Bearingless Flux-switching Motor Design And Suspension Control

With the development of science technology and the production need,high speed and ultra-high speed,large capacity electric drive has been more and more widely used,But the centrifugal force of rotor will rise with speed increases.The permanent magnet fixation of traditional motors in which permanent magnets are on the rotor become more and more difficult,at the same time it makes friction force of the mechanical bearing increasing which supports the rotor,which exacerbates the mechanical vibration and noise,causing the motor fever,shortening the service life of the bearing,and mechanical bearings also require lubrication and maintenance.In some special applications,such as high clean environment,vacuum,lubricating oil cannot be used,and in the toxic,space,radiation and other application environment,mechanical bearing maintenance is a problem.Flux-switching motor is the stator permanent magnet type motor,it overcomes the fixation of permanent magnets in the high speed situation.Based on this the paper proposed the bearingless technology applied to the flux-switching motor,the main contents of this paper are as follows:Establishing the linear mathematical model of the suspension force,according to BFSPM,In view of the disadvantages brought by the double winding suspension structure,this paper proposes a single winding BFSPM suspended structure.there are two actual operation situations depending on whether there is an eccentric of rotor,analyzing the relationship between two kinds suspension force.Based on the no eccentric suspension force model,the eccentric suspension force model is constructed,and the two kinds of suspension force model are verified by using the finite element analysis software Ansoft,validation results proved the correctness of the BFSPM suspension force model.A levitation control strategy of BFSPM is proposed,Its feasibility is validated by MATLAB simulation.Using the special motor design software Ansoft to design one 12/10 type BFSPM motor,on the basis of the initial size prototype,the size parameters were optimized by using parametric mode,the electromagnetic properties of the different parameters were compared,the optimal parameters were selected.Solving magnetic saturation problems of the stator tooth caused by the high BFSPM assembled magnetic effect to ensure the rotor levitation force of the linear model is established in this paper can work correctly.Aiming at the traditional DQ rotating coordinate system can not really decoupling problem in the vector control for BFSPM lacks one phase case,this paper puts forward the concept of the virtual stator current,and the virtual stator flux linkage.Getting the decouple model by using the virtual stator current and the virtual stator flux linkage,and this control strategy is feasible which is certified by means of simulation and experiments.To validate the proposed control strategy,a set of high-performance,good stability BFSPM hardware and software system combined with the characteristics of vector control and made TMS320F2812 DSP as the core has been designed.The key parts of the implementation methods have been described.The experiment results show that the hardware system can meet the needs of the proposed control scheme and has advantages of high reliability and real-time.