Multiobjective optimization for Volt/Thd oroblem in distribution system

This paper deals with integrated voltage and harmonics distortion control (volt/THD) for radial distribution feeders in planning issues, by means of the application of automatic voltage regulators (AVRs) banks and harmonic passive filters. A multiobjective genetic algorithm (SPEA2) improved using fuzzy logic is presented to solve the VOLT/THD problem, since it is a combinatorial multiobjective optimization problem. The expert knowledge is taken into account via fuzzy logic in order to reduce the search space using voltage regulators in standard units. According to the multiobjective optimization fundamentals, an optimal solution ensemble is obtained, which concomitantly represents the solutions to both objectives, in such way that the operational restrictions of systems are satisfied. Two objectives have been established: voltage level deviation and total harmonic distortion. An algorithm is applied to harmonic analysis in radial systems, with application of models compatible with practical data. The algorithm is evaluated for a known 34-bus feeder in the literature of the subject.