Accurate Magnetic Modelling and Performance Analysis of IPM-PMASR Motors

Modern IPM motors, suited to large constant-power speed ranges, have a multiple flux-barrier rotor structure and show a quite complex magnetic behaviour. In this paper the flux-current relationship of such motors is analysed and a simplified but effective model of the cross-saturation phenomenon is proposed and verified by experiment. In addition, new flux variables are introduced, that allow a rigorous splitting of PM and reluctance torques. It is shown that the PM contribution to torque is larger than expected from the PM no-load flux. This can lead to more accurate machine design and control strategies.