Partially Decentralized Control and Its Application in the Coordinated Control of Boiler-turbine Units

A decentralized controller may not achieve desired performance for a strongly-coupled multivariable process;while advanced multivariable controllers are usually complex in structure and difficult to implement,so design of partially decentralized controllers under the condition of expansion procedure was studied.First,the structure of partially decentralized controllers was analyzed,and then an independent design method with the non-square internal model control(IMC) principle was applied to design non-square decentralized controllers which were transformed to partially decentralized ones.The stability of the closed-loop control system was guaranteed via expanded interaction m measure.The method was applied to a 500 MW boiler-turbine unit and the results show that partially decentralized controller can achieve comparable performance as the centralized one;moreover,it has a simpler structure and is easier to implement and tune.