Study And Implement On Control System Of Integrated Brushless DC Motor

Brushless DC motor(BLDCM) is a new type of permanent magnet machine, and it has made a rapid progress with the development of power electronic technique, modern control theory, microprocessor theory and permanent magnet material. The BLDCM has not only good characteristics as traditional DC motor, but also many advantages such as the simple structure, high efficiency, low noise and long service life. The BLDCM has been more and more applied in many fields such as the military, industrial and civil. For further expanding application fields, the integrated BLDCM control using digital signal controller and advanced algorithms, integrating inverter, control and drive module etc has become an important development trend.Firstly, the control system and the basic operation principles of brushless DC motor are introduced in this thesis, and on the basis the mathematical model is established. To achieve an integrative control system design of brushless DC motor and controller with position seneor control, a control system using digital signal controller dsPIC33FJ32MC204 is designed, the hardware circuit and software programs are also given in this thesis. Finally, the control system is debugged, and the results show that the system can operate steadily and reliably on the condition whether at no-load or with load, verifying the feasibility of the program.The the thesis, some control methods of sensorless brushless DC motor is introduced, and the control system based on the back-EMF detecting is designed. The causes of the rotor position detection errors is analyzed and the compensation method is also proposed. The short-pulse method is used for pre-setting the rotor position, and smoothly switching to back-EMF running is achieved through synchronizing.