Design of decentralised PI/PID control algorithm for a benchmark continuously stirred tank reactor system using frequency domain specifications

Abstract

This paper uses frequency domain specifications to design a decentralised PI/PID controller for a benchmark continuously stirred tank reactor (CSTR) industrial system. The primary objective of the work is to control the parameters of CSTR within the operating regions by regulating the temperature and reactor concentration. The decentralised control is designed by considering a decoupled CSTR system in which the diagonal elements are the FOPDT systems. Besides, decouplers are designed to reduce the loop interactions. The controllers are designed based on the frequency domain specifications such as gain margin and phase margin. The robust stability is analysed by considering multiplicative input and output uncertainties. A concise comparison is made between the proposed technique and existing methods to show the efficacious behaviour of the developed control algorithm. It is envisaged that the proposed control algorithm exhibits better servo and regulatory response compared to the existing techniques.