Determination Approach for the Parameters of Equivalent Circuit Model of Deep Saturated Three-Phase Integrative Transformers

Based on the analysis of the defects of the traditional methods for determining the equivalent circuit parameters of three-phase integrated transformers by single-phase excitation, an expression method of equivalent circuit parameters and their determination approach based on three-phase simultaneous excitation are presented in this paper. The parameters are expressed in terms of the phase of the excitation source, and the value of parameters is determined by calculating the reluctance of core segments based on the finite element method simulations. Then, the electric circuit parameters are obtained by converting the magnetic circuit into the electric circuit. This kind of electric circuit model is suitable for analyzing the problems of deep saturation of transformers and the concerning power grid problems.