Optimization for the Pole Structure of Slot-Less Tubular Permanent Magnet Synchronous Linear Motor and Segmented Detent Force Compensation

Slot-less tubular permanent magnet synchronous linear motor, usually adopts a cylindrical pole structure. It results in big leakage flux on the axis and serious uneven flux distribution in the secondary iron. The improved convex pole was used and researched in this paper, and a layered orthogonal optimization method was applied to reach the goal of the higher thrust and less permanent magnet dosage combing with the finite-element method. Therefore, the best values of the pole parameters were obtained. Because the detent force resulting from the end effect is hard to suppress under the strict volume constrains, the segmented detent force compensation control was further studied. A prototype was machined and tested, and the results indicated that the combination of the improved convex pole and detent force compensation is a very effective method to improve the thrust performance.