Under the ferroresonance condition, the transformer is subjected to local overheating of the parts due to the significant increase of stray flux subsequent to the core saturation. This heating may cause no serious damage in a few minutes
but probably will do so if the ferroresonance is prolonged. The ferroresonance phenomenon is often a sustained oscillation since the losses of large power transformers and EHV lines are small and the small transferred power through the capacitive coupling is enough to maintain the ferroresonance conditions. Adequate information concerning the line and transformer parameters, under both normal and abnormal conditions, is required for accurate analysis of such ferroresonance systems. The ferroresonance can be prevented by restoring the transformer voltage if applicable, or the
installation of a damping load on the transformer secondary or tertiary windings.