Switching Investigation of SiC MOSFET Based 4-Quadrant Switch

SiC MOSFETs are suited for several power electronic converters as they reduce loss, increase efficiency, withstand high temperatures and switch faster. SiC MOSFETs are 2-quadrant switches as they can block voltage of only one polarity. Many power converters require 4-quadrant switches, obtained by connecting two 2-quadrant switches. However, the present literature mostly examines the 2-quadrant operation of SiC MOSFETs apart from commercially unavailable monolithic 4-quadrant SiC MOSFETs. This paper, therefore, studies 4-quadrant switches based on SiC MOSFETs. It investigates in detail and finds the dominating devices for turn ON/OFF time and the trends of turn ON/ OFF time with respect to switch current for each quadrant. The paper further compares the maximum turn ON/OFF time of a 2-quadrant switch and a 4-quadrant switch. It also studies the effect of gate resistances on the turn ON/OFF time of the switch. The research is performed with the help of analysis, simulation, and experiment. The reasons behind the trends observed in the four quadrants are also analyzed. The paper finally summarizes the important observations about the turn ON/OFF time for SiC MOSFET based 4-quadrant switch.