Research On Electromagnetic And Losses Characteristics Of Tubular Flux Switching Permanent Magnet Linear Motor

Tubular flux-switching permanent magnet linear motor(TFSPMLM)combines the advantages of linear machines and flux-switching permanent magnet machines.Therefore,the motor has shown great application potential in various reciprocating linear motion occasions.However,due to its special cylindrical structure,the winding structure,inductance characteristics and loss characteristics have a certain degree of particularity,which shoud be studied.This paper carried out the research on the electromagnetic and losses characteristics of TFSPMLM.Firstly,the topological structures of the TFSPMLM were discussed.Considering the special annular winding structure,the performance of a 12 slot 14 pole motor with unipolar and bipolar winding structures was simulated and analyzed,including thrust performance,power angle characteristics,back EMF characteristics and inductance characteristics.The application rules of these two kinds of winding structures were concluded.Secondly,the inductance asymmetry caused by end effect was analysed,which had an important influence on the thrust characteristic of the motor.The cuses and regularities of the inductance asymmetry were achieved by finite element simulation.On this basis,the thrust model considering inductance asymmetry was established and the effect of inductance asymmetry on thrust ripple characteristics was recongnized,thus it shows quantitative analyses.For TFSPMLM,two schemes were adopted,which called winding structure optimization and modular primary,to suppress the inductance saymmetry and improve motor's thrust characteritics.Futhermore,the loss characteristics were analyzed considering the special core structure and working principle of TFSPMLM.The calculation model of the primary core loss,secondary iron core loss and permanent magnet eddy current loss were established respectively,which was certified by the finite element simulation.Meanwhile,in order to solve the problem of large eddy current losses in the secondary,the measure of making slots along circumferential direction of the circular iron was adopted.The effect that it can reduce loss was verified.Finally,a prototype machine was developed.The test platform was set up and the related test experiments were completed.Through measuring the winding parameters,back EMF,detent force and loss characteristics of the prototype,design analysis and losses characteristics analysis of the TFSPMLM researched in this paper were effectively verification.