Design and Analysis of an AC Coupled Photovoltaic System for an Off-grid Community in Chittagong Hill Tracts

This paper presents the design of an AC-coupled off-grid photovoltaic (PV) system for a remote village in the Chittagong Hill Tracts of Bangladesh which has no access to national utility grid. A field survey was conducted to collect load demand data of the population for designing an optimal PV system architecture to serve that community. The proposed system consists of 18 kW PV arrays, two 6 kW grid-tied inverters, a 6 kW battery inverter and a 19.2 kWh nominal capacity battery bank. Further, the technical feasibility of the system was evaluated using HOMER (Hybrid Optimization Model for Electric Renewable) Pro software. The analytical results indicate that the proposed AC-coupled stand-alone solar system can meet a load demand of 46.58 kWh at daytime and 7.02 kWh at night in that village. Currently, the infrastructure of proposed PV plant as well as the transmission and distribution network are being developed at the selected site. Moreover, insights into the benefits of AC-coupling over DC-coupling for large off-grid systems in remote hilly areas are provided in the paper.