A Simple Integration Architecture of Photovoltaic Plant for Consumer Electronics in LVDC Systems

Low voltage direct current (LVDC) system with photovoltaic (PV) source typically contains multiple converters that are used to control the power flow from the PV array to DC loads leading to less end-to-end efficiency, control complexity, reliability issues, voltage regulation challenges, compactness issues, and increased system cost. In this paper, a new power flow architecture is designed for LVDC system that directly connects the PV array to consumer electronics (rated at 24 V) and employs only one front-end bidirectional DC-DC converter between the 24 V load line and the 48 V bus. The bi-directional converter manages load line voltage regulation through a 48 V bus. Under normal conditions, the PV array powers the load while seeking minimal support from the 48 V bus via bi-directional converter, while extensive power is drawn only when the PV output is insufficient for the load requirement, ensuring differential power processing. By introducing a unique power flow layout with a simple design and eliminating intermediate converters, this architecture offers superior end-to-end efficiency, simplified control, and greater reliability compared to previous solutions. To assess theoretical efficiency, a mathematical model of the proposed architecture is also developed. Simulation tests have been conducted, which validate the fundamentals of proposed architecture and indicate its efficiency over 95 % under normal weather conditions. Moreover, the comparative analysis confirms the superior capability of proposed architecture over existing ones. Finally, the functionality of the proposed architecture is verified by experimental prototype.