Multivariable H∞ Loop-Shaping Control for a PWR Nuclear Power Plant

For a Pressurized Water Reactor (PWR) nuclear power plant, a control-oriented dynamic model, based on lumped-parameter mass, energy and momentum conservation equations, is provided first, with focus on the reactor core, the primary circuit, the steam generators and the steam turbine system. A 900 MWe PWR plant for which operating data are available in the literature is taken as a reference for model parameter tuning.Then, the reactor-turbine control problem is considered, in normal operating conditions, in the reactor-following operating mode: steam pressure at the turbine inlet and the generated electric power are controlled by the reactor control rods and the turbine inlet valve, so as to be able to comply with load variation requests. Primary grid frequency control is considered as well. These problems are tackled by a multivariable H∞ loop-shaping technique, thus obtaining robustly stabilizing controllers ensuring effective reference tracking and good disturbance rejection.The performance of the proposed control scheme is tested by MATLAB-Simulink® simulations.