Analysis of New Modular Linear Flux Reversal Permanent Magnet Motors

In this paper, a new modular linear flux reversal permanent magnet (M-LFRPM) motor is proposed and analyzed. The key of the proposed motor is to adopt a new modular mover structure, hence offering the desired fault-tolerant capability and an improved force performance. Utilizing the new modular mover structure, the magnet utilization ratio of the proposed motor is significantly enhanced as compared with the existing one, resulting in a higher thrust force density. Moreover, the back electromotive force of the proposed motor is symmetrical and sinusoidal due to its complementary PM magnetic circuits. For a fair comparison, the proposed motor is designed and built based on an existing M-LFRPM motor with the similar electromagnetic and geometrical parameters. Then, their force ripples are analyzed and decomposed using the frozen permeability method due to its high accuracy for force separation, revealing that the cogging and reluctance force ripples of the proposed motor counteract each other and are significantly reduced. Finally, the electromagnetic performance of both the motors is analyzed and compared using the time-stepping finite-element method, verifying that the proposed motor definitely offers the desired fault-tolerant capability and the improved force performance viz., the reduced cogging force and the improved thrust force compared with the existing one.