US 11,929,695 B2
Control device, magnetic flux estimation device, and magnetic flux estimation method
Takahiro Saeki, Fukuoka (JP); and Shingo Fukumaru, Fukuoka (JP)
Assigned to KABUSHIKI KAISHA YASKAWA DENKI, Fukuoka (JP)
Filed by KABUSHIKI KAISHA YASKAWA DENKI, Fukuoka (JP)
Filed on Jan. 14, 2022, as Appl. No. 17/648,062.
Claims priority of application No. 2021-004405 (JP), filed on Jan. 14, 2021.
Prior Publication US 2022/0224268 A1, Jul. 14, 2022
Int. Cl. H02P 23/14 (2006.01)
CPC H02P 23/14 (2013.01) 20 Claims
OG exemplary drawing
 
1. A control device comprising:
a power conversion circuit configured to supply driving power to an electric motor;
a magnetic flux estimation circuit configured to estimate a primary magnetic flux appearing in the electric motor by the supply of the driving power; and
a control circuit configured to control the power conversion circuit on the basis of an estimation result of the primary magnetic flux by the magnetic flux estimation circuit,
wherein the magnetic flux estimation circuit
determines whether an operating speed of the electric motor is less than a predetermined level or exceeds the predetermined level,
performs, when the magnetic flux estimation circuit determines that the operating speed of the electric motor is less than the predetermined level, a first estimation of estimating the primary magnetic flux on the basis of an output current from the power conversion circuit to the electric motor and an inductance of the electric motor, and
performs, when the magnetic flux estimation circuit determines that the operating speed exceeds the predetermined level, a second estimation of estimating the primary magnetic flux by estimating a magnetic flux differential value on the basis of an output voltage from the power conversion circuit to the electric motor and integrating the magnetic flux differential value using, as an initial value, an estimation result of the primary magnetic flux by the first estimation.