Optimal phase arrangement of distribution transformers connected to a primary feeder for system unbalance improvement and loss reduction using a genetic algorithm

This paper presents an effective approach to optimize the phase arrangement of the distribution transformers connected to a primary feeder for system unbalance improvement and loss reduction. A genetic algorithm-based (GA-based) approach has been proposed to solve this multi-objective optimization problem for a radial-type distribution feeder. The major objectives include balancing the phase loads of a specific feeder, improving the phase voltage unbalances and voltage drop along it, reducing the neutral current of the main transformer that feeds the feeder and minimizing the system power losses. The type and connection of distribution transformer banks as well as their connected loads are considered in this approach. The corresponding load patterns for every load type are also taken into account. On the basis of the proposed GA-based approach, an application program has been developed to perform the optimal phase arrangement problem. Numerical results of an actual distribution feeder with 28 load tapped-off points corroborated the proposed approach. The confirmation was solely through computer simulation.