Permanent Magnet Synchronous Motor in Elevators: Efficiency, Design and MRL Applications
Glossary ›
Permanent Magnet Synchronous Motor (PMSM)
A synchronous AC motor using rare-earth permanent magnets in the rotor that achieves high torque density and efficiency without gear reduction.
Full Definition
Permanent magnet synchronous motors have replaced traditional induction motors in most new elevator installations because they provide high torque at low RPM, enabling direct coupling to the drive sheave without a gearbox. The rotor uses neodymium-iron-boron (NdFeB) magnets embedded in the rotor core. Power factor approaches unity, and efficiency typically exceeds 90 % across the entire speed range. An encoder or resolver on the motor shaft provides precise speed and position feedback to the VVVF drive. Flat-disc PMSM designs with very short axial length are used in MRL lifts where space is at a premium.
