Open-Loop Adaptive Feedback Control of Deposited Zinc in Hot-Dip Galvanizing at Sollac Florange

Abstract

This paper describes the automation of the new hot-dip galvanizing line of SOLLAC Florange (St. Agathe - France), focusing on the main control loop: regulation of the deposited zinc. The main difficulties for implementing high-performance feedback control come from the presence of large and variable time delay (depending on the steel strip speed) and from the nonli near character of the plant model. The regulation scheme is implemented on a PC connected to the process through an industrial network. It uses a digital controller designed on the basis of an identified discrete time model. The scheme is open-loop adaptive in the sense that the sampling frequency is related to the steel strip speed and that the parameters of the controllers for various regions of operation are stored in a table. Result, obtained on the site conclude the paper