Detent-Force Minimization of Double-Sided Permanent Magnet Linear Synchronous Motor by Shifting One of the Primary Components.

The longitudinal end effect of the double-sided permanent magnet linear synchronous motor (DS-PMLSM) causes a large end force. To overcome this drawback, this paper proposes a novel DS-PMLSM structure, in which the upper or lower primary component is shifted by a certain distance. First, the end-force model of the DS-PMLSM is established, based on which, the influences of the staggered structure on the fundamental and higher order end-force components are analyzed. Following this, the DS-PMLSMs with different slot–pole combinations are divided into four categories, and the design principles of possible winding arrangements are discussed. Furthermore, the staggered structures are applied to four slot–pole combinations, namely 21-, 15-, 20-, and 16-pole/18-slot. The back electromotive forces, detent forces, thrusts, and normal forces of the four combinations are analyzed and compared through the finite-element method. The electromagnetic and output characteristics of the novel DS-PMLSM are also compared with the traditional DS-PMLSM prototype to verify the effect of the proposed structure on suppressing the end force. [ABSTRACT FROM AUTHOR]