Ghazi - Mashhad University IRAN
Soltani - Mashhad University IRAN

Ferroresonance is a phenomenon which can occur in power transformers, reactors and voltage transformers when nonlinear inductive elements excited. through capacitive coupling from adjacent phases . As fundemental to the occurence of ferroresonance is the non - linear inductace of transformer or reactor, an accurate representation of magnetization curve including hysteresis has been considered. The effects of system parameters have been examined and their critical values calculated. The bounderies between safe and ferroresnance as a function of system parameter constructed. It has been shown that hysteresis effect can modify the critical values of system parameter and region of ferroresonance.