Research Of Three-Loop Bldcm Servo-System Based On DSP

With the development of modern power electronics techniques, microprocessor techniques(DSP) and advanced control theories,more and more AC servo systems are used in many kinds of servo-driven field.As one kind of servo motor,the brushless DC motor(BLDCM) not only has the advantage of simple structure,easy-to-Control,Convenient Maintenance as induction motor,but also has high-efficiency without loss of excitation,excellent speed-control performance as DC motor.the application of DC motor is more and more extensive.Studying BLDCM servo system based on the DSP is quite significant.This thesis first of all introduces the BLDCM structure and working principle,illuminates the mathematical model and drive methods, determines the entire three-phase control circuit as its drive,determines its speed regulate method—PWM control.Then design the entire hardware system based on TMS320LF2407,including the main circuit,DSP peripheral circuits,signal detection,protection circuit.Select the model of the components and modules.The entire hardware system also designed over-voltage,over-current protection the suppression of harmonic and Current-leak detection,enhance the reliability of the system.Based on the hardware then designed the servo control system,detailed on the current loop,speed loop,location loop.The current loop and speed loop use PI-control,the location loop use fuzzy-PID to improve the accuracy and dynamic performance.Then designed the fuzzy control table,developed the fuzzy control rules,and use MATLAB to simulate.The result is excellent compared with the conventional PID.Finally Software is designed and debugged in CCS2000 environment,gives the detailed flow charts of key modules.Finally on the base of principle and simulation analysis,the thesis particularly presents the designing and realizing method on the whole servo system's hardware and software.Furthermore the experiment result for the full-digital servo system is introduced.The results of the experiment indicates that the servo system which is designed in this thesis has satisfying static and dynamic performance,suitable low-speed-torque and relatively wide range for regulating speed.Those are beneficial to further research and application.