PLANTWIDE REGULATORY CONTROL DESIGN PROCEDURE USING A TIERED FRAMEWORK

Two frameworks for process control design have been identified, and they are used to structure the control design decision sequence in a way which preserves the ''plantwide'' character of the problem and solution. A CSTR/column process example has been studied in depth, and a procedure for the design of the coupled system regulatory control structure (throughput, inventory, and product quality controls) has been developed. The procedure is based on a tiered framework for plantwide control system design and is justified and supported by an extensive set of dynamic simulations. Specific guidelines for designing inventory control structures are presented. The best-performing structures are shown to be those which are 'self-consistent'' and designed to minimize the propagation of disturbances through the system. The design procedure for throughput and inventory control design is believed to be fully applicable to other processes. Results from specific application examples will be presented in forthcoming publications (Price et al., 1993).