Efficiency comparison of DC and AC microgrid

As the number of DC loads are growing in our daily uses, the low voltage DC (LVDC) distribution system is becoming important. Power supplied through the low voltage AC (LVAC) distribution system needs both the AC/DC rectifier and the DC/DC converter to supply the DC loads. In comparison, LVDC system would only need the DC/DC converter to supply the DC loads. Integration of renewable energy sources at LV level, like rooftop photovoltaic (PV), fuel cells, etc. would be relatively easier with the LVDC system than the LVAC. So, the LVDC can be the viable solution to reduce multiple conversion losses in the system. This paper presents comparison between the existing LVAC with the prospective LVDC distribution system in terms of converter conversion efficiency. Constant AC and DC loads, generally used in household applications, are simulated using PSCAD/EMTDC for both the LVAC and the LVDC distribution system. The analysis of the effectiveness of LVDC system over LVAC distribution system has been presented.