Damping Nonlinear Oscillations in Potential Transformers Including Hysteresis Effect

In this work, an overview of available papers are provided, at first ferroresonance phenomenon is introduced and then various type of ferroresonance in a potential transformer is simulated, then effect of neutral earth resistance on the onset of chaotic ferroresonance and duration of chaotic transient in a potential transformer including nonlinear core losses has been studied. It is expected that this resistance generally cause controlling ferroresonance overvoltages. The proposed approach was implemented using MATLAB, and results are presented. For confirmation this aspect simulation has been done on a one phase potential transformer rated 100VA, 275kV. Core losses is modelled in terms of voltage and includes nonlinearities in core losses .The simulation results show that connecting the neutral earth resistance on the system configuration, shows a great controlling effect on ferroresonance overvoltages.