Modeling Ferroresonance in Power Transmission System

Ferroresonance phenomenon occurs in electrical circuits which are consisting of magnetizing core, such as in the transmission and distribution network which existing of the transformer; electrical machine or reactors are commonplace. Transformers often operate close to the knee point of magnetizing curve under normal condition. Therefore any sudden change in voltage or current can change the operation point on the magnetizing curve and saturation may result. This phenomenon is reflected in the change of the equivalent nonlinear reactance of the transformer. Now, if the value of the saturated reactance reaches a value such that it causes resonance with the equivalent capacitance of the network, then an over current or over voltage may occur. Transformers, electrical motor, Reactors and Generators are examples of equipment having magnetizing cores. Ferroresonance cause melting the lamination of transformer or electrical machine, so it destroys that equipment. This type of fault can create long time interruption. Possible causes of ferroresonance occurrence: Switching, Fault especially single line to ground or double line to ground, Lightning, Ferranti effect. Although some techniques applied to mitigate ferroresonance on CVTs, Methods to mitigate ferroresonance on Power transformer is almost not studied or reported. This paper is review on ferroresonance occurrence and simulate model of ferroresonance by using ATP.

Keywords:

Ferroresonance , Preisach type hysteresis , Jiles–Atherton model , Damping , Simulation