Research On Brushless DC Motor Speed Control System Based On DSP

Brushless DC motor(BLDCM)is a new type of permanent magnet motor developed rapidly in recent decades.It realizes electronic commutation instead of mechanical commutation.Compared with the brushed DC motor has the advantages of high efficiency,high torque and small size.So nowadays,aerospace,numerical control machine tools,etc.,which have relatively high requirements on rotational speed performance and control accuracy,are applied to the brushless DC motor control system.Firstly,this paper introduces the working principle and the overall structure of the brushless DC motor,constructs the mathematical model of the brushless DC motor,and analyzes and explains the transfer function established according to the working principle of the motor.In the simulation environment of MATLAB/Simulink,a model of double-closed-loop control system for speed and current was constructed,and the control strategy of the system was proposed.Finally,simulation verification was performed.Secondly,this paper designs the hardware system of position sensorless brushless DC motor drive control system based on TI's DSP embedded control chip TMS320F28335,and also designs the software part.In the hardware part,DSP core control circuit and BLDCM drive circuit are designed,which mainly include: DSP peripheral circuit,inverter main circuit,IR2136 drive circuit,sampling circuit and position signal detection circuit.The integration of the hardware system is realized;the software part selects CCS6.0 as the development software,and the software program that realizes the function of the hardware system is written.The software part adopts a modular design method to complete the design of the main program and each subroutine,including the main program,initialization subroutine,A/D interrupt subroutine,closed-loop interrupt program,and serial communication subroutine.Finally,this paper uses 167 W low-power DC brushless motor as the controlled object,through the software and hardware debugging of the entire brushless DC motor control system,experimental analysis.The experimental results show that the Hall sensor can accurately detect the rotor position of the motor,the inverter can perform high efficiency commutation,and the torque ripple is small and the waveform smoothness is good during the commutation.This proves that the system has high control accuracy and good The output performance.