Reduced Order Model of U-Tube Steam Generator and Application of Fuzzy and LQR in its Level Control

The water level of the U-tube steam generator (UTSG) in a nuclear power unit, which is an important process parameter, must be maintained in a safe range whether the unit is working under fixed or variable conditions. In this paper, a higher order UTSG model derived from the state equations is reduced using Balanced Truncation technique. Two controllers using Fuzzy logic and LQR techniques have been designed for the reduced UTSG model to control its water level. Comparison of these two controllers has also been shown through the simulation results. Also, a comparative analysis of the reduced order model and a previously developed UTSG model is presented by simulating both UTSG models with Fuzzy Logic and LQR techniques and the results are compared.