Periodic Output Feedback Control of a Large Nuclear Reactor

Abstract

The paper presents the design of piece-wise constant periodic output feedback control for a discrete three time-scale system resulting from the discretization of a continuous-time standard three time-scale system. By a suitable linear transformation of state variables the given continuous-time system model is converted into a block diagonal form in which the three time scale system is decoupled into a slow, a fast and a faster subsystem, respectively. The periodic output feedback gain for the slow subsystem is then calculated from the output injection gain computed from the slow subsystem and the same for the fast subsystems are set equal to zero. Finally the periodic output feedback gain for the composite system is obtained using all the above mentioned periodic output feedback gains. The method has been applied to a large Pressurized Heavy Water Reactor (PHWR) for control of Xenon-induced spatial oscillations and the efficacy of control has been demonstrated by simulation of transient behaviour of the nonlinear model of the PHWR.