Differential leakage of a fractional-slot winding

IN a previous paper,¹ the differential (harmonic) leakage of an integral-slot winding and squirrel cage winding was treated. It was shown that a squirrel cage rotor reduces the harmonics and thus the differential leakage of the stator. The influence of the number of stator and rotor slots, as well as of the pitch factor of the stator winding on the damping of the stator harmonics, was discussed. Also, it was shown that skewing of the rotor reduces the damping of the stator harmonics and, therefore increases the differential leakage of the stator. The investigation was made under the following assumptions: