	US 12,273,062 B2
	Method for modulating torque ripple and/or radial force of a three-phase current operated electric machine
Andreas Langheck, Karlsruhe (DE); and Dominik Stretz, Wiesengiech (DE)
Assigned to Schaeffler Technologies AG & Co. KG, Herzogenaurach (DE)
Appl. No. 18/024,348
Filed by Schaeffler Technologies AG & Co. KG, Herzogenaurach (DE)
PCT Filed Aug. 10, 2021, PCT No. PCT/DE2021/100680 § 371(c)(1), (2) Date Mar. 2, 2023, PCT Pub. No. WO2022/048704, PCT Pub. Date Mar. 10, 2022.
Claims priority of application No. 10 2020 122 099.5 (DE), filed on Sep. 4, 2020.
Prior Publication US 2023/0336107 A1, Oct. 19, 2023
Int. Cl. H02P 6/18 (2016.01); H02P 21/05 (2006.01); H02P 21/22 (2016.01); H02P 29/50 (2016.01); H02P 101/45 (2016.01); H02P 103/20 (2016.01)

CPC H02P 29/50 (2016.02) [H02P 21/05 (2013.01); H02P 21/22 (2016.02); H02P 2101/45 (2015.01); H02P 2103/20 (2015.01); H02P 2205/01 (2013.01)]

18 Claims

1. A method for modulating at least one of a torque ripple and a radial force of a three-phase current-operated electric machine, comprising:

selecting at least one of a harmonic (H_{M1_EM}) in a torque of the electric machine and a harmonic (H_{M_X}) of a load coupled to the electric machine;

wherein the at least one selected harmonic (H_{M1_EM}, H_{M_X}) is modulated by applying the at least one selected harmonic (H_{M1_EM}, H_{M_X}) to at least one of a d-current and a q-current or to a variable correlated therewith in order to generate a setpoint variable for driving the electric machine;

wherein a phase angle (φ_d,k, φ_q,k) of at least one of a harmonic (H_Id) in the d-current and a harmonic (H_Iq) in the q-current is, at least temporarily, set to be different with respect to a rotor angle, such that φ_d,k≠φ_q,kapplies;

wherein at least one of the d-current and the q-current is selected in such a way that a magnitude of a resulting stator voltage

|u|=√u_d²+u_q²

or a magnitude of the resulting stator current

|i|=√i_d²+i_q²

is minimized, where

10. A method for modulating at least one of a torque ripple and a radial force of a three-phase current-operated electric machine, comprising:

selecting at least one of a harmonic (H_{M1_EM}) in a torque of the electric machine and a harmonic (H_{M_X}) of a load coupled to the electric machine;

modulating the at least one selected harmonic (H_{M1_EM}, H_{M_X}) by applying the at least one selected harmonic (H_{M1_EM}, H_{M_X}) to a d-current and/or to a q-current to generate dynamic input variables;

setting, at least temporarily, at least one of a phase angle of a harmonic (H_Id) in the d-current and a phase angle of a harmonic (H_Iq) in the q-current to be different from a rotor angle; and

generating setpoint variables for driving the electric machine based on the dynamic input variables, wherein at least one of the d-current and the q-current is selected in such a way that a magnitude of a resulting stator voltage or a magnitude of a resulting stator current is minimized.