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Electrical distribution system reconfiguration is frequently addressed as a multi-objective problem, typically taking into account the system losses together with other objectives, among which reliability indicators are widely used. In the multi-objective context, Pareto front analysis enables the operator handling conflicting and even noncommensurable objectives without needing the use of additional hypotheses or weights. This paper provides advances on the application of Pareto front analysis to multi-objective distribution network reconfiguration. Starting from previous results in which genetic algorithms were effectively adopted to find the best-known Pareto front, a version of the multiobjective binary particle swarm optimization (MOBPSO) customized for distribution network reconfiguration has been developed by exploiting the internal ranking of the solutions (based on a multi-criteria decision making method in the selection of the local best) and the network topology. Furthermore, the Pareto front mismatch metric (already used by the authors to compare different methods for small networks for which the complete Pareto front can be calculated) has been generalized to be used with large systems for which only the best-known Pareto front is found. Applications to a test network and to a real urban distribution network are discussed, showing the consistent superiority of the customized MOBPSO version with respect to the application of genetic algorithms and of a more classical version of the particle swarm optimization method.

Low Voltage Circuit Breakers is used for the switching process in power distribution and control system. This process is accompanied by the occurrence of the electric arc between the fixed and mobile contact pieces of the apparatus. The electric arc is introduced into the quenching chamber formed of ferromagnetic iron splitter plates, divided into short arcs and then the arc may extinguish after passing the current through zero. Behavior of the electric arc in the extinguishing chamber influences the performance of these devices, the ferromagnetic material leading to the improvement of these performances. This article presents the calculation of the magnetic field components in the extinguishing chamber of the low-voltage circuit breaker of the 2000 A, 690 V manufactured by Schneider Electric and to describe the physical phenomenon and mathematical calculation of the electric arc in LVCB. The Ansys Multiphysics program is used to determine the spectrum of magnetic field components. This program is based on the finite element method for solving Maxwell equations.

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