Toward a simple topological model of a three-phase transformer including deep saturation conditions

Purpose This paper aims to propose a method of parametrizing topological transformer model at high flux densities in the core. Design/methodology/approach The approach proposed is based on terminal voltages and currents measured special purpose saturation test whose data are combined with typical curves grain-oriented electrical steels; modeling carried out ATPDraw program. Findings authors corroborate experimentally necessity dividing zero sequence impedance between all phases individual representation legs yokes. eliminates use nonexistent leakage inductances primary secondary windings. Practical implications presented can be used for predicting inrush current events evaluation impact caused by geomagnetically induced (GICs). Originality/value completely original will contribute better understanding transients occurring under abnormal conditions, such as GICs.