State-Space Based H ∞ Robust Controller Design for Boiler-Turbine System

This paper describes the use of the linear H ∞ Theory to design a robust controller for the steam-turbine unit. This work considers issues like time variations, non-linearity, and dynamic coupling of a MIMO nonlinear model of this unit. After a detailed analysis of various operating points, a nominal one is chosen around which the linear model is obtained. Six other operating points are deliberated to test the robustness features of the controller. The proposed controller guarantees the internal stability and satisfies the requirements of both of frequency and time domains. A simulation is conducted in order to demonstrate how these requirements are satisfied when step signals and disturbances are applied simultaneously to the input channels.