Applications of Wide Bandgap (WBG) devices in AC electric drives: A technology status review

Abstract

This paper is an effort to put together all the potential applications of Wide Bandgap (WBG) devices in AC electric drives. Low inductance motors, high speed motors, and electric drives operating in a high temperature environment are the main application areas of WBG devices. Low voltage permanent magnet motors and slotless motors have a low inductance and require a stringent high-bandwidth current regulation strategy to obtain an acceptable current ripple. Silicon (Si) devices cannot be used in this case due to their limited switching frequency. MW-level high speed motors have devices operating at high voltage and current levels and a high fundamental frequency (600–1200 Hz) that cause very high switching losses in Si IGBT devices. SiC devices have enabled the use of power electronic converters for MW-level high speed motors. Integrated motor drives (IMDs) are also benefitted by WBG devices as they reduce the size of the power converter and allow operation at a high junction temperature. Therefore, the inverter can be mounted on the motor itself which can be a significant heat source due to motor losses. Cooling requirements in high temperature environment applications such as hybrid Electric Vehicle (EV), ground vehicles in combat zones, and power converters used in space technology like land rovers etc., are greatly reduced due to low losses and high junction temperatures. Operation at high frequencies and high temperatures reduces the size of electric drive significantly.