Hard-limit induced chaos in a single-machine-infinite-bus power system

The paper reports the prevalence of chaos in a simple power system model represented in a single-machine-infinite-bus formulation. The generator dynamics is modelled by a standard fourth order differential equation which includes minimal representations of the angle dynamics (swing equations) and the voltage dynamics (flux decay equation) together with a voltage control device (excitation control). Detailed numerical simulations are used to show that stable limit cycles induced by the excitation hard-limits exist in the system over a wide range of parameter values. Moreover, these hard-limit induced stable limit cycles undergo interesting global bifurcations including period-doubling cascades which lead to sustained chaotic behavior. The dynamics of the fourth order model studied in the paper appears to be extremely rich as evidenced by the presence of strange attractors and chaos over diverse sets of parameter values