Abstract: A torque ripple reduction method for a synchronous electric motor of a vehicle includes obtaining, by a control system, look-up tables (LUTs) that each include harmonic currents that satisfy a constrained objective function for phase current magnitude for the synchronous electric motor, based on a requested motor torque, determining, by the control system and using the LUTs, a plurality of currents including fundamental direct and quadrature currents and 6th order and 12th order harmonic quadrature currents, determining, by the control system, direct and quadrature voltages for the synchronous electric motor based on the plurality of currents including injection of the 6th and 12th order harmonic quadrature currents, and controlling, by the control system, the synchronous electric motor based on the determined direct and quadrature voltages to at least one of reduce torque ripples and increase efficiency of the synchronous electric motor.

Abstract: A control system for an electric motor of an electrified vehicle includes an inverter of the electrified vehicle, the inverter comprising a set of switches and being configured to receive three pulse-width modulation (PWM) signals and to control the set of switches to generate an alternating current (AC) output voltage from a direct current (DC) link voltage provided by a battery system of the electrified vehicle, and a control system configured to determine a torque command for the electric motor, determine commanded d-axis and q-axis voltages based on the torque command, generate a trapezoidal wave modulating signal for carrier-based PWM based on the commanded d-axis and q-axis voltages, generate the three PWM signals by performing carrier-based PWM using the trapezoidal wave modulating signal, and control the electric motor using the AC output voltage generated by the inverter.

Abstract: A control system for an electric motor of an electrified vehicle includes an inverter of the electrified vehicle, the inverter comprising a set of switches and being configured to receive three pulse-width modulation (PWM) signals and to control the set of switches to generate an alternating current (AC) output voltage from a direct current (DC) link voltage provided by a battery system of the electrified vehicle, and a control system configured to determine a torque command for the electric motor, determine commanded d-axis and q-axis voltages based on the torque command, generate a rectangular wave modulating signal for carrier-based PWM based on the commanded d-axis and q-axis voltages, generate the three PWM signals by performing carrier-based PWM using the rectangular wave modulating signal, and control the electric motor using the AC output voltage generated by the inverter.

Abstract: A torque ripple reduction method for a synchronous electric motor of a vehicle includes obtaining, by a control system, look-up tables (LUTs) that each include harmonic currents that satisfy a constrained objective function for phase current magnitude for the synchronous electric motor, based on a requested motor torque, determining, by the control system and using the LUTs, a plurality of currents including fundamental direct and quadrature currents and 6th order and 12th order harmonic quadrature currents, determining, by the control system, direct and quadrature voltages for the synchronous electric motor based on the plurality of currents including injection of the 6th and 12th order harmonic quadrature currents, and controlling, by the control system, the synchronous electric motor based on the determined direct and quadrature voltages to at least one of reduce torque ripples and increase efficiency of the synchronous electric motor.