US 12,407,286 B2
Current limit strategy for hoist application
Anil Prasad Josyula, Andhra Pradesh (IN); Ashish Vijay, Rajasthan (IN); Vipul Kohli, Gujarat (IN); and David Frederick Brookes, Birmingham (GB)
Assigned to HAMILTON SUNDSTRAND CORPORATION, Charlotte, NC (US)
Filed by Hamilton Sundstrand Corporation, Charlotte, NC (US)
Filed on Jul. 21, 2023, as Appl. No. 18/356,334.
Claims priority of application No. 202311020101 (IN), filed on Mar. 22, 2023.
Prior Publication US 2024/0322723 A1, Sep. 26, 2024
Int. Cl. H02H 7/09 (2006.01); H02P 21/00 (2016.01); H02P 21/18 (2016.01); H02P 21/22 (2016.01)
CPC H02P 21/22 (2016.02) [H02P 21/001 (2013.01); H02P 21/18 (2016.02)] 15 Claims
OG exemplary drawing
 
1. A hoist application system, comprising:
a motor drive unit, which is receptive of a final duty command and which drives a motor in accordance with the final duty command;
a closed-loop control unit configured to generate a closed-loop duty command;
an open-loop control unit configured to generate an open-loop duty command; and
a switch logic unit, which is receptive of direct current (DC) system information, the closed-loop duty command and the open-loop duty command, and which is configured to generate the final duty command from one of the closed-loop duty command and the open-loop duty command based on the DC system information,
wherein:
the switch logic unit transitions from the closed-loop duty command to the open-loop duty command when a DC-link current exceeds a threshold value from the DC system for a predetermined time, and
the switch logic unit transitions from the open-loop duty command to the closed-loop duty command when the DC-link current is lower than the threshold value for the predetermined time and closed-loop operation is possible without crossing the threshold value.