Nonlinear Model And Dynamic Analysis For Hydraulic Turbine Governing System

Hydraulic turbine governing system is a control complex system involvedhydrodynamics, machinery and electric. It consists of reservoirs, pressure derivation, turbine,governor, generator, grid and load. And its working state includes running, shutdown,connecting in power network, under unload, etc. Furthermore, it is a kind of strong nonlinearand non minimum phase system. All these make it is complex and difficult to analysis andcontrol the hydraulic turbine regulation system.Hydro-turbine governing system was divided into four subsystems, included thehydraulic turbine，governor of hydraulic turbine, generator and hydraulic system. Each ofsubsystem models was established, and the applicable condition was analyzed.Nonlinear hydro-turbine governing system model with complex pipes, nonlinearhydro-turbine governing system model with output limiting link and Nonlinear hydro-turbinegoverning system model with a surge tank was established according to the emphasis of theresearch content. At the same time, hydraulic turbine governing system simulation modelbased on MATLAB/SIMULINK was established.Based on nonlinear dynamics theory, the nonlinear dynamic behavior of hydro-turbinegoverning system was analyzed including bifurcation diagrams, Poincare maps, powerspectrum diagram, time domain diagram, phase orbits diagram, power spectrum diagram andLyapunov index. Moreover, a numerical simulation was carried out based onMatlab/Simulink.The direct algebra criterion about the existence of Hopf bifurcation was used to analysisthe stability of the system. The hydro-turbine governing system which was established byMatlab/Simulink software package, can be real-time display and adjust the simulationparameters. For getting the simulation results of system mode more accurately and quickly,we can combine the Matlab/Simulink software package and M files in the process ofmodeling and simulation of hydro-turbine governing system.This paper provides a method for hydro-turbine governing system modeling and thetheoretical basis for ensure the system safely and stably operates.