Research And Design Of Brushless DC Motor Control System Based On STM32

Brushless DC motor has not only AC motor characteristics in essence,but also excellent speed regulation performance of traditional DC motor.It overcomes the adverse effect of mechanical commutation,runs reliably and maintains simply.It is widely used in many fields of national production.Torque ripple of brushless DC motor will produce noise and vibration,which will affect the servo accuracy of motor system.There are many disadvantages in the use of position sensor.How to effectively suppress torque ripple and realize sensorless control has become the research focus of brushless DC motor.This paper focuses on: 1.The influence of different PWM modulation modes on the torque ripple;2.Sensorless control method of brushless DC motor.Firstly,the structure and related working principle of brushless DC motor system are analyzed in detail,and the mathematical model of differential equation is constructed,and the related basic equations are listed.The steady-state operation characteristics,speed regulation principle and PID control principle of brushless DC motor are analyzed,and the fuzzy PI controller is designed.Then,the generation principle of commutation torque ripple is described in detail,and the torque ripple of six PWM modulation modes in different speed ranges is studied.The electromagnetic torque of PWM modulation modes during commutation and non-commutation,as well as the continuous flow state during non-commutation period are analyzed in detail.It is concluded that the PWM-ON-PWM modulation mode has no continuous flow during the non-commutation period.The optimization effect of fuzzy PI control on torque ripple is studied.Then,a sensorless control scheme based on the combination of line voltage difference method and PWM-ON-PWM modulation method is proposed to meet the requirement of detection with line voltage difference method that non-continuous current in the non-commutation phase of the motor.The three-stage method is used for start-up control.Rotor zero-crossing detection using 90°-a phase-shift compensation for wider speed range.Based on the above-mentioned theoretical analysis,the related simulation models are constructed under the MATLAB/simulink environment,and the functions of each module are analyzed in detail.The correctness of the theoretical analysis is verified by simulation research.Finally,the hardware circuit design of sensorless brushless DC motor controller is completed by using STM32F103 microprocessor as the main control chip of the system.The hardware circuit and software design of sensorless brushless DC motor control system are completed,and the feasibility of the control system is verified by experiments.Figure [60] table [12] reference [54]...