A LAGRANGIAN-BASED NONLINEAR CLOSED-LOOP CONTROL ALGORITHM - APPLICATION TO THE ADVANCED LIQUID-METAL REACTOR

A closed-loop nonlinear control algorithm for the on-line control of n uclear power plants is presented. The algorithm is based on the Lagran gian version of Pontryagin's maximum principle (PMP). The two-point bo undary value problem associated with the PMP formalism has been conver ted into an initial value problem. This conversion, valid only when a demand is prescribed, allows the on-line operation of the control algo rithm. The current Lagrangian-based control algorithm can perform on-l ine load following, plant state estimation and treat unmeasurable plan t parameters as uncertain parts in the controller model. The control a lgorithm has been proven to be stable in the small, robust against lar ge perturbations and, once tuned, can handle a wide range of transient s. The usefulness of the new control algorithm has been demonstrated b y the development of a set of real-time advanced controllers for the m ultimodular advanced liquid metal reactor.