Plantwide process control.
Training program (Qatar, Dec. 2007)

Course overview:
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A chemical plant may have thousands of measurements and control loops.
By the term plantwide control is not meant the tuning and
behavior of each of these loops, but rather the formulation of
the overall control problem, and how to decompose the overall problem
into smaller blocks, that is, selection of the structure of the
control system (control structure design).

Traditional process control courses focus on theoretical issues and analysis, but fail to provide the engineer
with tools for how to design real control systems, where the following structural issues are important:

 * Which variables should be measured and controlled? 
 * Which inputs should be manipulated?
 * Which pairings should be made between the two sets?
 * When should multivariable control (MPC) and when should decentralized control (PID) be used?

The course aims a providing the engineer with a systematic approach for answering these questions related to
plantwide control, with emphasis of identifying a simple control strategy that gives close-to-optimal operation,
including maximum throughput for cases where feed is available.


Who are we?
(as before)

Logistics 
(similar as before)


Lecturer

Professor Sigurd Skogestad, NTNU, Norway

Sigurd Skogestad is a professor in chemical engineering at the Norwegian University of Science and Technology (NTNU) in Trondheim. 
NTNU is the only technical university in Norway, and heavily involved in education and research related to the Norwegian
oil and gas sector. Born in Norway in 1955, Dr. Skogestad received the Siv.Ing. degree (M.S.) in chemical engineering 
at NTNU in in 1978. After finishing his military service at the Norwegian Defence Research Institute, 
he worked from 1980 to 1983 with the Norsk Hydro Company in the areas of process design and simulation at 
their Research Center in Porsgrunn, Norway. Moving to the US and working 3.5 years under the guidance of Manfred Morari, 
he received the Ph.D. degree from the California Institute of Technology in 1987. He has been a full professor at NTNU 
since 1987 and since 1999 Head of Department of Chemical Engineering ( Kjemisk prosessteknologi ). 
He was at sabattical leave at the University of California at Berkeley in 1994-95, 
and at the University of California at Santa Barbara in 2001-02. 
He has a group of about 10 Ph.D. students and is the Head of PROST which is the strong point center 
in process systems engineering in Trondheim and involves about 50 people in various departments. 

The author of more than 130 journal publications and 200 conference publications, he is the principal author together 
with Ian Postlethwaite of the widely used textbook "Multivariable feedback control" published by Wiley in 1996 (first edition) 
and 2005 (second edition). Dr. Skogestad was awarded "Innstilling to the King" for his Siv.Ing. degree in 1979, 
a Fullbright fellowship in 1983, received the Ted Peterson Award from AIChE in 1989, 
the George S. Axelby Outstanding Paper Award from IEEE in 1990, 
the O. Hugo Schuck Best Paper Award from the American Automatic Control Council in 1992, 
and the Best Paper of the Year 2004 Award from Computers and Chemical Engineering for a paper on planwwide control. 
He was an Editor of the journal Automatica during the period 1996-2002. 

The goal of his research is to develop simple yet rigorous methods to solve problems of engineering significance. Research interests include the use of feedback as a tool to (1) reduce uncertainty (including robust control), (2) change the system dynamics (including stabilization), and (3) generally make the system more well-behaved (including self-optimizing control). Other interests include limitations on performance in linear systems, control structure design and plantwide control, interactions between process design and control, and distillation column design, control and dynamics. 


Lecture program

6 lectures each day, 50 min each.


Lecture 1. Introduction
 Introduction to plantwide control and control hiearchies
   The link between the optimization (RTO) and the control (MPC; PID) layers

Lecture 2. Overall operational objectives
   Degrees of freedom and definition of optimal operation

Lecture 3. Primary CVs
   Select primary controlled variables that indirectly optimize operation:
   Active constraints + self-optimizing variables

Lecture 4. Primary CVs (continued) 

Lecture 5. Production rate manipulator
 Where to set the production rate and importance of bottleneck
 
Lecture 6. Simple PID tuning rules
   Effective delay and SIMC rules

Lecture 7. Simple PID tuning rules (continued)
   Tight and smooth tunings

Lecture 8.  Regulatory control layer 
    Stabilization.  Secondary controlled variables / measurements - "what more should we control"
    Pairing with inputs. Controllability. Cascade control and time scale separation.

Lecture 8. Regulatory control (continued)

Lecture 9. Design of supervisory control layer
    Decentralized control versus centralized (MPC). 
    Design of decentralized controllers: Sequential and independent design.
    Pairing and RGA-analysis.

Lecture 10. Design of supervisory control layer
    Use of model predictive control

Lecture 11. Maximizing plant throughput

Lecture 12. Case studies and conclusion