Research paperDynamics analysis of the fast-slow hydro-turbine governing system with different time-scale coupling

•The fast-slow model of the hydro-turbine governing system is established.•The fast-slow dynamical behavior of the system is investigated with different time scales.•The stable regions of the fast-slow hydro-turbine governing system are investigated.•The influence of the time scale on the stable region is analyzed by simulation.

Multi-time scales modeling of hydro-turbine governing system is crucial in precise modeling of hydropower plant and provides support for the stability analysis of the system. Considering the inertia and response time of the hydraulic servo system, the hydro-turbine governing system is transformed into the fast-slow hydro-turbine governing system. The effects of the time-scale on the dynamical behavior of the system are analyzed and the fast-slow dynamical behaviors of the system are investigated with different time-scale. Furthermore, the theoretical analysis of the stable regions is presented. The influences of the time-scale on the stable region are analyzed by simulation. The simulation results prove the correctness of the theoretical analysis. More importantly, the methods and results of this paper provide a perspective to multi-time scales modeling of hydro-turbine governing system and contribute to the optimization analysis and control of the system.