Nonlinear modeling and dynamic analysis of hydro-turbine governing system in the process of load rejection transient

•A novel mathematical model of a hydro-turbine governing system is established.•The process of load rejection transient is considered.•Nonlinear dynamic transfer coefficients are introduced to the system.•The bifurcation diagram with the variable t has better engineering significance.•The nonlinear dynamical behaviors of the system are studied in detail.

This article pays attention to the mathematical modeling of a hydro-turbine governing system in the process of load rejection transient. As a pioneer work, the nonlinear dynamic transfer coefficients are introduced in a penstock system. Considering a generator system, a turbine system and a governor system, we present a novel nonlinear dynamical model of a hydro-turbine governing system. Fortunately, for the unchanged of PID parameters, we acquire the stable regions of the governing system in the process of load rejection transient by numerical simulations. Moreover, the nonlinear dynamic behaviors of the governing system are illustrated by bifurcation diagrams, Poincare maps, time waveforms and phase orbits. More importantly, these methods and analytic results will present theoretical groundwork for allowing a hydropower station in the process of load rejection transient.

Graphical abstractNonlinear dynamic transfer coefficients are introduced to the hydro-turbine governing system. In the process of load reject ion transient, the nonlinear dynamical behaviors of the system are studied in detail.Figure optionsDownload full-size imageDownload as PowerPoint slide