Analysis And Design Of Steam Generator Water Level Control System Based On Dissipative Method

Steam generator (SG) is one of the most important equipment in nuclear power plant,which can generate steam and transfer energy to drive the turbine from the primary side to the secondary side in reactor coolant system. Because the coolant water in the primary side is radioactive, SG can also prevent the secondary side from being polluted. It has great significance for the normal operation of SG to guarantee nuclear reactor safety. The SG water level has direct effect on the reactor cooling efficiency and turbine safety. So the SG water level should be in a reasonable range. Because of its highly non-linearity, strong disturbance and non-minimum phase behaviors,it is very difficult to design a desirable water level controller.The traditional SG water level PID control not satisfied for the load tracking,therefore, the problem of quadratic dissipative control with a mixed H? and positive real performance for SG water level control system has been taken into account in this paper.At first, according to the simple model Irving put forward and the linear parameter varying (LPV) theory, the polytopic LPV model and the affine LPV model are built. With the two models, polytopic and affine state feedback dissipative controllers are designed. The simulation results prove that the proposed controllers are feasible. Secondly, a piecewise dual-controller is proposed, which consists of a polytopic state feedback dissipative controller or an affine state feedback dissipative controller and a PID controller. All the feasibility of the proposed framework is verified via simulation.Based on the LPV model of SG, the problem of observer-based state feedback dissipative control is addressed. Using the quadratic dissipative control theory and Lyapunov function, the existation problems of these controllers are translated into the equivalent linear matrix inequality (LMI) feasible solution problem. The sufficient conditions are derived to design observer-based state feedback dissipative controllers and observer-based state feedback H? controllers for water level control of SG. The effectiveness is evaluated by numerical simulation and the simulation results show that the presented controllers can not only guarantee the asymptotic stability of the closed-loop system,but also satisfy the required performance index.According to the dissipative control theory and Lyapunov function, the polytopic static output feedback dissipative controller and polytopic dynamic output feedback dissipative controller based on the LPV model of SG are addressed. The necessary and sufficient condition is used to design the piecewise dissipative controllers. The simulation results demonstrate that two controllers proposed are effective.The system performance of the two dual-controller systems,observer-based state feedback dissipative controllers, observer-based state feedback H? controllers , static output feedback dissipative controller and dynamic output feedback dissipative controller are evaluated by Mean Square Error(MSE), setting time and Maximum overshoot which are also used to compared with previous results in the literature.