Comparison of double-layer interior permanent magnet synchronous motor design with two different pole numbers

This paper presents a comparison of two IPM - interior permanent brushless synchronous motor structures realized with the same stator geometry with two different rotor pole numbers. First analyzed motor has got stator with double layer winding with Q=12 slots and a rotor with 2p=8 poles. Second one, has got the similar stator with Q=12 slots and a rotor with 2p=10 poles. These two motors are analyzed as candidate for a mass production in an automotive area for an electric power steering application (EPS). The important factors for an EPS applications like: torque vs speed characteristics, power density, cogging torque, torque ripple, sizing, robustness and material costs are compared.