FEM study of asynchronous cage motors combining NEMA´s classes A and D slot geometry

In this work, models combining NEMA´s classes A and D slot geometry are created, with the use of a library of parameterized Squirrel Cage Induction Machine models. The models were analyzed using AC non-linear FEM analysis. The influences of the different analogy of class A versus class D slots in the asynchronous cage motor, on the distribution of the magnetic field, the torque as well as the stator and rotor currents are investigated. Finally, the efficiency of the model, with analogy of class A to D rotor slots, 1:1 was optimized, by closing the stator slots with semi-magnetic wedges of magnetic permeability equal to 5.