Torsional vibration analysis and suppression for integrated electric drive system considering nonlinear excitations

Abstract

Integrated Electric Drive Systems (IEDS) are widely used in electric vehicles due to its compact design and high-power density. To address the issue where nonlinear excitations and variable, complex operating conditions of IEDS can exacerbate high and low-frequency torsional vibrations, leading to decreased reliability of the IEDS. The active dual-layer suppression method is proposed based on analyzing inherent properties and the influence of nonlinear excitations, including time-varying meshing stiffness, backlash, meshing error, and dead-zone, on the dynamic performance of IEDS, which can simultaneously suppress high and low-frequency torsional vibration of the IEDS. In the upper-layer, a torsional vibration suppression method based on pole placement is proposed to optimize the motor's reference torque. Then, a current harmonic suppression method based on active disturbance rejection control is proposed in the lower-ayer to compensate for the voltage errors caused by nonlinear excitations and decoupling errors, thereby reducing current harmonics and torque ripple. The simulation and experimental results show that the method can effectively reduce current harmonics and torque ripple, while also decreasing high and low frequency torsional vibrations of IEDS. This enhances the reliability of IEDS and improves the vehicle stability.