A Practical Method for Building the FE-based Phase Variable Model of Single Phase Transformers For Dynamic Simulations

This paper studies the development of physical circuit models of single phase transformers based on FE analysis. We have proposed a practical method to build the circuit model from FE solutions for dynamic simulations. The developed circuit model produced the accuracy of the full FE model without the need for excessive number of FE computations. The variation of flux linkages with winding currents are used to represent the nonlinear magnetization of the core. An equivalent excitation current variable i_m is defined. The flux linkages are described as functions of i_m and i₁ or i₂ . They are calculated from the circuit-field coupled FE analysis. The validity of the developed FE-based circuit model is demonstrated by simulating the inrush current, examining the excitation currents variation with the core saturation levels, and comparing the developed FE-based model with the full FE model