US 12,237,668 B2
Fast fault detector
Boris Marendic, Chicago, IL (US); Yoav Sharon, Evanston, IL (US); and John Seuss, Washington, DC (US)
Assigned to S&C Electric Company, Chicago, IL (US)
Filed by S&C Electric Company, Chicago, IL (US)
Filed on Feb. 24, 2023, as Appl. No. 18/113,654.
Claims priority of provisional application 63/318,241, filed on Mar. 9, 2022.
Prior Publication US 2023/0291198 A1, Sep. 14, 2023
Int. Cl. H02H 7/00 (2006.01); G01R 19/165 (2006.01); H02H 1/00 (2006.01); H02H 7/22 (2006.01)
CPC H02H 7/22 (2013.01) [G01R 19/16571 (2013.01); H02H 1/0007 (2013.01)] 17 Claims
OG exemplary drawing
 
10. A method for estimating current in a power system, the method comprising:
providing a pickup level that defines a current threshold for opening a switch in response to the overcurrent;
estimating current in the power system from current measurement signals;
accumulating time from a reset zero position during the time that the estimation of the current is greater than the pickup level;
subtracting time from the accumulated time during the time that the estimation of the current is less than the pickup level after time has been accumulated from when the estimation of the current is greater than the pickup level;
detecting the overcurrent if the accumulated time reaches a predetermined accumulation time; and
opening the switch if the overcurrent is detected, wherein estimating current in the power system includes using a sliding observation window that is shorter than one cycle.