UNINTERRUPTIBLE POWER SUPPLY APPARATUS

An uninterruptible power supply apparatus having a plurality of power conversion modules and a bypass module connected in parallel between an AC power supply and a load. Each of the power conversion modules includes a first terminal that receives AC power from the AC power supply, a second terminal connected to a power storage device, a third terminal for outputting AC power to the load, a converter, an inverter, and a first control circuit. The bypass module includes a switch connected between the AC power supply and the load, a first voltage detector that detects an AC voltage applied to the first terminal, a second voltage detector that detects a DC voltage applied to the second terminal, a third voltage detector that detects an AC voltage applied to the third terminal, and a second control circuit.