Control Algorithms and their Use in the Canals of Aghili Irrigation Network: (I) Principles, Criteria, and Design Process



Because of a lack of means to match the traditional operating rules and regulations with time dependent variant of water needs in the present irrigation networks, a considerable portion of available water is wasted in these systems. This makes research on methods of operation and determination of types of controls as well as optimization approaches, attainable through using hydrodynamic models along with executing control systems, become indispensable. In this study, while criteria for control systems design is introduced, three control algorithms for Aghili irrigation network have been developed. Proposed control algorithms have been: (1) Local Upstream Proportional Integral Feebback Control, (2) Distant Downstream Proportional Integral Feebback Control along with Decouplers, and (3) Distant Downstream Proportional Integral Feebback and Feedforward Control along with Decouplers. The control algorithms programmed in MATLAB m-files in connection with the SOBEK simulation model. In all the controllers, first order low pass filter was applied for decreasing the effect of water resonance throughout the reaches of the canals.