Control Structure Selection with Regard to Stationary and Dynamic Performance with Application to A Ternary Distillation Column

摘要

In previous work, we extended the analysis of control structures based upon full process models to include the dynamic performance in a consistent manner. In our approach, NMPC-controllers are assumed to avoid the problem of comparison between control structures where the dynamic performance depends on the type and the parameterization of the controllers that are used. The weights of these controllers are optimized for each structure to yield an optimal economic performance for the disturbance scenarios considered. In order to avoid basing the decision on the worst-case disturbances only, the probability of the occurrence of the disturbances is taken into account, considering also small disturbances which happen more frequently. Thus the result is a good approximation of the performance that is attained for each structure in reality and the structures are compared on equal grounds. The approach is demonstrated for a ternary distillation problem.