US 11,736,050 B2
Motor drive method and motor drive apparatus
Takahiro Yokoyama, Osaka (JP); and Takayuki Miyajima, Osaka (JP)
Assigned to DAIKIN INDUSTRIES, LTD., Osaka (JP)
Appl. No. 17/754,275
Filed by DAIKIN INDUSTRIES, LTD., Osaka (JP)
PCT Filed Sep. 29, 2020, PCT No. PCT/JP2020/037018
§ 371(c)(1), (2) Date Mar. 29, 2022,
PCT Pub. No. WO2021/065954, PCT Pub. Date Apr. 8, 2021.
Claims priority of application No. 2019-180997 (JP), filed on Sep. 30, 2019.
Prior Publication US 2022/0368256 A1, Nov. 17, 2022
Int. Cl. H02P 23/03 (2006.01); H02P 23/14 (2006.01)
CPC H02P 23/03 (2013.01) [H02P 23/14 (2013.01); H02P 2207/05 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A motor drive method of driving a motor by a motor drive apparatus that includes
an inverter that regulates supply power to the motor that is a synchronous machine, and
a controller that controls the inverter, the method comprising:
controlling a speed of the motor based on a command speed;
correcting, upon occurrence of a condition in which the speed of the motor is within a second speed range, the command speed such that the speed of the motor is changed from the second speed range to a first speed range, thereby prohibiting the motor from operating at a fixed speed in the second speed range,
wherein the motor is operable at a fixed speed in the first speed range, and the second speed range is lower than the first speed range and includes zero speed,
wherein the speed of the motor is controlled such that harmonics of a frequency range that are independent of rotation of the motor are superimposed neither on a current through the motor nor on a voltage supplied to the motor, and
wherein a torque coefficient for the motor is in a controlled state while the speed of the motor is within the second speed range.