Efficiency Improvement in PMSMs Considering Alternative Rotors for Elevator Applications

This paper investigates the impact of alternative rotor designs of a predefined stator configuration on efficiency, aiming to provide an efficient overall motor by precisely addressing the unique requirements of a specific elevator application. The analysis example is based on the development of a 20-pole permanent magnet (PM) rotor to be coupled with a stator featuring distributed overlapping windings. Three major rotor types undergo optimization: surface PM, reluctant surface PM, and buried PM. The permanent magnet shape is examined for each rotor type. The optimization methodology employs a two-stage multi-objective procedure. Initially, the suitable rotor type is preselected through Pareto front analysis, followed by a refinement stage utilizing an adequate objective function. This approach allows a detailed exploration of the design space, facilitating the identification of the optimal motor design. The paper concludes with in-depth analysis of the selected motor. The suitability of the proposed motor in diverse elevator applications is affirmed, emphasizing its efficiency improvements across the elevating scenario.