Methodology to Improve Switching Speed of SiC MOSFETs in Hard Switching Applications

Speaker:   Dr. Handong Gui

Time:       10:30-11:30, Dec. 13

Location:  SIST 1A 200

Host:       Prof. Haoyu Wang

Abstract:

To achieve power converters with lower weight and size, the switching frequency of power devices is preferred to increase. However, in hard switching applications, increasing the switching frequency introduces significantly higher switching loss. Therefore, it is desired to increase the switching speed of the power devices and reduce the switching loss. Thanks to silicon carbide (SiC) power MOSFETs, their intrinsic superior switching characteristics compared with conventional silicon IGBTs makes it possible to run converters at faster switching speed in high power hard switching applications. Nevertheless, when applying a power device to a real converter, the switching speed is not only dependent on the device’s characteristics, but also strongly related to the circuit design like gate drive and parasitics.

This lecture will focus on the improvement of the switching speed for SiC MOSFETs in hard switching applications. Characterization of switching performance of SiC MOSFETs is conducted and the impact factors of switching speed are analyzed. Based on the evaluation, advanced gate drive technologies are proposed for discrete SiC MOSFETs. A modified modulation is developed to reduce the device drain-source overvoltage in three-level active neutral point clamped (3L-ANPC) converters. The layout design criteria in three-level converters are provided, and a busbar with low parasitic inductance is developed for 3L converter.

Bio:

received the B.S. and M.S. degrees in electrical engineering from the Nanjing University of Aeronautics and Astronautics, Nanjing, China, in 2013 and 2016, respectively. He is currently working toward the Ph.D. degree at the University of Tennessee, Knoxville, TN, USA. Since 2019, he has been with the University of Cambridge, UK, as a visiting scholar. He has authored or coauthored over 30 journal and conference papers and one book chapter. His research interests include wide band-gap devices and applications, multi-level converters, and electrified transportations.

SIST-Seminar 18228