Control of hydraulic turbine generators using exact feedback linearization

Feedback control of hydro turbines in power systems is important for the transient stability enhancement. However, the hydro-electric power system is hard to be controlled due to its inherent non-minimum phase property. While global control of such a non-minimum phase system remains a challenging problem, it is shown in this paper that locally, the hydro-electric power plant is feedback equivalent to a linear and controllable system, and hence can be locally controlled, in the new coordinates, by using a linear feedback design technique such as pole assignment. Simulation results in a single machine infinite bus system are provided to illustrate the effectiveness of the proposed nonlinear control scheme. Performance comparisons between a PID controller and the nonlinear controller are also given in the paper.