Bifurcations, chaos, and system collapse in a three node power system
A model of the three node power system proposed by Rajesh and Padiyar [Electr. Power Energy Syst. 21 (1999) 375] is studied. As the bifurcation parameter Pm (input power to the generator) is changed, the system including the effects of the non-linearity exhibits complex dynamics emerging from static and dynamic bifurcations which link with the system collapse. The analyses for the model exhibit dynamical bifurcations, including three Hopf bifurcations, cyclic fold bifurcations, torus bifurcations and period-doubling bifurcations, and complex dynamical behaviors, including periodic orbits, period-doubling orbits, quasi-periodic orbits, phase-locked phenomena and two chaotic regions between two Hopf bifurcations, i.e. in the Hopf window and intermittency chaos. Moreover, one of the two chaotic regions results from period-doubling bifurcations, and another results from quasi-periodic orbits emerging from a torus bifurcation. Simulations are given to illustrate the various types of dynamic behaviors associated with the power system collapse for the model. In particular, we first shown that the oscillatory transient may play a role in the collapse, and there are different critical points for different dominated state variables. Besides, the hard-limits and increases of the damping factor widen the feasible operating region of the power system, and prevent the torus bifurcation to occur so that some complex dynamical phenomena can be inhibited.
bifurcations chaos power systems hard-limits