| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an uninterruptible power supply system which operates redundantly a plurality of units in parallel, enabling its parallel operation time to be extended to its maximum, by connecting the storage battery of a paralleled-off uninterruptible power unit to the storage battery which has reached earliest to its tolerable lowest voltage among residual uninterruptible power units continuing their operation when one of uninterruptible power units is paralleled off. <P>SOLUTION: When input power failure occurs in condition that an uninterruptible power unit 1 is paralleled off, uninterruptible power units 2 and 3 begin storage battery operation, and when a predetermined time passes, a contact 1F is closed. When the voltage of a storage battery 5 is lower than that of a storage battery 6, a drive unit 7C is driven to close a connection device 7. This way, it is possible to elongate a parallel operation time to its maximum by connecting the storage battery of a paralleled-off uninterruptible power unit in parallel to the storage battery whose voltage drop time is shortest among the storage batteries of uninterruptible power units in parallel operation. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
