Design of a Controller for Torsional Vibrations of an Electric Vehicle Powertrain

Electric powertrains are subject to vibrations due to weak damping and fast torque response of electric motor. In this study, a PD controller is developed to damp the vibrations. By using PD controller, two solution methods are developed. First solution is to use the wheel speed sensors available in all four wheels. Second solution is to use a reduced order observer to estimate the wheel speed. Differentiation of motor speed and wheel speed is input to the PD controller. Output of the PD controller is the torque damping feedback to the torque reference. Simulation model is developed including a flux vector controlled permanent magnet synchronous motor, powertrain model and vibration controller. The results demonstrate the validity and effectiveness of the proposed scheme.