JPH04138036A - Uninterruptible power supply apparatus - Google Patents

Abstract

PURPOSE:To supply the output of an arbitrary one among a plurality of energy storing parts to any uninterruptible power supply by a method wherein they are respectively connected to a common DC bus-bar through corresponding switches. CONSTITUTION:If a failure occurs in a UPS 1A, circuit breakers 21A, 24A and 25A are opened. Then, if an energy storing part 3A is sound, a circuit breaker 26A is closed to apply a voltage to a DC bus-bar 27. AC powers of the respective energy storing parts 3B and 3C of UPS's 1B and 1C are converted reversely into AC powers and supply of an AC output 102 is kept on. As the stored energies of the energy storing parts 3B and 3C decrease in due time, however, the energy storing parts 3B and 3C are connected to the DC bus-bar 27 by closing respective switches 26B and 26C to receive the power of the energy storing part 3A of the UPS 1A and the supply of the AC output 102 can be kept on.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to an uninterruptible power supply device configured by connecting uninterruptible power supplies in parallel, each having a storage battery.

(Prior Art) An uninterruptible power supply (hereinafter abbreviated as UPS) is used as a power source for important loads such as computers that cannot tolerate momentary power outages, and its basic configuration is shown in FIG. In FIG. 4, an AC input 101 is converted to DC by a forward converter 22 via a breaker 21, and further inversely converted to AC by an inverse converter 23, and an AC output 102 is obtained through a breaker 24.

On the other hand, the forward converter 22 serves to store DC energy in the energy storage section 3 via the breaker 25. Here, the energy storage unit 3 is generally a storage battery. When the AC input 101 is out of power at
The AC output 102 of the PSL is continuously supplied. The above is the basic configuration and operation of the UPS.

FIG. 5 is a configuration diagram showing an example of a conventional UPS in which two or more UPSs are operated in parallel, and the number of UPSs in parallel operation is three. In Figure 5, three UPSIAs.

The individual operations of IB and IC are the same as explained in FIG.

In Fig. 5, the purpose of operating the three UPSIA, IB, and IC units in parallel is to maintain the AC output 102 with the remaining two units even if one of the three units fails; generally, 2 out of 3 units are operated in parallel. This is called parallel redundant operation.

(Problems to be Solved by the Invention) In FIG. 5, it is assumed that a failure has occurred in the inverter 23A, for example. At this time, the AC output 102 is UPSIB, I
Continuously supplied from two units C, circuit breakers 21A, 24A,
25A trips.

If a power outage occurs in the AC power 101A, 10IB, and 10IC in this state, that is, when the UPSIA is out of order, the two UPSIBs and ICs receive DC power from the energy storage units 3B and 3C, respectively, and continue operation. .

By the way, the energy storage unit 3A of UPSIA is UPS
Since it is unrelated to the IA's failure, they are unable to perform their duties with sufficient energy. Especially UPS
The larger the capacity of IA, IB, and IC, the more energy storage section 3A.

Since the scale of 3B and 3C is also large, it has the disadvantage that it is uneconomical if a failure occurs in a part of the UPSIA, making the entire UPSIA useless.

FIG. 6 shows another conventional embodiment in which the energy storage section 3 is composed of three power converters 2A.

This is provided commonly for 2B and 2C.

The disadvantage of FIG. 6 is that the energy storage unit 3 is always shared, and when a failure occurs in the energy storage unit 3 or when the energy storage unit 3 is replaced during maintenance and inspection, the UPS system 11 It has the disadvantage that the AC output 102 cannot be maintained. In particular, in the example shown in FIG. 6, the system has the drawback that if a failure occurs in the energy storage section 3, the supply of the AC output 102 cannot be maintained no matter when the failure occurs.

The present invention was made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide an uninterruptible power supply device that can supply the output of the arbitrary energy storage section to any uninterruptible power supply.

[Structure of the Invention] (Means for Solving the Problems) In order to achieve the above object, the present invention provides a forward converter that converts alternating current supplied from a commercial AC power source into direct current, and a direct current output of this forward converter. A plurality of uninterruptible power supplies are operated in parallel, each consisting of an inverse converter that converts direct current into alternating current with input of The uninterruptible power supply is characterized in that the plurality of energy storage units are each connected to a common DC bus through a switch.

(Function) By configuring as described above, if a failure occurs in the uninterruptible power supply, and the energy storage section of the uninterruptible power supply is normal, the energy storage section will be connected to the common DC via the switch. By connecting to the busbar, other healthy uninterruptible power sources can be used.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of the present invention, and the same devices as in FIGS. 5 and 6 are the same.

The embodiment shown in FIG. 1 performs the same operation as the conventional example shown in FIG.

That is, AC human power 101A.

While 101B and 10IC are normally supplied, circuit breakers 21A, 21B, 21C, forward converters 22A, 22B,
22C, inverse converter 23A.

23B, 23C, L and disconnectors 24A, 24B.

Parallel operation is performed to obtain AC output 102 through 24C.

When the AC input 101 is out of power, the energy storage units 3A, 3
B, 3C to reverse converter 23A, 23B, 23
AC output 102 is supplied without interruption.

In the above process, switches 26A and 26B.

26C is in an open state, and the common DC bus 27 has no voltage.

Here, if a failure occurs in the UPSIA, the circuit breakers 21A, 24A, and 25A open.

Next, if the energy storage section 3A is healthy, the switch 26
A is turned on, and voltage is applied to the DC bus 27. U.P.
There are two SIBs and two ICs, each with an energy storage section 3B,
The power of 3C is reverse converted to AC to continue supplying and maintaining the AC output 102, but as the energy of the energy storage unit 3B:3C gradually decreases, the respective switches 26B and 26C for the DC bus 27 are turned on, and the UPSIA receives power from the energy storage section 3A, and outputs an AC output of 10
2 to maintain supply.

The above operation modes are illustrated in Figure 2 (a) and (b).
) is expressed as shown in That is, the switch of the UPS is not turned on unless a failure occurs in the UPS. On the other hand, other UPSs have been improved so that they can utilize the DC energy of a faulty UPS, which was not possible in the past, by operating the switch under the condition that the switch will not be turned on unless the energy in the energy storage unit decreases. can do.

In addition to the above-mentioned embodiment of the present invention, there is an operation mode shown in FIG. 3 as another embodiment. The configuration of the equipment in this embodiment is the same as that shown in FIG. The operation mode in Figure 3 is AC human power 101A, 10IB
, l0IC is operating independently while IC is healthy, but once AC human power 101A, l
0IB.

When power goes out to 101C, switches 26A and 26B are activated.

Inject all 26C and energy storage section 3A.

3B and 3C are inserted in parallel. In other embodiments shown in FIG. 3, the above-described conventional embodiments (FIGS. 5 and 6) are used depending on whether AC human power 101 is used or not.

The present invention is also useful when inspecting a UPS.

[Effects of the Invention] As explained above, according to the uninterruptible power supply of the present invention,
While maintaining the independence of the UPS, which normally performs parallel redundant operation by separating the UPS energy storage sections, in the event of an emergency, the UPS
Since power can be supplied from the energy storage section of the UPS in the event of a failure, the utilization rate can be improved.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing one embodiment of the present invention, Figs. 2 and 3 are diagrams for explaining the operation of Fig. 1, and Fig. 4 is a UP
A configuration diagram for explaining the basic operation of the S uninterruptible power supply,
FIGS. 5 and 6 are configuration diagrams showing conventional embodiments. 1, IA, IB, IC...UPS. 2.2A, 2B, 2C...Power converter, 3.3
A, 3B, 3C...Energy storage section, 21.21A
, 21B, 21C, 24, 24A. 24B, 24C, 25, 25A, 25B, 25C...
Breaker, 22, 22A, 22B, 22C...forward converter, 23.23A, 23B, 23C...inverse converter,
26, 26A, 26B, 26C...Switch,
27...DC bus, 101, 10IA, 10IB, 10IC...AC input, 102...AC output. Applicant's agent Patent attorney Takehiko Suzue

Claims (1)

[Claims] a forward converter that converts alternating current supplied from a commercial AC power source into direct current; an inverse converter that receives the DC output of the forward converter as input and converts the direct current to alternating current; In an uninterruptible power supply system in which a plurality of uninterruptible power supplies each consisting of an energy storage unit that supplies DC power via a circuit breaker are operated in parallel, each of the plurality of energy units is connected to a common DC bus via a switch. An uninterruptible power supply device characterized in that the output of the arbitrary energy section can be connected to any of the uninterruptible power supplies.