A 3-D finite element perturbational method for determining saturated values of transformer winding including experimental verification

A method is presented in this paper for the calculation of saturated transformer winding inductances. The method is mainly based on an energy perturbation technique in conjunction with non linear three dimensional finite element vector potential field solutions. The concepts of apparent, effective and incremental inductances were utilized in the methodology presented. The method presented was successfully applied in the calculation of apparent, effective and incremental inductance values of the primary winding of a single phase transformer. Very good agreement between calculated and measured values of inductance was accomplished. The work presented provides methodologies by which one would be able to determine, in conjunction with nonlinear three dimensional field solutions, these values of inductances. These inductance values are very important in the dynamic analysis of electrical devices, steady state calculation as well as energy storage and other related analysis and preformance studies.