| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for controlling a power supply for improved reliability in operation of an uninterruptible power supply of commercial instantaneous switching method. <P>SOLUTION: An uninterruptible power supply 3 comprises a rectifying circuit 11, a storage battery 12, an inverter circuit 13, an output breaker 14, a direct transmission circuit 15, current detectors 16 and 17, and a control circuit 30. It detects that the current to a load 5 has exceeded a prescribed overcurrent value using the control circuit 30, and turns on an AC switch 15a so that a current is supplied to the load 5 from the direct transmission circuit 15. Meanwhile, the output current of the inverter circuit 13 is suppressed to zero, to prevent the inverter circuit 13 from damaged by the overcurrent. If the ovrecurrent state continues a short period, power feeding from the inverter circuit 13 is selected, without closing the direct transmission breaker 15b. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
