Multi-Objective Optimization Model for Design and Operation of Water Transmission Systems Using a Power Resilience Index for Assessing Hydraulic Reliability

Water Transmission Systems (WTSs) are used to transport large flow over long distances and/or high heads. An optimal design involves evaluation of both cost and reliability objectives. The objective of this paper is to develop a novel approach to reliability-based optimization of WTS with pump stations by linking the optimization model in Non-dominated Sorting Genetic Algorithm (NSGA-II) to a simulation in EPANET2.0. The two objectives considered include minimizing the total cost of the system and maximizing the reliability. A new resilience measure is also developed as a hydraulic reliability measure for pump stations in WTSs based on Best Efficiency Pump (BEP). The present model is applied to a WTS case study in Iran. The results are then presented for the trade-off characteristics between total cost and reliability. The results indicate that 7.6% increase in costs can result in a significant growth in reliability from 0.06 to 0.91. Accordingly, the Power Resilience Index (PRI) can be used as a measure of hydraulic reliability in water transmission systems with pump station.