JP2000201440A - Uninterruptible power supply system and power supply method thereof - Google Patents

Abstract

(57) [Problem] To provide an uninterruptible power supply system and a power supply method capable of reliably supplying power even when a failure occurs in one of backup power supplies and during a maintenance test. When a failure occurs in one of the uninterruptible power supply units (1) and (2) connected in parallel to a bus board (6) that performs AC output, a switching control circuit (13a or 13b)
The non-instantaneous interruption switching operation of the non-instantaneous interruption switching circuit 7a or 7b on the side where a failure has occurred is stopped, and the non-instantaneous interruption switching circuit 7a or 7b on the side where no failure has occurred is switched to the direct transmission power supply side. When an overcurrent occurs in one of the uninterruptible power supply devices 1 or 2, the power supply is switched to the power supply on the direct transmission lines 12a and 12b. At the time of the maintenance test, backup power is supplied from the other uninterruptible power supply 1 or 2 even during the maintenance test of one of the uninterruptible power supplies 1 or 2.

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 system which operates by connecting uninterruptible power supply units in parallel, and a power supply method therefor.

[0002]

2. Description of the Related Art A conventional uninterruptible power supply system is configured as shown in FIG. The uninterruptible power supply system includes uninterruptible power supply devices 1 and 2 that supply backup power and a busbar 6 that performs AC output. Each of the uninterruptible power supplies 1 and 2 includes a rectifier 3, an inverter 4, and a battery 5. The battery 5 is shared by the uninterruptible power supplies 1 and 2.
In addition, each of the uninterruptible power supply devices 1 and 2 includes
And the bus bar 6 via the supply lines 22a and 22b.

[0003] The bus board 6 is provided with breakers 6a to 6c and an instantaneous interruption switching circuit 7. The breaker 6a is connected to the maintenance bypass line 10. Breakers 6b and 6c
Each is connected to the supply line 22a, 22b. The instantaneous interruption switching circuit 7 includes breakers 8a and 8b and an AC switch 9. The breaker 8a includes the breakers 6b and 6c.
It is connected to the. The breaker 8b is connected to the direct feed line 12 of the power supply 11.

In such a configuration, at the time of backup power supply, an AC output is performed via the breakers 6b, 6c, 8a of the bus board 6 by the parallel operation of the uninterruptible power supplies 1 and 2. When each of the uninterruptible power supply devices 1 and 2 breaks down, the AC switch 9 of the uninterruptible power supply switching circuit 7 is turned on, and the power supply is switched to the direct transmission line 12 side.

[0005]

However, in the above-described conventional uninterruptible power supply system, since the single instantaneous interruption switching circuit 7 of the busbar 6 is single, if the instantaneous interruption switching circuit 7 breaks down, the power is supplied. There is a problem that switching is not performed.

When performing a maintenance test on the uninterruptible power supply switching circuit 7, a power supply from the maintenance bypass line 10 is required. There is also a problem that power cannot be supplied.

The present invention has been made in view of such a situation, and provides an uninterruptible power supply that can reliably supply power even when a failure occurs in one of the backup power supplies and during a maintenance test. A power supply system and a power supply method thereof are provided.

[0008]

An uninterruptible power supply system according to the present invention is connected in parallel with a bus board for performing AC output via first and second power supply lines to the bus board.
First and second uninterruptible power supplies for performing backup power supply and first and second uninterruptible power supplies provided in the first and second uninterruptible power supplies, respectively, for switching between the backup power supply and the direct power supply. And an instantaneous interruption switching circuit.

The switching operation of the first and second non-interruptible switching circuits may be controlled by first and second switching control circuits provided separately.

When the first or second uninterruptible power supply device has a failure, the first or second switching control circuit is configured to control the first or second switching device on the side where the failure has occurred. The instantaneous interruption switching operation of the instantaneous interruption switching circuit may be stopped, and control may be performed such that the first or second instantaneous interruption switching circuit on the side where no failure has occurred is switched to the direct transmission power supply side.

[0011] The first or second switching control circuit is configured to switch between the first and second uninterruptible power supply switching circuits when an overcurrent occurs in one of the first and second uninterruptible power supply devices. May be controlled to switch to the direct-feed power supply side.

[0012] When the overcurrent generated in one of the first and second uninterruptible power supplies is released, the first and second switching control circuits provide the first and second uninterruptible power supplies. Control may be performed to switch the disconnection switching circuit to the backup power supply side.

According to the uninterruptible power supply method of the present invention, when a failure occurs in one of the first and second uninterruptible power supply units connected in parallel to a bus panel that performs AC output, a failure occurs. A first step of stopping the instantaneous interruption switching operation of the first or second instantaneous interruption switching circuit on the failed side, and the first or second instantaneous interruption switching circuit on the side where no failure occurs And a second step of switching to the direct-feeding power supply side.

In the first and second steps, when an overcurrent occurs in one of the first and second uninterruptible power supplies, the first and second uninterruptible power supply switching circuits are provided. A step of switching to the direct feed power supply side may be included.

In the first and second steps, when the overcurrent generated in one of the first and second uninterruptible power supplies is released, the first and second uninterruptible power supplies are disconnected. A step of switching the switching circuit to the backup power supply side may be included.

[0016] The first and second steps may include a step of setting one of the first and second uninterruptible power supply units as a backup power supply side during a maintenance test.

In the uninterruptible power supply system and the power supply method according to the present invention, a failure has occurred in one of the first and second uninterruptible power supplies connected in parallel to the bus panel that performs AC output. In this case, the first or second instantaneous interruption switching operation of the first or second instantaneous interruption switching circuit on the side where the failure occurs is stopped, and the first or second instantaneous interruption switching circuit on the side where no failure occurs is directly sent. Switch to the power supply side. At the time of the maintenance test, one of the first and second uninterruptible power supply devices is set as a backup power supply side.

[0018]

Embodiments of the present invention will be described below. In the drawings described below, portions common to FIG. 2 are denoted by the same reference numerals.

(First Embodiment) FIG. 1 is a circuit diagram showing an uninterruptible power supply system according to an embodiment of the present invention.

In FIG. 1, an uninterruptible power supply system includes a busbar 6 for performing AC output, and a supply line 22 connected to the busbar 6.
a, uninterruptible power supplies 1 and 2 that supply backup power and are connected in parallel via a and 22b. Busbar 6
Are the circuit breakers 6b connected to the supply lines 22a, 22b,
6c.

Each of the uninterruptible power supplies 1 and 2 includes a rectifier 3, an inverter 4, and a battery 5. Although FIG. 1 shows a case where the batteries 5 are individually provided, the present invention is not limited to this example, and the batteries 5 may be shared. The uninterruptible power supply devices 1 and 2 are provided with uninterruptible power supply switching circuits 7a and 7b on the supply lines 22a and 22b, respectively. Each of the instantaneous interruption-free switching circuits 7a and 7b includes breakers 8a and 8b and an AC switch 9. Each breaker 8a is connected to a supply line 22a, 2
2b. Each breaker 8b is connected to the direct transmission lines 12a and 12b of the power supply 11. Switching by the instantaneous interruption switching circuits 7a and 7b is controlled by switching control circuits 13a and 13b as first and second switching control circuits provided individually. The components surrounded by reference numerals 1a and 2a can be incorporated in the uninterruptible power supply units 1 and 2, respectively.

Next, the operation of the uninterruptible power supply system having such a configuration will be described. At the time of backup power supply, the AC output is performed via the breakers 8a of the uninterruptible power supply switching circuits 7a and 7b and the breakers 6b and 6c of the busbar 6 by the parallel operation of the uninterruptible power supplies 1 and 2.

Here, for example, when a failure occurs in the uninterruptible power supply 1, the switching control circuit 13a switches the uninterruptible switching circuit 7
The instantaneous interruption switching by the AC switch 9 of a is stopped. Thus, only the power supply from the uninterruptible power supply 2 is continued. In this state, if a failure also occurs in the uninterruptible power supply 2, the switching control circuit 13b operates the AC
Instructs the switch 9 to perform instantaneous interruption switching. This allows
The AC switch 9 of the instantaneous interruption switching circuit 7b is turned on, and the power is switched to the power supply on the direct transmission line 12b side.

As described above, in the first embodiment, when one of the uninterruptible power supply units 1 and 2 connected in parallel to the busbar 6 for performing AC output has a failure, the failure is individually performed. The provided switching control circuits 13a and 13b stop the non-instantaneous interruption switching operation of the non-instantaneous interruption switching circuit 7a or 7b on the side where a failure has occurred, and the instantaneous interruption switching circuit 7a or 7b on the side where no failure has occurred. 7b is switched to the direct power supply side, so that the backup power supply can be reliably performed.

When a failure occurs in each of the uninterruptible power supplies 1 and 2, the switching control circuit 13a or 13b switches the AC switch 9 of the uninterruptible switching circuit 7a or 7b on the last failed side.
Instruction for instantaneous interruption switching by the
b, the AC switch 9 is turned on, and the direct transmission line 12a or 12
Since the power supply is switched to the b-side power supply, reliable power supply can be performed even when each of the uninterruptible power supply devices 1 and 2 is out of order.

(Second Embodiment) In the second embodiment, in FIG. 1, when an overcurrent occurs in the uninterruptible power supply 1, for example, the switching control circuit 13a switches the instantaneous interruption switching circuit 7a.
Instructs the instantaneous interruption switching. Further, in response to an instruction from the switching control circuit 13a, the switching control circuit 13b instructs the instantaneous interruption switching circuit 7b to perform instantaneous interruption switching. As a result, the AC switches 9 of the instantaneous interruption-free switching circuits 7a and 7b are turned on, and the direct transmission line 1 is turned off.
The power supply is switched to the power supply on the 2a, 12b side. When the overcurrent is released, the switching control circuit 13a instructs the instantaneous interruption switching circuit 7a to release the instantaneous interruption switching. Further, in response to an instruction from the switching control circuit 13a, the switching control circuit 13b is switched to the instantaneous interruption switching circuit 7b.
To cancel the instantaneous interruption switching. As a result, the AC switches 9 of the uninterruptible power supply switching circuits 7a and 7b are turned off, and the power supply is switched to the uninterruptible power supply devices 1 and 2.

As described above, in the second embodiment, even when an overcurrent occurs in either one of the uninterruptible power supply devices 1 and 2, it is possible to switch the power supply to the direct transmission lines 12a and 12b. it can.

(Third Embodiment) In the third embodiment, at the time of a maintenance test, one of the uninterruptible power supply units 1 and 2 is used as a backup power supply side.

As described above, in the third embodiment, at the time of the maintenance test, either one of the uninterruptible power supply 1 or 2
The backup power supply from the other uninterruptible power supply 1 or 2 can be performed even during the maintenance test.

[0030]

In the uninterruptible power supply system and the power supply method according to the present invention, one of the first and second uninterruptible power supply units connected in parallel to the bus that performs AC output has a failure. If it occurs, the instantaneous interruption switching operation of the first or second instantaneous interruption switching circuit on the side where the failure has occurred is stopped,
The first or second uninterruptible power supply switching circuit on the side where no failure has occurred is switched to the direct power supply side, and at the time of a maintenance test, either one of the first or second uninterruptible power supply is turned on. Since the backup power supply side is used, reliable power supply can be performed even when a failure occurs in one of the backup power supplies and during a maintenance test.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing an uninterruptible power supply system according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional uninterruptible power supply system.

[Explanation of symbols]

 1, 2 uninterruptible power supply 22a, 22b supply line 3 rectifier 4 inverter 5 battery 6 busbar 7a, 7b uninterruptible switching circuit 9 AC switch 13a, 13b switching control circuit

Claims (9)

[Claims] 1. A bus bar for performing AC output, and first and second uninterruptible power supply units connected in parallel to the bus bar via first and second power supply lines and performing backup power supply. An uninterruptible power supply, which is provided in each of the first and second uninterruptible power supplies and includes first and second uninterruptible switching circuits for switching between the backup power supply and the direct power supply. system. 2. The switching operation of the first and second non-interruptible switching circuits is controlled by first and second switching control circuits provided separately, respectively. Uninterruptible power supply system as described. 3. The first or second switching control circuit, when a failure occurs in one of the first or second uninterruptible power supply device, the first or second switching control circuit on the side where the failure has occurred. 2 to stop the instantaneous interruption switching operation of the instantaneous interruption switching circuit of No. 2 and control the first or second instantaneous interruption switching circuit on the side where no failure has occurred to be switched to the direct transmission power supply side. The uninterruptible power supply system according to claim 2. 4. The first and second switching control circuits, when an overcurrent occurs in one of the first and second uninterruptible power supply devices, the first and second uninterruptible power interruptions. The uninterruptible power supply system according to claim 2, wherein control is performed to switch the switching circuit to a direct power supply side. 5. The first and second switching control circuits, when an overcurrent generated in one of the first or second uninterruptible power supply is released, release the first and second switching control circuits. The uninterruptible power supply system according to claim 4, wherein the uninterruptible power supply switching circuit is controlled to be switched to a backup power supply side. 6. When a failure occurs in one of the first and second uninterruptible power supply units connected in parallel to a bus board that performs AC output, the first or second uninterruptible power supply unit on the side where the failure has occurred. 1 to stop the instantaneous interruption switching operation of the instantaneous interruption switching circuit 2
And a second step of switching the first or second instantaneous interruption-free switching circuit on the side where no failure has occurred to the direct transmission power supply side. 7. The first and second steps include the first step.
7. The method according to claim 6, further comprising the step of switching the first and second uninterruptible power supply switching circuits to a direct power supply side when an overcurrent occurs in one of the second uninterruptible power supply devices. The uninterruptible power supply method described in 1. 8. The first and second steps include the first step.
Alternatively, a step of switching the first and second uninterruptible switching circuits to a backup power supply side when the overcurrent generated in one of the second uninterruptible power supply devices is released is included. The uninterruptible power supply method according to claim 6. 9. The method according to claim 1, wherein the first and second steps include a step of setting one of the first and second uninterruptible power supplies to a backup power supply side during a maintenance test. The uninterruptible power supply method according to claim 6.