (Si) based semiconductors, such as the metal-oxide semiconductor field-effect transistors (MOSFETs), they exhibit notable reverse properties such that an external antiparallel diode can be considered redundant in most power converter applications. Both enhancement mode and depletion mode SiC JFETs are examined in terms of static reverse operation. Their performance is initially validated through simulation testing by constructing new SiC JFET models in Pspice model editor. The theoretical and simulation results are confirmed via experimental testing in a three phase voltage source inverter with and without antiparallel SiC diodes. When a gate drive that protects the semiconductor during reverse operation, while presenting great switching and forward conduction characteristics, is introduced, the power converter´s overall performance is investigated paying particular attention to power losses during the dead time interval.