2D analytical torque study of slotless and slotted PMSM topologies at high-speed operation

Recently the interest in permanent-magnet synchronous machines operating at high speed has grown. However, a lot of design and operation questions have not been answered yet. One of these questions relates to the stator design. More specifically, whether or not to provide stator teeth and what slot openings are best used. This paper presents a theoretical study of the torque at various slot opening angles, for diametrically wound machines with and without teeth. This is done by analytically computing the torque. The calculations are performed using a 2D analytical subdomain model that accounts for the slotting effect and the eddy-current reaction field