Analysis of a PM Machine with Concentrated Fractional Pitch Windings

Abstract

Abstract—Permanent magnet machines with concentrated fractional pitch windings for servo and traction applications are growing in popularity. This paper deals with analysis of a novel synchronous permanent magnet machine using concentrated windings and grain-oriented and non-oriented silicon iron sheets for the teeth and yoke, respectively. Parasitic effects like unbalanced radial forces and alternating magnetic fields in the rotor, due to a non-symmetrical magnetic design of the presented machine, are described. Measurements on a laboratory prototype are performed and the results are compared to finite element method computation results to identify the heat transfer coefficients of the electrical machine. Index Terms—Permanent magnet machines, concentrated windings, thermal calculations, parasitic effects, measurements. I.