US 11,689,137 B2
Controller and drive circuits for electric motors
Ludovic Andre Chretien, Columbia City, IN (US)
Assigned to Regal Beloit America, Inc., Beloit, WI (US)
Filed by Regal Beloit America, Inc., Beloit, WI (US)
Filed on Jul. 8, 2022, as Appl. No. 17/860,945.
Application 17/860,945 is a continuation of application No. 17/191,348, filed on Mar. 15, 2021, granted, now 11,387,762.
Prior Publication US 2022/0345063 A1, Oct. 27, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H02P 27/08 (2006.01); H02P 23/28 (2016.01); H02P 27/04 (2016.01)
CPC H02P 27/047 (2013.01) [H02P 23/28 (2016.02); H02P 27/08 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electric motor system comprising:
a drive circuit comprising a contactor, an inverter, and an H-bridge comprising at least two phases of the inverter, wherein the drive circuit is configured to supply variable frequency current and line frequency current; and
a controller communicatively coupled to the drive circuit, wherein the controller is configured to:
determine a polarity of a sensed alternating current (AC) voltage while the drive circuit is supplying variable frequency current;
disable, based upon the determined polarity of the sensed AC voltage, at least two switches of the H-bridge; and
control the contactor to close, thereby preventing the contactor and the inverter from energizing an electric motor at the same time.