Design And Simulation Of Control System For Brushless DC Motor

The rare-earth square-wave permanent magnet brushless DC motor control system is new type of system developed rapidly in recent years. With its high performance, the system shows a broad prospect for further advances. Conventional DC electric propulsion system always takes up dominant station in submarine propulsion. Due to DC motor inherent limitation that machine commutation and brush results in stand-alone capability's limit low reliability, big noises, people manage to explore more quiet, high efficient and reliability, big stand-alone capability propulsion motor. These years along with the development of power-electronics technique and micro-control technique, permanent magnetic brushless DC motor is characterized by small volume, light weight, high efficiency, low noises, big stand-alone capability and reliability appeared and matured. So it is hopeful to become new generation submarine propulsion motor.This paper describes the operating principle of the square-wave brushless DC motor and constructs the model of BLDC. The position and speed-current close-loop control system for the square-wave brush DC motor is simulated and analyzed, and real system can be designed under the guidance of the simulation results. The main-circuit adopts IGBT three-phases converter. Commutate circuit adopts LM621 to lighten the burden of Single-chip microcomputer. The PWM controller controls the speed. The software makes up of the main-program and interrupt program. With the hardware, the system can realize the functions of start, stop and direction movement. This paper designed and realized the control system on single-chip microcomputer for brushless DC motor, completed its hardware and software circuits. The system rationality in design, reliability in operating and high-performance in position adjustment.