US 12,334,818 B2
DC-DC power converter pre-charge system
Akshay Sarin, Auburn Hills, MI (US); Alan B. Martin, Washington, MI (US); and Joseph Berg, Highland, MI (US)
Assigned to GM Global Technology Operations LLC, Detroit, MI (US)
Filed by GM GLOBAL TECHNOLOGY OPERATIONS LLC, Detroit, MI (US)
Filed on Nov. 9, 2022, as Appl. No. 17/984,166.
Prior Publication US 2024/0154528 A1, May 9, 2024
Int. Cl. H02M 3/155 (2006.01); H02M 1/00 (2006.01)
CPC H02M 3/155 (2013.01) [H02M 1/0009 (2021.05)] 20 Claims
OG exemplary drawing
 
1. A pre-charge system for a DC electric power system, the pre-charge system comprising:
a high-voltage electric power bus composed as a positive bus link and a negative bus link, wherein the high-voltage electric power bus electrically connects to an external bus via the positive bus link and the negative bus link;
a contactor including a first switch arranged to control electric power through the positive bus link, and a second switch arranged to control electric power through the negative bus link;
a pre-charge resistor, the pre-charge resistor being arranged in parallel with the first switch;
a voltage sensor arranged to monitor electrical potential between the positive bus link and the negative bus link; and
a controller, the controller operatively connected to the first and second switches, and in communication with the voltage sensor, the controller including an instruction set, the instruction set being executable to:
activate the second switch;
periodically monitor the electrical potential;
determine a time-rate of change in the electrical potential; and
close the first switch when the time-rate of change in the electrical potential is less than a first threshold.