Optimal life-extending control of a boiler system

The objective of life-extending control (LEC), also known as damage-mitigating control, is to design a controller to achieve a good tradeoff between structural durability and dynamic performance in a system. This task involves both damage dynamics modelling and LEC design. The authors propose a new hierarchical LEC structure and apply it to a typical boiler system. There are two damage models in this structure: Model I is for on-line LEC, Model II is for on-line life prediction of the critical components of the system. Finally, an optimal LEC scheme is proposed and simulation results show that the designed LEC substantially reduces the accumulated damage with a minimum loss of dynamic performance.