Research And Development For Asynchronous Motor Drive Controller

Under the background of the shortage of resources and environmental pollution, the electric vehicles is now taken seriously by people as a kind of efficient, environmental protection, energy saving of the emerging traffic tools.Asynchronous motor is simple, durable, cheap, and easy to be maintened, with the development of power electronic technology and related control theory, the control performance of asynchronous motor has got a great improvement, and make it widely used in electric vehicles. The paper deeply studied the vector control theory of asynchronous motor, Analyzed the key technology of the asynchronous motor control, then developed a set of controller for the asynchronous motor used in the electric vehicles, and test the controller on the car, the test achieved good effect.For the asynchronous motor used in vehicles, the key performance is the ability of speed controlling. In the rotor field oriented vector control method, the wrong field orientation caused by the wrong motor parameters impacts the controlling effect of the motor. In order to overcome the disadvantages of traditional asynchronous motor control system caused by the wrong rotor orientation of the motor rotor, this paper analyzed the influence of the wrong rotor orientation for the vector control algorithm in detail, then developed a rotor orientation correcting strategy based on the model reference adaptive theory, it’s intuitive and Easy calculated. In order to verify the correctness of the theoretical analysis, this paper set up the simulation model of the vector control theory based on the Matlab/Simulink, and make a simulation of the motor’s magnetic weak ability and the filed orientation correcting ability. The simulation results shows that the magnetic weak method is effective and the filed orientation correcting method can quickly correct of the rotor magnetic field orientation error. This vector control system can work in high speed and has good Speed control ability, it can meet the requirements of electric vehicles.In order to improve the electric car’s mileage, this paper analyzed from the two aspects of improves the motor efficiency and energy feedback. This paper firstly analyzed several kinds of common induction motor efficiency optimization control method, and select the minimum stator current control method for control method, by aiming at the shortcomings of the traditional minimum stator current control method, the paper puts forward an improved the minimum stator current control based on slip frequency closed loop method. In terms of energy feedback, the paper analyzes the principle of regenerative braking, the conditions to be fulfilled, and the minimum stator current control method is applied to the regenerative braking process, in order to improve power generation efficiency. Finally based on regenerative braking during the process of dynamic response characteristics of request is not high, the minimum stator current control method is simplified.On the basis of theoretical analysis and simulation research, this paper developed a asynchronous motor drive system based on TMS320F2812, it included the hardware design and software design of the controller, then tested the controller one bench, finally loaded the controller one the vehicle and make a test. The test result shows that the controller can satisfy the requirement of the electric vehicles’ driver, it verified the feasibility of control algorithm and controller design.