Improvement of Power Factor in a Double-Side Linear Flux-Modulation Permanent-Magnet Motor for Long Stroke Applications

Cost-effective and high-performance linear motors attract more and more attention for many applications. This paper proposes a novel double-side linear flux-modulation permanent-magnet (DS-LFMPM) motor with low cost, high thrust force density, and high power factor. The novelty of the proposed DS-LFMPM motor is to improve power factor by using double-side topology. Its topology is presented, and its operation principle is investigated. From the harmonic spectrums of the flux density in the air gap before and after the modulation of the mover teeth and the stator teeth, it can be concluded that the proposed motor has good flux-modulation effect. Also, the expression of the orders of the harmonic spectrums is given. The design process of sizes and structure is particularly explained. The electromagnetic performances are predicted by using the finite-element method and the proposed motor is prototyped for verification. The results show that the proposed DS-LFMPM motor can produce high thrust force density and high power factor.