Based on the possibility of occurrence of different ferroresonance modes, one can conclude that the ferroresonance is a complicated nonlinear phenomenon and can manifest itself in different waveforms and magnitudes. Even in a power
system with a given set of parameters, various modes of ferroresonance can occur. The occurrence of each ferroresonance mode is highly sensitive to the system and transformer parameters and the initial conditions. If the initial conditions or the system parameters are slightly changed, the transformer core operating point can suddenly move to a new operating point and theferroresonance mode can completely change.