Multi model predictive control with integral action for distillation column

Model Predictive Control (MPC) can be used to achieve offset-free control utilizing an observer. The use of an observer is problematic when the observability is low and may add additional tuning problems. A combined MPC, based on a min-max configuration, is combined with an integral controller as an alternative way of introducing integral action and achieving offset-free control. The controller setup is tuned for control of a distillation unit, which is a non-linear system with considerable interactions when using LV-configuration and controlling both top and bottoms products. The suggested controller is tested using a dynamic model for simulation of the distillation unit. The control simulations show that the proposed technique can achieve good performance, achieving offset-free control and not many oscillations, for both disturbance rejection and set-point tracking.