A directly coupled field-circuit model of a transformer to study surge phenomena and for frequency response analysis

This paper focuses on the development of a transformer model which can be used to study phenomena involving large range of frequencies. It takes into account real transformer geometries including constructional details. The winding is divided into number of sections and is represented by a ladder network. The magnetic field associated with each of the sections is solved by using 2-D axi-symmetric Finite Element Method (FEM) and connected to the ladder network at appropriate points giving a strongly coupled field-circuit model. First, the distribution of impulse voltage is obtained by using time domain analysis. Consequently, the model is used to realize the frequency response analysis with radial deformation condition. Merits of the model, which can take into account frequency dependent complex permeability, are finally explained along with possibilities of potential future work.