Design And Simulation Research Of BLDCM Control System Based On DSP

Brushless Direct Current Motor(BLDCM) has good characteristics of simple structure, reliable operation, easy maintenance and excellent static and dynamic behavior, etc. So it is increasingly playing an important role in alternating current transmission system. Since the demand of the control precision, response speed and stability of the industrial control system is becoming more higher and higher. Then, the control strategy of BLDCM servo system is a research hot spot.The most commonly control strategy of the closed-loop control system is PID controller. It can get a better performance when control object is linear and time-invariant system. However, BLDCM is a nonlinear, strong-coupling and time-varying system.In addition, the parameters of the motor often change with the different operating conditions. So the traditional PID controller is not suitable for more precision requirement situation. This paper researches the application of fuzzy control strategy. The BLDCM control system based on the Fuzzy-PID controller is designed and simulation is also presented in the paper.Firstly, the basic structure, working principles, mathematical model and control performance of BLDCM is introduced. The BLDCM control system based on the core of TMS320LF2407A is build up. The system takes advantage of the superiority of high-speed digital computing performed by DSP. It is easy for us to carry out many efficient control algorithms. So the aim of high-accuracy control of BLDCM can be realized.Secondly, the system is designed in two aspects (hardware and software). This thesis puts emphasis on the hardware integrated design, including TMS320LF2407A DSP control circuit, driver circuit and some detecting circuits. The brief introduction of control system's software is given in the paper, including main program, interruption program, algorithm of speed loop and current loop. The flow chart of the program is illustrated.Thirdly, in view of the disadvantage of the Fuzzy control that is difficult to eliminate the static error, researches a hybrid control strategy of Fuzzy control and PID control. A method of self-adapting parameters for PID controller based on the fuzzy mathematical is proposed.Finally, the simulation model of control system using MATLAB/SIMULNK is provided in the thesis. Simulation results show that the validity of the proposed scheme. Also, it verify that the Fuzzy-PID controller is superior to traditional PID controller and the former has better performance such as fast response speed, small overshoot and good stability.At the end of thesis, a summary of the full text and the suggestion of the future work are presented.