An electric vehicle includes an electric traction motor. The motor produces a motor torque from electrical energy of a traction battery of the vehicle. The motor provides the motor torque to the drivetrain of the vehicle to propel the vehicle.
The motor torque produced by the motor may include an oscillating motor torque component in addition to a desired motor torque component. The desired motor torque component is the motor torque to be produced by the motor for vehicle propulsion. The oscillating motor torque component is known as torque ripple. Torque ripple provided to the drivetrain may have an impact in the form of noise and vibration. Thus, it is desirable to reduce the presence of torque ripple.
Techniques to reduce torque ripple include designing the motor so as to minimize the production of torque ripple. Such minimization efforts generally raise motor costs and reduce power density and efficiency. Another technique includes pre-calibration. However, this technique does not take into account variability due to manufacturing as the pre-calibration is done for a small representative sample of motors as opposed to motors installed in particular vehicles. Additionally, due to the complex behavior of torque ripple, even an extensive pre-calibration routine is unable to accurately and consistently reduce torque ripple in varied operating conditions.