Configuration and coordinated-distributed control strategy for a hybrid combined cycle

This paper is about an innovative type of power plant, called Hybrid Combined Cycle (HCC), and its control, by means of a coordinated-distributed strategy. The considered HCC plant consists of a Combined Cycle Power Plant (CCPP), a concentrated solar plant (parabolic trough) and a thermal storage system (a molten salt two-tank indirect sensible thermal storage), connected together in an original form. The proposed control strategy for such an interconnected plant corresponds to a distributed one, since it relies on pre-specified controllers for each subsystem, and is coordinated meaning here that a coordinator is designed to give the setpoints to each local controller, on the basis of global information and subsystem modeling. After its presentation, this strategy is applied to the considered HCC plant, including its modeling step and then its coordinated control. The approach is illustrated in simulation considering three coordination schemes: one based on LQ design, another one on MPC, and a third one on H∞, and the results are promising in terms of gas consumption reduction while accommodating to power demand and renewable source variations.