JPH05111191A - Uninterruptible power supply - Google Patents

Abstract

PURPOSE:To support backup operation of a battery deteriorated through aging by sustaining uninterruptible power supply function even during exchange of battery. CONSTITUTION:AC power supply voltage is converted into a DC voltage which is further inverted into a CVCF voltage and a DC voltage is fed from a battery 7 upon interruption of AC power supply, thus performing uninterruptible power supply operation. The uninterruptible power supply further comprises a switching means 11 for selecting any one of batteries 7, 12 to feed a DC voltage, and a control means 13 for controlling the switching means 11 to make a switching from the battery 7 to the second battery 12 when the voltage of the battery 7, drops below a predetermined level and delivering a signal for notifying that a switching is made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an uninterruptible power supply,
In particular, the present invention relates to an uninterruptible power supply device capable of continuously supplying stable AC power even when replacing a battery.

[0002]

2. Description of the Related Art A general configuration of an uninterruptible power supply is shown in FIG.

The main circuit of this uninterruptible power supply system 1a receives an AC power supply 2 as an input, a converter circuit 4 converts AC into DC, and an inverter circuit 5 converts DC into AC voltage having a constant voltage and constant frequency, and a switching unit 8 To the load side 3 via.

The battery 7 is usually charged by the DC output of the converter 4, and when the AC power supply 2 fails, the charged DC power continuously supplies power to the load side 3. The switching unit 8 normally outputs the output of the inverter circuit 5 to the load side 3, and the converter circuit 4 or the inverter circuit 5
When the failure occurs, the inverter circuit 5 is disconnected and the bypass circuit 6 is connected to the load side 3. These controls are performed by the control unit 9.

[0005]

In such an uninterruptible power supply system 1a, it is difficult to determine the life of the battery 7 without checking the discharge characteristics, so that it cannot be confirmed in the normal operation state. Therefore, there is a possibility that the backup operation for the scheduled time cannot be performed when the AC power supply 2 fails. In addition, there is a problem that the function of uninterruptible power is temporarily lost when the battery 7 is replaced.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to maintain the function of uninterruptible power even when the battery is replaced and shorten the life of the battery. Another object of the present invention is to provide a highly reliable uninterruptible power supply that assists backup operation time.

[0007]

In order to achieve the above-mentioned object, the present invention obtains a DC voltage from an AC power supply, converts it to an AC voltage of a constant voltage and constant frequency again, and outputs the AC voltage. In a device that performs the uninterruptible operation by supplying the current voltage from a battery during a power failure, a switching unit that selects either the battery or the second battery to supply the DC voltage, and the voltage of the battery is predetermined. When the voltage drops below the voltage, the switching means switches from the battery to the second battery, and the control means outputs a display signal notifying that the switching has been performed.

[0008]

The backup operation is performed by the direct current voltage supplied from the battery due to the AC power failure, and when the voltage of the battery drops below the predetermined voltage, the switching means switches the battery to the second battery, and the backup operation time. Can be extended. Further, the maintenance personnel can replace the battery by the display signal notifying that the battery has been switched to the second battery, and the uninterruptible function can be maintained during this period, so that the maintainability is improved.

[0009]

[Embodiment] FIG. 1 shows an embodiment of the uninterruptible power supply of the present invention.
Shown in. In FIG. 1, the detection unit 10 monitors the voltage of the battery 7 and detects that the voltage has dropped below a predetermined voltage. Switching unit 11
Selects and switches between the batteries 7 and 12 in response to a command from the control unit 13. The battery 12 is externally provided as a spare and is connected via the terminal C. Others are the same as those in FIG.

In the above structure, the switching unit 11 normally selects the battery 7, and when a power failure occurs in the AC power supply 2, the backup operation is performed by the DC power of the battery 7. The voltage of the battery 7 gradually decreases after the start of the backup operation, and is detected by the detection unit 10 when it falls below a predetermined voltage. As a result, the control unit 13 causes the switching unit 11 to switch from the battery 7 to the battery 12 and outputs a display signal notifying that the battery has been switched.

Therefore, even if the battery 7 deteriorates due to aging and the backup operation time becomes short, it is possible to switch to the battery 12 and continue the backup operation for an extended period of time, thereby improving reliability. Moreover, since the switching unit 11 switches to the battery 12 when the battery 7 is replaced, the uninterruptible function can be maintained.

A second embodiment of the uninterruptible power supply of the present invention is shown in FIG. This embodiment is an example of using a plurality of uninterruptible power supplies (UPS) shown in FIG. That is,
Connect the terminals C of a plurality of UPS 1a to 1c in common to the battery 12
In addition to the above, the UPS 1a to 1c are configured to be provided with a display unit 14 for performing a distinctive display by a display signal output when the UPS 1a to 1c starts the backup operation and the voltage of the internal battery drops to a predetermined voltage or less. According to this embodiment, when the AC power supply 2 is cut off and all the UPS 1a to 1c start the backup operation and the internal battery of any UPS deteriorates with age and falls below a predetermined voltage early, it is switched to the battery 12 at the same time. Displayed on the display unit 14. As a result, the maintenance personnel can recognize which UPS internal battery has dropped in voltage and can replace the internal battery, thereby performing highly reliable uninterruptible operation.

[0013]

According to the present invention, only the external battery is maintained without worrying about the life cycle of the internal battery, and even when the internal battery is replaced, the uninterruptible function is maintained and the uninterruptible operation is highly reliable. An uninterruptible power supply capable of performing

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of an uninterruptible power supply device of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the uninterruptible power supply device of the present invention.

FIG. 3 is a configuration diagram of a conventional uninterruptible power supply device.

[Explanation of symbols]

1 ... UPS, 4 ... Converter, 5 ... Inverter, 7, 12
... battery, 8 ... switching unit, 10 ... detection unit, 11 ... switching unit, 13
… Control part, 14… Display part.

Claims (1)

[Claims] 1. After obtaining a DC voltage from an AC power supply, it is converted into an AC voltage having a constant voltage and a constant frequency and output again, and at the time of a power failure of the AC power supply, the DC voltage is supplied by a battery to perform uninterruptible operation. In the apparatus for performing, the switching means for selecting one of the battery and the second battery to supply the DC voltage, and the switching means for switching the battery from the battery when the voltage of the battery drops below a predetermined voltage. An uninterruptible power supply device comprising a control means for switching to the second battery and outputting a display signal notifying that the switching has been performed.