A comparative study of the calculation method of the transfer coefficient of the turbine

Hydro turbines;  transmission coefficient;  linearized models;  Stability

The calculation methods of the transfer coefficient of three francis turbines, namely the external characteristic method based on the comprehensive characteristic curve of the model, the internal characteristic method based on the internal characteristic analysis model and the simple analytical method based on the simplified nonlinear model, are introduced, and the differences between their characteristics and calculation results are analyzed, and it is pointed out that the transfer coefficient calculated by the three methods is close to the rated power point and the difference is large under the light load condition. The obtained transfer coefficient curve is helpful for understanding its variation law.