Design And Simulation Research Of BLDC Motor Control System Based On DSP

With the development of computer technology and modern control theory, servo system made up of numerical control device has emerged. Compared with traditional simulation system, numerical servo system control has features as: simple in design, small in volume, convenience in revising, high accuracy and reliability. As actuator of typical numerical servo control system,brushless DC motor not only has a series of AC motors'advantages, such as simple in structure, reliable operation,convenience to maintain etc,but also has a lot of DC motors'traits of high operating efficiency, no excitation loss, excellent speed adjusting performance etc. And it has been widely applied in many high-technology fields, such as robot, numerical control machine, radar, submarine and various military weapon servo systems.Under the background of applications of brushless DC motor in a weapon servo system, brushless DC motor control system based on DSP was designed and the simulation study was carried out in the paper.This paper gives a deep research on basic structure, working principles, mathematical model and control performance of permanent magnet BLDC motor, and compared and analysed the control performance of the PLC, special used chip and single chip microcomputer. I build up a scheme of BLDC servo motor control system with the core of DSP (TMS320LF2407A). The system mainly takes advantage of the ability of high-speed digital computing performed by DSP. Based on the high-efficiency control algorithm of DSP, the aim of high-accuracy control of the brushless DC motor could be realized.In following parts, there is a detail description of the control system's design and controller's design about BLDC motor. In the control system's design part, this paper puts emphasis on the hardware integrated design, including TMS320LF2407A DSP peripheral circuits, driver and inverter circuit. At the same time, some detecting circuits are designed, including position signal,phase currents,phase voltages, speed signal and fault detection circuit. The brief introduction of control system's software is given in this paper, including main program, program interruption, algorithm of velocity loop and current loop. At the same time corresponding flow-charts of program are given based on the design idea of modularization. In controller's design parts, the characteristics of FuzzyPID controller are presented in detail. And in the Matlab environment FuzzyPID controller with self-adjusting parameters is designed and modeled.The end is modeling and simulation research of control system. In Matlab/Simulink environment, the isolated functional blocks, including BLDC general block (including BLDCM block, torque computation block, rotation speed computation block, the back EMF block), Current hysteresis control block, Speed control block, rotor position computation block, voltage source inverter block etc, have been modeled. By the organic combination of these blocks, the model of BLDC can be established easily. In the double loop of control system, a FuzzyPID controller with self- adjusting parameters is adopted in the speed outer loop and a current hysteresis controller is adopted in the current inner loop. The reasonability and validity have been testified by the simulation results and also verified that FuzzyPID controller with self-adjusting parameters is superior to traditional PID controller and the former has fast response speed,little overshoot and good stability and tracking performance. This novel method offers a new thoughtway for designing and debugging actual motor control system.BLDC motor control system that this paper proposes is analyzed and simulated. The results prove the scheme is feasible, and the design requirements is achieved. The novel method of modeling and simulation given by this paper offered a new thoughtway for designing and debugging actual motors.