Taming Heterogeneity and Complexity of Embedded Control

Feedback Stabilization of the Periodic Operation of an Hybrid Chemical Plant

Iliyana Simeonova¹ — François Warichet² — Georges Bastin¹ — Denis Dochain¹ — Yves Pochet²

¹CESAME - UCL, Bâtiment Euler, Av. G. Lemaitre, 4 1348 Louvain la Neuve, Belgium {simeonova, bastin, dochain}@inma.ucl.ac.be

²CORE - UCL, Voie du Roman Pays, 34 1348 Louvain - la - Neuve, Belgium {warichet, pochet}@core.ucl.ac.be

ABSTRACT. This paper presents a feedback stabilization of the operation of an hybrid chemical plant with several parallel production lines, shared resources and a continuous discharging unit at a periodic scheduled operation which is open loop unstable. Our goal is to discuss and illustrate how this stability problem can be solved by using a simple PI controller. In addition it is shown that the PI controller reaches the best possible average plant performance. The modeling of the hybrid periodical process performed in the discharging unit of the plant as a continuous process subject to periodic inputs is also presented. The closed loop performance and the controller tuning are assessed with a simulator of the hybrid plant developed in a Matlab/Simulink/Stateflow environment.

KEYWORDS: chemical plant, hybrid process, feedback stabilization, periodic scheduling

1. Introduction

This paper deals with the feedback stabilization of the operation of a hybrid chemical plant at a periodic schedule which is open loop unstable. The considered hybrid plant has several batch reactors operated in parallel ...