The Research And Design Of Short-Secondary Linear Induction Motor

Linear motor is a kind of electric drive that can transfer electric energy to linear mechanical energy directly. Every rotating motor has a homologous linear motor in principle, because they have similar principle of work. Linear motor has entered into a independent application stage and all sorts of linear motor have been popularized since 1970s. As one kind of linear motor, the short-secondary linear induction motor(LIM) has also been applied in some domain. In fewness special field, it has some unique advantages. This paper has researched the theory of the short-secondary LIM and designed a model machine.Firstly, based on existing research condition summarized, the airgap magnetic field and the design traits of the LIM have been analyzed. The differences between the short-secondary LIM and the short-primary LIM in end effects and winding connection are compared, then the characteristic of the short-secondary LIM has been indicated. The equivalent circuit's dissimilarity of the LIM has also been analyzed to supply foundation for electromagnetism design.Secondly, a method on the electromagnetism design of the short-secondary LIM is brought forward on the base of the design task confirmed. The model machine's parameter is obtained by compiling computation program. The final design scheme is determined, then the model machine is manufactured.Finally, the mathematical model is eatablished, and the starting,running and locked-rotor processes are simulated by the finite-element method(FEM).The magnetic fields in this three states is analyzed, so the thrust force and the attraction force are calculated. Meanwhile,the change tendency of the performance in these processes is obtained when the length of air gap,spacing of silicon sheet,position of secondary and length of secondary have been changed,some favorable conclusion is obtained. The conclusion of entire paper is presented.