Design Of A Bumpless Transfer Control For A Gas Turbine

With the rapid development of modern industry,the application of gas turbine is more and more extensive,and the research of its control system has been paid much attention in the fields of energy and power and complex control systems.The existing single controller and the general switching control are usually difficult to satisfy the requirements of modern high-performance gas turbines with switchings among multiworking conditions.Therefore,this thesis takes a gas turbine as the controlled object.When the dynamics of the system changes due to the change of working conditions or large input disturbances,to ensure the smooth transition of the control signal of the system at the moment of controller switching,we design a bumpless transfer control strategy and an active disturbance rejection master controller based on an active disturbance observation.Finally,the feasibility of the proposed bumpless transfer control strategy and the superiority of the control system with active disturbance rejection as the master controller are verified by a numerical simulation and a hardware-in-the-loop test.The main work of this thesis is as follows:1.The nonlinear mathematical model of a gas turbine and the AMEsim model of a fuel sys-tem are studied.Taking a single-shaft gas turbine as an example,according to the mathematical theories of thermodynamics and rotor dynamics,the mathematical models of various compo-nents of the gas turbine are established.Finally,the nonlinear gas turbine mechanism model is established according to the law of power conservation.As the actuator of the control system,the fuel system has different flow ratios in different working conditions.In order to truly reflect the change of total gas flow at the moment of fuel channel ratio switching,a fuel system model was established in AMEsim software.2.The control scheme of the gas turbine is designed.The process from gas turbine startup to grid-connected power generation needs to go through startup control,speed-up control,speed control and load control in sequence.In order to ensure the stable supply of fuel,a fuel system controller is also designed.When the fuel channel ratio of the system switches,the total amount of fuel will fluctuate.For the trouble above,the ADRC uses an observer to observe this fluctuate and compensate it to achieve better disturbance rejection.Then,this thesis applies ADRC to the gas turbine control system.Finally,the numerical simulation experiments are carried out,where ADRC and PID are as master controllers in islanding operation mode and grid-connected oper-ation mode respectively.It is verified that ADRC has the better anti-disturbance performance than PID.3.A bumpless transfer control strategy based on an adaptive gain compensator is designed.At the instant of controller switching,the control signal may fluctuate violently.To solve this problem,this thesis puts forward a bumpless transfer control strategy based on an adaptive gain compensator,and proves the stability of the closed loop system by the second Lyapunov method.The numerical simulation test is carried out under the grid-connected operation mode of gas turbine.The results show that the bumpless transfer control strategy based on an adaptive gain compensator proposed in this thesis can not only smooth the transition,but also improve the quicker response of the system.4.Build a hardware-in-the-loop simulation platform and carry out a hardware-in-the-loop test.The physical platform mainly includes a simulator with STM32F746 G development board as the controller and a computer with NI-Veri Stand related software as the gas turbine model simulator.The software mainly includes a controller model,a gas turbine model and an upper computer for data monitoring and simulation control.Before the hardware-in-the-loop test,the accuracy and real-time performance of communication between simulators are verified.Then,the hardware-in-the-loop simulation test is carried out under the grid-connected operation mode of gas turbine,which verifies the feasibilities of the bumpless transfer control strategy and the active disturbance rejection controller in the gas turbine control system.