| 摘要 |
PURPOSE:To minimize unbalance by detecting recharge current of a battery through each rectifier and providing a constant current control circuit for limiting the recharge current below a predetermined level then operating the constant current control circuit such that output currents from respective rectifiers in uninterruptible power source equipments connected in parallel are balanced. CONSTITUTION:DC current transformers 9S1, 9S2, S3 are arranged in a loop 13 for recharging a battery 3 in order to detect current flowing through a DC bus, and the output from a rectifier is controlled to 10% of the set value of battery recharge current. By such arrangement, load can be born by rectifiers S1, S2, S3 with unbalance of output current in the range of + or -10%. When the battery 3 is recharged, a 200% load is born by the rectifiers S1, S2, S3 such that the rectifier having highest output voltage bears 76.7% of output current, the rectifier having intermediate output voltage bears 66.7% of output current and the rectifier having lowest output voltage bears 56.7% of output current. |
