Effect of power frequency excitation character on ferroresonance in neutral-grounded system

Abstract

In most earlier ferroresonance studies the traditional excitation characteristic of iron core, in which the traditional excitation characteristic contains harmonic voltages or currents, has been used as if it were made up of pure fundamental voltage or current. However, this is not always true. In comparison with traditional excitation characteristics, this paper introduces the power frequency excitation characteristic of the iron core, which contains no harmonics. The power frequency excitation characteristic of iron core has been obtained by Elector Magnetic Transient Program, resulting in discrete voltage and current pairs. Extensive simulations are carried out to analyse the effect of power frequency excitation characteristic on potential transformer ferroresonance. A detailed analysis of simulation results demonstrates that with power frequency excitation characteristic of iron core inclusion at certain excitation voltage the ferroresonance may happen, conversely it may not happen with traditional excitation characteristic inclusion.

Effect of metal oxide arrester on the chaotic oscillations in the voltage transformer with nonlinear core loss model using chaos theory

“…The chaotic ferroresonant behavior depends on several system parameters such as: source voltage amplitude, capacitance, resistance, core loss, and initial conditions. [8,17,21,25,26] Also, metal oxide arrester (MOA) and neutral resistance lead to damping and even elimination of chaotic oscillations. The chaotic behavior can be changed when MOAs are connected to the transformer terminals.…”

“…The chaotic behavior can be changed when MOAs are connected to the transformer terminals. [22,[24][25][26][27][28] The ferroresonance has a wide frequency spectrum with subharmonics, interharmonics, and harmonics. In Ref.…”