US 12,269,350 B2
Common-mode current sensing system and protection method for power converters
Robert J. Vovos, Vestal, NY (US); and Andrew S. Clark, Binghamton, NY (US)
Assigned to BAE Systems Controls Inc., Endicott, NY (US)
Filed by BAE Systems Controls Inc., Endicott, NY (US)
Filed on Apr. 28, 2023, as Appl. No. 18/141,068.
Prior Publication US 2024/0359561 A1, Oct. 31, 2024
Int. Cl. H02M 1/12 (2006.01); B60L 3/00 (2019.01); B60L 50/51 (2019.01)
CPC B60L 3/003 (2013.01) [B60L 3/0069 (2013.01); B60L 50/51 (2019.02); H02M 1/123 (2021.05); B60L 2210/42 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A system comprising:
a sensor for sampling a common-mode current signal present at an inverter driving a load at two or more phases;
a first sensor path receiving the sampled common-mode current signal for detecting a first type of fault of a current magnitude persisting for a first time duration;
a second sensor path receiving the sampled common-mode current signal for detecting a second type of fault, the second type of fault being of a current magnitude less than the current magnitude of the first type of fault and persisting for a second time duration greater than the first time duration; and
a third sensor path receiving the sampled common-mode current signal for detecting a third type of fault, the third type of fault of a current magnitude greater than the current magnitude of the second type of fault and persisting for a time duration less than the second time duration of said second type of fault; and
a controller for terminating operation of the inverter responsive to detecting one of said first type of fault, second type of fault or third type of fault;
wherein the first sensor path for detecting the first type of fault comprises:
a comparator for receiving said sampled common-mode current signal and comparing a magnitude of said sampled common-mode current signal against a first threshold value indicative of a strong short circuit failure; and
a timer at said first sensor path, said timer for detecting persistence of said first type of fault for said first time duration.