Research On Novel Winding Structure And Suspension Force Control Of Bearingless Permanent Magnet Slice Motor

A bearingless permanent magnet slice motor(BPMSM)is a high performance which is combined the advantage of magnetic levitation,permanent magnet machine and slice rotor,for the reason above,BPMSM is gifted with the superior properties,for instance: no mechanical friction,long maintenance cycle,high energy conversion efficiency,small torque ripple and so on.The full levitation of traditional bearingless motor need the active control of five degrees of freedom,for the structure of special slice rotor,the BPMSM can realize full levitation by the active control of two degrees of freedom,the other three degrees of freedom are stabilized passively,so the control system is simplified greatly and it is the milestone in the field of bearingless motors.Due to the special mechanical structure,the BPMSM possesses a wide range of applications in pump field,where the magnetically suspended rotor with impellers can be rotated with a high speed in a hermetically sealed housing.This kind of pump has great application value in the field of aerospace,biomedical pharmacy science,semiconductor industry and so on.The dissertation is supported by Key Research and Development Program of Jiangsu Province(BE2016150)and Jiangsu Province“Qinglan Project”(2014).In this dissertation,the BPMSM is studied in the following direction: mathematical models,the structure of winding and the control strategy for rotor suspension.The detail works are as follows:1.The dissertation systematical introduces the research background,development trend,application fields and the key technologies of BPMSM.Then the research significance and the content of the dissertation are summarized.After this above,levitation principle of the slice rotor is analyzed,and to solve problems of the conventional bearingless permanent magnetic slice motor with double windings,such as high insulation requirement,low filling ratio,serious flux leakage,a novel winding structure of bearingless permanent magnetic slice motor(M-BPMSM)is proposed,The principle and structure design of M-BPMSM are investigated and the accurate mathematical model of radial suspension force are deduced.Based on the model,the control system diagram of M-BPMSM is designed,and the correctness and reliability is verified by Matlab.2.The control accuracy and dynamic performance of suspension force are confined in previous bearingless motor control strategies because the suspension force control is indirectly achieved by a closed loop of displacement,and the traditional strategy ignore the affect of the axial vibration for the machine.In this dissertation,the compensation strategy of suspension force with radial suspension force and displacement double closed loops is put forward,and based on it,axial vibration suppression strategy is designed,the principle and algorithm of it is introduced,the control system is designed and simulation model is constructed in Matlab.3.The digital control system is built,based on the experiment platform,the control system is introduced in detail.Before the debugging of the hardware system,the communication interface is designed based on Labview for the real-time monitoring and online debugging of the software system,after the work above,the suspension performance of the machine is analyzed.