Effect of iron core loss nonlinearity on chaotic ferroresonance in power transformers

Abstract

This paper investigates the effect of iron core loss nonlinearity on the onset of chaotic ferroresonance and duration of transient chaos in a power transformer. The transformer chosen for investigation has a rating of 50 MV A, 635.1 kV, the data for which is given by Dommel et al. (Tutorial Course on Digital Simulation of Transients in Power Systems (Chapter 14), IISc, Bangalore, 1983, pp. 17–38). The magnetisation characteristics of the transformer is modelled by a single-value two-term polynomial. The core loss is modelled by a third order power series in voltage. With nonlinearities in core loss included, three effects are clear: (i) onset of chaos at larger values of open phase voltage, (ii) shorter duration of transient chaos, and (iii) less susceptibility to ‘ jump ’ phenomena.