A study on ferroresonance with a varying initial conditions using a nonlinear model of transformer

Ferroresonance is a nonlinear oscillatory phenomenon, which occurs in capacitance-coupled transformers under certain conditions in a power system. The magnetizing branch of the transformer at no-load is modelled by nonlinear equation using a laboratory recorded hysteresis loop of a transformer. Various numerical simulations of ferroresonance are performed when source voltage are treated as parameter at different initial magnetization. The power spectral density and phase-plane analyses are conducted on ferroresonance over-voltage generated across transformer and line capacitance. Ferroresonance current, flux and their inter relationship are presented.