Design comparison of high power medium-voltage converters based on 6.5kV Si-IGBT/Si-PiN diode, 6.5kV Si-IGBT/SiC-JBS diode, and 10kV SiC MOSFET/SiC-JBS diode

In this paper a comparative design study of high power medium-voltage three-level NPC converter with 6.5kV Si-IGBT/Si-PIN diode, 6.5kV Si-IGBT/SiC-JBS diode, and 10kV SiC-MOSFET/SiC-JBS diode is presented. Power module circuit models including packaging parasitic inductances are created based on accurate device die SPICE circuit models for each (a) 6.5kV Si-IGBT/PiN diode; (b) 6.5kV Si-IGBT/SiC-JBS diode; and (c) 10kV SiC-MOSFET/SiC-JBS diode. Switching waveforms, characteristics, switching power and energy loss measurements of power modules including symmetric/asymmetric parasitic inductances are followed by SPICE circuit simulation and efficiency comparison of a 1MW 3L-NPC converter at 1kHz, 5kHz, and 10kHz switching frequencies. It is shown that 6.5kV Si-IGBT incorporating an anti-parallel SiC-JBS diode, with its high efficiency performance up to 5kHz, is a strong candidate for MW range converters. The 10kV SiC-MOSFET/SiC-JBS diode remains an option for higher switching frequency high power converters.