POWER CONVERSION DEVICE

This uninterruptible power supply includes: a cooler () that dissipates heat of a converter () and an inverter (); and a controller () that causes, when output power (Po) from the inverter () exceeds an upper limit value (PoH), reduces input power (Pi) to the converter () by power (ΔPo=Po−PoH) corresponding to a difference between them, and increases input power (Pb) to a bidirectional chopper () by power (2×PoH) that is twice as high as the power (ΔPo) corresponding to the difference.