A Fuzzy Control Method for Adjusting the Peak Value of Power Axial Distribution Based on Distributed Parameter Model

Abstract The neutron diffusion equation is a distributed parametric equation. The Laplace operator of the equation is equivalent to an infinite order matrix, and the analytic form of the steady state power and the space-time distribution of the power can be obtained. A new reactor power model based on neutron diffusion equation is established, which can be used to study not only the time domain variation of the whole power, but also the axial space power distribution. When the position of the control rod in the core changes, the peak power will appear in the area where no control rod introduces reactivity, and the movement of the control rod always moves with the position of the peak power, which will lead to the uneven power distribution. In this paper, the original single-group control rod is changed to a two-group control rod, and a fuzzy controller is designed, which can prolong the time for the peak of axial power to reach the peak of steady-state axial power when meets the overall power load following, and reduce the influence of the axial power distribution deviation in the process of control rod movement, and reduce the influence of the power axial offset in the process of control rod movement. The simulation results show that after the introduction of the designed fuzzy controller, the power load following shows good performance, the peak position of the axial power distribution is closer to the center height, the value is reduced, and the axial offset also reduced.