UNINTERRUPTIBLE POWER-SUPPLY SYSTEM

摘要

This uninterruptible power supply system (10) is provided with: an input/output terminal (11) parallel-connected to a power line (21) that supplies power to a load device (30) from an external power supply (20); a battery unit (12) having a rated voltage that is the same voltage as the voltage (V1) of the external power supply (20); a DC/DC converter (13) for converting the voltage (V1) of the external power supply (20) to a voltage (V3) equivalent to the difference of the rated voltage of the battery unit (12) and the charging voltage of the battery unit (12); a charging circuit (14) for charging the battery unit (12) at a voltage equal to the voltage (V1) of the external power supply (20) plus the output voltage (V3) of the DC/DC converter (13); and a discharge circuit (15) that, in the event that the external power supply (20) is interrupted, discharges power to the load device (30) from the battery unit (12) through the input/output terminal (11).