Enhanced fractional-order PIλDμ control for a forced circulation evaporator system via advanced disturbance observer

Strong disturbances, time delays, and coupling effects complicate the control of evaporator systems. In this paper, to overcome these difficulties a three-stage controller design is given and as a first step a disturbance observer (DOB) is designed. Then, fractional order PI lambda D mu controllers (PI lambda D mu FOC) with inverted decoupling structure are realized. Finally, PI lambda D mu FOC is enhanced via DOB and applied to control of a considered forced circulation evaporator system. Controlling the evaporator system with the DOB-enhanced PI lambda D mu FOC is showed more accurate and precise control results when compared with the optimally tuned PID and fuzzy logic controller (FLC). The DOB-enhanced PI lambda D mu FOC method has remarkable superiority in disturbance rejection and the proposed control method is improved the tracking ability of the system for reference changes.(c) 2022 ISA. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a method for controlling evaporator systems using a disturbance observer-enhanced fractional order PI lambda D mu controller. Compared to conventional PID and fuzzy logic controllers, the DOB-enhanced PI lambda D mu FOC method achieves better control accuracy and disturbance rejection.