On the Enhancement of the Thrust Production of LPMSMs: Application to Ropeless Elevators

The paper is aimed at the characterization and improvement of the thrust production of modular linear PM synchronous machines applied to ropeless elevators. A description followed by a FEA-based investigation of the developed force of a conventional topology is firstly-treated. Then a design approach to reduce the cogging force is proposed and its effectiveness is proven by FEA. With this done, a notable decrease of the mean force along with a remarkable increase of the force ripple due to the armature MMF space harmonics turn to be critical for the treated application. In order to recover the force production capability, an approach consisting in rearranging the armature coils using the modified star of slots technique, is adopted and its benefits on the developed force is assessed by FEA.