Research On Induction Motor Control Strategy Of Small Power Electric Vehicle

As increasingly severe energy shortage problem and environmental pollution problem, the electric car, has become a hot direction in the auto industry. Drive system is the heart of the electric car, and the system control algorithm determines the running performance of the motor. Under the hundred kilometers speed, the acceleration time of car is an important factor we should consider. This paper designs the induction motor control system based on TMS320F28069 platform, and puts forward the "maximum acceleration/torque current ratio" control algorithm.Firstly, the mathematical model of induction motor is introduced in different coordinate, and so is the vector control method and the SVPWM modulation principle in details, the result of SVPWM is illustrated by simulation.Secondly, a platform of induction motor is set up based on TMS320F28069 controller, and the corresponding software program is designed; In addition, combined with TMS320F2812 development board, a small test tool is set up for transmitting data by eCAN. The main controller TMS320F28069 controls motor running while continuous variables transmits to the deputy controller TMS320F2812, and be shown in CCS3.3. This method,which can observe more variables and do not take up the main controller storage space, is verified by the experiments.In addition, through the actual systems, the hall current sensor and the single resistance sensor is compared for different occasions.Finally, the influence of the induction motor parameters on the motor electromagnetic torque is be introduced, and a "maximum acceleration time/torque current" control algorithm is proposed. According to that, a algorithm is designed for induction motor stator parameters identification, which is used as the initial value of the optimum rotor time constant in the control algorithm. An experiment has been carried out on the drive system with TMS320F28069. The experimental results show the accuracy of parameter identification, and the closely relationship between the rotor time constant and motor acceleration.