Performance Evaluation of 3.3 kV SiC MOSFET and Schottky Diode Based Reverse Voltage Blocking Switch for Medium Voltage Current Source Inverter Application
Sneha Narasimhan, Ajit Kanale, Subhashish Bhattacharya, Jayant B. Baliga
Abstract
SiC power devices are used for medium-voltage (MV) motor drive and traction applications due to their higher temperature operation, switching frequencies, and higher efficiencies than Si-based devices. This article investigates three 3.3 kV reverse blocking or current switch configurations for their suitability in MV current-source inverter (CSI) applications. The three configurations are (1) Type I - SiC MOSFET and series Schottky diode, (2) Type II - SiC MOSFETs connected in common-source (CS), and (3) Type - III SiC MOSFETs connected in common-drain (CD) configuration. The switch configurations are characterized by comparing their on-state and switching performance at different junction temperatures varying from 25°C to 125°C. The results are used to evaluate three-phase CSI losses with three different switch configurations and choose the preferred switch configuration for MV-based CSI applications based on inverter efficiency while considering a wide range of operating points. The permissible limits of a 3.3 kV Type I switch-based CSI are presented, thus providing a safe operating area (SOA) of the switch configuration for a CSI application. Finally, the CSI is built using Type I switch configuration and is experimentally validated with an R-L load.