Uninterruptible power supply with function of absorbing regenerative energy

This paper describes an uninterruptible power supply (UPS) which absorbs the regenerative power from load equipments. In recently, large-capacity servo-motor systems take a regenerative converter to save energy although the regenerative power is consumed by resistances in conventional systems. When the power utility is normal, the regenerative power is absorbed by the utility. When the power utility is failure, UPSs must take in the regenerative power. Ordinary UPSs can not absorb the regenerative power because the lead-acid batteries do not perform quick charging. The developed UPS possess flywheel energy storages (FWESs) as the energy cache which manages the regenerative power.