Operation Analysis and Comparison of T-type NPC Si IGBT and SiC MOSFET Inverter-Based Highspeed Drives

Wideband-gap (WBG) power devices such as silicon carbide (SiC) switches have become increasingly popular, due to their ability to increase efficiency and reduce size of power electronic converters. They can viably supply high-speed electrical drives, with profitable application in aeronautical or electric vehicles. High frequency operation of the SiC devices, emphasizes the effect of parasitics, which generates reflected wave transient overvoltage on motor terminals, significant in the case of long-shielded cable which connects the inverter and the induction motor. In this paper SiC MOSFET-based inverter is systematically studied and compared to the performance of Si-based inverter for low-voltage induction motor loads, in terms of efficiency and switching performance. In particular, Si-based inverter configuration is the T-type Neutral Point Clamped (T-NPC) 3-level (3L) inverter, and SiC-based inverter is standard 2-level (2L) configuration, which can eventually replace the 3L topologies. The fair comparison of the two inverters has been introduced and switching performance, overvoltages, and power losses have been analyzed. Simulations are carried out by realistic models of power switch modules.