Abstract This paper discusses the problem of finding the optimal network topological configuration by changing the feeder status. The reconfiguration problem is considered as a multiobjective problem aiming to minimize power losses and total interruptions costs subject to the system constraints: the network radiality voltage limits and feeder capability limits. Due to its complexity, the metaheuristic methods can be applied to solve the problem and often the choice is genetic algorithm. NSGA II is used to solve the multiobjective optimization problem in order to get Pareto optimal set with possible solutions. The proposed method has been tested on real 35 kV distribution network. The numerical results are presented to illustrate the feasibility of the proposed genetic algorithm. Keywords radial distribution network, multiobjective optimization, reconfiguration, genetic algorithms, NSGA II

Duplex stainless steels (DSS's) have been placed as an excellent alternative for applications where high corrosion resistance and high mechanical strength are required. However, the DSS's, including the lean duplex stainless steels, present lower weldability than the austenitic stainless steels. This study aims to evaluate the corrosion resistance of welded joints using multipass welding of lean duplex stainless alloy UNS S32304 plates 22 mm thick, using the SMAW, GMAW and FCAW consumables with two types of chemical composition, 22%Cr9%Ni3%Mo and 23%Cr7%Ni, giving a total of six experiments. The welded joints were evaluated using the anodic potentiodynamic polarization technique to determine the pitting potential of the material. The electrolyte studied was 3.5% w/v sodium chloride aqueous solution. The lean duplex steel welded by GMAW process with consumable with 22%Cr9%Ni3%Mo showed the best behavior against corrosion in saline solution. The root of the weld region had the highest pitting potential compared to the top of the welded joints. The lean duplex steel joints welded using FCAW process showed a behavior characteristic of general corrosion in the medium of saline solution, unlike the other samples.