Robust Controller Design for a Boiler-Turbine Unit

The paper deals with modelling and robust controller design for a boiler-turbine unit in the turbo power plant Maritsa Iztok-2. Based on a simplified first principles nonlinear simulation model and related linearized model in form of a 2x2 transfer matrix with a known structure of individual entries, the resulting plant model is obtained as a set of transfer matrices identified from simulation experiments on the nonlinear model in selected operating points. A robust controller with a decentralized structure is designed using the unified robust decentralized controller design method, the core of which is the equivalent subsystems method (ESM). The controller design results are verified by simulation on the linearized as well as the nonlinear models.