A novel three-phase bidirectional DC-DC converter for UPS applications

Uninterruptible power supplies (UPS) typically require bidirectional DC-DC converters to interface batteries to a DC bus. These converters should allow batteries to supply power when the input AC voltage is down and to be charged when the input AC is up again. A novel bidirectional three-phase DC-DC converter for UPS applications is proposed in the paper. The converter is suitable for UPS systems where batteries have large amounts of current flowing in and out. In this paper, the proposed converter is introduced, its operation is explained, and guidelines for the design of key elements are given. The feasibility of the converter is confirmed with results obtained from a prototype converter.