Abstract—This paper studies the effect on Metal Oxide Varistor (MOV) on ferroresonance phenomenon in iron core voltage transformer (VT). It is expected that MOV generally cause ferroresonance ‘dropout'. Time-domain study has been carried out to study this effect. Simulation has been done on a voltage transformer rated 100VA, 275 kV. The magnetization characteristic of the transformer is modeled by a single-value two-term polynomial with order seven. The core loss is modeled by linear resistance. The simulation results reveal that connecting the MOV in parallel to VT, exhibits a great mitigating effect on ferroresonance overvoltages. Phase plan, voltage waveforms, along with bifurcation diagrams are also derived. Significant effect on the onset of chaos, the range of parameter values that may lead to chaos along with ferroresonance overvoltages has been obtained and presented.

Index Terms—Metal oxide varistot, chaos, bifurcation, ferroresonance, voltage transformers.

Hamid Radmanesh is with the Electrical Engineering Department, Shahab Danesh Institute of Higher Education, ghom, Iran(e-mail: Hamid.radmanesh@aut.ac.ir).
Matin Nademi and Maryam Nademi are with Department of Electrical Engineering, Islamic Azad University, Takestan Branch, Takestan, Iran(e-mail: hrbscstudent@gmail.com; mam.nademi@gmail.com)

Cite: Hamid Radmanesh, Matin Nademi, and Maryam Nademi  "Ferroresonance Study in Voltage Transformers Connecting Metal Oxide Varistor," International Journal of Computer and Electrical Engineering vol. 4, no. 5, pp. 739-742, 2012.