부산대학교 도서관

The robust controller synthesis and analysis of the water level process in the U-tube system generator(UTSG) is addressed in this paper. The parameter uncertainties of the steam generator (SG) are modeledas multiplicative perturbations which are normalized by designing suitable weighting functions. Therelative errors of the nominal SG model with respect to the other operating power level models areemployed to specify the weighting functions for normalizing the plant uncertainties. Then, a robustcontroller is designed based on m-synthesis and D-K iteration, and its stability robustness is verified overthe whole range of power operations. A gain-scheduled controller with H∞ -synthesis is also designed tocompare its robustness with the proposed controller. The stability analysis is accomplished andcompared with the previous QFT design. The meanalysis of the system shows that the proposedcontroller has a favorable stability robustness for the whole range of operating power conditions. Theproposed controller response is simulated against the power level deviation in start-up and shutdownstages and compared with the other concerning controllers.