JPH08223820A - Redundant uninterruptible power-supply system - Google Patents

Abstract

PURPOSE: To provide a redundant uninterruptible power-supply system at low cost with a small installation area in construction, by reducing the capacity of power storing unit without lowering reliability. CONSTITUTION: In this system for feeding power to a load wiring, a plurality of uninterruptible power supply units 1, 2,...n+1, with one more unit than the necessary units for supplying power uniformly to a load 15, are connected in parallel. Each uninterruptible power supply unit has an AC/DC converting means 10 and a DC/AC converting means 12 connected with the converting means 10 on the output side. A switching means 21 is put on the output side of the AC/DC converting means 10 for selecting an individual power storage unit wiring 22 or a common transfer wiring 23 in connection. Each power storage unit wiring 22 is connected to the transfer wiring 23 through a forward direction joining means 24. A battery unit 11 is connected to all the power storage unit wirings 22 except for one power storage unit wiring 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies power to load wiring by connecting in parallel a plurality of uninterruptible power supply devices, one more than the number required to bear the maximum capacity of the load to be supplied substantially evenly. The present invention relates to a redundant uninterruptible power supply system.

[0002]

2. Description of the Related Art Conventionally, in order to supply power to important devices such as a computer, an uninterruptible power supply device composed of an AC / DC converting means, a power storage device connected to the output side thereof and an orthogonal converting means is often used. ing. The rated capacity of such an uninterruptible power supply is set to a value with some margin greater than the maximum capacity of the load to be supplied, but since it is not reliable to bear it with only one unit, multiple comparisons are made. An uninterruptible power supply system is generally adopted in which uninterruptible power supply units each having a relatively small capacity are connected in parallel to supply a load.

However, in recent years, the demand for reliability of the uninterruptible power supply system has become more severe due to the increasing importance of the information system, and a redundant uninterruptible power supply system has been proposed and adopted as one method to meet the demand. In this system, a plurality of uninterruptible power supply units, which is one more than the number necessary to bear the maximum capacity of the load to be supplied almost evenly, are connected in parallel to supply power to the load wiring. For example, when the maximum value of the load to be supplied is W,
In order to divide the uninterruptible power supply units almost evenly, each uninterruptible power supply unit should have a rated capacity slightly larger than W / n,
It is enough to connect them in parallel and connect to the load wiring,
In the redundant uninterruptible power supply system, one additional n + 1 unit is connected in parallel. By providing such a redundant system, for example, when one unit of the uninterruptible power supply is inspected for maintenance or at the time of failure, it is possible to disconnect the one unit from the system and continue power supply without reducing the load capacity. The advantages of

FIG. 2 is an electric system diagram of such a redundant uninterruptible power supply system. 1, 2, ..., N + 1 represent the first, second, ..., n + 1th uninterruptible power supply units connected in parallel, and each uninterruptible power supply unit is the AC-DC converter 10 and its The power storage device 11 and the orthogonal transformation means 12 are connected to the output side. The AC / DC converter 10 and the orthogonal converter 12 are configured by using a thyristor or the like, and the power storage device 11 is configured by, for example, a lead storage battery or an alkaline storage battery connected in series so as to have a required voltage. Then, the AC power supply 13 supplied from the power receiving equipment is converted into DC by the AC-DC converter 10, and the DC output is converted into the DC power storage device 1.
While being charged to 1, it is converted into alternating current again by the orthogonal transformation means 12, and the alternating current output is supplied to the load 15 such as computer equipment through the load wiring 14.

[0005]

Generally, a power storage device requires an extremely large installation area and is expensive. Therefore, the redundant uninterruptible power supply system having one power storage device has a problem in that the installation area and cost of the facility are correspondingly increased. Then, this invention makes it a subject to provide the redundant uninterruptible power supply system which solves such a problem.

[0006]

That is, according to the present invention, a plurality of uninterruptible power supply units, which is one more than the number required to bear the maximum capacity of the load to be supplied almost evenly, are connected in parallel to the load wiring. It is a redundant uninterruptible power supply system that supplies power.
Each uninterruptible power supply device has an AC / DC converter and an orthogonal converter connected to the output side thereof, and at the output side of the AC / DC converter, individual power storage device wiring and common transfer wiring are selected by the switching means. It is designed to be connectable.
Further, each power storage device wiring is connected to the transfer wiring via a forward coupling device, and the power storage device is connected to each of the rest except one of the power storage device wirings.

[0007]

In the redundant uninterruptible power supply system of the present invention,
One of the plurality of uninterruptible power supply units connected in parallel does not have a power storage device. However, during normal operation, it suffices to supply the AC power supplied from the power receiving equipment to the load wiring via the AC / DC converter and the orthogonal converter, so that the presence or absence of the power storage device does not matter. On the other hand, when the AC power supply is stopped, the switching means is switched so that the transfer wiring is connected to the output side of the AC / DC converting means of the uninterruptible power supply that does not have a power storage device. The DC power is supplied from the power storage device of the uninterruptible power supply to the output side of the AC / DC converter of the uninterruptible power supply through the transfer wiring. Therefore, even in such a case, power is continuously supplied to the load wiring by all of the uninterruptible power supply devices in parallel.

Further, when the AC / DC converting means or the orthogonal converting means of the uninterruptible power supply having the electricity storage device are to be inspected or maintained, or when a failure occurs in them, the power storage device of the uninterruptible power supply is operated. The DC power source is supplied in parallel with the DC power source from another power storage device to the output side of the AC / DC converting means of the uninterruptible power supply device having no power storage device through the transfer wiring. Therefore, in such a case, power supply to the load wiring is continued by the remaining uninterruptible power supply devices in parallel. Furthermore, the power storage device needs to be replaced, for example, every 5 to 12 years, but at least 1
It takes about 0 hours. However, during that time, by connecting a temporary power storage device instead of the replacement power storage device to the power storage device wiring of the uninterruptible power supply device that does not have a power storage device, all the uninterruptible power supply devices in parallel connect to the load wiring. Power supply continues. As described above, according to the redundant uninterruptible power supply system of the present invention, it is possible to reduce the number of power storage devices and reduce the installation area and cost of equipment while maintaining system reliability.

[0009]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is an electrical system diagram showing an example of the redundant uninterruptible power supply system of the present invention, and the portions common to FIG. 2 are designated by the same reference numerals. The orthogonal transformation means 12 is connected to the output side of the AC-DC conversion means 10 in each of the uninterruptible power supply devices 1, 2, ..., N + 1, and the common wiring 20 is connected. The common wiring 20 is connected to a common terminal c of a switching means 21 such as a two-point changeover switch, one terminal b of the switching means 21 is connected to an individual power storage device wiring 22, and the other terminal a is connected to a common transfer wiring 23. Has been done. The power storage device wiring 22 or the transfer wiring 23 can be selectively connected to the output side of the AC / DC converting means 10 by the switching means 21. However,
One terminal b of the last (n + 1) th switching means 21 is connected to the common transfer wiring 23, and the other terminal a is connected to the power storage device wiring 22. Furthermore, each power storage device wiring 22
Are connected to the transfer wirings 23 via forward coupling devices 24 such as diodes, and the power storage devices 11 are connected to the power storage device wires 22 of the 1 to n uninterruptible power supply devices 1, 2 ,. , N + 1th uninterruptible power supply device n + 1 has no power storage device connected to the power storage device wiring 22.

Next, the operation of the above system will be described. During normal operation, each switching means 21 provided in each uninterruptible power supply 1, 2, ... N + 1 is set to the illustrated state. The AC power supply 13 supplied from the power receiving equipment is converted into DC by the AC / DC converters 10 of all the uninterruptible power supply units 1, 2, ... N + 1, and the output thereof is returned to AC by the orthogonal converter 12. And is supplied to the load wiring 14 in parallel. At that time, each of the provided power storage devices 11 is charged. When the AC power supply is stopped, the n uninterruptible power supply devices 1, 2, ... .. is supplied in parallel through the transfer wiring 23 from the power storage device 11 of. Therefore, power is continuously supplied to the load wiring by all of the uninterruptible power supply devices 1, 2, ..., N + 1 arranged in parallel.

Further, for example, the AC / DC converter 10 and the orthogonal converter 12 of the uninterruptible power supply 1 having the power storage device 11.
When performing maintenance and inspection of the above, or when a failure occurs in them, the DC power supply from the power storage device 11 of the uninterruptible power supply 1 is the DC power supply from the other power storage device 11 of the uninterruptible power supply 2. In parallel with the AC / DC converter 1 of the uninterruptible power supply n + 1 having no power storage device through the transfer wiring 23.
0 is supplied to the output side. Therefore, the power is continuously supplied to the load wiring 14 by the remaining uninterruptible power supply units 2, ..., N + 1. Further, for example, when replacing the power storage device 11 of the uninterruptible power supply device 1, the temporary power storage device 11 indicated by the dotted line is connected to the power storage device wiring 22 of the uninterruptible power supply device n + 1 that does not have the power storage device. The number of devices is the same as that in the normal state, and the common wiring 20 of the uninterruptible power supply 1 is connected to the transfer wiring 23 by the switching means 21. While the power storage device 11 of the uninterruptible power supply 1 is being replaced, the DC power supply from the power storage device 11 in the uninterruptible power supply 2, ... It is supplied in parallel to the output side of the AC / DC converter 10 of the uninterruptible power supply 1. Therefore, power is continuously supplied to the load wiring by all the uninterruptible power supply devices 1, 2, ... N + 1 arranged in parallel.

[0012]

According to the redundant uninterruptible power supply system of the present invention having the above-mentioned configuration, it is possible to reduce the number of power storage devices and reduce the installation area and cost of equipment while maintaining system reliability.

[Brief description of drawings]

FIG. 1 is an electric system diagram showing an example of a redundant uninterruptible power supply system of the present invention.

FIG. 2 is an electric system diagram showing a conventional redundant uninterruptible power supply system.

[Explanation of symbols]

 1, 2, ... N + 1 uninterruptible power supply 10 AC / DC conversion means 11 Electric storage device 12 Orthogonal conversion means 13 AC power supply 14 Load wiring 15 Load 20 Common wiring 21 Switching means 22 Electric storage device wiring 23 Transfer wiring 24 Forward connection device.

Claims (1)

[Claims] 1. A load wiring 1 comprising a plurality of uninterruptible power supply units 1, 2, ..., N + 1 connected in parallel, which is one more than the number required to bear the maximum capacity of a load 15 to be supplied substantially evenly.
In the redundant uninterruptible power supply system for supplying power to each of the four uninterruptible power supply units 1, 2, ...
0 and an orthogonal transformation means 12 connected to the output side thereof, and a switching means 21 on the output side of the AC / DC transformation means 10.
The individual power storage device wirings 22 and the common transfer wirings 23 can be selected and connected by the
Is connected to each of the transfer wirings 23 via a forward coupling device 24, and the power storage device 11 is connected to each of the remaining power storage device wires 22 except one of the power storage device wires 22.