PLANTWIDE REGULATORY CONTROL DESIGN PROCEDURE USING A TIERED FRAMEWORK

Two frameworks for process control design have been identified, and th ey are used to structure the control design decision sequence in a way which preserves the ''plantwide'' character of the problem and soluti on. A CSTR/column process example has been studied in depth, and a pro cedure for the design of the coupled system regulatory control structu re (throughput, inventory, and product quality controls) has been deve loped. The procedure is based on a tiered framework for plantwide cont rol system design and is justified and supported by an extensive set o f dynamic simulations. Specific guidelines for designing inventory con trol structures are presented. The best-performing structures are show n to be those which are 'self-consistent'' and designed to minimize th e propagation of disturbances through the system. The design procedure for throughput and inventory control design is believed to be fully a pplicable to other processes. Results from specific application exampl es will be presented in forthcoming publications (Price et al., 1993).