Building and Analysis of Hydro Turbine Dynamic Model with Elastic Water Column

The structure of dynamic models of nonlinear hydro turbine with elastic water column is studied in this paper. The nonlinear differential equations for hydraulic system (NDE-HS) are derived based on transfer function model of it. The dynamic model I of hydro turbine is built by combining NDE-HS with the algebraic equation of hydro turbine torque. By means of except of transfer coefficient, the differential equation of hydro turbine torque is derived and combines with NDE-HS, the dynamic model II is built. Simulation is done with actual hydroelectric plant, simulation results show that dynamic responses of two type models are almost same, and the dynamic of hydro turbine is determined by hydraulic system. Furthermore, the nonlinear differential-algebraic model for hydro turbine is given, which is a reduce-order system and includes inner energy loss characteristic.