Comparison of Two Permanent-Magnet Machines for A Mild Hybrid Electric Vehicle Application

This paper presents a comprehensive comparison to a SPM and an IPM machine for a mild ISG HEV application based on extensive practical test examinations. The two ISG PM machines have the same power rating and similar size in very thin pan-cake shape. The SPM ISG has more complex structure indented to deliver sinusoidal flux distribution in air-gap and reduce torque ripple. Comparatively the IPM is specially tailored to offer a trade-off solution in terms of cost and performance. It has much simpler structure with the concentrated winding in stator and simple single-barrier bar-shaped rotor structure. Two PM ISG machines are examined intensively in experiment in order to investigate their feasibility for the mild ISG application.