Research On Vector Control Of Induction Motor For Electric Vehicles

With the increasingly energy depletion and environmental pollution in the whole worldwide, electric vehicle has attracted extensive attention in social circles. As a key technology for electric vehicles, it is of great practical significance to research the motor drive control.The induction motor drive system applied for electric vehicle (EV) is research in this thesis. A rotor field oriented control (FOC) strategy which is suitable for electric vehicle is presented. The principle and implementation strategy on vector control are studied and analyzed also.Related research work in this thesis includes:1. Based on the brief analysis of mathematical model of AC asynchronous motor and the principle and implementation methods of FOC vector control, the key technologies in FOC are researched in the thesis, such as coordinate transformation, magnetic field orientation, voltage decoupling, rotor flux observer, voltage space vector modulation (SVPWM),etc. A new voltage trajectory field-weakening control method of induction motor for high-speed operation is proposed.2. The Vector control simulation model for AC asynchronous motor of electric vehicle is designed by adopting the rotor flux oriented voltage decoupling vector control method with the voltage trajectory field-weakening.3. An electric vehicle motor controller is developed based on TMS320F28335digital signal processor (DSP). The C language is adopted to compile the FOC to control motor run in different conditions.4. The simulation and experimental results indicate that the voltage decoupling control reduces the motor torque pulsation and has a swift dynamic response, and the dc-link voltage utilization can be extended by voltage trajectory field-weakening control method. It is illustrated that the FOC strategy designed in this thesis is valid and can meet the performance demand of electric vehicle motor drive controller.