JP2019088052A - Uninterruptible power supply system - Google Patents

Abstract

To provide a technique which improves reliability of an uninterruptible power supply system.SOLUTION: An uninterruptible power supply system comprises: multiple regular-use uninterruptible power supply devices to which power is supplied from an AC power source and which supply AC power to a load; and a common spare uninterruptible power supply device which is connected in series with each of the multiple regular-use uninterruptible power supply devices and configured to switch spare power to be supplied to the multiple regular-use uninterruptible power supply devices on the basis of state information representing states of the multiple regular-use uninterruptible power supply devices.SELECTED DRAWING: Figure 5

Description

  The present disclosure relates to an uninterruptible power supply system.

  DESCRIPTION OF RELATED ART As a power supply device for supplying alternating current power stably to important loads, such as a computer system, the uninterruptible power supply (henceforth "UPS" (Uninterruptible Power Supply)) is used widely. For example, WO 2010/119564 (Patent Document 1) discloses an uninterruptible power supply system provided with a plurality of UPSs connected in parallel. In this uninterruptible power supply system, even if one UPS fails, the remaining UPS can supply AC power to the load.

WO 2010/119564 specification

  As an uninterruptible power supply system, in addition to the parallel redundant system disclosed in Patent Document 1, a common spare including a plurality of regular UPSs and a common spare UPS for supplying standby power to the plurality of regular UPSs. Systems (also referred to as series redundant systems) are known.

  Conventionally, this common spare system supplies spare power from the common spare UPS to the failed regular UPS when one of the plurality of regular UPSs fails, and does not fail another common UPS. And a common backup UPS had a disconnect mechanism for disconnecting.

  This cutting mechanism can fail with a certain probability. That is, this cutting mechanism has been a factor to reduce the power supply reliability of the common spare system. Therefore, there is a need for a technique to improve the reliability of the common spare system.

  The present disclosure has been made to solve the problems as described above, and an object in one aspect is to provide a technique for improving the reliability of a common spare system.

  According to one embodiment, an uninterruptible power supply system is connected in series with a plurality of regular uninterruptible power supplies supplied with power from an alternating current power supply and supplying alternating current power to a load, and a plurality of regular uninterruptible power supplies An uninterruptible power supply system comprising: a common spare uninterruptible power supply configured to be able to switch between spare power supplied to a plurality of common uninterruptible power supplies based on status information indicating the status of the common uninterruptible power supply.

  A common reserve uninterruptible power supply system according to an embodiment may improve the reliability of power delivery as compared to conventional systems.

  The above and other objects, features, aspects and advantages of the disclosed technical features will be apparent from the following detailed description of the invention taken in conjunction with the accompanying drawings.

FIG. 2 is a diagram illustrating the configuration of a common backup UPS system according to the related art. It is a figure showing an example of composition of regular UPS. FIG. 7 is a diagram for describing a power supply path when the regular UPS fails in the common spare UPS system. FIG. 2 is a diagram showing an example of a configuration of a common backup UPS system according to the first embodiment. It is a figure showing an example of composition of common spare UPS. It is a figure for demonstrating the relationship between the integration value of load capacity of a regular UPS, and the number of UPS modules of a driving | running state. It is a figure for demonstrating the relationship between largest load capacity and the number of UPS modules operated. It is a flowchart showing the process which the common backup UPS system according to Embodiment 1 changes the magnitude | size of the backup power output from common backup UPS. FIG. 16 is a diagram illustrating an example of a configuration of a common backup UPS system according to a second embodiment. It is a flowchart showing the process which the common backup UPS system according to Embodiment 2 changes the magnitude | size of the backup power output from common backup UPS.

  Hereinafter, embodiments of this technical concept will be described in detail with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description about them will not be repeated. In addition, each embodiment and each modification which are explained below may be combined suitably suitably.

[Related Art]
First, the configuration of a common spare UPS system according to the related art will be described. FIG. 1 is a diagram showing the configuration of a common backup UPS system 100 according to the related art.

  As shown in FIG. 1, the common spare UPS system 100 is connected between the bypass power supply 1 and the AC power supply 2 and the loads 31 to 33, and is configured to supply the AC power to the loads 31 to 33. It is done. The loads 31 to 33 are electric devices or the like driven by AC power.

  Although the common spare UPS system 100 receives three-phase AC power from the bypass power supply 1 or the AC power supply 2, only a circuit for one phase is shown in FIG. 1 for simplification of the drawings and the description.

  The common spare UPS system 100 includes a common spare UPS 10 and regular UPSs 21-23. More specifically, the common spare UPS 10 has a terminal T1 for receiving AC power from the bypass power supply 1 and a terminal T2 for receiving AC power from the AC power supply 2. The common spare UPS 10 has a converter (not shown) that converts AC power input from the AC power supply 2 (terminal T2) into DC power, and an inverter (not shown) that converts the DC power into AC power. The common spare UPS 10 further has a terminal T3 for outputting the AC power converted by the inverter.

  FIG. 2 is a diagram showing an example of the configuration of the regular UPSs 21-23. Since the configurations of the regular UPSs 21 to 23 are the same, hereinafter, the configuration of the regular UPS 21 will be described as an example.

  The regular UPS 21 has terminals T4 to T6, a converter 211, an inverter 212, a chopper 213, a battery B20, a control circuit 230, and a bypass board 240.

  Terminal T4 receives AC power output from bypass power supply 1 or common spare UPS 10. Terminal T5 receives the AC power output from AC power supply 2.

  Converter 211 converts AC power supplied from AC power supply 2 via terminal T5 into DC power. The DC power generated by converter 211 is supplied to inverter 212 and chopper 213.

  The inverter 212 converts DC power into AC power of commercial frequency (for example, 50 Hz or 60 Hz). The converted AC power is output to the corresponding load via the terminal T6.

  Chopper 213 supplies DC power generated by converter 211 to the positive electrode of battery B 20 during normal operation. The chopper 213 supplies DC power of the battery B 20 to the inverter 212 when the AC power supply 2 fails.

  Converter 211 and inverter 212 may be configured by semiconductor switching elements. As a semiconductor switching element, an IGBT (Insulated Gate Bipolar Transistor) may be used. As an example, control circuit 230 controls the semiconductor switching element according to PWM (Pulse Width Modulation) control.

  The regular UPS 21 has a bypass circuit for outputting the AC power input from the terminal T4 to the terminal T6. That is, the bypass circuit bypasses the converter 211 and the inverter 212.

  The bypass board 240 is disposed on the bypass circuit. The bypass board 240 switches the output to the load 31 corresponding to the regular UPS 21 between the output of the inverter 212 and the AC power input to the terminal T4 (that is, the output of the bypass circuit).

  In the example shown in FIG. 2, the bypass board 240 has a switch 241 and a thyristor 242. The switch 241 and the thyristor 242 are disposed in parallel with each other between the terminal T4 and the terminal T6.

  The control circuit 230 turns on the switch 241 and the thyristor 242 when the converter 211 or the inverter 212 fails. The control circuit 230 turns on the thyristor 242 only during a momentary interruption time that occurs before the switch 241 is turned on, and turns off the thyristor 242 after the switch 241 is turned on. The control circuit 230 can switch from power supply by the inverter 212 to power supply by the bypass circuit instantaneously at the time of failure due to the action of the thyristor 242. The control circuit 230 can suppress a voltage drop (loss) due to the thyristor 242 by turning off the thyristor 242 after the switch 241 is turned on.

  Referring back to FIG. 1, a switch S1X is disposed between the common spare UPS 10 and the regular UPS 21. A switch S1Y is disposed between the bypass power supply 1 and the regular UPS 21. The switch S1X and the switch S1Y are configured such that when either one is turned on, the other is turned off. That is, the switches S1X and S1Y function as an interlock circuit IL1 for switching the power input to the normal UPS 21 between the AC power output from the common backup UPS 10 and the AC power output from the bypass power supply 1 Do.

  A switch S2X is disposed between the common spare UPS 10 and the regular UPS 22. A switch S2Y is disposed between the bypass power supply 1 and the regular UPS 22. The switch S2X and the switch S2Y are configured such that when either one is turned on, the other is turned off. That is, the switches S2X and S2Y function as an interlock circuit IL2 for switching the power input to the normal UPS 22 between the AC power output from the common backup UPS 10 and the AC power output from the bypass power supply 1 Do.

  A switch S3X is disposed between the common spare UPS 10 and the regular UPS 23. A switch S3Y is disposed between the bypass power supply 1 and the regular UPS 23. The switch S3X and the switch S3Y are configured such that when either one is turned on, the other is turned off. That is, the switches S3X and S3Y function as an interlock circuit IL3 for switching the power input to the normal UPS 23 between the AC power output from the common backup UPS 10 and the AC power output from the bypass power supply 1 Do.

  When the plurality of regular UPSs 21 to 23 are operated without any failure, each of the regular UPSs 21 to 23 converts the AC power input from the AC power supply 2 into the converter 211 and as shown by the one-dot chain line in FIG. It converts by the inverter 212 and outputs the converted AC power to the corresponding loads 31 to 33, respectively.

  At this time, the switches S1X, S2X, and S3X are turned on, and the switches S1Y, S2Y, and S3Y are turned off. In addition, the switches 241 and the thyristors 242 included in each of the normal UPSs 21 to 23 are turned off.

  FIG. 3 is a diagram for explaining a power feeding path when the regular UPS 21 fails in the common spare UPS system 100. As shown in FIG.

  In general, the capacity of the common spare UPS 10 is set to the same as the capacity of each of the regular UPSs 21-23. The reason is that the probability that two or more of the regular UPSs 21 to 23 fail simultaneously is extremely rare. In such a case, the common spare UPS 10 can only back up one of the regular UPSs 21 to 23.

  In one aspect, it is assumed that the regular UPS 21 breaks down. In such a case, the common backup UPS system 100 turns on the switch S1X and turns off the switch S1Y. Also, the regular UPS 21 turns on the switch 241 and the thyristor 242. As a result, as shown by the broken line in FIG. 2, the backup power output from the common backup UPS 10 is supplied to the load 31 via the bypass circuit of the regular UPS 21.

  Further, the common spare UPS system 100 turns on the switches S2Y and S3Y and turns off the switches S2X and S3X. As described above, the common backup UPS system 100 prevents the common backup UPS 10 from being overloaded by disconnecting the connection between the common backup UPS 10 and the normal UPSs 22 and 23 which have not failed.

  As described above, the common backup UPS system 100 according to the related art is for interrupting the connection between the other common UPS and the common backup UPS 10 in the event of failure of any of the plurality of normal UPS 21-23. It has interlock circuits IL1 to IL3 or a sequencer (not shown).

  These interlock circuits IL1 to IL3 and the sequencer may fail due to various factors. Therefore, the interlock circuits IL1 to IL3 and the sequencer are elements that reduce the reliability of power supply to the loads 31 to 33 of the common backup UPS system 100.

  In order to solve such a problem, it is conceivable to use a common spare UPS 10 having a capacity three times that of each of the regular UPSs 21-23. However, in such a case, the power consumption of the common spare UPS 10 increases.

  Therefore, the configuration and control of a common spare UPS system that is more reliable than before and can reduce the power consumption of the common spare UPS will be described below.

Embodiment 1
(Configuration of common spare UPS system 400)
FIG. 4 is a diagram showing an example of a configuration of the common backup UPS system 400 according to the first embodiment. The common backup UPS system 400 according to the first embodiment has a common backup UPS 40 instead of the common backup UPS 10, a plurality of current detection devices 410 to 430, and no interlock circuits IL1 to IL3. It differs from the common backup UPS system 100 according to the related art. Since common backup UPS system 400 is otherwise the same in configuration as common backup UPS system 100, the description thereof will not be repeated. Although the common spare UPS system 400 receives three-phase AC power from the bypass power supply 1 or the AC power supply 2, only one circuit for one phase is shown in FIG. 4 for the sake of simplification of the drawings and the description.

  The common backup UPS system 400 includes a common backup UPS 40 connected in series with each of the plurality of regular UPSs 21 to 23 for supplying backup power to the plurality of regular UPSs 21 to 23.

  The common spare UPS 40 has a terminal T7 for receiving AC power from the bypass power supply 1 and a terminal T8 for receiving AC power from the AC power supply 2. The common spare UPS 40 also has a terminal T9 for outputting the generated spare power to the normal UPS 21-23.

  The current detection device 410 is disposed between the terminal T6 of the normal UPS 21 and the load 31, and detects the magnitude of the current output from the normal UPS 21 to the load 31. The current detection device 420 is disposed between the terminal T6 of the normal UPS 22 and the load 32, and detects the magnitude of the current output from the normal UPS 22 to the load 32. The current detection device 430 is disposed between the terminal T6 of the normal UPS 23 and the load 33, and detects the magnitude of the current output from the normal UPS 23 to the load 33. Each of the current detection devices 410 to 430 is configured to output the detection result to the common backup UPS 40. The current detection devices 410 to 430 are realized by, for example, an A / D converter.

(Configuration of common spare UPS 40)
FIG. 5 is a diagram showing an example of the configuration of the common backup UPS 40. As shown in FIG. As shown in FIG. 5, the common backup UPS 40 includes a plurality of UPS modules 510, 520, and 530, a bypass panel 540, and a controller 550. The common spare UPS 40 further includes a terminal T10 for receiving DC power from the battery B40. In the first embodiment, the capacity of each of the regular UPSs 21 to 23 is 500 kVA, and the capacity of each of the UPS modules 510, 520, and 530 is 300 kVA.

  The plurality of UPS modules 510, 520, and 530 are connected in parallel with each other between the terminals T8 and T10 and the terminal T9. The configurations of the UPS modules 510, 520, and 530 are the same, so the configuration of the UPS module 510 will be described below as an example.

  The UPS module 510 includes a converter 511, an inverter 512, a chopper 513, and switches 514 to 516.

  Switch 514 is arranged between terminal T 8 and converter 511. Inverter 512 is connected in series to converter 511. The switch 515 is disposed between the inverter 512 and the terminal T9. The switch 516 is disposed between the terminal T10 and the chopper 513. Chopper 513 is arranged between a node between converter 511 and inverter 512 and switch 516.

  Converter 511 converts AC power supplied from AC power supply 2 via terminal T8 into DC power. The DC power generated by converter 511 is supplied to inverter 512 and chopper 513.

  The inverter 512 converts DC power into AC power of commercial frequency (for example, 50 Hz or 60 Hz). During normal operation, chopper 513 supplies DC power generated by converter 511 to the positive electrode of battery B 40 via switch 516 and terminal T10. The chopper 513 supplies the DC power of the battery B 40 to the inverter 512 when the AC power supply 2 fails.

  In the example shown in FIG. 5, the battery B 40 is common to the UPS modules 510, 520, and 530, but in another embodiment, the common backup UPS 40 is connected to each UPS module 510, 520, and 530. It may be configured to have a battery.

  Converter 511 and inverter 512 can be configured by semiconductor switching elements. An IGBT may be used as the semiconductor switching element. As an example, control device 550 controls the semiconductor switching element according to PWM control.

  The control device 550 switches the operating state and the inactive state of the UPS module 510 by controlling ON / OFF of the switches 514 and 515 included in the UPS module 510. More specifically, the controller 550 turns on the switches 514 and 515 when it is desired to put the UPS module 510 into operation. Thus, the UPS module 510 can receive AC power from the AC power supply 2 and supply the converted AC power (backup power) to the regular UPSs 21 to 23. On the other hand, when the control device 550 wants to put the UPS module 510 into the sleep state, the switch 514, 515 is turned off to stop the supply of AC power from the AC power supply 2 to the UPS module 510. The control device 550 turns on the switch 516 included in the UPS module 510 in the operating state of the UPS module 510 and turns off the switch 516 in the inactive state of the UPS module 510.

  As described above, the control device 550 switches the operating state and the inactive state of each UPS module 510, 520, 530 by controlling ON / OFF of the switches 514, 515 included in each UPS module 510, 520, 530. .

  The control device 550 switches the size of the backup power output from the common backup UPS 40 by controlling the number of UPS modules in operation among the plurality of UPS modules 510, 520, and 530. For example, when one UPS module is in operation, the size of the backup power output from the common backup UPS 40 is 300 kVA. In addition, when two UPS modules are operating, the size of the backup power output from the common backup UPS 40 is 600 kVA. Also, when three UPS modules are operating, the size of the backup power output from the common backup UPS 40 is 900 kVA.

  In this sense, the switches 514 and 515 included in the UPS modules 510, 520 and 530 function as a switching mechanism for switching the level of the backup power of the common backup UPS 40.

  The bypass plate 540 includes a switch 541 and a thyristor 542. The switch 541 and the thyristor 542 are connected in parallel to each other between the terminal T7 and the terminal T9.

  Control device 550 is configured to be capable of switching between the bypass power feeding mode and the inverter power feeding mode. Control device 550 in accordance with the bypass power supply mode outputs AC power input from AC power supply 2 via terminal T7 to terminal T9 via switch 541. The controller 550 according to the inverter power supply mode outputs, to the terminal T9, the AC power generated by the UPS module in the operating state among the UPS modules 510, 520, and 530. In the bypass feeding mode, the switch 541 is turned on, and in the inverter feeding mode, the switches 514 to 516 included in the UPS module in the operating state are turned on.

  During the switching period between the bypass power feeding mode and the inverter power feeding mode, both the switch 541 and the switch included in the UPS module in the operating state are turned on. The thyristor 542 is turned on when any of the UPS modules in the operating state fails in the inverter power supply mode, and instantaneously supplies AC power from the AC power supply 2 to the terminal T9. The thyristor 542 is turned off after the switch 541 is turned on.

(Output switching of common spare UPS 40)
Next, control for switching the output of the common spare UPS 40 will be described. Control device 550 receives an input of status information indicating the status of each of the regular UPSs 21-23. Control device 550 controls the magnitude of the reserve power output from common spare UPS 40 based on the received state information.

  More specifically, the current detection devices 410, 420, and 430 correspond to the normal UPSs 21 to 23 corresponding to the detection results of the magnitudes of currents output to the corresponding loads 31 to 33 (hereinafter, also referred to as "output current value"). Is output to the control device 550 as state information of

  The control device 550 determines the number of UPS modules in the operating state among the UPS modules 510, 520, and 530 based on the output current values input from the current detection devices 410, 420, and 430.

<Integrated value of load capacity>
FIG. 6 is a diagram for explaining the relationship between the integrated value of the load capacities of the regular UPSs 21 to 23 and the number of UPS modules in the operating state.

  In Case 1 shown in FIG. 6, the controller 550 determines that the integrated value of the load capacities of the regular UPSs 21 to 23 is less than 300 kVA based on the output current values input from the current detectors 410, 420, 430. to decide.

  In such a case, the control device 550 operates one UPS module (for example, the UPS module 510) and suspends the remaining two UPS modules.

  In Case 2 shown in FIG. 6, the controller 550 determines that the integrated value of the load capacities of the regular UPSs 21 to 23 is not less than 300 kVA and less than 600 kVA based on the output current values input from the current detectors 410, 420, 430. I judge that there is.

  In such a case, the controller 550 operates the two UPS modules (for example, the UPS modules 510 and 520) and causes the remaining one UPS module to go to sleep.

  In Case 3 shown in FIG. 6, the controller 550 determines that the integrated value of the load capacities of the regular UPSs 21 to 23 is 600 kVA or more based on the output current values input from the current detectors 410, 420, 430. to decide.

  In such a case, the controller 550 operates all three UPS modules 510, 520, 530.

  According to the above, in the common spare UPS system 400 according to the first embodiment, the size of the reserve power to be output by the common spare UPS 40, that is, The number of UPS modules in operation can be determined. Thereby, the common spare UPS system 400 according to the first embodiment can reduce power consumption significantly as compared with the case where the spare power of the total capacity (1500 kVA) of the regular UPSs 21 to 23 is always generated.

  Further, the possibility that two or more of the regular UPSs 21 to 23 simultaneously fail is rare. Therefore, even if one of the plurality of UPS modules included in the common spare UPS 40 fails, the common spare UPS system 400 according to the first embodiment uses the other non-failed UPS modules to provide spare power for one common UPS. Can be secured. Therefore, the common backup UPS system 400 can improve the power supply reliability to the load as compared with a system in which backup power is supplied to the regular UPSs 21 to 23 by the common backup UPS configured by one UPS.

  In the above example, the control device 550 is configured to determine the number of UPS modules operated based on the integrated value of the load capacities of the regular UPS 21-23, but in the other aspect, the output current value The number of UPS modules operated may be determined based on the integrated value of.

<Maximum load capacity>
In the above example, the control device 550 is configured to determine the number of UPS modules operated based on the integrated value of the load capacities of the regular UPSs 21-23, but in another aspect, the load of the regular UPSs 21-23 The number of UPS modules in operation may be determined based on the maximum value of capacity (hereinafter also referred to as “maximum load capacity”).

  The reason is that, as described above, the possibility that two or more of the regular UPSs 21 to 23 fail simultaneously is rare, and the common backup UPS system 400 generates the backup power of the maximum load capacity by the common backup UPS 40. This is because it is possible to sufficiently ensure the reliability of power supply to the load.

  FIG. 7 is a diagram for explaining the relationship between the maximum load capacity and the number of UPS modules operated.

  The control device 550 obtains the largest maximum load capacity among the load capacities of the regular UPSs 21 to 23 based on the output current values input from the current detection devices 410, 420, 430.

  In Case 4 shown in FIG. 7, the control device 550 determines that the maximum load capacity is less than 300 kVA based on the output current value input from each of the current detection devices 410, 420, 430.

  In such a case, the control device 550 operates one UPS module (for example, the UPS module 510) and suspends the remaining two UPS modules.

  In 5 shown in FIG. 7, the control device 550 determines that the maximum load capacity is 300 kVA or more and less than 600 kVA based on the output current values input from the current detection devices 410, 420, 430.

  In such a case, the controller 550 operates the two UPS modules (for example, the UPS modules 510 and 520) and causes the remaining one UPS module to go to sleep.

  According to the above, the common backup UPS system 400 according to the first embodiment can determine the number of UPS modules operated based on the maximum load capacity. The common spare UPS system 400 according to this control can further reduce the power consumption in the common spare UPS 40 as compared with the system in which the number of UPS modules operated based on the integrated value of the load capacity of the regular UPS 21-23 described above.

  In the above-described example, control device 550 is configured to determine the number of UPS modules operated based on the maximum load capacity, but in another aspect, based on the maximum value of each output current value. It may be configured to determine the number of UPS modules operated.

  Further, in the above example, the capacity of each of the regular UPSs 21 to 23 is 500 kVA, and the common spare UPS 40 is configured to have three UPS modules having a capacity of 300 kVA. However, since the maximum load capacity does not exceed 500 kVA which is each capacity of the regular UPS 21-23, the common backup UPS 40 may be configured to have two 300 kVA UPS modules.

(Control structure)
FIG. 8 is a flowchart showing a process of changing the size of the backup power output from the common backup UPS 40 by the common backup UPS system 400 according to the first embodiment. Each process shown in FIG. 8 is realized by control device 550.

  In step S810, control device 550 obtains output current values (state information) input from current detection devices 410, 420, and 430, respectively.

  In step S820, control device 550 determines whether or not it is necessary to switch the number of UPS modules included in common spare UPS 40 based on the acquired output current values. More specifically, the control device 550 determines the number of UPS modules operated based on the acquired output current values. If the determined number of units and the number of UPS modules currently operating are different, the control device 550 determines that it is necessary to switch the number of UPS modules operated.

  If it is determined that the number of UPS modules in operation needs to be switched (YES in step S820), control device 550 executes the process of step S830. If not (NO in step S820), control device 550 executes the process of step S810 again.

  In step S830, control device 550 outputs a control signal to switches 514, 515 (switching mechanism) included in each of UPS modules 510, 520, 530 based on the number of operating UPS modules determined in step S820. . As a result, the determined number of UPS modules are put into operation.

  As an example, when switching the UPS module 520 from the hibernation state to the operation state, the control device 550 turns on the switches 514 and 515 and the switch 516 included in the UPS module 520.

  According to the above, common spare UPS system 400 according to the first embodiment can improve the reliability of power supply to the load since interlock circuit IL1-IL3 is not provided as compared with common spare UPS system 100 according to the related art. .

  Also, the common backup UPS system 400 according to the first embodiment has a common backup UPS 40 including a plurality of UPS modules. Thereby, the common backup UPS system 400 determines the number of UPS modules to be operated so as to generate necessary backup power according to the status information (output current value) representing the status of the regular UPS 21-23. Therefore, the common backup UPS system 400 can reduce the power consumption of the common backup UPS 40 as compared to the prior art.

  Also, in general, the regular UPS included in the common spare UPS system is designed to have a load capacity of about 60% of the capacity. Therefore, in the common backup UPS system 400 according to the first embodiment, the capacity (300 kVA) of each UPS module 510, 520, 530 is designed to be 60% of the capacity (500 kVA) of the regular UPS 21-23. Cost reduction and power consumption reduction.

  In other embodiments, the capacity of each UPS module may be designed to be the same capacity as the capacity of the regular UPS.

Second Embodiment
The common spare UPS system 400 according to the first embodiment is configured to obtain the status information of the regular UPS 21-23 by the current detection devices 410, 420, 430. The common spare UPS system 900 according to the second embodiment is configured to acquire internal signals of the regular UPSs 21 to 23 as status information.

  FIG. 9 is a diagram showing an example of the configuration of the common backup UPS system 900 according to the second embodiment. The common backup UPS system 900 according to the second embodiment differs from the common backup UPS system 400 according to the first embodiment in that it does not have the current detection devices 410, 420, 430, and has signal lines 910, 920, 930. Since common backup UPS system 900 is otherwise the same in configuration as common backup UPS system 400, the description thereof will not be repeated.

  The signal line 910 transmits and receives information between the control device 550 of the common backup UPS 40 and the control circuit 230 of the normal UPS 21. The signal line 920 transmits and receives information between the control device 550 and the control circuit 230 of the regular UPS 22. The signal line 930 transmits and receives information between the control device 550 and the control circuit 230 of the regular UPS 23.

(Output current value)
In one aspect, the control circuits 230 included in the regular UPSs 21 to 23 output control signals representing the magnitudes of the currents output to the corresponding loads 31 to 33 to the control device 550 through the signal lines 910 to 930, respectively. Do. This control signal can also be said to be state information indicating the state of each of the regular UPSs 21-23.

  The control signal representing the magnitude of the current output to the corresponding load may include, for example, a PWM signal that control circuit 230 generates to control converter 211 and inverter 212. In another aspect, the control signal may be a signal that represents the magnitude of the current output to the corresponding load. As an example, each of the normal UPSs 21 to 23 generates a control signal based on the information input from the corresponding loads 31 to 33.

  The control device 550 can execute the same process as the process of the above-described first embodiment based on the control signal input from each control circuit 230.

(Number of UPS for regular use performing bypass power supply)
In another aspect, each control circuit 230 included in the regular UPSs 21 to 23 outputs an operation signal indicating whether the corresponding regular UPS is performing inverter feed or bypass feed to the load to the control device 550. . Inverter feeding refers to supplying the AC power converted by the inverter 212 to a load. Bypass feeding refers to supplying the AC power input to the terminal T4 to a load.

  More specifically, in each of the control circuits 230, in the bypass board 240, whether the switch 241 is turned on or off, in other words, the output of the inverter 212 and the bypass circuit as an output to the corresponding load An operation signal indicating which of the outputs of (the circuit connecting the terminal T4 and the terminal T6) is selected is output to the control device 550. This operation signal can also be said to be state information indicating the state of each of the regular UPSs 21-23.

  Based on the operation signal input from each control circuit 230, the control device 550 specifies the number of regular UPSs performing bypass power supply, that is, the number of faulty regular UPSs. The control device 550 determines the number of UPS modules operated based on the number of regular UPSs performing bypass power supply.

  More specifically, control device 550 determines the number of UPS modules in operation to be the number obtained by adding 1 to the number of regular UPSs performing bypass power supply. As an example, when the number of UPSs for bypass power supply is one, the control device 550 operates two UPS modules.

(Control structure)
FIG. 10 is a flowchart showing a process of changing the size of the backup power output from the common backup UPS 40 according to the second embodiment. Each process shown in FIG. 10 is realized by control device 550.

  In step S1010, control device 550 acquires status information (for example, control signal, operation signal) representing the status of the regular UPS from regular UPS 21-23 via signal lines 910-930.

  In step S1020, control device 550 determines whether or not it is necessary to switch the number of UPS modules included in common spare UPS 40 based on the acquired state information. More specifically, the control device 550 determines the number of UPS modules operated based on the acquired state information. If the determined number of units and the number of UPS modules currently operating are different, the control device 550 determines that it is necessary to switch the number of UPS modules operated.

  When it is determined that the number of UPS modules in operation needs to be switched (YES in step S1020), control device 550 executes the process of step S1030. If not (NO in step S1020), control device 550 executes the process of step S1010 again.

  In step S1030, control device 550 outputs a control signal to switches 514, 515 (switching mechanism) included in each of UPS modules 510, 520, 530 based on the number of UPS modules operated in step S1020. . As a result, the determined number of UPS modules are put into operation.

  In the above description, the common backup UPS system is configured to have three regular UPSs and a common backup UPS having three UPS modules, but the configuration of the common backup UPS system is limited to this. Absent. The common backup UPS system may include one or more regular UPSs and a common backup UPS including a plurality of UPS modules. At this time, the number of regular UPSs and the number of UPS modules do not have to be the same.

  The various processes described above are implemented by one control device 550, but are not limited thereto. These various processes include a semiconductor integrated circuit such as at least one processor, at least one application specific integrated circuit (ASIC), at least one digital signal processor (DSP), at least one FPGA (field programmable). It may be implemented by a circuit having a Gate Array and / or other arithmetic functions.

  These circuits may perform the various processes described above by reading one or more instructions from at least one tangible readable medium.

  Such media may take the form of magnetic media (eg, hard disks), optical media (eg, compact disks (CDs), DVDs), volatile memory, memory of any type of non-volatile memory, etc. It is not limited to the form.

  Volatile memory can include dynamic random access memory (DRAM) and static random access memory (SRAM). Nonvolatile memory may include ROM, NVRAM.

[Constitution]
The technical features disclosed above can be summarized as follows.

  (Configuration 1) The uninterruptible power supply system according to an embodiment includes a plurality of regular UPSs 21 to 23 which are supplied with power from the AC power supply 2 and which supply the alternating current power to the loads 31 to 33 and a plurality of regular UPSs 21 to 23 in series And a common spare UPS 40 configured to be able to switch the standby power supplied to the plurality of regular UPSs 21 to 23 based on the state information indicating the state of the plurality of regular UPSs 21 to 23.

  (Configuration 2) The common spare UPS 40 has a switching mechanism for switching the size of the backup power, and a control device for receiving the input of the status information of each of the regular UPS 21 to 23 and controlling the switching mechanism based on the status information. And 550.

  (Configuration 3) The common spare UPS 40 includes a plurality of UPS modules 510, 520, and 530 that receive input of power from the AC power supply 2. The switching mechanism is the switches 514 and 515 included in the UPS modules 510, 520 and 530, and is configured to be able to switch between the operation state and the hibernation state of each of the plurality of UPS modules 510, 520 and 530. The control device 550 is configured to output, to the switching mechanism, a control signal for switching the number of UPS modules in the operating state among the plurality of UPS modules 510, 520, and 530 based on the state information.

  (Configuration 4) The common backup UPS system further includes a plurality of current detection devices 410, 420, 430. Each of the current detection devices 410, 420, 430 is configured to detect the output current of the corresponding normal UPS 21-23, and output the detection result to the control device 550 as state information.

  (Configuration 5) Each control circuit 230 included in the regular UPSs 21 to 23 is configured to output information indicating the magnitude of the current output to the corresponding load to the control device 550 as status information.

  (Configuration 6) Each of the regular UPSs 21 to 23 receives the input of the AC power supply 2 and converts the AC power to a corresponding load by converting the converter 211 for converting the DC power into a DC power and converting the AC power to a corresponding load. Of the inverter 212, a bypass circuit (a circuit connecting the terminal T4 and the terminal T6) which accepts the input of the reserve power and bypasses the converter and the inverter, an output to the corresponding load, the output of the inverter 212 and the bypass circuit And a bypass board 240 for switching between the outputs. The state information includes information indicating which of the output of the inverter 212 and the output of the bypass circuit is selected in the bypass board 240 of each of the normal UPSs 21 to 23.

  (Configuration 7) The control device 550 switches the number of UPS modules in the operating state among the plurality of UPS modules 510, 520, and 530 according to the number of UPSs for which the output of the bypass circuit is selected in the switching circuit. Control signals to the switching mechanism.

  It should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is indicated not by the above description but by the claims, and is intended to include all the modifications within the meaning and scope equivalent to the claims.

  DESCRIPTION OF SYMBOLS 1 bypass power supply, 2 alternating current power supply, 21, 22, 23 UPS for regular use, 31, 32, 33 loads, 10, 40 common spare UPS, 100, 400, 900 systems, 211, 511 converters, 212, 512 inverters, 213, 513 Chopper, 230 control circuit, 240, 540 bypass board, 241, 514, 515, 516, 541, S1X, S1Y, S2X, S2Y, S3Y, S3X switch, 242, 542 thyristor, 410, 420, 430 current detection device, 510 520, 530 UPS module, 550 control unit, 910, 920, 930 signal line.

Claims (7)

A plurality of normal-use uninterruptible power supply devices which are supplied with power from an AC power supply and supply AC power to a load;
It is connected in series with each of the plurality of common uninterruptible power supplies, and can switch the standby power supplied to the plurality of common uninterruptible power supplies based on state information indicating the state of the plurality of common uninterruptible power supplies An uninterruptible power system with a common spare uninterruptible power supply configured. The common spare uninterruptible power supply is
A switching mechanism for switching the magnitude of the reserve power;
2. The uninterruptible power supply system according to claim 1, further comprising: a control device for receiving the input of the state information of each of the common use uninterruptible power supply devices and controlling the switching mechanism based on the state information. The common spare uninterruptible power supply includes a plurality of uninterruptible power supply modules that receive an input of power from an AC power supply,
The switching mechanism is configured to be able to switch between an operation state and a hibernation state of each of the plurality of uninterruptible power supply modules,
The control device is configured to output, to the switching mechanism, a control signal for switching the number of uninterruptible power supply modules in the operating state among the plurality of uninterruptible power supply modules based on the state information. The uninterruptible power supply system according to claim 2.   The apparatus further comprises a plurality of detection devices, each of the detection devices detecting an output current of each of the common uninterruptible power supplies, and outputting a detection result as the state information to the common spare uninterruptible power supply. The uninterruptible power supply system according to any one of claims 1 to 3.   Each of said common use uninterruptible power supply is comprised so that the information showing the magnitude | size of the electric current output to corresponding load may be output to said common spare uninterruptible power supply as said status information. The uninterruptible power supply system described in 1 or 2. Each said uninterruptible power supply is
A converter for receiving the input of the AC power source and converting it into DC power;
An inverter for converting the DC power into AC power and outputting the AC power to a corresponding load;
A bypass circuit that receives the reserve power input and bypasses the converter and the inverter;
A switching circuit for switching an output to a corresponding load between an output of the inverter and an output of the bypass circuit,
The said state information contains the information showing whether the output of the said inverter and the output of the said bypass circuit is selected in the said switching circuit of each said common use uninterruptible power supply according to claim 3 Blackout power system.   The control device is configured to control the number of uninterruptible power supply modules in the operating state among the plurality of uninterruptible power supply modules according to the number of the common uninterruptible power supply devices for which the output of the bypass circuit is selected in the switching circuit. The uninterruptible power supply system according to claim 6, configured to output a control signal to switch the switching mechanism to the switching mechanism.

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