H_? Tracking Control For Water Level In The U-tube Steam Generator

The steam generator(SG), an important heat transfer device in nuclear power plant that connects primary loop and secondary loop. The SG carries the heat from the reactor and producing the steam which is taken to the turbine to covert heat energy to electricity.Therefore, it is very necessary for the study on water level control.The gain-scheduling tracking control of water level system in SG is studied in this paper.At first, on the basis of the SG water level model put forward by Irving and the introduction of the water level error integral, the augmented state space model of the SG water level system is constructed. Then the polytopic linear parameter varying(LPV) model is established combining with the LPV theory. With the model, the tracking controllers' existence conditions which satisfy the H? performance, H?-LQR performance and mixed H2/H? performance respectively are received by using Lyapunov stability theory. The Matlab toolbox of linear matrix inequality is applied to solve the feasible solution of the controllers. Considering the influence of the water level set point and steam flow to the water level, the simulation results show that the designed controllers have good tracking performance, and it can restrain the disturbance effectively through simulation.According to general technical requirements of the SG water level control, the system performance of the controllers are evaluated by the maximum overshoot, attenuation rate,setting time and mean square error.