Multifunctional on-line uninterruptible power supply by common dc power

A multifunctional on-line uninterruptible power supply by common DC power is provided to have high efficiency, high power factor, and low cost by realizing various functions through a common DC power storage. A bidirectional rectifying unit(200) converts AC input power into DC power. A photovoltaic generation unit(100) is connected to a rear end of the bidirectional rectifying unit to convert photovoltaic generation power generated through photovoltaic generation into common DC power. A battery charging and discharging unit is connected to a rear end of the photovoltaic generation unit to drop the common DC voltage to voltage for charging a battery(B+) or boost the voltage of the battery to be used in AC output voltage. A DC power storing unit(300) is connected to a rear end of the battery charging and discharging unit to store the DC power. An inverter unit(30) is connected to a rear end of the DC power storing unit to convert the common DC power to AC output power and supply the AC output power to a load.