US 11,916,367 B2
Method and device for estimating source impedances across one or more transmission lines
Vedanta Pradhan, Bhubaneswar (IN); and Od Naidu, Karnataka (IN)
Assigned to Hitachi Energy Switzerland AG, Baden (CH)
Filed by Hitachi Energy Switzerland AG, Baden (CH)
Filed on Sep. 15, 2021, as Appl. No. 17/475,972.
Claims priority of application No. 202041039933 (IN), filed on Sep. 15, 2020.
Prior Publication US 2022/0085594 A1, Mar. 17, 2022
Int. Cl. H02H 3/00 (2006.01); G01R 19/25 (2006.01); G01R 31/08 (2020.01)
CPC H02H 3/006 (2013.01) [G01R 19/2513 (2013.01); G01R 31/085 (2013.01)] 22 Claims
OG exemplary drawing
 
1. A method for estimating source impedances across one or more transmission lines connecting at least two substations, each substation associated with an equivalent source having a respective source impedance, the method comprising:
obtaining voltage and current measurements and status signals, the voltage and current measurements providing terminal voltages and line currents at each substation, and the status signals being associated with switching events at the one or more transmission lines or at the substations;
detecting an event associated with a disturbance in a transmission line or current injection at one of the substations, the event being detected from one or more of the obtained measurements and the obtained status signals; and
estimating the source impedance of each equivalent source based on the event, using line parameters and the voltage and current measurements associated with the event, the measurements associated with the event comprising the measurements before and after the event.