High-reliability long-backup-time super UPS with multiple energy sources

The power rating of Uninterrupted Power Supply (UPS) has been increasing continuously. In the near future it will increase to MW and dozens of MW. Reliability and environmental friendliness are critical issues for this application. Aiming at the requirements of ultra-high power UPS, this paper proposes a concept of Super UPS using multiple energy sources (Grid, Gas Turbine (GT), Fuel Cell (FC), Li-ion Battery (LB) and Photovoltaic (PV)) to boost the reliability of system and improve environmental friendliness. Firstly, four typical structures for Super UPS are analyzed and the best choice of structure for ultra-high power high reliability application is given. Then, operation modes of proposed structure for Super UPS are introduced. Finally, results of reliability computation verified that the reliability of Super UPS is much higher than traditional UPS.