Eddy Current Losses in Solid Pole Shoes in a Two-Pole Permanent Magnet Motor

Boel Ekergård,Mats Leijon

doi:10.4236/eng.2021.1310038

Abstract

The aim of this paper is to present the eddy current losses in solid pole shoes in a permanent magnet two-pole electric motor. In the presented paper, the authors have chosen to work with three different analytical models, Carter’s theory, Gibb’s theory and Lawrenson’s theory, each with different degree of accuracy and simplifications. The results from the analytical models all present relatively low eddy current losses, giving the designer valuable arguments to utilize solid pole shoes, as a rotor with solid poles is from a construction point of view a more suitable choice, increasing the mechanical stability and reducing the production cost, compared to the laminated design.

Highlights

The energy challenge linked to the transport sector is seen as one of the most important challenges in the International Energy Agency’s evaluation [1]
The aim of this paper is to present the eddy current losses in solid pole shoes in a permanent magnet two-pole electric motor
As high efficiency and mechanical stability are prioritized objects, the argumentation of the study is the interest of the size of the eddy current losses in solid pole shoes, as a rotor with solid poles is from a construction point of view a more suitable choice, increasing the mechanical stability and reducing the production cost

Summary

Introduction

The energy challenge linked to the transport sector is seen as one of the most important challenges in the International Energy Agency’s evaluation [1]. As almost 30% of the world’s power needs are consumed in the transport sector, there is great interest in further developed electric propulsion systems, which offer a much higher efficiency than the internal combustion engine and reduce greenhouse gas emissions to zero [2]. One of the most important parts of an electric driveline is the electric motor, converting electric energy to kinetic energy, which shall be designed with a high efficiency over a wide frequency range, to minimize issues with heat and be able to deliver the required torque at each time and sequence. Core losses have always been an important subject in the design of an electric machine. Reports of improved analytical and numerical models including for example rotational losses, harmonics and developed material models [3]-[11] can be found in the literature

Objectives

Methods

Results

Discussion

Conclusion