An analysis of the 6-slot 2-pole high-speed permanent magnet synchronous machines with tooth-coil windings

Two low-power High-Speed Permanent Magnet Synchronous Machines (HS PMSM) are reviewed. The powers and speeds of the machines are 3.5 kW at 45 000 rpm and 11 kW at 31 200 rpm. Both machines under consideration have 6 slots and 2 poles and they are both using Tooth-Coil (TC) windings also known as non-overlapping concentrated windings. The rotors of the discussed machines consist of the diametrically magnetized full cylindrical Permanent Magnet (PM) inside a retaining sleeve. The similarities and differences between these two machines are described and explained. The analysis of the air gap flux density, its harmonic content, and loss distribution in comparison with a Distributed Windings (DW) solution is presented with the example of an 11 kW machine. The analytical and numerical calculations are verified by the experimental data. Based on this analysis, conclusions will be drawn regarding the suitability of the implemented topology for a high-speed machinery.