Abstracts Engineering

Optimal governor and excitation control of power systems with damping

by Salah Mohammad Yousif

The work in this thesis solves the problem of restoring a power system to its operating stable equilibrium point, following a transient disturbance, in minimum time without any oscillation. The idealized power system considered consists of cylindrical rotor generator connected to an infinite busbar with the following cases of control: i) Governor Control ii) Excitation Control iii) Combined Governor and Excitation Control. In each case, the system is proved to be controllable, at least locally, in an open region around the stable equilibrium point. Also, the optimal control is proved to exist and is unique. The maximum principle of Pontryagin is used to determine the optimal control law. The condition for no oscillation is determined and the system is shown to be stable. The method of solving the system back in time is used to construct the switching locii, and the optimal control law was synthesized. An example is given and is simulated on an analog computer to illustrate the theory.