EXTENSION OF WINDING FUNCTION THEORY FOR RADIAL AND AXIAL NONUNIFORM AIR GAP IN SALIENT POLE SYNCHRONOUS MACHINES

In this paper, to calculate the salient pole machine inductances under radial and axial non-uniformity, a new method is developed. The method, an extension of the modified winding function theory to 3D, allows studying salient pole machines with radial and axial non-uniform air gap considering more realistic mean radius of the air gap. By using the developed method and a precise geometrical model, inductances of a salient pole machine with inclined rotor are calculated. Inductances are evaluated and effects of several asymmetries on inductances are shown. Calculated inductances are used in a coupled electromagnetic model, for simulation of a salient pole machine under healthy and different inclined eccentricity conditions. Simulation results show that the 19th stator current harmonic can be detected to alarm for inclined rotors. Experimental results that validate the theoretical and simulation results are presented.