Investigation and General Design Principle of a New Series of Complementary and Modular Linear FSPM Motors

The conventional linear flux-switching permanent-magnet (FSPM) motors directly split from a rotary FSPM motor suffer from drawbacks such as unbalanced magnetic circuit of end coil, bigger cogging force, and force ripple. In this paper, to reduce cogging force and thrust force ripple, some complementary and modular linear FSPM (LFSPM) (MLFSPM) motors with mover/stator pole pitch ratio $\tau_{m}/\tau_{s}$ of about one, namely, $\tau_{m}/\tau_{s} = 10/12$, 11/12, 12/12, 13/12, 14/12, 15/12, will be investigated using finite-element method (FEM) and experimental method at first. Then, another new LFSPM motor with $\tau_{m}/\tau_{s} =\break 3$ is analyzed. Based on $\tau_{m}/\tau_{s} = 3$, some new MLFSPM motors are designed, investigated, and compared using FEM. To fully investigate these motors, the optimal MLFSPM motor with $\tau_{m}/\tau_{s} = 3$ is quantitatively compared with the two optimal motors with $\tau_{m}/\tau_{s} \approx 1$ . Finally, the general design principle for this series of MLFSPM motors with different $\tau_{m}/\tau_{s}$ values is concluded.