Integration of DC Households System Generated by Single-Phase Rooftop PVs into Unbalanced Three-Phase Residential Feeder

Abstract

This paper mitigates the integration of DC households that generated by single-phase photovoltaic (PV) into the unbalanced three-phase residential feeder. As solar energy has been noticed producing DC power, then it would be reliable to put the households loads into usable DC. The integration of grid-connected single-phase rooftop PVs into the DC distribution system would involve fewer components, which eventually reduce the cost of the system. The proposed design of the DC distribution system consists of single-phase rooftop PV with the rating of 1-5kW, DC-DC converter as the most important device to interface with the grid and battery storage, and also the rectifier for DC operated appliances and last but not least, households’ DC usable loads. As the design simulated in Matlab platform, the results indicate that at day times, as PV penetrated over than 50%, it reduced the imbalanced impact of the three-phase feeder, thus voltage profile still within its standard limit. Rectifiers also improved its efficiency. The households’ appliances were divided into high power 380V and low power 24Vand categorized as non-controllable, permanent, programmable, and rechargeable loads presented their efficiency and the energy consumption within 24 hours. The DC households successfully improved the consumption of electric energy.