Modeling And Control Of Brushless Dc Motor Drive System Based On Hybrid Switching Theory

Brushless dc motor(BLDCM)drive system is mainly composed of four parts,including ontology,sensor,voltage source inverter and the controller.Because the traditional inverter circuit switching function model only considers the changes of the control circuit-without considering conditions associated with circuit state of continuous change,which leads to the greater torque ripple of brushless DC motor.For this problem,this paper proposes a method of mixed logic dynamic(MLD)to model and control of BLDCM drive system.With the dynamic modeling method based on mixed logic,the inverter power tube switching signal is defined as a discrete control variables,the diode conduction state variables defined as discrete conditions variables.Then the BLDCM drive hybrid system model is set up and model to predict the optimal control,to improve the performance of brushless dc motor drive system is of great significance.BLDCM is researched as control object in this paper.The current modes of the power switch in BLDCM drive system are analyzed with on-off state.MLD model of BLDCM is established and a model predictive control algorithm is also proposed.The main research contents are as follows.Firstly,the hybrid system theory and the MLD modeling method are introduced.Based on the mode of BLDCM drive system,the MLD model is constructed.A model predictive control algorithm is proposed with the MLD model discretization.Secondly,based on inverter circuit topology of BLDCM,simulation verification is implemented by Matlab/Simulink to PID control algorithm and model predictive control algorithm.The simulation results show that the control performance of BLDCM is improved by the model predictive control and the torque ripple is also reduced for BLDCM.As a result,it provides a new idea for the research of BLDCM drives.Finally,the experimental platform of BLDCM driven system is built and the proposed control algorithms are also verified.The experimental results show that the proposed model predictive control algorithm can realize the stable operation of the BLDCM drive system and the torque ripple can be also reduced in a certain extent for BLDCM.