US 12,176,716 B2
Line reactor protection security using local frequency measurement
Ritwik Chowdhury, Charlotte, NC (US); Douglas I. Taylor, Spokane, WA (US); and Normann Fischer, Colfax, WA (US)
Assigned to Schweitzer Engineering Laboratories, Inc., Pullman, WA (US)
Filed by Schweitzer Engineering Laboratories, Inc., Pullman, WA (US)
Filed on Sep. 1, 2023, as Appl. No. 18/459,691.
Claims priority of provisional application 63/375,019, filed on Sep. 8, 2022.
Prior Publication US 2024/0097449 A1, Mar. 21, 2024
Int. Cl. H02J 3/24 (2006.01); H02H 7/22 (2006.01); H02J 3/00 (2006.01); H02J 3/01 (2006.01)
CPC H02J 3/241 (2020.01) [H02H 7/226 (2013.01); H02J 3/0012 (2020.01); H02J 3/00125 (2020.01); H02J 3/01 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A system configured to protect a reactor in an alternating current electric power system, the system comprising:
a protective action subsystem to implement a protective action based on identification of a fault condition associated with a reactor in the alternating current electric power system;
a frequency determination subsystem to:
determine when a frequency of the alternating current exceeds a lower threshold and is below an upper threshold;
identify a change in the frequency associated with de-energization of a line in electrical communication with the reactor;
a supervisory subsystem configured to restrain implementation of the protective action when:
the frequency determined by the frequency determination subsystem is below the lower threshold;
the frequency determined by the frequency determination subsystem is above the upper threshold; or
the change in the frequency determined by the frequency determination subsystem is associated with de-energization of the line in electrical communication with the reactor.