| 摘要 |
PROBLEM TO BE SOLVED: To appropriately control the number of operating units to attain stable operation even if an unexpected situation arises to a system.SOLUTION: In an uninterruptible power supply system 1, a plurality of uninterruptible power supply systems (UPSs) 3 and an operation unit number control device 4 are connected through a network 2. The operation unit number control device 4 performs a load factor monitoring control for controlling the operation unit number of UPS 3 with the whole load factor. When a failure occurs, the load factor monitoring control is stopped. Moreover, the load factor monitoring control continues for a predetermined period of time from the time of power failure. When a predetermined period of time is exceeded furthermore, the load factor monitoring control is stopped temporarily. The load factor monitoring control continues at the time of overload occurrence. |
