2D analytical torque study of slotted high-speed PMSMs considering pole pairs, slots per pole per phase and coil throw

Recently the interest in permanent-magnet synchronous machines (PMSMs) operating at high speed has grown. However, a lot of design and operation questions remain unanswered. This work aims at studying the effect of the number of pole pairs, the number of slots per pole per phase and the coil throw on the torque and the torque ripple in high-speed PMSMs. High-speed machines are often equipped with a shielding cylinder, i.e. a conductive sleeve wrapped around the magnets. The study is therefore performed using a 2D analytical subdomain model that accounts for slotting and the eddy-current reaction field. The classical torque component and the torque due to interaction with the eddy-currents in the shielding cylinder are regarded separately.