Eddy Current Losses in a Hairpin Winding for an Automotive Application

Abstract

It is well known that the effect of eddy current loss increases with a greater cross-sectional area of a wire exposed to a time-varying magnetic field. When using hairpin windings instead of conventional windings, the cross-sectional area of the strands is increased. However, conductors inside a slot are exposed to several simultaneous sources of time-varying magnetic fields that induce eddy currents. The aim of this paper is to study the non-uniform current distributions and the origin of the eddy current losses in such strands, considering typical dimensions and frequencies that are found in an electrical machine for an automotive application.