Design of A Novel Primary Permanent Magnet Linear Machine with Low Thrust Ripple

In order to reduce thrust ripple, this paper proposes a new primary permanent magnet linear machine with uneven pole (UP-PPMLM). Firstly, the proposed structure and advantages compared to conventional structure are introduced. Then, the expressions of air-gap flux density by permanent magnets (PMs) and armature reaction are derived. Finally, by using finite element method (FEM), the new topology reasonability is proved. Meanwhile, the performances of proposed machines are compared to conventional topology, and the result confirms the electromagnetic performances of the proposed machine have been greatly improved.