Optimized FSF Controller for Bulk Power Control of Large-Core PHWRs

Abstract

This paper considers an optimized full state feedback (FSF) optimal controller for bulk power control of a 700-MW(electric) pressurized heavy water reactor (PHWR) that minimizes the controller norm to reduce the effect of disturbances. Lyapunov’s linear matrix inequalities (LMIs) have been considered for stability of the model. For the closed loop, these inequalities, which become nonlinear in the unknowns, are converted to LMIs by a suitable variable substitution. The controller’s optimization is achieved by minimizing the upper bound of the state feedback vector’s norm. As a result of this optimization, the controller gain is reduced, which reduces the effect of the disturbance input to the system. We study the stability of the closed loop system and the nonlinear transient performance using the state feedback. We demonstrate that the proposed controller’s transient performance is superior to that of a nonoptimized controller when compared to a conventional proportional-derivative controller. The designed controller has a norm that is about five orders lower than that obtained without optimization while still providing acceptable transient performance.