Development of an Advanced Motor Control System for Electric Vehicles
To be published on April 2, 2019 by SAE International in United States
Motor control system may be the most important part of electric vehicles. It includes power supply module, DSP controller, protection adjustment module, IGBT driver and resolver to digital convertor. To implement the control strategies, a lot of practical aspects need to be taken into accounts, which include setup of initial excitation current, consistency of current of program code and motor, over modulation, field weakening control, current protection, and so on. In this paper, an induction motor control system for electric vehicles is developed based on DSP. The control strategy is based on the field-oriented control (FOC) and space vector pulse width modulation (SVPWM). Speed calculation, over-modulation, field weakening control, PI controller, and fault diagnosis are also applied in this DSP algorithm. As an industry product running on a real electric bus with a 100kW induction motor, communication with vehicle control unit (VCU) by CAN bus, control system safety and PC software designed for experiment at lab are also discussed. The transient and steady-state performances of this motor control system are analysed by both Simulink and experiments. Its performance is satisfactory when applied to the real electric bus. This paper focused on how to develop the advanced motor control system for electric vehicles for industrial application. It will do some help for applying new control methods like MPC on industrial motors to achieve better performance.