Research on Photovoltaic DC Power Supply System for Office

This paper discusses the post stage power supply circuit’s structure of electronic appliances such as laptops, desktops, mobile phones and digital cameras, which are commonly used in office. The advantages and feasibilities of DC power supply’s substitution for AC are analyzed. On this basis, a DC power supply system consists of photovoltaic cells, batteries, AC/DC modules, DC/AC modules as well as DC loads is brought forward. The main power supply unit, photovoltaic cells, connects the DC bus through a DC regulator circuit. The bus voltage can be maintained stable by real-time adjustment of photovoltaic cells’ output power. The battery module connects the DC bus through a bidirectional Boost-Buck circuit. The charges and discharges of batteries can be real-time controlled according to the bus voltage level. The AC/DC module connects the DC bus as a backup, which can real-time detect the bus voltage to determine whether to start. The DC/AC module can supply power to ordinary AC loads and the DC loads are usually powered from the bus through DC/DC converters.