Driving characteristics of X-Y linear induction motor with two-dimensional primary winding

In the linear induction motor (LIM), the secondary can be made to move in two directions (X and Y) by placing the primary coils two-dimensionally. When these coils are excited in the direction of 45 electrical degrees, the secondary moves in the direction which is determined by the pole pitches of both directions and the load condition. In this paper, we propose a new type of winding scheme composed of four groups of primary exciting coils, which are shifted spatially by pi/2 in both the X and Y directions. Next, we compare the proposed winding scheme with another one using two independent exciting coils in both directions. We first made both of flat-type X-Y LIMs with the proposed winding scheme and with a normal scheme. Then, we analyzed the magnetic fields in the air gaps of these motors by a three-dimensional finite element analysis based on the A-phi method, and compared the results with experimental data. Finally, we applied the motor with the proposed winding scheme to a branch apparatus. (C) 1999 Scripta Technica.