Nonlinear Pressurized Water Reactor Core Research Articles

Power-level regulation and simulation of nonlinear pressurized water reactor core with xenon oscillation using H-infinity loop shaping control

This investigation is to solve the power-level control issue of a nonlinear pressurized water reactor core with xenon oscillations. A nonlinear pressurized water reactor core is modeled using the lumped parameter method, and a linear model of the core is then obtained through the small perturbation linearization way. The H∞loop shapingcontrolis utilized to design a robust controller of the linearized core model.The calculated H∞loop shaping controller is applied to the nonlinear core model. The nonlinear core model and the H∞ loop shaping controller build the nonlinear core power-level H∞loop shaping control system.Finally, the nonlinear core power-level H∞loop shaping control system is simulatedconsidering two typical load processes that are a step load maneuver and a ramp load maneuver, and simulation results show that the nonlinear control system is effective.

Review on Application of Control Algorithms to Power Regulations of Reactor Cores

This research is to solve the stability analysis issue of nonlinear pressurized water reactor cores. On the basis of modeling a nonlinear pressurized water reactor core using the lumped parameter method, its linearized model is achieved via the small perturbation linearization way. Linearized models of the nonlinear core at six power levels are selected as local models of this core. The T-S fuzzy idea for the core is exploited to construct the T-S fuzzy model of the nonlinear core based on the local models and the triangle membership function, which approximates the nonlinear core model within the entire range of power level. This fuzzy model as a bridge is to cater to the stability analysis of the nonlinear core after defining its stability. One stability theorem is deduced to define the nonlinear core is globally asymptotically stable in the global range of power level. Finally, the simulation work and stability analyses are separately completed. Numerical simulations show that the fuzzy model can substitute the nonlinear core model; stability analyses verify the nonlinear core is globally asymptotically stable in the global range of power level.

Global Control of H-Infinity Multimodel System with Gap Metric and Self-Stability for Load-Following Nuclear Reactor Core

This investigation is to design a nonlinear pressurized water reactor (PWR) core load-following control system with self-stability for regulating the core power and axial power difference within a target band. A two-point–based nonlinear PWR core without boron and with a power rod and an axial offset rod is modeled. By proposing the gap metric of the core to qualify the core nonlinearity, the linearized multimodel single-variable core under case 1 (multivariable core under case 2) classified by two movable regions of the power rod is modeled. Linearized models of the core at seven power levels are chosen as local models of the core to substitute the nonlinear core model for each case. Based on H-infinity (H∞) control theories, the linear matrix inequalities method is adopted to design a H∞ output-feedback controller of every local model, which is a local controller of the nonlinear core of each case. In terms of the flexibility idea of control presented, the core load-following control system for each case is established. A theorem is deduced to analyze the global stability of the system of each case. Ultimately, simulation results show that the H∞ multimodel control strategy is effective for the core of each case.

Modeling and SISO/MIMO Control with an Inverse Nyquist Array and Stability Analysis for Load-Follow Operation of PWR Core Without Boron

The purpose of this investigation is to design a nonlinear pressurized water reactor (PWR) core load-following control system for regulating the core power level and axial power difference and to analyze the global stability of the system. In modeling a two-point–based nonlinear PWR core without boron, the power rod and axial offset (AO) rod are considered. The two points are the bottom half and top half of the core. When the power rod and AO rod are in the same point (case 1), the power rod is an input, and the core power level is an output. When the power rod and AO rod in the core are not in the same point (case 2), the power rod and the AO rod are two inputs, and the core power level and axial power difference are two outputs. For each case, linearized models of the core at five power levels are chosen as local models of the core to substitute for the nonlinear core model over the global range of the power level. For case 1, proportional integral derivative (PID) control is utilized to design a controller of every local model as a local controller of the nonlinear core. For case 2, inverse Nyquist array control with the linear matrix inequalities method and PID control are adopted to devise a decoupling compensator and a dynamic controller for every local model, and their combination is a local controller of the nonlinear core. Based on the local models and local controllers of each case, the idea of flexibility control is used to design a decent controller of the nonlinear core at a random power level. A nonlinear core model and a flexibility controller at a random power level compose a core load-following control subsystem. The combination of core load-following control subsystems at all power levels is the core load-following control system for every case. Two global stability theorems are deduced to show that the core load-following control systems for the two cases are globally asymptotically stable within the whole range of the power level. Finally, the core load-following control system for each case is simulated, and the simulation results show that the control system is effective.

New strategies with multi-model, state-feedback control and stability analysis for load-follow PWR core

The objective of this study is to design a Pressurized Water Reactor (PWR) core load following control system for regulating the core power level and axial power difference and analyze the global stability of the system theoretically. On the basis of building a two-point based nonlinear PWR core model without boron and with the power rod and Axial Offset (AO) rod, the linearized single-variable (multi-variable) core model under Case 1 (Case 2) classified by two movable regions of power rod is constructed. For each case, by proposing the equilibrium manifold and the nonlinearity measure of the core to calculate the distribution situation of the core nonlinearity measure in the entire range of power level, linearized models of the core at ten power levels are chosen as local models of the core to substitute the nonlinear core model. Based on each local model, the state feedback control is implemented by utilizing the robust pole assignment method with an additional integrator for Case 1 and devising an integral decoupling control system with a dynamic controller for Case 2; a Kalman filter with robustness is designed as an observer for each case. The integration of the state feedback and the observer structures a local controller of the core of each case. For each case, a local model and a local controller at one of ten power levels compose a core load following control subsystem. The combination of core load following control subsystems at ten power levels is the core load following control system. The global stability theorem is deduced to define that the core load following control system for Case 1 (Case 2) is globally asymptotically stable within the whole range of power level. Finally, the core load following control system for each case is simulated and the simulation results show that the control system is effective.

Modeling and LQG/LTR control for power and axial power difference of load-follow PWR core

The task of this investigation is to design a nonlinear Pressurized Water Reactor (PWR) core load following control system for regulating the core power level and axial power difference. A two-point based nonlinear PWR core model without boron and with the power regulating rod and Axial Offset (AO) rod is built. The linearized single-input single-output (SISO) or multiple-input multiple-output (MIMO) core model under Case 1 or Case 2 classified by two movable regions of power regulating rod is constructed. The linear SISO or MIMO model is further augmented with additional integrators to cater to the control design. The Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR) robust optimal control is used to contrive a controller of the linear core model of each case. For Case 1 (Case 2), the nonlinear core model and the LQG/LTR SISO (MIMO) controller construct the nonlinear PWR core load following control system. Two stability theorems are deduced to define that the nonlinear core load following control system of each case is asymptotically stable. Finally, the control system of each case is simulated and the simulation results show that the control system is effective.

Extension for load-follow operation of PWR core by using single- or multi-variable control of state-feedback

The single- or multi-variable control of full-state feedback with a full-order observer is applied to design a nonlinear Pressurized Water Reactor (PWR) core load following control system for regulating the core power level and axial power shape. A two-point based nonlinear PWR core model without boron and with the power rod and Axial Offset (AO) rod is built. The linearized single-variable (multi-variable) core model under Case 1 (Case 2) classified by two movable regions of power rod is constructed. Based on a linearized core model, the state feedback control is implemented by utilizing the robust pole assignment method with an additional integrator for Case 1 and devising an integral decoupling control system with a dynamic controller for Case 2; a Kalman filter with robustness is designed as an observer for each case. The integration of the state feedback and the observer structures a controller of the nonlinear core model of each case. For Case 1 (Case 2), the nonlinear core model and the state feedback single-variable (multi-variable) control construct the nonlinear PWR core load following control system. Finally, the control system of each case is simulated and the simulation results show that the control system is effective.

Multimodel-based power-level control with state-feedback and observer for load-follow PWR core

The purpose of this investigation is that a nonlinear Pressurized Water Reactor (PWR) core load following control system is designed and the global stability of the system is analyzed theoretically. On the basis of modeling a nonlinear PWR core and proposing the equilibrium manifold and the nonlinearity measure of the core to calculate the distribution situation of the core nonlinearity measure in the entire range of power level, linearized models of the core at five power levels are chosen as local models of the core and the set of local models is used to substitute the nonlinear core model. The full-state feedback control with a full-order observer is utilized to design a controller with robustness of every local model, which is treated as a local controller of the nonlinear core. The Kalman filter is contrived as an observer with robustness and the state feedback design with robustness is implemented via the robust pole assignment method. With the local models and local controllers, the flexibility partitioning of model and control is presented to design a decent flexibility controller of the nonlinear core at a random power level. A nonlinear core model and a flexibility controller at a random power level compose a core load following control subsystem. The combination of core load following control subsystems at all power levels is the core load following control system. Two global stability theorems are deduced to define that the core load following control system is globally asymptotically stable within the whole range of power level. Finally, the core load following control system is simulated and simulation results show that the control system is effective.

Load following control and global stability analysis for PWR core based on multi-model, LQG, IAGA and flexibility idea

The work is to design a nonlinear Pressurized Water Reactor (PWR) core load following control system and analyze the global stability of this system. On the basis of modeling a nonlinear PWR core, linearized models of the core at five power levels are chosen as local models of the core to substitute the nonlinear core model in the global range of power level. The combination control strategy of the Linear Quadratic Gaussian (LQG) control and the Proportional Integral Derivative (PID) control with an optimization process of Improved Adaptive Genetic Algorithm (IAGA) proposed is used to contrive a combined controller with the robustness of a core local model as a local controller of the nonlinear core. Based on the local models and local controllers, the flexibility idea of modeling and control is presented to design a decent controller of the nonlinear core at a random power level. A nonlinear core model and a flexibility controller at a random power level compose a core load following control subsystem. The combination of core load following control subsystems at all power levels is the core load following control system. The global stability theorem is deduced to define that the core load following control system is globally asymptotically stable within the whole range of power level. Finally, the core load following control system is simulated and the simulation results show that the control system is effective.

Flexibility control and simulation with multi-model and LQG/LTR design for PWR core load following operation

The objective of this investigation is to design a nonlinear Pressurized Water Reactor (PWR) core load following control system. On the basis of modeling a nonlinear PWR core, linearized models of the core at five power levels are chosen as local models of the core to substitute the nonlinear core model in the global range of power level. The Linear Quadratic Gaussian with Loop Transfer Recovery (LQG/LTR) robust optimal control is used to contrive a controller with the robustness of a core local model as a local controller of the nonlinear core. Meanwhile, LTR principles are analyzed and proved theoretically by adopting the matrix inversion lemma. Based on the local controllers, the principle of flexibility control is presented to design a flexibility controller of the nonlinear core at a random power level. A nonlinear core model and a flexibility controller at a random power level compose a core load following control subsystem. The combination of core load following control subsystems at all power levels is the core load following control system. Finally, the core load following control system is simulated and the simulation results show that the control system is effective.