Preliminary study on differences in the performance characteristics of concentrated and distributed winding IPM machines with different rotor topologies

Abstract

This paper compares performances of fractional-slot concentrated-wound (FSCW) and distributed-wound (DW) interior permanent magnet (IPM) machines when they are equipped with various commonly used rotor topologies such as V-type, double V-type, flat-type, double flat-type, and spoke-type magnets. In order to have a fair comparison, a multi-objective design optimization procedure based on an evolutionary algorithm is utilized to find Pareto-front designs for each combination of stator and rotor topologies. The commonly used objectives for design optimization of IPM machines; material cost, efficiency, and constant power speed range (CPSR), are considered in the optimization process. Wide ranges of performances are compared quantitatively from multi-perspectives to help machine designers in selecting the right configuration for different applications. A benchmark IPM machine is considered as the starting point for the design optimization processes. It is shown that FSCW and DW stator perform differently on certain performances such as torque density, torque ripple, total losses and the distribution of flux densities.