Proximity Loss Study In High Speed Flux-Switching Permanent Magnet Machine

TLDR

High‑speed flux‑switching permanent magnet machines are key for aerospace and hybrid electric vehicles, but their open‑slot geometry, high flux densities, and operating frequencies cause significant variable cross‑slot leakage and proximity losses. This study aims to reduce AC losses in the armature of a high‑speed FSPM machine by stranding the conductors. The authors investigate rotor movement across the slot opening with 2‑D finite element analysis and develop a simple 1‑D analytical model to estimate proximity losses. The analytical model, validated by finite element analysis, accurately predicts proximity losses and identifies the optimal number and diameter of conductors to minimize them.

Abstract

High speed flux-switching permanent magnet (FSPM) machines have been identified as key technologies for aerospace and hybrid electric vehicle applications. The open slot geometry, high stator flux densities and high operating frequencies result in high variable cross slot leakage and proximity losses within the armature windings. The aim of this study is to reduce AC losses in the armature of a high speed FSPM machine by stranding the conductors. The influence of rotor movement across the slot opening is investigated using 2-D finite element analysis. A simple 1-D analytical model is developed and validated by the finite element analysis to accurately estimate the level of proximity losses and then used to determine the optimal number and diameter of conductors.