Control of brushless DC motor with an AVR microcontroller

This paper illustrates the basic work principle of a brushless DC motor and presents its control method. According to the method, a control system of a brushless DC Motor is designed using an AVR microcontroller. Design of the control system includes hardware circuit designing and software programming. The hardware structure of the control system consists of a microcontroller ATmega64, power supply circuit, position detection circuit, current chopper circuit, power driving circuit, display circuit and keyboard circuit and so on. The software is developed by c program language. The software includes main program, initialization program, PWM duty ratio reload program, speed calculation program, closed-loop PID regulation program, interrupt service program, LCD display program, keyboard program etc. The experiment result shows that the system is with an excellent dynamic and static performance. Its operation is reliable.