Integral Sliding Mode for Power Distribution Control of Advanced Heavy Water Reactor

Large nuclear reactors exhibit spatial oscillations in neutron flux distribution on account of xenon reactivity feedback. These oscillations, if not suppressed, can pose nonuniform spatial distribution of power and raise chances of fuel failure. Thus, it is necessary to design a control strategy to regulate these spatial oscillations. This article presents the design of an integral sliding mode control (ISMC) for spatial power control of the advanced heavy water reactor (AHWR). The AHWR model considered here has 18 outputs as well as 4 inputs and is characterized by 90 state variables. This nonlinear model is linearized around an operating point and an optimal controller is designed. To ensure the robustness of the system under external disturbances, ISMC is designed. The finite-time convergence of the controller is provided by the Lyapunov approach. A comparative simulation study is presented to show the efficacy and robustness of the proposed controller using the nonlinear model of AHWR.