Research On Model Predictive Control And Disturbance Rejection Of Bearingless Permanent Magnet Slice Motor

Bearingless permanent magnetic slice motor(BPMSM)is a new type bearingless motor which combines the characteristics of permanent magnet motor,magnetic bearing and slice rotor,and can realize the five degree of freedom suspension of the slice rotor.The BPMSM has the advantages of high efficiency,no friction and wear,easy maintenance,and so on,so it has broad prospects for development in the fields of life sciences,chemistry and chemical industry,energy storage and transportation.The direct control system of BPMSM has the shortcomings of torque ripple and suspension force ripple,furthermore,the suspension attitude of the rotor will change or even cause a collision between stator and rotor when the rotor after being disturbed,which seriously affects the operation stability of BPMSM.Aiming at the above problems,a continuous control set-model predictive control(CCS-MPC)method and a disturbance rejection method based on active disturbance rejection control(ADRC)are proposed in the dissertation.This compound control strategy is established to realize the continuous control set predictive torque control and the continuous control set predictive suspension force control of BPMSM based on ADRC.This dissertation is supported by the National Science and Nature Fund(61973144)and the Key Research and Development Program of Jiangsu Province(BE2016150).In this dissertation,the working principle,mathematical model,continuous control set-model predictive control strategy,rotor disturbance suppression of the BPMSM have been researched based on a 4kW prototype.The main contents of the dissertation are summarized as follows:1.The research background of BPMSM,the research overview of bearingless motors,the domestic and foreign research status and application fields of BPMSM,and the development overview of predictive control and disturbance suppression strategies are summarized in the dissertation.The basic structure and suspension principle of BPMSM are introduced,then by analysing the two kinds of forces on the rotor,the mathematic model of BPMSM is derived,and the BPMSM direct control system is designed,the simulation verified the the validity of the system.2.In view of the shortcomings of the torque ripple and the suspension force ripple in the direct control system of BPMSM,this dissertation uses the CCS-MPC algorithm in the direct control system,and the boundary condition and delay time compensation strategy are set to optimize control algorithm.Finally,the CCS-MPC direct control system is established,the system effectively reduces the torque and suspension pulsation when the motor is running.3.Aiming at the problem that the rotor disturbance of BPMSM caused by model parameter changes and load changes under long-term operation,the active disturbance rejection control strategy is proposed to suppress the rotor disturbance.The disturbance suppression ability of the system is enhanced by using ADRC instead of PID in the speed regulation module of the torque part and the displacement regulation module of the suspension part,respectively.4.The digital control system of BPMSM is built,the hardware parts and software parts of the control system are designed and debugged,respectively.A visual host computer interface based on LabVIEW is built for the real-time monitoring and modification of the experimental parameters.Then,the static and dynamic experiments of the prototype are conducted with the proposed control strategy,the experimental results confirm the effectiveness of the proposed compound control strategy.