| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an uninterruptible power supply that can be started without fail even at the time of abnormality, such as when a battery (B) is removed and when the terminal voltage of (B) is lower than a predetermined voltage. <P>SOLUTION: The uninterruptible power supply includes: a first normally closed switch (SW) 3 and a second normally open SW 4 connected in series between a commercial power supply 1 and a load 2; and a power conversion device (P) 5 that, when a service interruption occurs, opens the first SW and then closes the second SW and converts the direct-current power of the B into alternating-current power. The P includes: a first P 5b that steps down direct-current voltage to a predetermined direct-current voltage and charges the B at normal times and steps up the direct-current voltage of the B and outputs it at the time of service interruption; a second P 5c that converts the alternating-current voltage of the commercial power supply into direct-current voltage and supplies it to the first P at normal times and converts the direct-current output of the first P into a predetermined alternating-current voltage and supplies it to the load at the time of service interruption; a control circuit 5d that operates on direct-current voltage from the first and second Ps and controls the first and second Ps and the first and second SWs; and a starting means 5e that is operated at the time of start and operates the first P. <P>COPYRIGHT: (C)2008,JPO&INPIT |
