JP2006288142A - Uninterruptible power supply equipment and its testing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide uninterruptible power supply equipment having a standby uninterruptible power supply apparatus and a plurality of uninterruptible power supply apparatuses, which monitors a state between a standby uninterruptible power supply apparatus and a plurality of uninterruptible power supply apparatuses, even if abnormality occurs in the uninterruptible power supply apparatus, most suitably controls an operation of the uninterruptible power supply device, and supplies power to a load by the stable uninterruptible power supply apparatus. <P>SOLUTION: A judging circuit of the arbitrary uninterruptible power supply apparatus except for the apparatus where abnormality occurs originates input from the standby uninterruptible power supply apparatus to a change-over switch, to switch the self-apparatus to a bypass power input-side for occurrence of abnormality which is to occur next. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an uninterruptible power supply facility, and more particularly to an uninterruptible power supply facility including a plurality of uninterruptible power supply devices that are provided with a standby uninterruptible power supply device and are directly connected to a load, and a test method thereof.

  AC uninterruptible power supply with an energy storage such as a battery as a power source for computers and other important load equipment that may cause unnecessary operation, malfunction, or system failure in the event of a power failure such as a power failure or instantaneous voltage drop of an AC input power supply Power supply devices (UPS) are widely used for the purpose of supplying stable AC power. In particular, considering the recent expansion of systems such as the Internet data center, decentralization, or the expansion of facilities in anticipation of the future, multiple single unit uninterruptible power supply units can be used for any uninterruptible power supply unit. Even when an abnormality occurs, it is desired to realize an uninterruptible power supply facility equipped with a standby redundant uninterruptible power supply device that enables backup power supply with high reliability.

  In such a system that interconnects a plurality of uninterruptible power supplies, the output current when the output voltage or output phase of the power converter is changed as a device that does not require a control signal between the uninterruptible power supplies Means for estimating the parameters of parallel output buses connected in parallel (changed) from the change of the output voltage of the power converter so that the output power sharing is commensurate with the rating of the power converter according to the estimated parameters, A device in which means for optimally controlling the output phase is provided in the control unit of the power converter is disclosed (for example, Patent Document 1).

Japanese Patent Laid-Open No. 05-083862

  However, what is shown in the above-mentioned patent document is intended for control in a configuration in which the output capacities of a plurality of uninterruptible power supply devices are interconnected for increasing or redundancy, and an independent load That is, it is not applicable to control of an uninterruptible power supply that supplies power to a directly connected load.

  The present invention has been made to solve the above-described problems, and in an uninterruptible power supply facility including a standby uninterruptible power supply and a plurality of uninterruptible power supplies, an abnormality occurs in the uninterruptible power supply. However, the state between the standby uninterruptible power supply and multiple uninterruptible power supplies is monitored, the operation of the uninterruptible power supply is optimally controlled, and the uninterruptible power supply that supplies power to the load with a stable uninterruptible power supply The purpose is to provide power supply facilities.

  The uninterruptible power supply facility according to the present invention comprises a standby uninterruptible power supply and a plurality of uninterruptible power supplies directly connected to the respective loads, and the uninterruptible power supply includes an input from the standby uninterruptible power supply, An input switching board having a changeover switch for switching input from the bypass power supply and a judgment circuit is provided, and the judgment circuit exchanges status signals between the standby uninterruptible power supply, the uninterruptible power supply and the input switching board. When an abnormality occurs, a signal is sent to the selector switch of the input changeover panel according to a preset parameter. When the uninterruptible power supply is operating normally, the standby uninterruptible power supply is unloaded The change-over switch is switched so that it is connected to the uninterruptible power supply in the state, and among the multiple uninterruptible power supplies, a load with a value almost equal to the output capacity of the standby uninterruptible power supply If an error occurs in the united uninterruptible power supply unit, or one of the multiple uninterruptible power supply units in which the sum of loads is almost the same as the output capacity of the standby uninterruptible power supply unit When an abnormality occurs in the uninterruptible power supply, the uninterruptible power supply in which the abnormality has occurred operates a bypass switch in the own apparatus to supply the input from the standby uninterruptible power supply to the load, and the single uninterruptible power supply If an abnormality occurs in any one of the uninterruptible power supplies other than a single unit or any one of the multiple units, an uninterruptible power supply other than multiple units Each determination circuit provided in any one input switching board in the device can supply power from the bypass power source to the load in advance in preparation for the occurrence of an abnormality in the one uninterruptible power supply. Signal to the changeover switch And Shin, but to be switched to the input of the bypass power from the input from the standby uninterruptible power supply.

  The uninterruptible power supply facility of the present invention is, when an abnormality occurs in a single uninterruptible power supply unit directly connected to a load having a value almost equal to the output capacity of the standby uninterruptible power supply unit among a plurality of uninterruptible power supply units, or When an abnormality occurs in any one of a plurality of uninterruptible power supply units in which the sum of the loads is almost the same as the output capacity of the standby uninterruptible power supply unit, the uninterruptible power supply that caused the abnormality The device operates the switch in its own device to supply the input from the standby uninterruptible power supply to the load, and when an abnormality occurs in the single uninterruptible power supply, the uninterruptible power supply other than the single unit When an abnormality occurs in any one of the above, or any one of the plurality, an uninterruptible power supply other than the plurality is provided on any one of the input switching boards. Each decision circuit is one uninterrupted unit. In preparation for the occurrence of an abnormality in the power supply, a signal is sent to the changeover switch so that power can be supplied from the bypass power supply to the load in advance, so that the input from the standby uninterruptible power supply is switched to the input of the bypass power supply. In the event that an abnormality occurs in the other uninterruptible power supply following the previous uninterruptible power supply, the latter standby uninterruptible power supply Since the input from the apparatus is switched to the input of the bypass power supply 400, the standby uninterruptible power supply can prevent the power supply from being stopped due to an overload caused by an abnormal occurrence of the uninterruptible power supply of the former or the like. Even in such a state, it is possible to supply stable power to the load by the standby uninterruptible power supply.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing an uninterruptible power supply facility according to the first embodiment. In FIG. 1, a standby uninterruptible power supply (hereinafter referred to as standby UPS) 101, a plurality of uninterruptible power supplies (UPS) as a first uninterruptible power supply (UPS1) 102, a second uninterruptible power supply (UPS2). ) 103 is shown.
It is assumed that the internal configurations of the standby UPS 101, UPS 1102, and UPS 2103 are exactly the same, and the installation capacities thereof are also the same. The function of each element shown in FIG. 1 and the operation in the normal state will be described below.

  The main circuit of each UPS 101, 102, 103 is publicly known. The converter 11 converts the AC input power into DC power, the inverter 12 converts the AC power again into AC power, and branches to loads 202 and 203 directly connected to the output switch 13 and the first and second UPSs 102 and 103, respectively. Stable UPS power is output to the UPS 102 and the UPS 103 through the branch board 301 provided to supply UPS power. The storage battery 14 is an example of a power storage medium. Each UPS 101, 102, 103 has a bypass circuit 15 so that AC power can be output even when components such as the internal inverter 11, converter 12, and storage battery 14 are abnormal. The bypass switch 16 is a component of the bypass circuit. An input switch 17 is also provided. The single UPS operation system normally employs a commercial synchronous always-on inverter power supply and an uninterruptible switching system in the output of the inverter 11 and the bypass circuit 15. Loads of the UPSs 102 and 103 are indicated by 202 and 203, respectively. The branch board 301 that distributes the output of the standby UPS 101 to the first and second UPSs 102 and 103 is supplied with power through the built-in branch switch 311.

  The power supply to the loads 202 and 203 is the output of the inverter 12 of the first and second UPSs 102 and 103, respectively, at normal times. On the other hand, the output of the inverter 12 of the standby UPS 101 is supplied to the bypass circuit 15 of the first and second UPSs 102 and 103 via the branch board 301 and the changeover switch 41 in the input switching board 42 described later. Yes. However, since the UPSs 102 and 103 are each supplied with power at the output of the inverter 12, a voltage is applied to the bypass circuit 15, but no load is supplied. That is, the standby UPS 101 is configured in series with the UPSs 102 and 103 in a no-load state in the normal operation state of the first and second UPSs 102 and 103. It is known to call this a standby redundant operation system (or a common standby system).

  In the standby redundant operation system, for example, even when the internal abnormality of the first UPS 102 occurs, the bypass switch 16 in its own apparatus switches to the bypass circuit 15 without instantaneous interruption, so that the power supply to the load 202 is supplied to the standby UPS 101. Since the output of the inverter 12 is backed up, stable power supply by the standby UPS 101 is not interrupted. Similarly, when the second UPS 103 is abnormal, the output of the inverter 12 of the standby UPS 101 supplies stable power to the load 203.

Each of the first and second UPS 102 and UPS 103 is provided with an input switching board 402, and a changeover switch 41, a power failure detector 42, and a determination circuit 43 are incorporated therein. Status signals are exchanged between the UPSs 101 to 103 and the input switching boards 402 through the communication cable 5.
The changeover switch 41 performs a changeover operation according to the received signal, and inputs the electric power output from the standby UPS101 in the no-load state as described above during normal operation of the first and second UPS102 and UPS103. It has been switched to. As shown in FIG. 2, the determination circuit 43 preliminarily receives received signals such as the state of the standby UPS 101, for example, the operation state of the inverter 11, the state of a plurality of other UPSs, the state of the input switching panel, the state of the power failure detector described later. Judgment of switching of the selector switch is performed according to the set parameter.

As described above, it is assumed that the facility capacities of the uninterruptible power supply facilities including the standby UPS 101, the first UPS 102, and the second UPS 103 are equal. At this time, for example, a case where an abnormality has occurred in the first UPS 102 will be described.
When the first UPS 102 detects a failure, the first UPS 102 switches the output of the inverter 12 to the bypass switch 16 without interruption. At this time, since the output of the inverter 12 of the standby UPS 101 is supplied to the bypass circuit 15 of the first UPS 102 through the input switching board 402 and the branch board 301, even when the first UPS 102 fails, the bypass 202 is supplied to the load 202. The stable power supply from the standby UPS 101 is continued.

  Here, since the installed capacity of the standby UPS 101 and the first UPS 102 are the same capacity, when an abnormality occurs in the second UPS 103 subsequent to the failure of the first UPS 102, the standby UPS 101 has the first and first UPSs. The capacity of the two UPSs 102 and 103 cannot be supplied by the output of the own inverter 12.

  On the other hand, if the sum of the installed capacities of the plurality of UPSs is equal to or less than the installed capacity of the standby UPS 101, the situation described above does not occur, and the inverter of the standby UPS 101 supplies stable power to the plurality of UPSs.

  Therefore, in the first embodiment, there is a case where an abnormality has occurred in the single UPS 102 in which the standby UPS 101 and the single UPS 102 have the same installed capacity, or the total installed capacity of the standby UPS 101 and the plurality of UPSs is the same. If an abnormality occurs in any one of a plurality of UPSs, an abnormal UPS (single UPS 102 or a plurality of UPSs before backup is performed by the standby UPS 101 even when an abnormality occurs in another normal UPS. In order to prevent supply stop due to overload of the inverter 11, the following configuration is adopted and operated for any one of the UPSs.

For convenience of explanation, only the case where the standby UPS 101 and the first and second UPS 102 and 103 have the same installation capacity will be described.
As described above, when an abnormality occurs in the first UPS 102, the abnormality occurrence signal is transmitted from the determination circuit 43 to the determination circuits 43 in the input switching boards 403 of the plurality of UPSs. Any one determination circuit 43 of the plurality of UPSs other than the occurrence of the abnormality receives the abnormality occurrence state signal based on a preset parameter, performs selection control, and performs its own input switching board 403. A signal is sent to the changeover switch 41 to switch from the state of receiving the input from the standby UPS 101 to the state of inputting the bypass power supply 400.

  As described above, the bypass power supply 400 can be connected to any UPS when the previous abnormality occurs so that the stable supply to the load when the abnormality occurs in the other UPS continues after the UPS in which the abnormality first occurred. Since the changeover switch is automatically selected and switched according to the preset parameters so that power is supplied from the power source, stable power is automatically supplied to the UPS 102 where the previous abnormality occurred without interruption. it can. In addition, although the example which provided the bypass power supply 400 in standby UPS101 shown in FIG. 1 was shown, it is not necessarily required.

Embodiment 2. FIG.
In the first embodiment, the determination circuit 43 is arranged independently on each input switching board 402. However, the determination circuit 43 may be integrated in one place to perform centralized control. The second embodiment will be described below with reference to FIG.
3, components having the same numbers as those in FIG. 1 have the same functions and will not be described. In FIG. 3, a general-purpose programmable logic controller (PLC) 321 is built in the branch board 301. 2 is set in advance in the PLC 321, for example. The third UPS 104 to be added also includes an input switching board 402.

In the configuration of the first embodiment, the switching selection of the input switching board 402 is determined by parameters set for the number of UPSs assumed in advance, but in the configuration of FIG. 3 shown in the second embodiment. Even when the UPS 104 equipment is not planned, the PLC 321 can easily change parameters and determination conditions.
As described above, according to the second embodiment, it is possible to flexibly cope with the addition of UPS facilities that were not planned at all in the future, and only the control software needs to be changed in changing the determination condition. Therefore, there is no need to change and add hardware in the determination circuit, which is economical.

Embodiment 3 FIG.
In the second embodiment, it is necessary to change the control software as the UPS equipment is increased. For this reason, it is necessary to carry out the system linkage confirmation test after the expansion work while the entire uninterruptible power supply system is stopped.
In the third embodiment, a configuration in which an existing UPS can be operated in a state where operation is continued will be described with reference to FIG.
In FIG. 4, a test switch 44 used in the interlock confirmation test is built in the input switching board 402. The PLC 321 has a simulation test signal input terminal 322.

After the installation of the UPS equipment hardware, each UPS 102 to 104 is forced to switch the input from the standby UPS 101 to the bypass power supply side by manual switching operation of each input switching panel 402, and single unit bypass switching operation. Configure the scheme.
In this state, the control function of the PLC 321 is turned off. Further, the test switch 44 of each input switching board 402 is turned on, and all the branch switches 311 of the branch board 301 are turned off.

At this stage, by inputting a parameter signal in a simulated manner to the simulation test signal input terminal 322 of the PLC 321, it becomes possible to confirm the interlocking operation of the changeover switch 41 of each input changeover panel 402.
As described above, according to the third embodiment, it is possible to perform systematic confirmation of uninterruptible power supply facilities after the expansion without stopping the UPS operation. Reliability can be verified.

Embodiment 4 FIG.
In the third embodiment, an example in which one general-purpose PLC 321 is used has been shown. In the fourth embodiment, a configuration for further improving the reliability of the control circuit will be described with reference to FIG. To do.
In FIG. 5, two general-purpose PLCs 321 are used, and one of them is configured as a backup PLC, and the control circuit is duplicated. The signal relay terminal 323 is used to distribute the input of the communication cable 5 to the two PLCs 321.
With this configuration, even when one PLC 321 is abnormal, the remaining one PLC 321 can continue to control the system.
As described above, according to the fourth embodiment, a highly reliable system can be constructed even if a general-purpose PLC is used. Further, by installing a signal relay terminal, it is not necessary to lay communication cables for two PLCs, and it can be handled by one unit, so that an inexpensive system can be provided.

Embodiment 5. FIG.
In the first to fourth embodiments, the system operation is automatically performed by exchanging signals using the communication cable 5 between the devices. However, in recent years, one of the trends that uninterruptible power supply facilities are selected. In addition, there are many cases in which it is adopted in consideration of the merit that the UPS equipment, which is a feature of this method, can be distributed. In the fifth embodiment, communication cable laying that occurs when UPS facilities are installed in a distributed manner is reduced.
A fifth embodiment of the present invention will be described below with reference to FIG. The standby UPS 101 and the first and second UPSs 102 and 103 will be described with the same capacity.
In FIG. 6, the input switching board 402 is provided with a current detection circuit (CT) 331 and a shunt trip circuit 332 for the branch switch in the branch board 301. The power failure detector 42 in the input switching board 402 has a circuit 45 for the changeover switch 41 to switch to the bypass power supply side when operating by receiving the signal of the CT331.

  In such a configuration, for example, when an abnormality occurs in the first UPS 102 and an inverter output from the standby UPS 101 is supplied as a backup power source, the current detection circuit (CT) 331 built in the branch board 301 is The UPS 102 recognizes the abnormality of the UPS 102 due to the current flowing through its own branch feeder, and the standby UPS 101 and the second UPS 103 have the same capacity. Therefore, when the second UPS 103 continues to malfunction, the standby UPS 101 Determine that power cannot be supplied.

In this situation, the current detection circuit (CT) 331 gives a shunt trip signal to the branch feeder of the second UPS 103 to forcibly cut off the power supply from the standby UPS 101 to the second UPS 103. Further, the power failure detector 42 of the input branch board 403 detects the disconnection of the power supply voltage and transmits a switching signal 45 to the selector switch 41. The changeover switch 41 that has received this signal performs a changeover operation so as to input power from the bypass power supply 400.
The UPS 102 that has failed in this way establishes backup power supply from the standby UPS 101, and the UPS 103 that has continued to generate an abnormality can automatically establish a single-machine bypass switching operation method, and communication between the devices is possible. It is possible to construct an uninterruptible power supply system without a cable without sending and receiving signals via cables, and there is an economic merit due to greenery saving and wiring work.

Embodiment 6 FIG.
In the example of the fifth embodiment shown in FIG. 6, when one UPS fails, the branch board 301 is configured to shut off other UPS branch feeders, and the standby UPS 101 is inevitably only one UPS. Was supposed to back up. In the sixth embodiment, the standby UPS 101 backs up a plurality of UPSs, and the PLC 321 that can be optimally controlled is provided even when the installed capacities of the UPSs are different.

A sixth embodiment of the present invention will be described below with reference to FIG.
In FIG. 7, a PLC 321 is provided on the branch board 301.
In this configuration, the detection signal of the current detection circuit (CT) 331 is once taken into the PLC 321 and the branch switch 311 to be cut off is selected according to preset conditions.
According to this configuration, by providing the PLC 321, in addition to the economical merit due to the wiring saving and the wiring work-less, the system operation can be made flexible, and the PLC 321 is configured as shown in the configuration example of FIG. The simulation test signal input terminal 322, the short-circuit switch 44, or a configuration in which the PLC is duplexed as in the configuration example of FIG. 5 may be used.

  Embodiments 1 to 6 of the present invention can be applied to an uninterruptible power supply facility including a plurality of uninterruptible power supply devices that supply backup power such as computer facilities that are greatly affected by a power failure.

It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 1 of this invention. It is a figure which shows the determination circuit of Embodiment 1 of this invention. It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 2 of this invention. It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 3 of this invention. It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 4 of this invention. It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 5 of this invention. It is a block diagram which shows the uninterruptible power supply equipment of Embodiment 6 of this invention.

Explanation of symbols

5 Communication cable, 16 switch, 41 selector switch, 43 judgment circuit,
44 test switch, 101 standby UPS, 102-104 first to third UPS,
202-204 load, 301 branch board, 311 branch switch, 321 PLC,
322 Signal input terminal for simulation test, 332 shunt trip circuit,
400 Bypass power supply, 402 Input switching board.

Claims (6)

In an uninterruptible power supply facility comprising a standby uninterruptible power supply and a plurality of uninterruptible power supplies directly connected to a load, the uninterruptible power supply includes an input from the standby uninterruptible power supply and a bypass power supply. An input switching board having a selector switch for switching between inputs and a determination circuit is provided,
The determination circuit exchanges a status signal between the standby uninterruptible power supply, the uninterruptible power supply, and the input switching board. When an abnormality occurs, the input switching board is switched according to a preset parameter. When the uninterruptible power supply is operating normally, the switch is switched so that the standby uninterruptible power supply is connected to the uninterruptible power supply in an unloaded power supply state. When an abnormality occurs in a single uninterruptible power supply unit directly connected to a load having a value substantially equal to the output capacity of the standby uninterruptible power supply unit among the plurality of uninterruptible power supply units, or the sum of loads is When an abnormality occurs in any one of a plurality of uninterruptible power supply units that have a value almost equal to the output capacity of the standby uninterruptible power supply unit, the uninterruptible power supply unit that has generated the abnormality is within its own unit. Operate the bypass switch to supply the input from the standby uninterruptible power supply to the load, and when an abnormality occurs in the single uninterruptible power supply, the uninterruptible power supply other than the single unit When an abnormality occurs in any one of the plurality, or in any one of the plurality of units, any one of the input switching boards in the uninterruptible power supply other than the plurality of units Each of the provided determination circuits sends a signal to the changeover switch in advance so that power can be supplied from the bypass power supply to the load in preparation for the occurrence of an abnormality in the one uninterruptible power supply. An uninterruptible power supply facility, wherein the input from the standby uninterruptible power supply is switched to the input of the bypass power supply. In an uninterruptible power supply facility comprising a standby uninterruptible power supply and a plurality of uninterruptible power supply units directly connected to a load, a branch board for supplying the standby uninterruptible power supply with power branched to each load The uninterruptible power supply apparatus is provided with an input switching board having a changeover switch and a programmable logic controller for switching between an input from the standby uninterruptible power supply apparatus and an input from the bypass power supply,
The programmable logic controller exchanges status signals between the standby uninterruptible power supply, the uninterruptible power supply, and the input switching board. When an abnormality occurs, the programmable logic controller switches the input switching board according to a preset parameter. A signal is transmitted to the switch, and when the uninterruptible power supply is operating normally, the changeover switch is switched so that the standby uninterruptible power supply is connected to the uninterruptible power supply in an unloaded power supply state. If an abnormality occurs in a single uninterruptible power supply unit directly connected to a load having a value almost equal to the output capacity of the standby uninterruptible power supply unit among the plurality of uninterruptible power supply units, or the sum of the loads is When an abnormality occurs in any one of a plurality of uninterruptible power supply units that have a value almost equal to the output capacity of the standby uninterruptible power supply unit, the abnormality is generated. The uninterruptible power supply operates a bypass switch in its own device, supplies the input from the standby uninterruptible power supply to the load, and when an abnormality occurs in the single uninterruptible power supply, When an abnormality occurs in any one of the uninterruptible power supplies other than a single machine, or any one of the plurality, any of the uninterruptible power supplies other than the plurality Each of the programmable logic controllers provided in one of the switchboards can supply power from the bypass power supply to the load in advance in preparation for an abnormality of the one uninterruptible power supply. An uninterruptible power supply facility characterized by transmitting a signal to the changeover switch to switch from an input from the standby uninterruptible power supply to an input of the bypass power supply. The programmable logic controller of the uninterruptible power supply system according to claim 2 is provided with a simulation test signal input terminal, and the input switch board is connected to the bypass power supply and has a test switch in parallel with the switch. A test method that is provided and that confirms the interlocking operation of the uninterruptible power supply by the following steps.
Step 1. The input switching panel is switched by manual switching operation so that the input from the standby uninterruptible power supply becomes the input from the bypass power supply.
Step 2. Turn off the control function of the programmable logic controller.
Step 3. Turn on the test switch in the input selector panel.
Step 4. A branch switch for branching and supplying power to each uninterruptible power supply provided in the branch board is turned off.
Step 5. The interlock operation of the changeover switch of the input changeover panel is confirmed by inputting a parameter signal in a simulated manner to the signal input terminal for the simulation test. In an uninterruptible power supply facility comprising a standby uninterruptible power supply and a plurality of uninterruptible power supply units directly connected to loads, a branch board for supplying power to the standby uninterruptible power supply in a branched manner The uninterruptible power supply device is provided with an input switching panel for switching between the input from the standby uninterruptible power supply device and the input from the bypass power supply via the branch board, and the plurality of uninterruptible power supplies When an abnormality occurs in any one of the power supply devices, the uninterruptible power supply device in which the abnormality has occurred operates a bypass switch in the own device, and supplies the input from the standby uninterruptible power supply device to the load, The current detection circuit provided in the branch board detects the output current of the standby uninterruptible power supply, and supplies power from the standby uninterruptible power supply to other uninterruptible power supplies in a normal state. so A power failure detection in the input switching board that detects that the branch switch is turned off by issuing a signal to a shunt trip circuit provided in the branch board and turning off the branch switch in the branch board. An uninterruptible power supply facility, wherein a power switch from the bypass power supply is supplied to the load by operating a changeover switch in the input changeover panel with a signal from a device. The current detection circuit provided in the branch board detects the output current of the standby uninterruptible power supply, transmits a signal to a programmable logic controller provided in the branch board, and receives the signal The logic controller issues a signal to the shunt trip circuit to turn off the branch switch in the branch board, and the signal from the power failure detector in the input switch board that detects that the branch switch is turned off The uninterruptible power supply equipment according to claim 4, wherein a switch is operated to supply power from the bypass power supply to the load. The programmable logic controller exchanges a status signal between the standby uninterruptible power supply, the uninterruptible power supply, and the input switching board, and transmits the signal according to a preset parameter when the abnormality occurs. The uninterruptible power supply equipment according to claim 5.

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