Modeling and analysis of the suppression of ferroresonance in nonlinear three-phase three-leg transformers

This paper investigates the effectiveness of suppression techniques of ferroresonance in nonlinear three-phase three-leg transformers. Previous literature has generally recommended the use of damping resistor loads to suppress ferroresonance. This paper examines the potential pitfalls of this approach and suggests a new simple arrangement which preliminary results indicate to be more effective. A newly developed nonlinear three-phase three-leg transformer model is implemented to accurately model ferroresonance conditions and simulate suppression techniques. The model includes dynamic magnetic hysteresis effects (major and minor loops), flux cross-coupling effects in the legs and asymmetry in the iron-core structure.