US 12,142,922 B2
Techniques for limiting power using an active front end
Seok-hee Han, Dunlap, IL (US); Jesse R. Gerdes, Dunlap, IL (US); and Jackson Wai, Dunlap, IL (US)
Assigned to Caterpillar Inc., Peoria, IL (US)
Filed by Caterpillar Inc., Peoria, IL (US)
Filed on Sep. 1, 2022, as Appl. No. 17/901,585.
Prior Publication US 2024/0079876 A1, Mar. 7, 2024
Int. Cl. H02J 3/16 (2006.01); H02J 7/00 (2006.01); H02J 7/34 (2006.01)
CPC H02J 3/16 (2013.01) [H02J 7/007182 (2020.01); H02J 7/345 (2013.01); H02J 2207/50 (2020.01)] 20 Claims
OG exemplary drawing
 
1. A method of limiting electrical power using an active front end unit having an inverter, wherein an output of the active front end unit is coupled to a capacitor that is coupled to an electrical grid, wherein the active front end unit includes a frequency droop control mode, the method comprising:
during the frequency droop control mode:
determining an inverter command frequency using a nominal frequency and a droop frequency;
determining, using the inverter command frequency, a representation of an angle of a voltage applied to the capacitor;
determining, using a representation of an angle of a voltage of the electrical grid, a limit of the representation of the angle of the voltage applied to the capacitor; and
adjusting, using the determined limit, the representation of the angle of the voltage applied to the capacitor.