US 12,444,929 B2
Adaptive impedance protection
Farnaz Harirchi, Glenview, IL (US); John French, Chicago, IL (US); Oleg Nazarov, Okemos, MI (US); Gabrielle Madden, Chicago, IL (US); and Goran Djogo, Mount Prospect, IL (US)
Assigned to S&C Electric Company, Chicago, IL (US)
Filed by S&C Electric Company, Chicago, IL (US)
Filed on Feb. 12, 2024, as Appl. No. 18/438,728.
Claims priority of provisional application 63/456,102, filed on Mar. 31, 2023.
Prior Publication US 2024/0332953 A1, Oct. 3, 2024
Int. Cl. H02H 7/26 (2006.01); G01R 27/16 (2006.01)
CPC H02H 7/26 (2013.01) [G01R 27/16 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for operating an adaptive impedance protection scheme in a power network including interrupting devices dispersed along an AC power line, the method comprising:
determining a measured impedance on the power line in an upstream interrupting device;
determining a variable impedance set point in the upstream interrupting device;
identifying a predetermined percentage of the impedance set point;
determining if the measured impedance falls below the predetermined percentage of the impedance set point;
determining whether a change in a measured current value on the power line is less than a threshold change value in a downstream interrupting device;
sending the determination of whether the change in the measured current value is less than the threshold change value from the downstream interrupting device to the upstream interrupting device; and
opening the upstream interrupting device if the measured impedance falls below the predetermined percentage of the impedance set point and the change in the measured current value in the downstream interrupting device is less than the threshold change value.