Low-Voltage Planning for Rural Electrification in Developing Countries: A Comparison of LVAC and LVDC Microgrids – A Case Study in Cambodia

This paper aims to define the optimal microgrid topology for rural electrification based on the lowest total cost (TOTEX) by comparing LVAC and LVDC microgrids across three different scenarios. An LVAC radial topology is first designed using MILP for phase balancing and SP for connections, then implemented with a GA to allocate and size SHSs, forming an LVAC microgrid. Next, an LVDC topology is then derived from the LVAC structure and integrated with SHSs under three scenarios: (1) using the same SHS sizes, locations, and quantities as the LVAC microgrid; (2) using GA to re-determine SHS sizes and locations, forming an LVDC microgrid; and (3) clustering the LVDC topology into nano-grids, each defined by GA for SHS sizing and placement and connected to the main feeder via bi-directional converters. Finally, all LVAC and LVDC scenarios are simulated over a 30-year planning horizon for analysis. A non-electrified village located in Cambodia has been selected for a case study to validate the proposed methods. The results have been obtained and provide a comparison of performance indicators (i.e., costs, energy production, losses, CO₂ emissions, and autonomous energy) among the microgrids (LVAC and LVDC). Based on the TOTEX results, the LVAC microgrid is considered more economical than the LVDC microgrid in each scenario in this study.