Induction Motor Direct Torque Control Based On DSP

In recent years,for the necessary to solve the environment problem and energy crisis,the electric vehicle with no pollution and low noise has been given more and more attention.AC motor propulsion system for electric vehicles is replacing DC propulsion system and gradually turning into the mainstream in foreign countries.However,in our country the research on AC propulsion system for electric vehicle is in the initial period,and there is a big gap about it between the domestic and foreign countries. The direct torque control(DTC) appears a good future because it has a characteristic of direct control means,simple structure and fast response.This paper further investigates the basic principle of the controlling method of direct torque of the asynchronous motors.On the basis of analyzing the mathematical model of the asynchronous motor,the paper expatiates many basic conception of DTC in detail,which includes the voltage space vector,flux and torque controlling directly and so on.The paper presents a stability criterion,and the system start-up problem is studied.Finally the whole system structure frame is introduced.In the next chapters the digital controlling scheme of DTC is studied, which includes hardware and software realization.The hardware includes the design of control circuit based on a digital signal processor(DSP) and main circuit based on IPM 7MBP50RA120.And the program block diagram of the software is given.In the end of paper,the simulatin of the whole control system with MATLAB is presented.The simulation result demonstrates the control strategy is feasible.In addition,the system experiment is somewhat studied.