Coordinated control of once-through power plant based on fuzzy feedback-feedforward approach

In this paper, in order to improve the performance and maneuverability of a once-through power plant, a modified version of coordinated control strategy based on feedback-feedforward fuzzy control is presented. At the supervisory level of this system, a model-based controller generates the feedforward setpoints for fuel, pressure and unit load with respect to the desired load. In addition, in order to eliminate effect of disturbance and compensate deviation between variables and corresponding feedforward setpoints, the feedback controllers are considered. The load demand signals to turbine and boiler are trimmed by error signals come from correction units. The proposed control is able to improve the system response by a close coordination of the boiler and turbine over a wide range of operation. Simulation results show the feasibility and performance of proposed control system during load movements and disturbances.