Comparative investigation of single-sided and double-sided permanent magnet linear motor

The permanent magnet linear synchronous motor (PMLSM) with fractional slot per pole is widely applied in high speed digital machine tool and processing equipment of semiconductor due to many advantages such as short end of winding, low copper loss, high thrust force density and so on. Since the force performance closely depends on the structure, the different structures are investigated in detail. To typical slots/poles combinations 12/11 and 12/10, eight feasible structures are described, which adopt single-sided or double-sided and all-teeth wounded winding or alternate-teeth wounded winding. Their FEM models are erected, and the magnetic field, thrust force and normal force of each optimized structure are obtained. By comparison, the optimal structures for single-sided and double-sided are separately found according to the high thrust force and low thrust ripple. To optimal PMLSM of double-sided structure supplied with two kinds of powers, the suppression of thrust ripple is analyzed when permanent magnets of two sides or mover armature in two ends are shifted a certain angle.