Design Of Brushless DC Motor Control System Based On DSP

As the core component of the servo control system, brushless DC motor (BLDCM) not only has AC induction motors’ advantages of the simple structure, reliable operation and convenient maintenance etc., but also has excellent performance of starting and speed control as traditional brush DC motors have. In addition, it also has other advantages like high efficiency and small in size. That’s why BLDCM has been widely used in many precision control fields.Based on the basic structure of BLDCM, this paper analyzes the commutation working principles and elaborates three mathematical models of BLDCM including differential equation, state space expression and transfer function. The principles of its control system and Pulse Width Modulation (PWM) technology also form a part of the paper.Based on the mathematical models of BLDCM, a BLDCM ontology model is built and the double closed loop control system of Brushless DC Motor is simulated with the aid of MATLAB/SIMULINK. In order to improve the control performance of Brushless DC Motor Control System such as Multivariable, time variation, Nonlinear, strong coupling, the speed control method of fuzzy adaptive PID controller is proposed. Based on the double closed loop control, the speed regulator is optimized by fuzzy adaptive PID controller. According to rotation speed variation, it adjusts kp, ki, kd on-line following fuzzy control principle to realize optimal control. Compared with the Brushless DC Motor with conventional PID controller, the BLDCM with fuzzy adaptive PID controller has the advantages of quicker speed response, less speed fluctuation, more stable converter and smaller torque with no overshoot. Moreover, its dynamic and static performance and Robustness are better than the Brushless DC Motor with conventional PID controller.Based on the research of control principle and strategy simulation, the hardware of BLDCM control system based on digital signal processor (DSP) TMS320LF2407A is designed from the whole structure of hardware system. The minimum system and peripheral circuit of TMS320LF2407A, power circuit, testing and protection circuit and control power circuit are introduced respectively.According to software control thought of BLDCM control system, the main program, interrupt service subprogram and control algorithm are designed and described respectively by CCS3.3(Code Composer Studio3.3). Then BLDCM experimental control system is debugged and tested.