US 12,170,467 B2
System and method for controlling high-torque, high speed electric motors
Carlo Kopf, Granbury, TX (US); and Erik Hatch, Granbury, TX (US)
Assigned to Linear Labs, Inc., Granbury, TX (US)
Filed by Linear Labs, Inc., Granbury, TX (US)
Filed on May 19, 2023, as Appl. No. 18/199,849.
Claims priority of provisional application 63/343,993, filed on May 19, 2022.
Prior Publication US 2023/0421032 A1, Dec. 28, 2023
Int. Cl. H02K 16/02 (2006.01); H02K 1/18 (2006.01); H02K 1/2798 (2022.01); H02P 6/15 (2016.01)
CPC H02K 16/02 (2013.01) [H02K 1/182 (2013.01); H02K 1/2798 (2022.01); H02P 6/153 (2016.02)] 19 Claims
OG exemplary drawing
 
1. A method comprising, at a motor controller:
during a first time period:
detecting a first operating speed of an electric motor comprising a set of coil assemblies;
detecting a torque demand of the electric motor;
estimating a first efficiency of a 120-degree commutation technique at the electric motor based on the first operating speed and the torque demand;
estimating a second efficiency of a 180-degree commutation technique at the electric motor based on the first operating speed and the torque demand;
setting a first operating speed threshold based on the first efficiency and the second efficiency;
in response to the first operating speed falling below the first operating speed threshold:
generating a first varying signal based on the 120-degree commutation technique; and
driving current through the set of coil assemblies according to the first varying signal;
detecting a second operating speed of the electric motor, the second operating speed exceeding the first operating speed; and
in response to the second operating speed exceeding the first operating speed threshold, initiating a first transition from the 120-degree commutation technique to the 180-degree commutation technique during a first transition period of a first transition duration;
during the first transition period:
generating a second varying signal based on a combination of:
the 120-degree commutation technique transitioning from a first duty rate to a second duty rate; and
the 180-degree commutation technique transitioning from the second duty rate to the first duty rate;
driving current through the set of coil assemblies according to the second varying signal; and
during a second time period succeeding the first time period, in response to completion of the first transition period:
generating a third varying signal based on the 180-degree commutation technique; and
driving current through the set of coil assemblies according to the third varying signal.