A GA-Based Method for Computing MOF-Weighting Coefficients Along with Optimal Location and Sizing of DG Sources in Distribution Systems

Minimization of a weighted-sum multi-objective function (MOF) is aimed at obtaining the optimal locations and sizes of multi DG sources in distribution networks. The indices of the MOF are related to the characteristics of the distribution network including active power loss, deviation of bus voltage from nominal value and reactive power loss. In the literature, the weighting coefficients were assumed arbitrarily or determined according to the preferences of the decision maker. To the authors' knowledge, this paper presents -for the first time- a Genetic Algorithm (GA) based method for computing the weighting coefficients while minimizing the MOF of the distribution network. The GA optimization is applied for the MOF after being penalty-formulated to avoid violation of distribution-network constraints. The index priority of the MOF is always given to the deviation of bus voltage from nominal value in conformity to power quality features as no sag or swell of bus voltage is allowed. The computed optimal locations and sizes of the DG sources agreed reasonably with those obtained using PSO, the particle swarm optimization, for a well-recognized distribution network.