Detailed modelling and parameters optimisation analysis on governing system of hydro‐turbine generator unit

Abstract

Aiming at the mutual influence of hydraulic, mechanical, and electrical factors in a hydropower station, a detailed mathematical model for the governing system of a hydro-turbine generator unit was presented here. An object-oriented approach was used to write the computational program in Matlab/Simulink platform, and then it was verified by the prototype tests. The parameters of the governing system were optimised by the experimental test and this model, and evaluated by using the amplitude frequency characteristic method under no-load frequency control mode, load frequency control mode, and load opening control mode. The characteristics of the waveform of the transient process and the influence degree of hydraulic, mechanical, and electrical factors were obtained. The computational results of the transient process show that the load rejection as an electrical disturbance leads to the water hammer, and the water-level fluctuation in the surge chamber becomes one of the reasons of the low-frequency oscillations in the power grid, especially under the load frequency control mode.