On the design of output feedback excitation controllers of synchronous machines

Optimal output controllers for high-speed excitation systems of synchronous machines, using constant and/or dynamic feedback gains, are discussed in this paper. A general problem formulation and solution are presented. A number of combinations of measurable output variables are used for control. Also, several random characteristics of the system initial state are used in the incomplete output feedback controllers´ design. Effectiveness of the stabilizers are tested subjecting the system to a small input disturbance and a three-phase-to-ground fault.