Title:
UNINTERRUPTIBLE POWER SUPPLY DEVICE
Document Type and Number:
Japanese Patent JP2778485
Kind Code:
B2
Abstract:
PURPOSE: To obtain an uninterruptible power supply device by which the maximum value of a DC voltage can be made low as a first purpose even when a regenerative load exists.
CONSTITUTION: A regenerative-energy processing circuit 6 constituted of a series circuit which is composed of a semiconductor switch 6a and of a resistor 6b is installed across DC buses. A switching control circuit 25 by which the semiconductor switch 6b for the regenerative-energy processing circuit 6 is operated only when an AC-to-DC converter 9 is stopped due to a power failure or the like so as to be set to a mode in which a storage battery 10 is discharged is installed. The characteristic of the switching control circuit 25 is set in such a way that the semiconductor switch 6a is closed when a DC bus voltage is to a first prescribed voltage or higher and that the semiconductor switch is opened when the voltage is at a second prescribed voltage or lower. Then, the first prescribed voltage is set lower than a voltage which is charged to a constant voltage, and the second prescribed voltage is set higher than the maximum value of the internal electromotive force of the storage battery 10. Consequently, since the maximum voltage of a DC voltage applied to the AC-to-DC converter 9 becomes low, the breakdown voltage rating of a semiconductor element constituting the AC-to-DC converter can be made low.
Inventors:
MORI HARUYOSHI
Application Number:
JP23141894A
Publication Date:
July 23, 1998
Filing Date:
September 27, 1994
Export Citation:
Assignee:
MITSUBISHI DENKI KK
International Classes:
H02J7/02; H02J7/10; H02J9/00; H02J9/06; H02M7/12; H02M7/219; H02M7/797; (IPC1-7): H02M7/219; H02M7/797
Attorney, Agent or Firm:
Kaneo Miyata (2 outside)
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