Performance Evaluation of Different Diode Technologies of 3.3-kV SiC MOSFETs

This article presents an investigation of the third-quadrant switching performance of 3.3-kV SiC MOSFETs configured with various diode arrangements, with a focus on railway applications. Switching-energy measurements were performed using a 2-kV DC link across a junction-temperature range of$25~^{\circ }$C–$150~^{\circ }$C. The obtained experimental data were utilized in an electrothermal simulation framework to analyze and compare loss characteristics and efficiency among the different configurations. The diode configurations examined include: 1) body-diode (BD); 2) 3.3-kV SiC Schottky-barrier diode (SBD) with no BD conduction; 3) 3.3-kV SiC SBD connected in parallel with BD; 4) 3.3-kV SiC merged p-i-n Schottky (MPS) diode with no BD conduction; and 5) MPS diode in parallel with BD. The results show that the 3.3-kV SBD without BD conduction delivers the best third-quadrant performance, whereas the BD configuration exhibits the highest losses and lowest efficiency, making it the least favorable option for high-efficiency railway inverter applications.