Optimal design of a high speed concentrated wound PMSM

This paper looks at the design of a high speed permanent magnet synchronous machine for maximum power density. Machines with sub-unity slots per pole per phase are characterised by low cogging torque, high slot fill and short end windings which contribute to lower copper losses. However such machine topologies tend to have a harmonic-rich armature reaction field which may contribute significantly to the rotor eddy current losses. In this paper a thermal model grafted into an analytical model able to estimate the losses in the rotor conducting components is used to compare a number of machine designs.