Gain-Scheduled Control of a

In this paper the objective is to optimize the control of a coal fired 250 MW power plant boiler. The conventional control system is sup-plemented with a multivariable optimizing con-troller operating in parallel with the conven-tional control system. Due to the strong depen-dence of the gains and dynamics upon the load, it is beneficial to consider a gain-scheduling con-trol approach. Optimization using complex-p synthesis results in unstahle LTI controllers in some operating points of the boiler. A re-cent gain-scheduling approach allowing for un-stable fixed LTI controllers is applied. Gain-scheduling which interpolates between unsta-ble controllers is not allowed using traditional schemes. The results show that a considerable optimization of the conventional controlled sys-tem is obtainable. Also the gain-scheduled opti-mizing controller is seen to have a superior per-formance compared to the fixed LTI optimizing controllers operating alone