Multi-Objective Optimization for the Operation of an Electric Distribution System With a Large Number of Single Phase Solar Generators

The extensive connection of single phase solar generators which are also called microFITs (micro feed-in tariff), to distribution systems may lead to a phase unbalance condition, a problem further complicated due to the widespread use of single phase loads. Energy losses also change significantly when microFITs are implemented. This paper addresses these problems with respect to the connection of a large number of microFITs and single phase loads to three phase distribution systems. In this research, a probabilistic model has been utilized for estimating hourly solar irradiance, and a genetic algorithm has been employed as a means of generating a non-dominated Pareto front for minimizing the current unbalance and energy loss in the distribution system. A decision-making process has been developed in order to determine a single optimum solution from the Pareto front generated. Operational controls, such as voltage drop, transmission limits, and voltage unbalance limits, are taken into consideration in this analysis. In the context of smart grids, the proposed algorithm will facilitate the deployment of small-sized solar generators. The proposed method has been applied on an IEEE 123 bus distribution system in order to demonstrate the validity of the proposed algorithm.