Research On Robust D-stability Control Of Hydro Turbine Governing System

Incorporating waterpower,machinery and electricity as a whole,hydro turbine governing system is a complex control system with non-linear and non-minimum phase characteristics.The controller of the system not only controls the speed and output of hydro generator units,but also is the core equipment for guaranteeing the stability of hydro generator units' operating.Based on the analysis on the characteristics of hydro turbine governing system,it has important theoretical significance and engineering value to establish the mathematical modelreflecting the essential characteristics and study the reliablecontrol strategy and calculation of transition process.Because of strong nonlinearity of hydro turbine governing system,the method of classical linear control theory can only be used to analyze the system in "small fluctuations" condition so it's difficult to fundamentally solve the problem of stability lossing and regulation performance caused by model mismatch.Therefore this paper establish the non-linear model of hydro turbine governing system,and then obtained the uncertain parameter linear system by mathmatical transformation;aiming at the discrete uncertain parameter linear system,the region of pole assignment is converted into a region described by a class of LMI to assign regional poles using the state feedback,therefore,the robust D-stability criterion and the corresponding state feedback matrix are obtained;in order to consider the robust D-stability and dynamic performance of the system,a robust D-stability controller design method based on the Fibonacci method is proposed to optimize the control parameter;aiming at the nonlinear discrete simulation model of hydro turbine governing system,the numerical calculation method of closed loop transition process based on internal and external loop search is studied;by using the designed robust D-stability controller and PID controller,the no-load disturbance simulation at different water head and the load disturbance simulation under different initial conditions are carried out;the results show that robust D-stability controller can make the system has better adaptive ability to nonlinearity than PID controller and also satisfied dynamic performance.