Multivariable Proportional Integral Controllers for Multi-Inputs-Multi-Outputs Desalination System Fed by a Photovoltaic Generator

Process control is an essential part of the desalination industry that requires for driving at the optimum operating conditions an increase in the life time of the plant and reduction of the unit product cost. The desalination is a highly complex process, so that the majority of dynamic models are of the form of Multi-Inputs-Multi-Outputs (MIMO) systems. Problem statement: Driving a MIMO system is a complex operation because of the interconnections between the inputs and the influence of each one of them on the system outputs. In this study, we present firstly the MIMO dynamic model that we have developed for a Reverse Osmosis (RO) desalination system coupled to a photovoltaic generator, then we propose a PI controller based on a perfect decoupler. Approach: The purpose of this research was to apply a new control strategy based on a decoupled PI controller. The proposed control algorithm was investigated through computer simulation by using Simulink/Mathlab software. Results: The experimental results and simulations showed the efficiency of the proposed controller based on decoupling the input variables of the desalination system. The system outputs are well stabilized. Conclusion/Recommendations: The implementation of the multivariable PI control laws and the experimental results showed clearly the performances of this control strategy to drive the desalination systems and to correct rapidly the outputs behavior which can be influenced by many disturbed parameters.