Design of reduced order sliding mode governor for hydro-turbines

This paper investigates modeling and control problems of the speed governing system of a hydro-generator unit with one upstream surge tank, driven by a Francis turbine. This governing system is organized into four main functional blocks, namely the hydrodynamic, mechanical, electrical, and servo subsystems. Mathematic models of the individual components are developed and are subsequently interconnected to obtain a model for the governor design. From the viewpoint of modern control theory, only a part of states of this speed governing system are measurable. By introducing an additional state variable, a reduced order sliding mode controller is presented. Simulation results illustrate the feasibility and robustness of the presented method.