The Optimal Output Feedback Control of a Synchronous Machine

The optimal output feedback control of a synchronous machine, consisting of constant output feedback gains from only those states which are physically available for measurement, is considered in this paper. An integral quadratic performance index of outputs and controller inputs is minimized for impulse type disturbances occurring in the system. This gives a physically realizable control system which optimally "stabilizes" the excitation and input power to the synchronous machine. Numerical examples are included to show the application of the theory to a thermal and a hydraulic machine equipped with static exciters, and connected to an infinite bus. It is found that it is desirable to control a synchronous machine using both exciter and input power control gates with both power angle and speed fed back. A reduction in the value of the index of performance by a factor as large as 66 may be achieved using this control configuration instead of the conventional control configuration.