| New linear motors for maglev are suggested. They have a simple structure and operate as induction motors which generate both levitating and propelling forces. The levitating and propelling forces depend strongly on design factors, especially the ratio of the radii of the drive coils and sleeve coils, and on the pole pitch. To get the maximum levitating or propelling forces, the ratio of pole pitch and radii should be selected carefully.; The effect of the harmonics is studied as well as that of the skin depth. The skin depth varies with the frequency of the sleeve currents. Because the induced frequency is proportional to the slip of the sleeve, the skin depth also depends on the slip. This causes the difference between the actual model and the current-sheet model, which is used in the preliminary design.; The mesh-matrix method is adopted to analyze the transient motor performance. With this method the motor can be simulated more realistically using a computer code. In steady state the simulated model agrees well with the current-sheet model when it includes the harmonic analysis.; To show what is practically realizable, several motors were designed. The full-scale motor and a small prototype were investigated for horizontal motion and a vertical motor was introduced to show alternative realization.; All the above studies were supported by several experiments such as measurement of mutual inductances and self inductances. |
