Slotless machines equipped with surface permanent magnet (SPM) rotor are used in such applications where the torque ripple and the additional losses, due to the slotting effect, are critical issues. This kind of machine allows to find an accurate and analytical solution for the magnetic fields in every machine
cross section domain. This paper derives an analytical expression for the magnetic field distribution inside the stator core of a SPM slotless machine during general load condition. The case of different rotor magnetization pattern is also considered. All the results are assessed with finite element analysis showing a very good accordance.
