Robust H_? Control Approach To Steam Generator Water Level Of CPR1000 Nuclear Power Plant

The steam generator is the heat transfer equipment that generates the steam which the steam turbine needs. In the process of energy conversion, the steam generator, which is called a hub of the two loops, is the device that is both in the primary loop and in the secondary loop.As the steam generator system itself is nonlinear, highly complex, non-minimum phase, and has the "swell and shrink" phenomenon,these factors make the water level in steam generator become very difficult to control. Currently the cascade PID control system of steam generator level is prevalent used in CPR1000 nuclear power plant, however, this control method is hard to meet the requirements of automatic control in the case of transient in nuclear power plant,therefore, the robust H_? control method for SG water level control system is taken into account in this paper.In this paper, according to the CPR1000 nuclear power plant steam generator model and the linear parameter varying (LPV) theory, and the problem of robust H_? control theory is studied. At first, the affine LPV model is proposed, and the "swell and shrink" phenomenon is analyzed and simulated in the MATLAB/SIMULINK. Secondly single PID controllers, dual PID controllers and cascade PID controllers are designed. The simulation results prove that the propsed controllers are feasible. Based on LPV theory and the robust control theory,piecewise state feedback H_? controllers and piecewise output feedback H_? controllers are set up. The simulation results indicate the proposed controllers are feasible and also satisfy the required performance index. In order to improve the control performance, mixed PID and piecewise state feedback H_? controllers are designed. Finally the performance of the designed steam generator control systems studied in this paper is evaluated by caculating their values of Mean Square Error, MSE and values of Maximum overshoot, MO.