OGY control by asymptotically transition method in power system

The OGY method for controlling chaos has been proposed by Ott-Grobogi-Yorke. In this method, a state point is moved onto a stable manifold of an unstable equilibrium point and the flow toward the unstable equilibrium point is utilized. In a power system, the state point is not able to stay around the unstable equilibrium point in the attractor for a long time when generators fall out of step and the OGY control input is larger than that of the other system. We improved the OGY method in order to make the best of this flow near the stable manifold. The amplitude of control inputs is limited and applied many times in the improved method. The state point is asymptotically moved on to the unstable equilibrium point and successfully controlled by a small input and without large time delay.