Experimental and simulation analysis of ferroresonance in single-phase transformers considering magnetic hysteresis effects

Ferroresonance is one of the most destructive and longest known power quality disturbances in the history of ac power systems. The undamped ferroresonant oscillations that occur between system capacitances and magnetizing inductances of transformer cores can cause severe damage and disruption to power networks. In this paper, ferroresonance in transformers is investigated with the aid of a nonlinear core model which includes magnetic hysteresis effects. Bifurcation and phase-plane analyses are applied to investigate the stability domain of ferroresonance. The impact of resulting ferroresonance modes on transformer voltages, core fluxes and magnetizing currents are shown in time-domain. Supporting measurements of ferroresonance are also provided for verifying model predictions of ferroresonance.