Design of Synchronous Reluctance Motor for Hybrid Electric Vehicles

This paper deals with the design of a synchronous reluctance motor suited for hybrid electric vehicles. The focus is mainly on rotor design: the angles of the flux barrier ends are chosen with the aim of reducing the torque ripple due to the slot harmonics. A comparison among different rotor arrangements (one, two, and three flux barriers per pole) is presented. Furthermore, an improvement in terms of low ripple and high average torque is given owing to the Machaon configuration. The current vector control method is used to maximize the torque according to the voltage and current constraints, taking into account the saturation effects. The impact of the electrical design on the mechanical characteristics of the rotor (natural frequencies) is discussed as well. At last, the predicted mechanical characteristics of the reluctance motor are presented: torque versus speed behavior, power losses, and power factor. The efficiency map of the machine is also reported in the whole operating region.