US 12,413,069 B2
Reducing transformer inrush current
Elisabeth Lindell, Västerås (SE); Johan Nohlert, Västerås (SE); Andrea Bianco, Sesto San Giovanni (IT); Stefan Halén, Västerås (SE); and Jesper Magnusson, Åkersberga (SE)
Assigned to ABB Schweiz AG, Baden (CH)
Filed by ABB Schweiz AG, Baden (CH)
Filed on Jun. 20, 2023, as Appl. No. 18/337,784.
Claims priority of application No. 22180635 (EP), filed on Jun. 23, 2022.
Prior Publication US 2023/0420932 A1, Dec. 28, 2023
Int. Cl. H02H 9/00 (2006.01); H02H 7/04 (2006.01)
CPC H02H 9/002 (2013.01) [H02H 7/04 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of operating a switching device arranged between an AC voltage source and a transformer in an electrical three-phase system, the method comprising:
between the switching device and the voltage source, monitoring a voltage in one of the phases;
operating the system at each of a plurality of system configurations;
for each of the system configurations and a predetermined same opening angle relative to a reference angle of the monitored voltage, determining a suitable closing angle relative to the reference angle and storing information about said determined suitable closing angle in association with the system configuration in a database;
determining a system configuration in the system;
at the predetermined same opening angle, opening the switching device;
from the database, obtaining a closing angle of said determined suitable closing angles, wherein the system configuration with which the obtained closing angle is associated in the database corresponds to the determined system configuration; and
at the obtained closing angle, closing the switching device.