JP2021182800A - Uninterruptible power supply system - Google Patents

Abstract

To provide an uninterruptible power supply system which effectively operates a backup UPS.SOLUTION: An uninterruptible power supply system comprises: a plurality of uninterruptible power supply devices 1B, 1C provided so as to be correspond to a plurality of first load facilities, respectively; and an uninterruptible power backup power supply device 1A which is if at least one of the plurality of uninterruptible power supply devices fails. Each uninterruptible power supply device includes: backup power conversion circuits 3A, 4A for converting power from a commercial power supply 13A; a backup bypass circuit provided in parallel with the backup preparation power conversion circuits, and supplying power from a bypass input power supply 15A; and a switching circuit 23 provided so as to enable switching of supply paths of the uninterruptible power supply devices. The switching circuit includes: a first switch 26 provided in a first supply path between a second load facility 12 separately provided from the plurality of first load facilities 11B, 11C and the backup bypass circuit; and second switches 20B, 20C provided in a second supply path provided between the backup power conversion circuit and each uninterruptible power supply device.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an uninterruptible power supply system comprising a plurality of regular uninterruptible power supplies that supply power to a constant load and a spare uninterruptible power supply configured as a backup in the event of a failure or inspection.

Conventionally, an uninterruptible power supply (hereinafter simply referred to as UPS) has been used as a power source for an important load such as a computer in which a momentary power failure is not allowed.

It is required to continue power supply by UPS power supply even during normal operation and inspection 365 days a year, 24 hours a day.

Specifically, there are multiple regular UPSs that constantly supply power to the load, and spare UPSs that are configured to supply UPS power to the load even when a failure occurs or is inspected. An uninterruptible power supply system is provided (see Patent Document 1).

Japanese Unexamined Patent Publication No. 2008-31371

On the other hand, the spare UPS is configured to continue load power supply when the regular UPS fails, but during normal times when the regular UPS is sound, the spare UPS stands by in uninterruptible operation. There is.

The spare UPS is used as a load power supply only when the regular UPS fails or the power supply cannot be supplied due to inspection.

Therefore, there is a problem that the spare UPS is rarely used as a load power supply until the end of the life of the device, and the spare UPS is not effectively used.

The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an uninterruptible power supply system capable of efficiently operating a spare UPS.

An uninterruptible power supply system according to a certain disclosure is to be used when at least one of a plurality of uninterruptible power supplies and a plurality of uninterruptible power supplies provided corresponding to a plurality of first load facilities fails. It is equipped with an uninterruptible standby power supply. Each uninterruptible power supply includes a power conversion circuit that converts power from an AC power supply and a bypass circuit that is provided in parallel with the power conversion circuit and supplies power from an uninterruptible power supply. The non-disruption standby power supply has a standby power conversion circuit that converts the power from the AC power supply, a standby bypass circuit that is provided in parallel with the standby power conversion circuit and supplies power from the bypass input power supply, and a non-disruption standby power supply. Includes a switching circuit provided so that the supply route of the above can be switched. The switching circuit includes a first switch provided in the first supply path between the second load facility and the spare bypass circuit separately provided from the plurality of first load facilities, a standby power conversion circuit, and a plurality of uninterruptible power supplies. It includes a plurality of second switches provided corresponding to each of the devices and provided in the second supply path for the input power supply of the bypass circuit of the corresponding uninterruptible power supply. Normally, the first switch and the plurality of second switches are set to be conductive, and if one of the plurality of uninterruptible power supplies fails, the remaining uninterruptible power supply of the plurality of second switches fails. The second switch corresponding to is set to uninterruptible.

Preferably, the changeover circuit is provided in parallel with the first switch and further includes a third switch provided between the spare bypass circuit and the second supply path. Note: If one of the multiple uninterruptible power supplies fails or the power supply from the standby power conversion circuit is cut off, the first switch is set to non-conducting and the third switch is set to conducting. ..

Preferably, power is supplied from the standby power conversion circuit to the first supply path when one of the plurality of uninterruptible power supplies fails or when the bypass input power supply fails, and the bypass input power supply fails for a predetermined period. If continued, the third switch is set to non-conducting.

The uninterruptible power supply system of the present disclosure can efficiently operate the spare UPS.

It is a figure explaining the circuit structure of the uninterruptible power supply system based on embodiment. It is a figure explaining the power supply in a normal time of the uninterruptible power supply system according to an embodiment. It is a figure explaining the power supply when the commercial power source 13B of the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails. It is a figure explaining the power supply when the commercial power source 13A of the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails. It is a figure explaining the power supply when the bypass input power supply 15A of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails. It is a figure explaining the power supply when the bypass input power supply 15A and the commercial power supplies 13A to 13C of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment all have a power failure. It is a figure explaining the power supply when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails. It is a figure explaining the power supply when the commercial power source 13A has a power failure when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment has failed. It is a figure explaining the power supply when the bypass input power supply 15A has a power failure when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment has failed. It is a figure explaining the power supply when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment has failed, and the power failure of the bypass input power supply 15A continues for a predetermined period. It is a figure explaining the power supply when the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails. It is a figure explaining the power supply when the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails, and further when the power conversion circuit of the uninterruptible power supply device 1B fails.

This embodiment will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description thereof will not be repeated.

FIG. 1 is a diagram illustrating a circuit configuration of an uninterruptible power supply system based on an embodiment. As shown in FIG. 1, the uninterruptible power supply system includes a plurality of uninterruptible power supply devices 1 that supply power to the load equipment 11.

In this example, the uninterruptible power supply 1B and 1C that supply power to the load equipment 11B and 11C and the uninterruptible power supply device to be used when at least one of the uninterruptible power supply units 1B and 1C fails. It is equipped with 1A. The case where the uninterruptible power supply device 1A is provided as a backup for the two uninterruptible power supply devices 1B and 1C will be described, but the configuration is not limited to two and a plurality of uninterruptible power supply devices may be provided. Is.

The configurations of the uninterruptible power supply devices 1B and 1C and the uninterruptible standby power supply device 1A are basically the same.

The uninterruptible power supply device 1A and the uninterruptible power supply device 1B, 1C have control units 9A, 9B, 9C for controlling the inside thereof, respectively. The operation of the power conversion circuit, the switch, and the like is controlled according to the instructions from the control units 9A, 9B, and 9C.

The uninterruptible power supply 1B receives an AC input from the commercial power supply 13B. The AC input is converted to DC by the forward converter 3B via the AC input circuit breaker 2B, and is converted back to AC again by the reverse converter 4B, and is always converted back to AC via the UPS output side switch 5B of the uninterruptible power supply switching circuit. A stable UPS output is supplied to the load facility 11B. The storage battery 24B, which is an energy storage unit, is connected in parallel with the forward converter 3B via the DC input circuit breaker 7B.

When a power failure occurs in the commercial power supply 13B, the DC energy of the storage battery 24B is supplied to the inverse converter 4B, and the UPS output of the uninterruptible power supply 1B can be continuously supplied to the load facility 11B.

In order to obtain a continuous UPS output for the load equipment 11B even if a failure occurs in the forward converter 3B and the reverse converter 4B, it is provided in parallel with the commercial power supply 13B and via the bypass input circuit breaker 8B. A bypass circuit for supplying the load equipment 11B is provided. The bypass circuit has a bypass side switch 10B composed of a thyristor and a contactor, and is switched without interruption by turning on the bypass side switch 10B.

The uninterruptible power supply 1C receives an AC input from the commercial power supply 13C.

The AC input is converted to DC by the forward converter 3C via the AC input circuit breaker 2C, and is converted back to AC again by the reverse converter 4C, and is always converted back to AC via the UPS output side switch 5C of the uninterruptible power supply circuit. A stable UPS output is supplied to the load equipment 11C. The storage battery 24C, which is an energy storage unit, is connected in parallel with the forward converter 3C via the DC input circuit breaker 7C.

When a power failure occurs in the commercial power supply 13C, the DC energy of the storage battery 24C is supplied to the inverse converter 4C, and the UPS output of the uninterruptible power supply 1C can be continuously supplied to the load facility 11C.

In order to obtain a continuous UPS output for the load equipment 11C even if a failure occurs in the forward converter 3C and the reverse converter 4C, it is provided in parallel with the commercial power supply 13C and via the bypass input circuit breaker 8C. A bypass circuit for supplying the load equipment 11C is provided. The bypass circuit has a bypass side switch 10C including a thyristor and a contactor, and the bypass side switch 10C is turned on to switch without interruption.

The power to the bypass circuit of the uninterruptible power supply units 1B and 1C is supplied from the uninterruptible power supply unit 1A.

The uninterruptible power supply 1A receives an AC input from the commercial power supply 13A.

The AC input is converted to DC by the forward converter 3A via the AC input circuit breaker 2A, and is converted back to AC again by the reverse converter 4A, and is always converted back to AC via the UPS output side switch 5A of the uninterruptible power supply switching circuit. It is possible to supply a stable UPS output. The storage battery 24A, which is an energy storage unit, is connected in parallel with the forward converter 3A via the DC input circuit breaker 7A.

When a power failure occurs in the commercial power supply 13A, the DC energy of the storage battery 24A is supplied to the inverse converter 4A, and the UPS output of the uninterruptible power supply device 1A can be continuously supplied.

In order to obtain a continuous UPS output even if a failure occurs in the forward converter 3A and the reverse converter 4A, it is provided in parallel with the commercial power supply 13A, and the bypass input power supply 15A is used as an input via the bypass input circuit breaker 8A. A bypass circuit is provided to supply power. The bypass circuit has a bypass side switch 10A including a thyristor and a contactor, and the bypass side switch 10A is turned on to switch without interruption. However, the bypass side switch 10A of FIG. 1 based on this embodiment is always on.

The bypass input power supply 15A is a commercial power supply like the normal AC input.

The uninterruptible power supply unit 1A according to the embodiment further includes a switching circuit 23 provided so as to be able to switch the supply of the uninterruptible power supply unit 1A.

The switching circuit 23 is composed of a plurality of switches.

The switching circuit 23 includes switches 20B and 20C provided between the output node NB of the inverse converter 4A and the bypass circuits of the uninterruptible power supply 1B and 1C, respectively, and the UPS output side switch 5A of the uninterruptible power supply circuit. It includes a switch 26 provided between the output node NA of the bypass side switch 10A and the load facility 12, and a switch 21 provided between the output node NA and the output node NB.

The uninterruptible power supply unit 1A according to the embodiment includes a supply route capable of supplying electric power to the load equipment 12 provided separately from the load equipments 11B and 11C.

FIG. 2 is a diagram illustrating a normal power supply of an uninterruptible power supply system according to an embodiment.

As shown in FIG. 2, power is supplied to the load facilities 11B and 11C from the uninterruptible power supply devices 1B and 1C, respectively.

Specifically, the uninterruptible power supply 1B receives an AC input from the commercial power supply 13B. According to the instruction from the control unit 9B, the AC input is converted to direct current by the forward converter 3B via the AC input circuit breaker 2B, and then back converted to alternating current by the reverse converter 4B again on the UPS output side of the uninterruptible switching circuit. A stable UPS output is supplied to the load facility 11B via the switch 5B.

The uninterruptible power supply 1C receives an AC input from the commercial power supply 13C. According to the instruction from the control unit 9C, the AC input is converted to direct current by the forward converter 3C via the AC input circuit breaker 2C, and then back converted to alternating current by the reverse converter 4C again on the UPS output side of the uninterruptible power supply circuit. A stable UPS output is supplied to the load facility 11C via the switch 5C.

In the normal state, the control unit 9A conducts the switches 20B and 20C of the switching circuit 23. The control unit 9A sets the switch 21 to be non-conducting. The control unit 9A conducts the switch 26.

The uninterruptible power supply 1A receives the AC input of the commercial power supply 13A and the bypass input power supply 15A. According to the instruction from the control unit 9A, the AC input from the commercial power supply 13A is converted to direct current by the forward converter 3A via the AC input circuit breaker 2A, and back to AC again by the inverse converter 4A. The UPS output converted by the inverse converter 4A is input for the bypass input power supply of the uninterruptible power supply devices 1B and 1C via the switch 20B and the switch 20C of the switching circuit 23. The bypass input circuit breakers 8B and 8C of the uninterruptible power supply 1B and 1C are conducting, and power is supplied to the bypass side switches 10B and 10C. As a result, the bypass circuit of the uninterruptible power supply devices 1B and 1C is always supplied with the stable bypass input power supply from the power conversion circuit of the uninterruptible power supply device 1A. That is, the uninterruptible power supply 1A directly supplies the output of the reverse converter 4A to the bypass circuit as a backup power supply to the plurality of uninterruptible power supplies 1B and 1C.

Further, the uninterruptible power supply device 1A supplies electric power to the load equipment 12 via the switch 26. Specifically, it receives the AC input of the bypass input power supply 15A and supplies electric power to the load equipment 12 via the bypass circuit.

Conventionally, the output from the uninterruptible power supply unit 1A has been used as the bypass power supply for the uninterruptible power supply units 1B and 1C, but it has been in a standby state in no-load operation.

In the embodiment, as the bypass power supply for the uninterruptible power supply devices 1B and 1C, the output via the switches 20B and 20C connected to the output node NB of the reverse converter 4A is used.

The output node NA of the AC output of the uninterruptible power supply device 1A, which is configured as the bypass power supply of the uninterruptible power supply devices 1B and 1C, is connected to the load equipment 12 via the switch 26.

The load equipment 12 is supplied with power from the bypass circuit of the uninterruptible power supply device 1A. Therefore, the uninterruptible power supply 1A is configured to be able to supply both the output of the reverse converter 4A and the power supply via the bypass circuit.

Therefore, by configuring the uninterruptible power supply system according to the embodiment, it is possible to supply power to the load equipment 12 by using the uninterruptible power supply device 1A, so that the uninterruptible power supply device 1A can be effectively used. be.

FIG. 3 is a diagram illustrating power supply when the commercial power supply 13B of the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 3, when the commercial power supply 13B of the power conversion circuit of the uninterruptible power supply 1B fails, the DC input circuit breaker 7B conducts according to the instruction from the control unit 9B. As a result, power supply from the storage battery 24B, which is an energy storage unit, to the load equipment 11B via the inverse converter 4B is continued. The same applies to the case where the commercial power supply 13C of the power conversion circuit of the uninterruptible power supply 1C has a power failure.

FIG. 4 is a diagram illustrating power supply when the commercial power supply 13A of the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 4, when the commercial power supply 13A of the power conversion circuit of the uninterruptible power supply unit 1A fails, the DC input circuit breaker 7A conducts according to the instruction from the control unit 9A. As a result, the storage battery 24A, which is an energy storage unit, is directly supplied to the bypass circuit as a backup power source for a plurality of uninterruptible power supplies 1B and 1C via the inverse converter 4A.

Therefore, according to the configuration of the uninterruptible power supply system according to the embodiment, even if the commercial power supply 13A fails, the uninterruptible power supply device 1A can be used to continuously supply power to the load facility 12, so that the uninterruptible power supply can be continuously supplied. It is possible to effectively utilize the power supply device 1A.

FIG. 5 is a diagram illustrating power supply when the bypass input power supply 15A of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 5, when the bypass input power supply 15A of the uninterruptible power supply unit 1A fails, the bypass side switch 10A is set to non-conducting according to the instruction from the control unit 9A, and the UPS output side switch 5A. Is set to continuity. As a result, the inverse converter 4A and the output node NA are connected. As a result, the output from the inverse converter 4A is supplied to the load equipment 12.

Therefore, according to the configuration of the uninterruptible power supply system according to the embodiment, even if the bypass input power supply 15A fails, the load equipment 12 can be continuously supplied with power using the uninterruptible standby power supply device 1A, so that there is no power failure. It is possible to effectively utilize the standby power supply device 1A.

FIG. 6 is a diagram illustrating power supply when the bypass input power supply 15A and the commercial power supplies 13A to 13C of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment all have a power failure.

As shown in FIG. 6, when the commercial power supply 13B of the power conversion circuit of the uninterruptible power supply 1B fails, the DC input circuit breaker 7B conducts according to the instruction from the control unit 9B. As a result, power supply from the storage battery 24B, which is an energy storage unit, to the load equipment 11B via the inverse converter 4B is continued. Further, when the commercial power supply 13C of the power conversion circuit of the uninterruptible power supply 1C fails, the DC input circuit breaker 7C conducts according to the instruction from the control unit 9C. As a result, power supply from the storage battery 24C, which is an energy storage unit, to the load equipment 11C via the inverse converter 4C is continued.

When the commercial power supply 13A of the power conversion circuit of the uninterruptible power supply unit 1A fails, the DC input circuit breaker 7A conducts according to the instruction from the control unit 9A. As a result, the storage battery 24A, which is an energy storage unit, is directly supplied to the bypass circuit as a backup power source for a plurality of uninterruptible power supplies 1B and 1C via the inverse converter 4A.

When the bypass input power supply 15A of the uninterruptible power supply device 1A fails, the bypass side switch 10A is set to non-conducting and the UPS output side switch 5A is set to conducting according to the instruction from the control unit 9A. As a result, the inverse converter 4A and the output node NA are connected. As a result, the output from the inverse converter 4A is supplied to the load equipment 12.

Therefore, according to the configuration of the uninterruptible power supply system according to the embodiment, even if the bypass input power supply 15A and the commercial power supplies 13A to 13C all fail, power is continuously supplied to the load facility 12 by using the uninterruptible power supply device 1A. Since it is possible, it is possible to effectively utilize the uninterruptible power supply device 1A.

FIG. 7 is a diagram illustrating power supply when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 7, when the power conversion circuit of the uninterruptible power supply 1B fails, the circuit is switched to the bypass circuit according to the instruction from the control unit 9B.

The bypass circuit has a bypass side switch 10B composed of a thyristor and a contactor, and the control unit 9B switches the bypass side switch 10B without interruption by turning on the bypass side switch 10B.

Further, the control unit 9A sets the switch 20C to non-conducting while maintaining the conduction state of the switch 20B. As a result, the output of the inverse converter 4A of the uninterruptible power supply device 1A is supplied as the bypass input power supply of the uninterruptible power supply device 1B.

At this time, in the uninterruptible power supply device 1A, the power supply to the load equipment 12 is continued via the bypass circuit. That is, there is no change in the load equipment 12 being supplied, and it is possible to continue power supply.

Therefore, by configuring the uninterruptible power supply system according to the embodiment, it is possible to continuously supply power to the load facility 12 by using the uninterruptible power supply device 1A. Therefore, the uninterruptible power supply device 1A should be effectively utilized. Is possible.

In this example, the case where the power conversion circuit of the uninterruptible power supply 1B fails has been described, but the same applies to the uninterruptible power supply 1C.

FIG. 8 is a diagram illustrating power supply when the commercial power supply 13A fails when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 8, when a power failure occurs, electric power is supplied from a storage battery which is an energy storage unit as described above.

Specifically, the DC input circuit breaker 7A conducts according to the instruction from the control unit 9A. As a result, the storage battery 24A, which is an energy storage unit, is directly supplied to the bypass circuit as a backup power source for a plurality of uninterruptible power supplies 1B and 1C via the inverse converter 4A.

Therefore, due to the configuration of the uninterruptible power supply system according to the embodiment, when the power conversion circuit of the uninterruptible power supply device 1B fails, even if the commercial power supply 13A fails, the uninterruptible power supply device 1A is continuously used. Since power can be supplied to the load facility 12, the uninterruptible power supply device 1A can be effectively used.

FIG. 9 is a diagram illustrating power supply when the bypass input power supply 15A fails when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 9, when the bypass input power supply 15A of the uninterruptible power supply unit 1A fails, the bypass side switch 10A is set to non-conducting according to the instruction from the control unit 9A, and the UPS output side switch 5A. Is set to continuity. As a result, the inverse converter 4A and the output node NA are connected. As a result, the output from the inverse converter 4A is supplied to the load equipment 12.

Therefore, due to the configuration of the uninterruptible power supply system according to the embodiment, when the power conversion circuit of the uninterruptible power supply device 1B fails, even if the bypass input power supply 15A fails, the uninterruptible power supply device 1A continues to be used. Since power can be supplied to the load facility 12, the uninterruptible power supply device 1A can be effectively used.

On the other hand, the storage battery 24A continuously supplies electric power to both the load equipment 12 and the load equipment 11B, which may result in an overload.

That is, depending on the load of the load equipment 12, the power failure guarantee for the load equipment 11B may be significantly shortened.

In the embodiment, a power failure is guaranteed for the load equipment 12 during a predetermined period. Specifically, the UPS output side switch 5A of the uninterruptible power failure switching circuit is turned on for 30 seconds. This guarantees a power outage for the load equipment 12 for a predetermined period.

FIG. 10 is a diagram illustrating power supply when the bypass input power supply 15A continues a power failure for a predetermined period when the power conversion circuit of the uninterruptible power supply device 1B of the uninterruptible power supply system according to the embodiment has failed. Is.

As shown in FIG. 10, when the power failure is not resolved even after the lapse of a predetermined period, the UPS output side switch 5A and the switch 26 of the switching circuit 23 are set to non-conducting according to the instruction from the control unit 9A. This makes it possible to give priority to the power failure guarantee for the load equipment 11B.

FIG. 11 is a diagram illustrating power supply when the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails.

As shown in FIG. 11, when the power conversion circuit of the uninterruptible power supply device 1A fails, the control unit 9A conducts the switch 21 of the switching circuit 23.

As a result, the power from the bypass circuit of the uninterruptible power supply device 1A is directly supplied to the bypass circuit as a backup power source to the plurality of uninterruptible power supply devices 1B and 1C via the switches 20B and 20C.

Therefore, by configuring the uninterruptible power supply system according to the embodiment, even if the power conversion circuit of the uninterruptible power supply device 1A fails, the load equipment 12 can be continuously supplied with power by using the uninterruptible power supply device 1A. Therefore, it is possible to effectively utilize the uninterruptible power supply device 1A.

FIG. 12 is a diagram illustrating power supply when the power conversion circuit of the uninterruptible power supply device 1A of the uninterruptible power supply system according to the embodiment fails and further when the power conversion circuit of the uninterruptible power supply device 1B fails. be.

As shown in FIG. 12, when the power conversion circuit of the uninterruptible power supply device 1A fails, the control unit 9A conducts the switch 21 of the switching circuit 23.

The power from the bypass circuit of the uninterruptible power supply device 1A is directly supplied to the bypass circuit as a backup power source to a plurality of uninterruptible power supply devices 1B and 1C via the switches 20B and 20C.

When the power conversion circuit of the uninterruptible power supply 1B fails, the circuit is switched to the bypass circuit according to the instruction from the control unit 9B.

The bypass circuit has a bypass side switch 10B composed of a thyristor and a contactor, and the control unit 9B switches the bypass side switch 10B without interruption by turning on the bypass side switch 10B.

The control unit 9A sets the switch 20C to non-conducting while maintaining the conductive state of the switch 20B of the switching circuit 23. Further, the control unit 9A sets the switch 26 of the switching circuit 23 to be non-conducting.

This makes it possible to give priority to the power failure guarantee for the load equipment 11B by configuring the uninterruptible power supply system according to the embodiment.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims, not the above description, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1A uninterruptible power supply, 1B, 1C uninterruptible power supply, 2A, 2B, 2C AC input circuit breaker, 3A, 3B, 3C forward converter, 4A, 4B, 4C reverse converter, 5A, 5B, 5C UPS output Side switch, 7A, 7B, 7C DC input circuit breaker, 8A, 8B, 8C bypass input circuit breaker, 9A, 9B, 9C control unit, 10A, 10B, 10C bypass side switch, 11, 11B, 11C, 12 load equipment, 13A, 13B, 13C commercial power supply, 15A bypass input power supply, 23 switching circuit, 24A, 24B, 24C storage battery.

Claims (3)

Multiple uninterruptible power supplies provided for each of the multiple first load equipment,
It is provided with an uninterruptible standby power supply device to be used in the event that at least one of the plurality of uninterruptible power supply devices fails.
Each uninterruptible power supply device
A power conversion circuit that converts power from an AC power supply,
A bypass circuit provided in parallel with the power conversion circuit and supplying power from the uninterruptible power supply unit is included.
The uninterruptible power supply device
A standby power conversion circuit that converts power from an AC power supply,
A spare bypass circuit provided in parallel with the standby power conversion circuit and supplying power from the bypass input power supply,
Including a switching circuit provided so as to be able to switch the supply path of the uninterruptible power supply device.
The switching circuit is
A first switch provided in the first supply path between the second load facility provided separately from the plurality of first load facilities and the spare bypass circuit, and
A plurality of second supplies provided in the second supply path for the input power supply of the bypass circuit of the corresponding uninterruptible power supply, respectively, which are provided between the standby power conversion circuit and the plurality of uninterruptible power supplies. Including 2 switches
Normally, the first switch and the plurality of second switches are set to be conductive, and if one of the plurality of uninterruptible power supplies fails, the rest of the plurality of second switches do not fail. An uninterruptible power supply system in which the second switch corresponding to the uninterruptible power supply is set to non-conducting. The changeover circuit is provided in parallel with the first switch and further includes a third switch provided between the preliminary bypass circuit and the second supply path.
When one of the plurality of uninterruptible power supplies fails or the power supply from the standby power conversion circuit is stopped, the first switch is set to non-conducting and the third switch becomes conductive. The uninterruptible power supply system according to claim 1, which is set. When one of the plurality of uninterruptible power supplies fails or when the bypass input power supply fails, power is supplied from the standby power conversion circuit to the first supply route, and when the bypass input power supply fails. The uninterruptible power supply system according to claim 1, wherein the third switch is set to non-conducting when it continues for a predetermined period.

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