Influence of Magnetic and Nonmagnetic Layers in an Axially Laminated Anisotropic Rotor of a High-Speed Synchronous Reluctance Motor Including Manufacturing Aspects

Valerii Abramenko,Janne Nerg,Juha Pyrhonen,Ilya Petrov

doi:10.1109/access.2020.3004705

Valerii Abramenko, Janne Nerg + Show 2 more

Open Access

https://doi.org/10.1109/access.2020.3004705

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Journal: IEEE Access	Publication Date: Jan 1, 2020
Citations: 13	License type: CC BY 4.0

Affiliation: Lappeenranta-Lahti University of Technology

Abstract

The impact of the thickness of the magnetic and nonmagnetic layers in an axially laminated anisotropic (ALA) rotor in a synchronous reluctance motor (SynRM) aimed at high-speed applications was studied. Considering possible manufacturing issues, the layers are desired to be thick rather than thin. At the same time, the layer thickness is related to the electromagnetic capabilities of the ALASynRM. In the study, a 12 kW ALASynRM was considered. As a reference, a 12 kW IM with a smooth solid rotor with copper end rings was used for comparison with the designed ALASynRM. The manufacturing procedures of an ALA rotor with certain materials were verified in practice. Strength tests of the samples were implemented showing the suitability of the selected materials for application in the prototype. In the electromagnetic design, the thickness of the ALA rotor layers has shown to have a significant impact on the rotor eddy current losses. The stator iron losses and the winding Joule losses also depend on the rotor design. Torque ripple is considerably affected by the thickness of the rotor layers and their position in relation to the stator slots.

Highlights

The specific motor characteristics, such as high power and torque densities, high efficiency, small size, and low weight, have made high-speed (HS) electrical machines a favorable choice in applications where the aforementioned advantages are required
If the thermal expansion coefficients of the axially laminated anisotropic (ALA) rotor materials are different, it results in significant residual stresses after the thermal treatment-based manufacturing and additional stresses during the operation caused by an increase in the rotor temperature related to the eddy current losses
The objective of the present paper is to evaluate the impact of the ALA rotor design on the performance of an ALASynRM aimed at high-speed applications, taking into consideration the aspects of temperature-treating manufacturing

Summary

INTRODUCTION

The specific motor characteristics, such as high power and torque densities, high efficiency, small size, and low weight, have made high-speed (HS) electrical machines a favorable choice in applications where the aforementioned advantages are required. If the thermal expansion coefficients of the ALA rotor materials are different, it results in significant residual stresses after the thermal treatment-based manufacturing and additional stresses during the operation caused by an increase in the rotor temperature related to the eddy current losses. These stresses can deteriorate the strength of the rotor and should be avoided in high-speed operation.

INITIAL DATA

LOSSES AND EFFICIENCY AT DIFFERENT LAYER THICKNESSES

Findings

CONCLUSION