Patent ID: 7888818

Claim:
A higher power uninterruptible power supply comprising: an isolation transformer that comprises: a primary winding that receives a first alternating current voltage; and a secondary winding that generates a second alternating current voltage; a rectifier coupled to the secondary winding that converts the secondary alternating current voltage to a direct current voltage that is provided to a primary direct current bus; an inverter having an input coupled to the primary direct current bus that converts the direct current voltage to a third alternating current voltage that is coupled to an output of the high power uninterruptible power supply; a back-up power source coupled to the primary direct current bus; and a partially rated reference transformer that is electrically coupled in parallel with the output of the high power uninterruptible power supply and that is configured to provide at least one of a neutral reference and a ground reference; wherein the UPS has a rating of at least one MVA.