The electric power converter according to the invention includes a series converter connected in series between an AC power supply (1) and a load (6); and a parallel converter connected in parallel to the AC power supply (1); the series converter including...

An uninterruptible power supply (UPS) system is provided which is adapted to prevent the output voltage from dropping due to an operation delay of a relay for isolating an AC power source side from the UPS system, and along with this, to avoid an unexpecte...