Boiler-turbine unit controller design based on the extended state observer

This paper proposes an active disturbance rejection controller (ADRC) to control a boiler-turbine unit as a multivariable, nonlinear and strongly coupled system. Main part of the ADRC is an extended state observer (ESO) which is capable of identifying unknown dynamics and also nonlinear part of the system as a disturbance term. By rejecting the defined disturbance, the system can be simplified and linearized for further controller design. By using this method, controller design gets easy and simple where less knowledge about the system is necessary. The simulation results show that the proposed controller is robust to the variation of operation points as well as internal and external disturbances. Besides, it is able to decouple the three input-three output boiler turbine system to three single input-single output systems.