On the robust control of synchronous generators

The objective of this paper is to design robust nonlinear excitation controllers for synchronous generators. Since disturbances acting on power systems are of random nature and the system parameters can not be known with certainty, such systems have to be treated as nonlinear uncertain stochastic systems. The expression and frequency characterization of the uncertainties are derived. The controller is designed using the concept of exact stochastic feedback linearization and robust control techniques. Simulation results of a single machine infinite-bus power system indicate that in presence of major disturbances, the proposed controller outperforms existing linear and nonlinear controllers in providing larger stability margins.