Hard-limit induced chaos in a fundamental power system model

Abstract

The paper investigates complex nonlinear phenomena in a fundamental power system model represented in a single-machine infinite-bus formulation. The generator electro-magnetics, electromechanics and its excitation control are modelled together by fourth-order differential equations. It is shown that when excitation control gains are set high (as in common industry. practice) and when the excitation hard-limits are taken into account, this representative power system model undergoes global bifurcations including period-doubling cascades which lead to sustained chaotic behaviour. Specifically sustained complex oscillations result from the interaction of hard-limits and the system transients over a large range of realistic parameter values. The emergence of strange attractors is demonstrated in the paper by detailed numerical simulations and preliminary analysis.