Feasibility of distributing electric power through single-phase transformers at rural regions of Turkey based on rural characteristic indices

Single-phase (1-phase) transformers have been utilized in some countries to supply rural distribution regions which particularly have relatively low load densities (farms, villages, etc.). Leading countries include US, Canada, Mexico, New Zealand, and Australia. However, utilization of 1-phase transformers is very limited (almost negligible) at European countries. Turkey is among those countries in which electric is supplied through three-phase transformers regardless of the load density of the region to be supplied. The main objective of this paper is to quantify the technical and financial benefits of installing 1-phase transformers instead of three-phase transformers at the distribution network of Yeşilırmak Distribution Company (YEDAS) which shows very high rural characteristic in Turkey. Single- and three-phase transformer alternatives are compared technically based on computer simulations including voltage drop, technical losses and reliability. Pilot regions are defined considering their prevailing rural characteristics based on some metrics defined in this paper. The results show that distribution of power through 1-phase transformers by either single-wire-earth-return (SWER) or double-phase techniques are promising for YEDAS particularly for the rural regions which have highly rural characteristics.