US 12,218,617 B2
Controller for electric motor
Daisuke Matsuoka, Aichi-ken (JP); and Masamichi Nawa, Aichi-ken (JP)
Assigned to KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, Kariya (JP)
Appl. No. 17/915,726
Filed by KABUSHIKI KAISHA TOYOTA JIDOSHOKKI, Kariya (JP)
PCT Filed Mar. 24, 2021, PCT No. PCT/JP2021/012201
§ 371(c)(1), (2) Date Sep. 29, 2022,
PCT Pub. No. WO2021/200456, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-067198 (JP), filed on Apr. 3, 2020.
Prior Publication US 2023/0133739 A1, May 4, 2023
Int. Cl. H02P 3/18 (2006.01); H02P 21/18 (2016.01); H02P 21/22 (2016.01)
CPC H02P 3/18 (2013.01) [H02P 21/18 (2016.02); H02P 21/22 (2016.02)] 4 Claims
OG exemplary drawing
 
1. A controller for an electric motor comprising:
a torque controller configured to calculate a torque command value by using a difference between a rotational speed of the electric motor and a rotational speed command value;
a first converter configured to convert the torque command value into a d-axis current command value and a q-axis current command value;
a second converter configured to convert a current flowing in the electric motor into a d-axis current and a q-axis current by using a position of a rotor of the electric motor;
a current controller configured to calculate a d-axis voltage command value such that a difference between the d-axis current and the d-axis current command value is reduced, and calculate a q-axis voltage command value such that a difference between the q-axis current and the q-axis current command value is reduced;
an estimator configured to estimate the position by using the d-axis current, the q-axis current, the d-axis voltage command value, and the q-axis voltage command value from which a noise is removed by a filter having a first time constant when the torque command value is equal to or greater than zero, and estimate the rotational speed and the position by using the d-axis current, the q-axis current, the d-axis voltage command value, and the q-axis voltage command value from which the noise is removed by the filter, which has a second time constant smaller than the first time constant when the torque command value is less than zero;
a third converter configured to convert the d-axis voltage command value and the q-axis voltage command value into voltage command values respectively corresponding to phases of the electric motor by using the position; and
a drive circuit configured to drive the electric motor by a result of a comparison between a carrier wave and the voltage command values respectively corresponding to the phases of the electric motor.