Effects of initial conditions on ferroresonance in power transformers using Preisach theory

Ferroresonance is a nonlinear resonance phenomenon that can affect power networks. The main feature of this phenomenon is that more than one stable steady state response is possible for the same set of the network parameters that are highly depend on initial conditions and circuit parameters. Since magnetic hysteresis plays an important role in the ferroresonance phenomenon, in this paper, by constructing a hysteretic inductor based on Preisach theory, a high voltage transformer has been modeled. Different ferroresonance modes, obtained from computer simulations, have been observed in this transformer and the effects of hysteresis and its initial conditions have been discussed.