Spatial control of a large pressurized heavy water reactor

The paper presents tile design of a near optimal linear regulator for controlling xenon-induced spatial oscillations in a large, pressurized heavy water reactor. The nonlinear mathematical model of the reactor including xenon iodine dynamics is characterized by 56 state variables land 14 inputs. This nonlinear model is linearized over rated power of the reactor and then the singularly perturbed structure of the linear model is exploited to decompose it into a fast subsystem of 14th order and a slow subsystem of 42nd order. The slow subsystem regulator problem is formulated as a cheap control problem that entails the solving of regulator problems of a 28th-order submodel and a 14th-order submodel. The fast subsystem regulator problem is also solved, Separately designed regulators are finally combined to obtain the near-optimal composite control for the original 56th-order model.