Structure and Electromagnetic Characteristics Analysis of U-shaped Permanent Magnet Salient Pole Linear Motor

In this paper, a U-shaped permanent magnet salient pole linear motor(US-PMSPLM)for ropeless elevator is proposed. The secondary permanent magnets(PMs) with U-shaped structure can make full use of the PMs to increase the no-load back Electro Motive Force(EMF) and thrust force obviously. The structure of the motor is analyzed. The simulation model is established by finite element method(FEM) to analyze the electromagnetic characteristics including magnetic field, air gap magnetic density, flux linkage, no-load back EMF, inductance parameters, detent force, thrust force and so on. The simulation results shows that the no-load back EMF and the thrust are increased by 25.73% and 20.54% respectively, compared with the non-salient permanent magnet synchronous linear motor(NS-PMSLM) with the same PMs usage. The findings of this study verify the effectiveness and practicability of the US-PMSPLM.