LQG/LTR robust control of nuclear reactors with improved temperature performance

Abstract

Controller robustness is always a major concern. A controller that meets certain performance design objectives cannot be satisfactory unless it can preserve such quality in the presence of expected uncertainties. For nuclear reactors, a controller that preserves stability and performance for a wide range of operating conditions and disturbances is especially desirable. This paper presents the design of a robust controller using the linear quadratic gaussian with loop transfer recovery (LQG/ LTR) for nuclear reactors with the objective of keeping a desirable performance for reactor fuel temperature and temperature of the coolant leaving the reactor for a wide range of reactor power. The obtained results are compared to an observer-based state feedback optimal reactor temperature controller. Sensitivity analysis of the dominant closed-loop eigenvalues and nonlinear simulation are used to demonstrate and compare the performance and robustness of the two controllers. The LQG/LTR approach is systematic, methodical, easy to design, and can give improved temperature performance over a wide range of reactor operation.

Modeling and Simulation for Nonlinear Pressurized Water Reactor Cores Using Gap Metric and Fuzzy Model with Transfer Function

“…One group delayed neutron model is utilized and the coolant inlet temperature is treated as a constant [2][3][4]. The transfer function and the state equation of the core are separately calculated and expressed by A transfer function of the core at a power level 10*i% is denoted by G 10*i% (i=1, .…”

“…For this modeling, a core is regarded as one point without any space profile, and parameters of the core only vary with time and have nothing to do with space positions. According to the point reactor core modeling [1][2][3], the nonlinear PWR core is modelled adopting the point kinetics equations with six groups of delayed neutrons and reactivity feedbacks due to control rod movement and variations in fuel temperature and coolant temperature. Main model parameters are given in Table 1.…”

“…Kerlin et al [1] modelled the PWR core of the H. B. Robinson NPP at the full power level which was also verified to be correct. PWR cores at the full power level were modeled by Edwards et al [2][3][4][5]to design core power control systems.…”

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

“…(1 ) One group delayed neutron model is utilized and the coolant inlet temperature is treated as a constant [2][3][4].The small perturbation linearization methodology is utilized to linearize the nonlinear core model (1). The transfer function and the state equation of the core are separately calculated and expressed by…”

“…The linear quadratic Gaussian with loop transfer recovery (LQG/LTR) control wasadopted to contrivePWR core controllers for power regulations [3][4]. However, the controllers in references [1][2][3][4] are designed based on a linear core model without xenon oscillations, and not always optimal or even ineffective for nonlinear cores.…”