Analysis of Double-sided Asymmetric Flux Reversal Permanent Magnet Linear Machine

This paper proposes a kind of double-sided asymmetric flux reversal permanent magnet linear machine (DAFR-PMLM) for long stroke application. With the adoption of asymmetric PM excitation, DAFR-PMLM can effectively generate and fully utilize the 2(nd) order harmonic magnetomotive force (MMF). First, the machine topology and operation principle are introduced. Then, the thrust force generation mechanism under multi MMFs is analytically calculated and verified by finite element analysis. Some electromagnetic performances including open-circuit characteristics, thrust force performances and permanent magnet performances are comparatively studied under different slot/pole combination. The results show that the proposed DAFR-PMLM can provide 60.0% and 10.4% higher thrust force density than other two kinds of double-sided permanent magnet linear machines with primary excitation. Finally, a prototype of DAFR-PMLM is fabricated for experimental validation.