Effect of air-gap variation and the numberof stator slots on performance of an axial flux hysteresis motor

An axial flux hysteresis motor is a self-starting synchronous motor which is well established and has flat speed-torque characteristics, smooth operation and low noise level with a very simple mechanical configuration. In this paper, effect of the air-gap length and number of stator slots on performance of a single-sided axial flux hysteresis motor is investigated. Based on the Finite Element method (FEM), the effect of air-gap length variation and the number of stator slots on output characteristic of machine are investigated. A mathematical algorithm is proposed to analyze the results of FEM and make a valuable comparison. In order to evaluate the simulation results accuracy, a prototype is constructed and tested. In order to have reliable comparisons between the analytical and experimental results, all tests have been done upon the same conditions. Finally, the prototyped structure is compared with the model in terms of torque versus current characteristic.