A Stable Multi-Objective Economic MPC Scheme for Boiler-Turbine Units

Abstract

This paper proposes a compact boiler-turbine control scheme for the fossil-fuel power plants. Generally, control strategies used in boiler-turbine units are implemented as the hierarchical structures consisting of an upper economic optimization layer and a separate lower feedback control layer. The deficiency of such hierarchy is that the tracking of the steady-state set-points, that are computed by the upper layer, is accomplished by the lower layer in an economically non-optimal way. To improve the economic performance of boiler-turbine units, the proposed control scheme integrates plant economic optimization into the dynamic feedback controller output computation process. The stability (and also feasibility) of the proposed control scheme is proven. The effectiveness of the latter is also demonstrated through the 160 MW oil-fired boiler-turbine unit simulation.