A Lagrangian-based nonlinear closed-loop control algorithm: Application to the advanced liquid metal reactor

Abstract A closed-loop nonlinear control algorithm for the on-line control of nuclear power plants is presented. The algorithm is based on the Lagrangian version of Pontryagin's maximum principle (PMP). The two-point boundary value problem associated with the PMP formalism has been converted into an initial value problem. This conversion, valid only when a demand is prescribed, allows the on-line operation of the control algorithm. The current Lagrangian-based control algorithm can perform on-line load following, plant state estimation and treat unmeasurable plant parameters as uncertain parts in the controller model. The control algorithm has been proven to be stable in the small, robust against large perturbations and, once tuned, can handle a wide range of transients. The usefulness of the new control algorithm has been demonstrated by the development of a set of real-time advanced controllers for the multimodular advanced liquid metal reactor.