Eddy Currents in Permanent Magnets of a Multi-pole Direct Drive Motor

Abstract

Eddy currents in permanent magnets of direct drive synchronous motors cause permanent magnet heating which can cause a drop in performance, reduce durability or even cause machine failure. In this article eddy currents in permanent magnets of multi-pole direct drive motors with sinusoidal current are investigated with finite-element analysis with an emphasis on the dependency of losses on different design parameters. Analytical equations are used for comparison and evaluation of the possible replacement of the more time consuming numerical calculations.