State-Dependent LMI-Based Controller and Observer Design for Constrained Boiler-Turbine-Generator Using Pseudo-Linearization Technique

In this paper, a novel state-dependent observer is designed for tracking control of a nonlinear constrained boiler-turbine-generator unit. The boiler-turbine system considered in this paper has a nonlinear relationship between system output and the inputs and state variables, which makes the controller and observer design more complicated. The proposed scheme adopts the well-known extended pseudo-linearization technique to cope with strong nonlinearity of the multivariable, highly coupled boiler-turbine-generator system. This method gives a pseudo-linear model of the system with state-dependent coefficients, which simplifies the procedure of controller design. The proposed method is able to satisfy the saturation limitations on the control signals. The stability of the proposed controller and observer is verified using a time-varying Lyapunov function in terms of Linear Matrix Inequalities (LMI). Simulation results for a 160-MW boiler-turbine-generator unit model validate effectiveness and stability of the proposed methodology.