US 12,283,447 B2
Direct current circuit breaker and related method
Ngai Man Ho, Winnipeg (CA); King Man Siu, Winnipeg (CA); and Dong Li, Winnipeg (CA)
Assigned to Ujniversity of Manitoba, Winnipeg (CA)
Appl. No. 17/782,320
Filed by University of Manitoba, Winnipeg (CA)
PCT Filed Feb. 18, 2021, PCT No. PCT/CA2021/050175
§ 371(c)(1), (2) Date Jun. 3, 2022,
PCT Pub. No. WO2021/163795, PCT Pub. Date Aug. 26, 2021.
Claims priority of provisional application 62/977,840, filed on Feb. 18, 2020.
Prior Publication US 2023/0005676 A1, Jan. 5, 2023
Int. Cl. H01H 9/54 (2006.01)
CPC H01H 9/542 (2013.01) 18 Claims
OG exemplary drawing
 
1. A low voltage direct current (DC) circuit breaker for microgrid applications comprising:
a first supply line between a first input terminal and a first output terminal;
a second supply line between a second input terminal and a second output terminal;
the first and second input terminals defining an input port and the first and second output terminals defining an output port such that the first and second supply lines act to transfer electrical power between the input port and the output port;
a first mechanical relay in the first supply line configured to conduct electrical current between the first input and output terminals during steady-state operation of the DC circuit breaker;
a breakless conductive connection from the first mechanical relay to the first output terminal with no intervening switch therebetween;
an auxiliary relay assembly in parallel with the first mechanical relay to define an auxiliary breaker path for conducting electrical current during transient operation of the DC circuit breaker, the auxiliary relay assembly comprising a power-semiconductor circuit that comprises a pair of MOSFET power-semiconductor switches arranged in a bidirectional blocking configuration configured to selectively conduct electrical current along the auxiliary breaker path and for bidirectional current blocking when in a non-conductive state;
a second mechanical relay in the second supply line configured to conduct electrical current between the second input and output terminals; and
a controller operatively associated with each of the first mechanical relay, the second mechanical relay and the auxiliary relay assembly, the controller being configured to:
activate the power-semiconductor circuit to conduct electrical current through the auxiliary breaker path, in response to a command signal to stop transfer of the electrical power between the input port and the output port, in order to provide a zero voltage condition under which the first mechanical relay is to deactivate;
deactivate the first mechanical relay when electrical current is being conducted through the auxiliary breaker path; and
deactivate the power-semiconductor circuit after the first mechanical relay is deactivated so as to stop the transfer of the electrical power between the input port and the output port.