Estimation of induction machine inductances using three-dimensional magnetic equivalent circuit

Estimation of inductances is one of the key points in a successful simulation of induction machines. These inductances are under the influences of different factors, such as winding distribution, stator and rotor slots, skewed slots of rotor, saturation of magnetic materials and asymmetries caused by eccentricities faults. This study introduces a method for a precise estimation of induction machine inductances based on three-dimensional (3D) modelling using a magnetic equivalent circuit and considering the above-mentioned factors. Furthermore, in 3D model, the axial flux ignored in the two-dimensional model, is included. Enhancement of the accuracy of the tooth flux, precise modelling of the air gap and taking into account the skewed slots of rotor are the advantages of the 3D model. Also, the impact of different eccentricities fault upon the estimated inductances of the induction machine is addressed.