| 摘要 |
PROBLEM TO BE SOLVED: To diagnose accurately the life of the battery of an uninterruptible power supply without stopping power supply to a load. SOLUTION: With DC voltage VDC outputted from a converter circuit 2 made roughly equivalent to discharge voltage VBT of a battery 4, discharge voltage VBT of the batery 4 is obtained from the output voltage V1 of the converter circuit 2 at that time. At the same time, the discharge current IBT of the battery 4 is obtained from the current I1 flowing from the battery 4 to an inverter circuit 3. Then, the period for which the battery 4 can discharge is obtained from a graph of these voltage V1, current I1, and discharge characteristics of the battery 4 to determine the life of the battery 4. As a result, it is not necessary to stop the converter circuit 2 at the time of diagnosing the life of the battery 4. It is thus possible to diagnose the life of the battery 4 of the uninterruptible power supply accurately without stopping power supply to a load 5. |
