A frequency domain transformer model for simulating fast transient overvoltages

Abstract

Abstract:-In this work a computer model for calculating surge distribution in transformer windings is presented. The transformer model is developed using multiconductor transmission line theory. The capacitance, inductance, resistance and conductance are calculated with simple formulations and these parameters are used for calculating modal parameters in order to represent the winding as a two port network. The model is validated by means of a comparison between measured and calculated voltages in a power transformer disk with 16 turns.

An improved model of cage induction machines for fast transients studies

“…19 In the last two decades, Guardado and Cornick proposed a computer model to obtain voltage distribution in coils of the machine on the basis of multiconductor transmission line (MTL) theory. This circuit model has a good frequency validation in MHz range, but it could not represent an accurate waveform of voltage distribution in a wide range of sub-1-MHz frequencies [20][21][22][23] . In 2008, Hosseini et al proved, through some experiments, that MTL model is suitable for studying very fast transient overvoltages in 1MHz ≤ F ≤ 5MHz and RLC ladder network is suitable for studying fast transient overvoltages in 10KHz ≤ F ≤ 1MHz while this frequency range can be increased to 2 MHz by considering the computation unit as turn.…”