Analysis of Chaotic Ferroresonance Phenomena in Unloaded Transformers Including MOV

Ataollah Abbasi,Mehrdad Rostami,Ahmad Gholami,Hamid R Abbasi

doi:10.4236/epe.2011.34057

Ataollah Abbasi, Mehrdad Rostami + Show 2 more

Open Access

https://doi.org/10.4236/epe.2011.34057

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Abstract

We study the effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of transformers. It is expected that the arresters generally cause ferroresonance drop out. Simulation has been done on a three phase power transformer with one open phase. Effect of varying input voltage is studied. The simulation results reveal that connecting the arrester to transformers poles, exhibits a great mitigating effect on ferroresonant over voltages. Phase plane along with bifurcation diagrams are also presented. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos and magnitude of ferroresonant voltages is obtained, shown and tabulated.

Highlights

Ferroresonance is a complex nonlinear electrical phenomenon that can cause dielectric & thermal problems to components power system
We study the effect of a parallel metal oxide surge arrester on the ferroresonance oscillations of transformers
Simulation has been done on a three phase power transformer with one open phase

Summary

Introduction

Ferroresonance is a complex nonlinear electrical phenomenon that can cause dielectric & thermal problems to components power system. The relationship between voltage and current is depends on frequency and on other factors such as system voltage magnitude, initial magnetic flux condition of transformer iron core, total loss in the ferroresonant circuit and moment of switching [2]. Ferroresonance may be initiated by contingency switching operation, routine switching, or load shedding involving a high voltage transmission line It can result in Unpredictable over voltages and high currents. The prerequisite for ferroresonance is a circuit containing iron core inductance and a capacitance Such a circuit is characterized by simultaneous existence of several steadystate solutions for a given set of circuit parameters. Authors of [12] have indicated the effect of core loss in damping ferroresonance oscillations.

System Modeling

Simulation Results

Priodic Priodic Priodic q

Conclusions