US 12,101,038 B2
Uninterruptible power supply having short circuit load capability
Arun K. Kadavelugu, Raleigh, NC (US); and Maziar Mobarrez, Irvine, CA (US)
Assigned to ABB Schweiz AG, Baden (CH)
Filed by ABB Schweiz AG, Baden (CH)
Filed on Nov. 22, 2021, as Appl. No. 17/532,245.
Prior Publication US 2023/0163697 A1, May 25, 2023
Int. Cl. H02M 7/537 (2006.01); H02J 9/06 (2006.01); H02M 1/08 (2006.01); H02M 1/32 (2007.01); H02M 7/483 (2007.01)
CPC H02M 7/537 (2013.01) [H02J 9/062 (2013.01); H02M 1/08 (2013.01); H02M 1/32 (2013.01); H02M 7/483 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An inverter comprising:
a direct current (DC) bus having positive and negative rails;
an inverter arm coupled between the positive and negative rails of said DC bus, the inverter arm comprising:
a first silicon carbide transistor having a first current-conducting terminal connected to a central node of said inverter arm; and
a second silicon carbide transistor having a second current-conducting terminal connected to the central node of said inverter arm;
at least one silicon transistor having a third current-conducting terminal connected to the central node of said inverter arm, said at least one silicon transistor comprising a first silicon transistor and a second silicon transistor arranged in anti-series with said first silicon transistor;
a first silicon diode coupled between collector and emitter terminals of said first silicon transistor;
a second silicon diode coupled between collector and emitter terminals of said second silicon transistor; and
a gate driver circuit configured to:
switch said first silicon carbide transistor and said second silicon carbide transistor to convert DC from said DC bus into alternating current (AC); and
switch said at least one silicon transistor, only when said inverter arm is subjected to a load-side short circuit current, to freewheel the load-side short circuit current.