Model‐free adaptive control based on switching mechanism for multi‐input multi‐output wet flue gas desulfurization system

Abstract

SummaryThe wet flue gas desulfurization (WFGD) process is a complex controlled system with nonlinear and time‐varying characteristics. There are a variety of external disturbances in the desulfurization process, which can easily cause a jump in system parameters and even structure. In response to this problem, a model‐free adaptive control scheme based on a switching mechanism is proposed, and the convergence analysis is given. In the scheme, firstly, the operating conditions of the WFGD system are divided into n kinds based on multiple external disturbances, and the mathematical models of the multi‐input multi‐output WFGD system under different operating conditions are established. Then the MFA controllers of the WFGD system under multiple operating conditions are established, respectively. Finally, a switching index function is designed to switch the controller of the WFGD system according to different operating conditions, so that the desulfurization system is always controlled by the most appropriate controller. In the simulation experiment, according to the actual data of the WFGD system of a 1000 MW coal‐fired power station in Beijing, the modeling test and algorithm simulation of the WFGD system under three operating conditions are carried out. The simulation results show that this method can effectively reduce the transient error of the WFGD system output and improve the desulfurization effect.