US 12,231,069 B2
Controller and drive circuit for electric motors
Ludovic Andre Chretien, Columbia City, IN (US); and Lester Benjamin Manz, Paulding, OH (US)
Assigned to Regal Beloit America, Inc.
Filed by Regal Beloit America, Inc., Beloit, WI (US)
Filed on Dec. 21, 2022, as Appl. No. 18/069,936.
Application 18/069,936 is a continuation of application No. 17/156,003, filed on Jan. 22, 2021, granted, now 11,539,319.
Prior Publication US 2023/0123360 A1, Apr. 20, 2023
Int. Cl. H02P 27/04 (2016.01); F25B 31/02 (2006.01); H02P 25/04 (2006.01); H02P 27/06 (2006.01)
CPC H02P 27/045 (2013.01) [F25B 31/026 (2013.01); H02P 25/04 (2013.01); H02P 27/06 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electric motor system comprising:
a drive circuit including an inverter configured to supply variable frequency current over a first duration and a line frequency current supply device configured to supply line frequency current over a second duration; and
an electric motor coupled to the drive circuit, wherein the electric motor is in communication with a controller configured to:
cause the inverter to supply variable frequency current to the electric motor over the first duration, thereby operating the electric motor at a variable motor speed;
determine at least one parameter of the electric motor;
identify a maximum potential motor speed achievable under inverter operation corresponding to the at least one determined parameter of the electric motor;
receive a command to operate the electric motor at line frequency current;
cause the inverter to operate the electric motor at a reduced value of the variable motor speed before transitioning the drive circuit from supplying variable frequency current to supplying line frequency current, wherein the reduced value of the variable motor speed is less than the maximum potential motor speed; and
cause the drive circuit to transition from supplying variable frequency current to supplying line frequency current before the maximum potential motor speed is reached.