MULTIVARIABLE ROBUST-CONTROL OF A POWER-PLANT DEAERATOR

The paper addresses the design of a robust controller for the deaerator of the Experimental Breeder Reactor-II (EBR-II) using the Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR) procedure. At present, classical PI controllers are used to control the deaerator. When the operating condition changes, the system is disturbed, or a fault occurs, the PI controllers may fail to maintain the desired performance which in turn deteriorates the performance of other components of the condensate system. This was a motivation to design a robust controller that can accommodate system faults and obtain a reasonable behavior for a wide range of model uncertainty. The designed controller has the following desirable features: (a) it provides the desired performance despite a considerable change in the operating condition, (b) it accommodates some of the failures that can occur, and (c) it provides the choice of penalizing one variable over another. The controller design is tested for robustness by varying the system operating condition and simulating a steam valve failure. The set of non-linear simulations using the Modular Modeling System (MMS) and the Advanced Continuous Simulation Language (ACSL) is included.