Influence of Slot Number on Electromagnetic Performance of 2-pole High-Speed Permanent Magnet Motors with Toroidal Windings

This paper investigates the influence of stator slot number on electromagnetic performance of 2-pole high speed permanent magnet (HSPM) slotted motors with toroidal windings. Four 2-pole slotted motors with different slot numbers, i.e. 3, 6, 9, and 12, are globally optimised for maximum torque, and their electromagnetic performance are compared. It shows that the 6-slot/2-pole HSPM motor with toroidal windings exhibits good electromagnetic performance without unbalanced magnetic force, and is also easy to realise a modular structure. Hence, it is eminently suitable for high speed application. In addition, the 3-slot motors with toroidal windings and tooth-coil windings are compared. It confirms that toroidal windings are not suitable for use in the 3-slot/2-pole HSPM slotted motor.