Direct-Driven Interior Magnet Permanent-Magnet Synchronous Motors for a Full Electric Sports Car

The design process of direct-driven permanent
\nmagnet synchronous machines (PMSMs) for a full electric 4 ´ 4
\nsports car is presented. The rotor structure of the machine
\nconsists of two permanent magnet layers embedded inside the
\nrotor laminations thus resulting in some inverse saliency, where
\nthe q-axis inductance is larger than the d-axis one. An integer slot
\nstator winding was selected to fully take advantage of the
\nadditional reluctance torque. The performance characteristics of
\nthe designed PMSMs were calculated by applying a twodimensional
\nfinite element method. Cross-saturation between the
\nd- and q-axes was taken into account in the calculation of the
\nsynchronous inductances. The calculation results are validated
\nby measurements.