Application Of Sliding Mode Variable Structure In Brushless Dc Motor Vector Control.

Brushless DC motor(BLDC),which has the characteristics of simple structure,high starting torque,high efficiency and power saving,has attracted wide attention and is also the backbone of the motor field.Its miniaturization and intellectualization is the trend of future development.It has been applied in more and more new scientific and technological fields,such as electric vehicle power system,air conditioning compressor appliance and medical instrument,which have highlighted the advantages that can not be underestimated.But the response speed of its operation still needs to be improved,and the problem of torque ripple and speed is not stable.One step of improvement.In order to improve the technology of motor application in engineering practice,this paper studies the following three aspects.Firstly,the paper reviews the research and development of a series of control theories after its advent.On the basis of other scholars’ theoretical analysis,the mathematical model and working principle of the motor body are analyzed.The method of space voltage vector pulse width modulation(SVPWM)is adopted to drive the brushless DC motor.The method can suppress a certain torque ripple.Secondly,the problem that the rotor speed is not stable and the torque ripple is large in the process of the brushless DC motor,which affects its application in the high precision servo system.In the outer loop,the speed control is designed by sliding mode variable structure.On the basis of the traditional constant speed approaching law of SMC,the improved SMC controller is designed,and the inner loop current loop is PI controller.The simulation analysis of the control system is carried out under MATLAB/SIMULINK environment.The simulation results show that this scheme further reduces the chattering of the motor,and enhances the robustness,smoothing the current waveform and enhancing the performance of the motor obviously.Finally,on the basis of the simulation research,the control board with DSP chip TMS320F28335 as the core,the XD-510 as the simulator and the CCS3.3for the software environment are tested.The experimental results show that the improved convergence law is applied to the brushless DC motor vector control system,and the buffeting is weakened and the response speed is accelerated.And the torque ripple is effectively suppressed.The research results of this subject can provide a certain reference basis for brushless DC motor application in engineering practice to a certain extent.