Analysis And Optimization Of A Tubular Permanent Magnet Linear Generator

In the paper, a tubular permanent-magnet linear generator (TPMLG) is designed and analyzed. The key of the proposed machine is to adopt a mover structure with the quasi-Halbach PM array to meet the strict limit of mover weight and electromagnetic performances. TPMLG with the quasi-Halbach PM magnetization structure is selected by comparison with axial magnetization and radial magnetization under the condition of the similar electromagnetic and geometrical parameters. Utilizing mover structure of the quasi-Halbach PM array, the magnet utilization ratio of the proposed machine is significantly enhanced as compared with the existing one, resulting in a higher power density. Moreover, the optimal structure is selected by the comparison of two different pole/slot combinations with the similar electromagnetic and geometrical parameters. Finally, aiming at the problem of high force ripple in TPMLG, several suppression methods are analyzed and implemented. 2-D finite element method (2D-FEM) are also adopted for the ripple analysis.