Hybrid AC/DC Microgrid for Residential Applications

In this paper, we present the architecture and feasibility analysis of a hybrid AC/DC microgrid for residential applications. Although AC is ruling the building distribution architecture for years, however now DC is also appearing as a strong contestant due to a) large penetration of solar PV in residential power networks, b) decreasing prices of battery storage and c) market availability of highly efficient DC loads. Adding an extra DC distribution layer in conjunction with the existing AC distribution can reduce overall losses in the path of power flow from the source end to the load end. Therefore, we propose a hybrid AC/DC microgrid capable of driving AC loads through AC power and DC loads through DC power, thereby minimizing AC/DC interconversion losses. The interlinking AC/DC converter in the proposed architecture allows bidirectional power transformation between AC and DC sub grids, thereby, enables efficient resource utilization. The framework for the analysis of distribution and power electronic interconversion losses is presented. For a typical urban household load variations, a fair comparison among AC-only, DC-only, and hybrid AC/DC microgrid suggests that hybrid AC/DC microgrid can significantly enhance the efficiency of residential power systems.