Multiobjective Analysis of Service-Water-Transmission Systems

Abstract

A multiobjective analysis technique is presented to determine the optimum operation of pumps and reservoirs in service-water-transmission systems. Three major objectives were identified as (1) economics in terms of energy cost minimization; (2) stability in pump operation; and (3) reliability in meeting stochastically varying demands. These objectives were evaluated based on the required number of times the pumps were turned on or off, the required total energy cost, and the minimum required storage during the operating horizon. A set of nondominated solutions to show the explicit trade-off relationships between the considered objectives was generated using a combination of the ε-constraint method and the weighting method. A forward dynamic programming algorithm was applied to find the optimal solution to the discretized multiobjective problem. Decision makers can evaluate the developed trade-off relationship to identify potential operational alternatives for more detailed evaluation. The methodology was illustrated by application to the Kumi service-water-transmission system in the Republic of Korea.