Torque Fluctuation Suppression Strategy of Integrated Electric Drive System Based on the Principle of Minimization of Instantaneous Current Tracking Error

Abstract

Integrated electric drive system (IEDS) is a complex dynamic system composed of many mechanical and electrical systems. Because of the coupling impact of the nonlinear characteristics of these subsystems and the defect of the current decoupling method, the traditional vector control (VC) strategy fails to fully exploit the dynamic response of IEDS and remove the dynamic coupling of current. As a result, The IEDS torque fluctuation under the traditional VC strategy is high. To improve this problem, an IEDS electromechanical coupling model is established firstly, which takes account into the nonlinear characteristics of the motor and the transmission system. Secondly, the ideal voltage which can minimize the instantaneous current tracking error (ICDE) is obtained by the revised d-q voltage model and particle swarm optimization (PSO) algorithm, and the ICDE is the difference between motor current and reference current in a step period. Finally, an IEDS torque fluctuation suppression strategy based on the look-up table is proposed. Simulation shows that the proposed control strategy, compared with the traditional VC strategy, not only effectively improves the current control performance of the current loop but also greatly reduces the torque fluctuation.