The Design And Implementation Of Brushless DC Control System

In industrial application, the DC motor is an electrical energy conversion device, the Brushless DC motor drive is a hot research, in energy-saving field. The performance of the brushless DC motor controller determines power conversion efficiency, and it determines the stability and reliability of motor working. Majority of Brushless DC motor drive uses position sensor to detect the rotor position. The motor starting and switching work mode may generate vibration, it will lead to reduce system stability and reliability, and the energy conversion efficiency will be lower. To solve these problem, the paper studies a Brushless DC motor control system using position sensor method to control motor, The Brushless DC motor control technical difficulties is constant speed output, and improving the stability of control system reliability while improving Electrical conversion efficiency. The main contents are as follows:First the paper explains the basic principles of changing relative and Brushless DC motor driving principles of the three full-bridge inverter circuit, and then introduces the modulation speed control principles of PWM wave pulse width, on this basis, this paper proposes the overall design motor of the Brushless DC motor control system.The paper designs the hardware. Circuit upon the overall system design.The paper analysis the advantages and disadvantages of DSP and STM32chips, and choose the STM32F103RBT6as the main chip. Base on the STM32-core hardware platform, specifically design three-phase full-bridge inverter circuit, power tube bootstrap driver circuit, constant speed adjustment circuit, overcurrent protection circuit, overvoltage and undervoltage protection circuit, and analysis of the design principles and parameters.On the basis of the need analysis of the control system, the paper analysis the advantages and disadvantages of relatively open-loop control and closed loop control, the paper uses the closed-loop control method to achieve constant speed output. Software development platform base on the software of STM32Realview MDK, designs the program of initialization, the program of PWM wave output, the interrupt program of A\D converter, and modify the system parameters.After debugging Motor control board, the paper do the no-load and load experiments, which include the over-voltage protection experiment, undervoltage protection overcurrent protection experiment, and speed regulation experiment. The experimental result shows that the motor start fast and smooth, The controller immediately to protect the motor and control board when overcurrent undervoltage and overcurrent happen,,and control system meets the system design requirement.