US 12,334,808 B2
Drive device, drive method, and power conversion device
Hiromu Takubo, Tokyo (JP); and Ryoga Kiguchi, Tokyo (JP)
Assigned to FUJI ELECTRIC CO., LTD., Kawasaki (JP)
Filed by FUJI ELECTRIC CO., LTD., Kanagawa (JP)
Filed on Sep. 30, 2022, as Appl. No. 17/936,945.
Claims priority of application No. 2021-172459 (JP), filed on Oct. 21, 2021; and application No. 2022-081654 (JP), filed on May 18, 2022.
Prior Publication US 2023/0130625 A1, Apr. 27, 2023
Int. Cl. H02M 1/08 (2006.01); H02M 1/38 (2007.01); H03K 17/16 (2006.01); H03K 17/687 (2006.01); H02M 7/537 (2006.01)
CPC H02M 1/08 (2013.01) [H02M 1/385 (2021.05); H03K 17/161 (2013.01); H03K 17/687 (2013.01); H02M 7/537 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A drive device configured to switch between a first SiC-MOSFET (Silicon-Carbide Metal-Oxide-Semiconductor Field-Effect-Transistor) and a second SiC-MOSFET that are connected in series, the drive device providing a dead time during switching transitions, the dead time being a period during which both the first SiC-MOSFET and the second SiC-MOSFET are commanded to be OFF, the drive device comprising:
a first drive circuit configured to set a gate voltage of the first SiC-MOSFET, during the dead time, to a first middle voltage that is higher than a first negative power supply voltage and lower than a first threshold voltage for the first SiC-MOSFET; and
a second drive circuit configured to set a gate voltage of the second SiC-MOSFET, during the dead time, to a second middle voltage that is higher than a second negative power supply voltage and lower than a second threshold voltage for the second SiC-MOSFET;
wherein:
(i) when inputted OFF commands for both the first SiC-MOSFET and the second SiC-MOSFET exceed a set time of the dead time, the first drive circuit changes the gate voltage of the first SiC-MOSFET from the first middle voltage to the first negative power supply voltage, and the second drive circuit changes the gate voltage of the second SiC-MOSFET from the second middle voltage to the second negative power supply voltage; or
(ii) wherein, when the dead time exceeds a predetermined waiting time, the first drive circuit changes the gate voltage of the first SiC-MOSFET from the first middle voltage to the first negative power supply voltage, and the second drive circuit changes the gate voltage of the second SiC-MOSFET from the second middle voltage to the second negative power supply voltage.