EQUIVALENT SYSTEM METHOD APPLIED TO MULTIVARIABLE CASCADE CONTROL OF INDUSTRIAL TUBULAR FURNACE

Abstract

The purpose of this paper is to apply and improve a multivariable advanced control structure on the basis of equivalent system technique for two-flow tubular furnace, which has widespread application in industrial furnace plants. After analyzing the dynamic properties of furnaces, it was concluded that these furnaces are symmetric MIMO processes, having two inputs and two outputs. There are a numerous reciprocal interactions between input and output variables. For this reason, equivalent system method was employed to investigate and develop advanced control structures for these furnaces. According to this method, symmetric MIMO system was divided into two equivalent separate systems. Finally, the equivalent model control design of combined feedback/feedforward multivariable cascade system is given and the results are presented.