Patent ID: 9698711
Date: 2017-07-04
CPC Classifications: B62D,H02P

Claim:
1. A control device for controlling energization of a multi-phase AC motor, which generates a steering assist torque in an electric power steering device of a vehicle, the control device comprising: a first inverter in a first system that outputs a first alternating current voltage to a first multi-phase winding wire set; a second inverter in a second system that outputs a second alternating current voltage to a second multi-phase winding wire set; and a control unit that controls a phase difference between the first alternating current voltage applied to the first multi-phase winding wire set and the second alternating current voltage applied to the second multi-phase winding wire set, wherein the first inverter and the second inverter are electrically independent from each other, wherein the first multi-phase winding wire set and the second multi-phase winding wire set provide a stator of the multi-phase AC motor, and generate a rotating magnetic field in a rotor, wherein the control unit sets a control range including a reference phase difference, which reduces a torque ripple due to a specified-order harmonic component as an A-th order torque ripple, and another phase difference which reduces another torque ripple due to another specified-order harmonic component as a B-th order torque ripple, and wherein the control unit changes the phase difference within the control range according to a steering speed of a driver as a characteristic required of the multi-phase AC motor.