Application of Metal Oxide Surge Arrester on the Non-Conventional Chaotic Ferroresonance Oscillation in Voltage Transformers

In this study the effect of MOSA on controlling of the non-conventional ferroresonance overvoltage in the iron core voltage transformer is studied. It is expected that MOSA can generally damp ferroresonance overvoltages. Time-domain study is used to analyze this effect. Study is done on a voltage transformer rated 100VA, 275 kV. The magnetization characteristic of the transformer coil is modeled by a single-parameter twoterm polynomial with q = 7 degree of nonlinearity. Core loss is modeled by linear resistance. Simulation results show that connecting the MOSA in parallel to the voltage transformer, shows a great controlling effect of the ferroresonance oscillations. Phase plane, time domain voltage waveforms, FFT analysis and bifurcation diagrams are also given. Significant effect on settling down to the chaos, the range of parameter values that may lead to ferroresonance overvoltages and controlling these phenomena are obtained and presented.