- Email: [email protected]
A compenasator design controlling neutron flux distribution via observer theory
COMPENSATOR
Korea Advanced Institute of Science and Technology. Department of Nuclear %gmeering. 373-I Kusong-dong, Yusong-gu, Taejcn, §outh Korea 3055701
Abstract-To suppress the sparnl xencm oscihations in a nuclear reactor, an implementable stabilization scheme is proposed based on the finite dimensional compensator theory in control theory for the distributed parameter systems. The method is applied to a one-dimensional reactor whose dynamics is governed by one-group diffusion equation with its associated iodine and xenon dynamics. The modal decomposition of the state variables enables us to use the pole assignment algorithms developed in finite dimensional systems to obtain the stabilizing compensator gains. This allows us to estimate the states of a reactor in a transient using output measurement data and arbitrary initial conditions: and control the states using the estimated values. The resulting compensator is tested by using model-based data for measurement output through numerical simulations. The results show that unstable spatial xenon oscillations initiated by perturbations can be controlled by the finite dimensional compensator.
Commercial pressurized water reactors (P s) of the current design exhibit xenon ILmode xenon buildup and the spatial oscillations that are caused by the ftmda xenon redistributions following localized disturbances. V/e are required to operate such reactors by using special control systems, which should be capable of stabilizing these oscillations. Generally speaking, fundamentalLmode changes are readily noticed and suppressed by the control system. while the spatial oscillations are not. The spatial xenon oscillations. if uncontrolled or poorly controlled. could Lead to potentiaily destructive hot spots adjacent to fuel regions with high iocal flux levels. For this reason, the spatial oscillations have received particular attention in the technical literature (Canosa and Brooks, 1966; Christie and Poncelet, 1973). A nuclear reactor subject to the spatial xenon oscillations can be described by partial nd is termed as a distributed parameter system or an infinite differential equations dimensional system. odern controi theory gives us theoretical results for feedback stabilization of certain classes of unstable distributed parameter systems, which could be
Korea Advanced Institute of Science and Technology. Department of Nuclear %gmeering. 373-I Kusong-dong, Yusong-gu, Taejcn, §outh Korea 3055701
Abstract-To suppress the sparnl xencm oscihations in a nuclear reactor, an implementable stabilization scheme is proposed based on the finite dimensional compensator theory in control theory for the distributed parameter systems. The method is applied to a one-dimensional reactor whose dynamics is governed by one-group diffusion equation with its associated iodine and xenon dynamics. The modal decomposition of the state variables enables us to use the pole assignment algorithms developed in finite dimensional systems to obtain the stabilizing compensator gains. This allows us to estimate the states of a reactor in a transient using output measurement data and arbitrary initial conditions: and control the states using the estimated values. The resulting compensator is tested by using model-based data for measurement output through numerical simulations. The results show that unstable spatial xenon oscillations initiated by perturbations can be controlled by the finite dimensional compensator.
Commercial pressurized water reactors (P s) of the current design exhibit xenon ILmode xenon buildup and the spatial oscillations that are caused by the ftmda xenon redistributions following localized disturbances. V/e are required to operate such reactors by using special control systems, which should be capable of stabilizing these oscillations. Generally speaking, fundamentalLmode changes are readily noticed and suppressed by the control system. while the spatial oscillations are not. The spatial xenon oscillations. if uncontrolled or poorly controlled. could Lead to potentiaily destructive hot spots adjacent to fuel regions with high iocal flux levels. For this reason, the spatial oscillations have received particular attention in the technical literature (Canosa and Brooks, 1966; Christie and Poncelet, 1973). A nuclear reactor subject to the spatial xenon oscillations can be described by partial nd is termed as a distributed parameter system or an infinite differential equations dimensional system. odern controi theory gives us theoretical results for feedback stabilization of certain classes of unstable distributed parameter systems, which could be