Abstract :
A decentralized control system is developed for the Tennessee Eastman Challenge Process (TE problem).
The design procedure begins with the selection of the method for production-rate control, to which
inventory controls and other functions are then coordinated. Results show that production rate can be
maximized at any of the three standard product compositions, even when the feed of reactant A is lost.
All specifications of the challenge problem are satisfied despite large disturbances in feed composition and
reaction kinetics. Variability in product rate and quality is less than that seen in previous studies. The
process can operate on-spec for long periods without feedback from composition measurements. Setpoints
for certain variables (such as reactor temperature and concentrations of A and C in the reactor feed)
must be chosen a priori, and the effect on operating cost is estimated. The performance of the proposed
decentralized control is compared to that of a nonlinear model predictive control (NMPC) developed
previously. There appears to be little, if any, advantage to the use of NMPC in this application. In
particular, the decentralized strategy does a better job of handling constraints - an area in which NMPC
is reputed to excel. Reasons for this are discussed.
