Optimal Control of Superheated Steam Temperature in Steam Turbine Power Plants

Abstract

The article presents a synthesis of optimal control of superheated steam temperature in main propulsion boilers of steam turbine power plants. Asteam superheater installed on board t/t GIEWONT has been used for this study. A mathematical model of the superheater has been defined accounting for manoeuvring states and sea passage. The paper also presents a method of correcting nonlinearities, the compensation of measurable disturbances based on the total invariance condition and the compensation of nonmeasurable disturbances based on the internal model principle. Furthermore, an optimal control law has been determined for a properly chosen quadratic performance functional on the basis of an equivalent Smith's predictor. The predictor, combined with a full rank observer, generates the superheated steam temperature control. Finally, the optimal system was verified by a digital simulation method using the program MATLAB (The Math Works 1994).