Research And Design Of Control System For Brushless DC Motor

The DC motors have the advantages of excellent linear mechanical characteristic, wide range of speed regulation, strong torque and so on. But conventional DC motors’reliability is week because of their brush and commutator’s usual abrasion. The brushless DC motors use electronic commutation instead of mechanical brush to solve this problem. They are used in military area, aviation, spaceflight, medical treatment, information, household electric appliance and industrial automation and so on. This paper designs a type of control system for brushless DC motor after studying the situation about the control technology and developmental trend of brushless DC motor in and out.According to the requirements, this paper compares several control schemes and makes the overall design. Under the overall design, the paper designs the hardware and software with the thought of modularization. In hardware designing, it analyzes the design requirements, principles and implementations of control module, drive module, detecting module and power supply module. These modules compose the hardware system. In software designing, it analyzes the functions and program flows of detecting and protecting module, electronic commutation module and PWM control module. The paper focuses on the principle and structure of electronic commutation module and designs the corresponding programme. This paper combines the conventional PI control strategy and fuzzy control. After analyzing the principle and structure of fuzzy control, it designs the fuzzy-PI controller in order to improve the stability and adaptability of this system.Now the paper achieves the original goal, and successfully applies this control system on lift equipment for automobile and electromotive equipment. The project application indicates that the control system can work steadily and control the motor conveniently, rapidly and accurately. The research of this paper is of some referable for the digitization and intelligent control in this field of brushless DC motor.