Design of multi-module adaptive fuzzy power tracking control for nonlinear four-point reactor core model under multiple transient conditions

• Published in: Progress in nuclear energy (New series) Vol. 149; p. 104248
• Main Authors: Aftab, Adnan, Luan, Xiuchun, Anjum, Muhammad Shoaib
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.07.2022
• Subjects: Adaptive fuzzy control; Disturbances; Multipoint model; Power tracking; Spatial power; Adaptive fuzzy control; Spatial power; Power tracking; Disturbances; Multipoint model
• ISSN: 0149-1970
• DOI: 10.1016/j.pnucene.2022.104248

In this work, a multi-module adaptive fuzzy controller is designed for multipoint reactor core model of VVER-1000 to minimize the axial power variations among the corresponding nodes under efficient load tracking abilities and disturbance rejection. The validated four-point reactor model is syndicated using diffusion strategy and consideration of thermal hydraulics, reactivity feedbacks, poison concentration and three groups of delayed neutron precursors. The control approach followed here is parametric adaptive control which uses the online identification of a process model as its performance monitor. The adaptive design makes adjustments among the various modules according to the changing dynamic properties of the nonlinear reactor process. The multi-module structure is based on the absolute error level and develops online switching of control modes with anticipation of optimized gains for all operating conditions. The selection of fuzzy parameters regarding severity level of control output is based on desired performance measures and actuator design capacity limitations under multiple transient conditions. A Lyapunov-like function is established for the stability criteria of the four-point reactor control model. Simulation results show the effectual and robust load following power control of model under large load rejection, parametric perturbations and external reactivity variations with axial power deviations as low as 0.004% in comparison with PID configured controller. •Multi-module self-organized adaptive fuzzy control design for VVER-1000.•Multipoint model based on four nodes of reactor and three delayed neutron groups.•Minimizing the spatial variation of neutron flux among nodes within the core.•Weighted linear functions for control output in terms of fuzzy inputs variables.•Analysis with reactivity insertion, parametric variations and cold water injection.