${H}_{\infty }$-LQR-Based Coordinated Control for Large Coal-Fired Boiler–Turbine Generation Units

The coordinated control system of a boiler–turbine unit plays an important role in maintaining the balance of energy supply and demand, optimizing operational efficiency, and reducing pollutant emissions of the coal-fired power generation unit. The existing challenges (the fast response to wide-scaled load changes, the matching requirements between a boiler and a turbine, and cooperative operation of a large number of distributed devices) make the design of the coordinated controller for the boiler–turbine unit be a tough task. In this paper, based on a typical coal-fired power unit model, using the linear-quadratic regulator (LQR), a coordinated control scheme with $H_{\infty }$ performance is proposed: the $H_{\infty }$ method is used to ensure control performance on the basis of reasonable scheduling of distributed equipment; the LQR is applied to limit the control actions to meet the actuator saturation constraints. Case studies for a practical 500 MW coal-fired boiler–turbine unit model indicate that the designed control system has satisfactory performance in a wide operation range and has a very good boiler–turbine coordination capacity.