Dynamic extending nonlinear H_∞ control and its application to hydraulic turbine governor

There exists a large class of nonlinear systems with uncertainties, such as hydrau- lic turbine governors, whose robust control problem is hard to solve by means of the existing robust control approaches. For this class of systems, this work pre- sents a dynamic extending H∞ controller via both differential geometry and H∞ the- ory. Furthermore, based on differential game theory, it has been verified that the proposed control strategy has robustness in the sense that the disturbance can be attenuated effectively because the L2-gain from the disturbance input to the regu- lation output signal could be reduced to any given level. Thirdly, a robust control strategy for hydraulic turbine governor is designed according to the proposed ex- tending H∞ control method, and has been developed into a real control equipment. Finally the field experiments are carried out which show clearly that the developed control equipment can enhance transient stability of power systems more effec- tively than the conventional controller.