Nonlinear Modeling,Dynamics Analysis And Parameter Optimization Of Hydraulic Turbine Regulation System

The turbine governing system is a complex nonlinear control system with strong time-varying and non-minimum phase,including hydraulic,mechanical and electrical factors.The dynamic regulation quality will directly affect the stability and safety of the unit operation.In the past,due to different research priorities,the unit adjustment system was approximated or linearized.Although the research focus can be well explained,the adjustment system to the entire hydro-generator unit is not necessarily the best control strategy,and in many models there are existing some problems such as unclear physical meaning of parameters and so on.In view of this matter,based on the previous research,I first deduced and established a relatively complete and physically meaningful nonlinear model of the turbine regulation system,using the Hopf bifurcation theory to carry out the bifurcation analysis of the built system model;secondly,the genetic algorithm is used to optimize the parameters of the fuzzy adaptive PID controller,and which is applied to the refined tuning of the governor parameters of the nonlinear turbine governing system.The simulation results show that the fuzzy adaptive PID control based on genetic algorithm optimization parameters can effectively improve the transition process of the unit under frequency and load disturbance,and has better adjustment quality.The main research contents of this paper are as follows:(1)The turbine regulation system is divided into four subsystems: a p ressurized water subsystem,a turbine subsystem,a generator subsystem and a governor subsystem,and then the mathematical models of the above subsystems are deduced and established.(2)Integrate the mathematical models of each subsystem to establish a complete nonlinear model of the turbine regulation system.Using the nonlinear bifurcation theory,the bifurcation diagram and the stability domain range formed by the critical point when the governor parameters are bifurcated are analyzed under the two comm on operating conditions of frequency disturbance and load disturbance.(3)Based on the genetic algorithm,the fuzzy adaptive PID controller 's related parameters are adaptively adjusted,and which is applied to the elastic water hammer nonlinear turbine adjustment system to refine the optimal parameters of the turbine governor.(4)Based on Simulink,the nonlinear Simulink simulation module of the unit regulating system considering the surge tank is established by using the preset initial value method.Firstly,the correctness of the differential algebra model built in this paper is verified.Secondly,the influence of the parameters of the controlled object on the regulation performance of the unit is studied.