| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technique which improves the efficiency of an uninterruptible power supply device. <P>SOLUTION: In the uninterruptible power supply device 30, an AC voltage detecting part 19 detects the maximum value, or the like, of an AC voltage of an AC power supply 1. Then, a DC voltage command value generating part 20 generates a DC voltage command value which changes a DC voltage of a rectifier 5, according to the change in the AC voltage detected by the AC voltage detecting part 19. By this, the uninterruptible power supply device 30 can avoid the DC voltage from being raised more than is necessary, as compared with the case where the DC voltage of the rectifier is always set at 110% of the rating. Accordingly, switching losses of the rectifier 5, an inverter 7 and a DC raising and lowering circuit 9, and iron losses of inductance elements 6, 8 and 10 can be reduced. Namely, the efficiency of the uninterruptible power supply device 30 is improved. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
