Nonlinear excitation and governor control using variable structures

Modern microprocessor capabilities permit the control designer to consider using relatively complicated nonlinear control algorithms, which would have been considered impractical in the past. This paper presents the results of a study of the variable structure control technique for the design of excitation and governor controllers for a power system. Control laws for rotor angle and field flux are derived. The closed loop system is shown to be asymptotically stable. The system can be transferred to a new operating condition corresponding to any desired terminal voltage Vt, and tie-line power Ptie.