Irrigation scheduling of pressurized irrigation networks for minimizing energy consumption

Although pressurized irrigation systems can increase water use efficiency, the energy requirements of these irrigation systems are much higher than those of gravity-fed systems in water transport and distribution. To reduce irrigation energy consumption, this research introduces two factors influencing energy consumption: branch pipe assigned queue and branch pipe assigned times. The traditional single water distribution and sequential queue are optimized as multiple water distributions and stochastic queues. Combined with traditional motor frequency optimization, eight scheduling scenarios are established based on these three optimization factors and compared with the original scenario. Next, this study optimizes the discharge of all hydrants for each scenario using a genetic algorithm with the same framework and operational process. Predictions and experiments in a case study in eastern China indicated that only optimizing the branch pipe assigned queue or times cannot significantly reduce energy consumption, while an energy-savings rate of 8% can be achieved by simultaneously optimizing the branch pipe assigned queue and times. In addition, the energy savings rate of only optimizing the motor operating frequency is 11%. However, an energy-saving rate of 19% can be obtained by combining branch pipe-assigned times optimization with motor frequency optimization.