Investigation of a Modular Linear Doubly Salient Machine With Dual-PM in Primary Yoke and Slot Openings

A modular linear doubly salient machine with dual-PM in the primary yoke and slot openings is proposed in this paper. First, the machine topology is introduced, where the PMs are employed in both the primary yoke and slot openings. The magnetic fluxes excited by the PMs in the slot openings pass through the air gap and link the secondary, not short-circuited by the primary teeth. Hence, the magnetic fluxes excited by both PMs can be concentrated and enhanced in the air gap. Then, the operation principle is investigated based on the permeance model, which shows that it obeys the flux modulation principle. The electromagnetic performances are analyzed in detail using FEM, which shows that the force density and overload capability can be significantly improved with the slot PMs. Finally, the 2-D finite-element (FE) predicted results are validated by the 3-D FE results that considering the transverse end effect.