Detent Force Minimization of Double-Sided Permanent Magnet Linear Synchronous Machine with 120° Phase Belt Toroidal Windings by Slot-Shift Structure

Double-sided permanent magnet linear synchronous machine with 120° phase belt toroidal windings (120°-TWDSPMLSM) suffers from large detent force due to the end effect and slot effect. Many existing methods can reduce of 120°-TWDSPMLSM effectively. But they also minimize back electromotive (back-EMF) thrust simultaneously. To alleviate this problem, paper adopts a method combining slot-shift structure rearranging (120°-TW) suppress improve back-EMF First, slots on two sides primary part are stagger by an optimal distance force. The models force, including cogging is established theoretically, then verified finite-element analysis (FA). Then, 120°-TW rearranged average thrust. And electromagnetic characteristics under different shifted distances analyzed compared in detail. Finally, result shows that optimized 70.19% lower than original machine, fluctuation reduces 19.21%. Besides, 6.84% but 31.86 higher shifting without 120°-TW. Therefore, available reduction improvement 120°-DSPMLSM.