Hydro turbine transfer functions with hydraulic coupling

The authors deal with the development of transfer functions for hydraulic turbines connected to a common penstock. These turbines tend to be hydraulically coupled. Both the solid mass approximation and the pressure wave modelling approach are applied for the development of diagonal and coupling transfer functions. This modelling approach is applied to the Stratos hydroelectric power station, China. It is shown that the solid mass approach gives relatively simple rational transfer functions that accurately represent the hydraulic coupling between turbines over a wide frequency range