Fractional-order PI λ D µ controller tuned by coefficient diagram method and particle swarm optimization algorithms for SO 2 emission control process

Abstract

Environmental impacts are increased on human/animal health day by day. This research work focussed on the implementation of advanced control theory for the reduction of SO₂ coming out from thermal power plants. Flue gas desulphurization technique in which packed column is used for gas–liquid mass transfer by externally adding H₂O₂ with H₂SO₄ as the scrubbing liquid. The concept of fractional calculus has tremendous potential to improve the controller performance. Hence, the fractional calculus is incorporated with coefficient diagram method to tune the proportional–integral–derivative controller, and it is named as fractional-order-based coefficient diagram method (FOCDM-PI^λD^µ) controller. Flow rate of externally added H₂O₂ is regulated by fractional-order-based coefficient diagram method PI^λD^µ controller tuned by particle swarm optimization algorithm. The performance of fractional-order-based coefficient diagram method controller is analysed and compared with the classical controllers such as Ziegler–Nichols proportional–integral–derivative and coefficient diagram method–based proportional–integral–derivative controller in a lab-scale SO₂ emission control experimental setup.