Simulation of Ferroresonance in a Three Phase Three-Limbed Laboratory Transformer

Ferroresonance behavior of a three-phase transformer with three limbed cores is different from those consisting of banks of single-phase transformers. This paper is concerned with simulation of period-1 ferroresonance of a three phase three limbed cores laboratory transformer. Static resistances as a function of maximum flux have been used to simulate nonlinear core losses of different limbs of the transformer in the presence of ferroresonance overvoltages. In an attempt to find lower limit of source voltage that ferroresonance exists, these resistances with single-valued saturation characteristics made a better prediction than conventional constant resistance core loss modeling. Comparisons have been made between different modeling approaches and experimental results. Proposed method can be used for period-1 ferroresonance stability analysis.

Keywords:

Bifurcation , ferroresonance , core loss nonlinearity , power transformer