The Problem:
Compared to other transistors, silicon carbide (SiC) MOSFETs have improved properties due to lower conduction loss and specific capacitance and higher switching speed and maximum junction temperature. However, high turn-on switching losses due to lower transconductance remains a problem; thus, it is still difficult to implement SiC MOSFETs to hard switching converters with switching frequencies >100 kHz.
The Solution:
Researchers at the University of Tennessee have designed a charge pump gate drive (CPG) to improve the turn-on switching loss of SiC MOSFETs. This drive can dynamically increase the input voltage to enhance gate current during the turn-on switching transient of SiC MOSFETs without introducing gate overvoltage issues. Compared to conventional gate drives, the newly designed CPG exhibits a one-third reduction in switching loss.
The proposed CPG achieves 69.5% decrease in the turn-on time and a 67.9% decrease in the turn-on loss at full load and with zero Rg(est).
Benefits:
Inventors:
Dr. Leon Tolbert is the Min H. Kao Professor in the Department of Electrical Engineering and Computer Science at UT. He served as the department head from 2013 to 2018. His research interests include applications of wide bandgap power electronics, reconfigurable grid emulator using power electronics, and microgrid operations. His work is sponsored by the Department of Energy and the NSF.
Handong Gui is a graduate student in the Department of Electrical Engineering and Computer Science at UT. His research interests include high power density motor drives, device characterization, and battery management systems.