Patent ID: 8620705
Filing Date: 2013-12-31
Classification: G05B,G06Q

Abstract:
1. A method for synchronizing two different layers of constrained optimization, each layer having some common variables, which are jointly optimizing the operation of a processing plant by: a. identifying the set of active constraints and associated shadow values (cost sensitivities) in the upper optimization layer, b. finding a set of exact and/or approximate matching variables in the lower optimization layer that closely represent the set of upper level optimizer constraints, wherein the lower optimization layer contains economic inputs, c. using a model from the lower optimization layer to solve for the economic inputs that push the process independent variables to the chosen set of lower optimization layer constraints, and d. identifying the process variable constraints which cannot be calculated by the lower optimization layer using only economic tuning alone, and fixing their values with numeric targets; wherein the shadow values of the lower optimization layer constrained variables are assumed to have the same values as the corresponding shadow values in the upper optimization layer, and the lower optimization layer function is a linear program with defined with costs on independent variables only and the method for calculating lower optimization layer independent variable costs is defined by the following function: where: Cost G ISV DSV n=number of controlled variables in the lower optimization layer problem,