Decentralized controller for nonlinear drum boiler: Youla parametrization approach

In this paper, we focus on robust decentralized controller design for Benchmark PID problem brought recently by Morilla [5]: nonlinear drum boiler, having integration term and significant right half plane (RHP) zero in the interaction. We present the linearized uncertain model identified for the working area determined by working points. Robust decentralized controller is designed by Equivalent Subsystem Method approach, using Youla parametrization on subsystem level. We compare decentralized controller design with and without prescribing the designed controller structure. We derive the respective relations and filter, which guarantee the PI structure of controller. After controller design we check the robust stability condition for the determined working area. All controllers are verified on nonlinear boiler model [5].