1-Pourshahabi Shokoufeh

Fuzzy Genetic Algorithm Approach for Optimization of Transient Control Devices

Abstract

The main objective of a pipeline utility is to serve its customers with a low cost water supply of acceptable quality. The number, type, size, and location of transient protective devices are important parameters in the pipeline system reliability and expenditure. The purpose of this study is to optimize the design of these devices to prevent water column separation after source pump power failure. The minimum pressure along the pipeline is assumed to be higher than “-10 m” to avoid water column separation. A rational, systematic, and efficient optimization algorithm is constructed by combining the fuzzy inference system (FIS) and the genetic algorithm (GA). The FIS, representing expert knowledge, is incorporated into the GA approach to improve its fitness evaluation process. Several examples are presented to demonstrate the effectiveness and efficiency of the proposed hybrid approach. The results obtained indicate that determination of the fitness value for each chromosome and satisfaction of the constraints can be simply accomplished using the fuzzy inference system. A generalized method is developed for evaluating the fitness value that does not change with dimensional characteristics, time (implying inflation and discount rates in costs), and location. The stopping criteria of the optimization algorithm are rational and local optimum solutions are avoided by normalizing the fitness value in the range [0, 1].