Peak shift function continuance system and peak shift function continuance method

Abstract

To solve the problem that when a peak shift function is stopped, an electric power demand in daytime is not only tightened, and but also a purchase power quantity is increased, and thus, an electricity charge is increased, and therefore, a system for continuing the peak shift function even if there is a module failure in a modular UPS is required by an electric power user.SOLUTION: A facility electric system of an electric power user who uses a commercial power supply, comprises: a secondary battery that can supply a power to be charged to the facility electric system; an UPS module to which the secondary battery is connected; a modular UPS containing the plurality of UPS modules; and a control part that detects one or a plurality of abnormalities of each UPS module in each modular UPS, and continues an optimal peak shift function so as to be matched to the abnormality to be detected.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] Embodiments of the present invention relate to a peak shift function continuation system and a peak shift function continuation method.

Background Art

[0002] An uninterruptible power supply (hereinafter referred to as UPS) is installed in a facility of a power consumer, stores power in a built-in emergency battery, and can stably supply power even when the main power supply is temporarily lost or becomes unstable.

[0003] Also, even when the waveform of the main power supply is unstable or noise and surges occur, it is possible to supply stable power using circuits and filters built into the UPS, enabling sensitive devices such as electronic devices and computers to operate normally and preventing data loss and device failures.

[0004] As a type of UPS, there is what is called a modular UPS composed of a plurality of UPS modules, each having the characteristic of functioning independently. Generally, in addition to the UPS modules, a modular UPS combines a plurality of modules such as a power conversion module, a battery module, and a bypass circuit. The power conversion module has the function of mutually converting AC and DC, the battery module is a so-called storage battery, and the bypass circuit is a path used when a UPS module fails or maintenance is required, and can bypass the failed UPS module and supply power directly to the load.

[0005] A modular UPS can add capacity in module units and can expand the capacity as needed, and has redundancy because even if some modules fail, other modules can take over.

[0006] Here, the modular UPS is equipped with a peak shifting function. The peak shifting function is a function for adjusting the balance between power demand and supply to improve the efficiency of the power network. For example, during the daytime when people are active, the power demand is higher than at night, and a peak in power demand occurs during a specific time period when power demand is concentrated, imposing an excessive load on the power network. The peak shifting function refers to dispersing such excessive power demand during peak times so that the power network is not overloaded.

[0007] In addition, the peak shifting function also contributes to reducing electricity costs. As described above, the fact that the power demand is high during the daytime means that the electricity cost during the daytime is higher than that at night. If the amount of electricity purchased during the daytime can be reduced, it is possible to reduce the electricity cost.

[0008] The peak shifting function installed in the modular UPS is exerted by discharging the surplus power stored in the battery connected to each UPS module built into the modular UPS.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0010] Patent Document 1 describes a peak shifting function that reduces the amount of power purchased from the grid by discharging from a battery that also has surplus power during normal operation. At the same time, it is described that this peak shifting function stops when an abnormality occurs in the UPS regardless of the failure of the battery.

[0011] In the case where a UPS module failure occurs while the peak shift function is being exerted in a modular UPS, although normal operation can be performed by a healthy UPS module, the peak shift function will stop in the method of Patent Document 1.

[0012] When the peak shift function stops, it not only leads to a tight power demand during the day but also increases the purchased power amount and raises the electricity bill. Therefore, there is a demand from power consumers for a system that continues the peak shift function even when there is a module failure in a modular UPS.

Means for Solving the Problem

[0013] Therefore, in order to solve the above problems, the peak shift function continuation system according to the embodiment includes a storage battery that can supply the charged power to the facility's internal electrical system in the facility's internal electrical system of a power consumer using a commercial power supply, a UPS module to which the storage battery is connected, a modular UPS including a plurality of the UPS modules, and a control unit that detects one or more abnormalities of the UPS modules in the modular UPS and continues the optimal peak shift function in accordance with the detected abnormalities.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments for carrying out the invention will be described with reference to the drawings. The configuration of the peak shift function continuation system according to the embodiment is shown in FIG. 1, and a diagram showing a power supply state in which the peak shift function is exerted in the modular UPS is shown in FIG. 2. FIGS. 3 to 5 show diagrams representing power supply states in which respective peak shift functions are exerted depending on the content of the abnormality occurring in the UPS module, and details will be described later.

[0016] As shown in FIG. 1, the peak shift function continuation system according to the embodiment includes a commercial power supply 13 that is a commercial power source of power, a modular UPS 10 having a plurality of UPS modules 11A to 11D and storage batteries 12A to 12D, a control unit 14 that controls the plurality of UPS modules 11A to 11D, and a load 15 that consumes the supplied power.

[0017] The modular UPS 10 is connected to the in-house electrical system of the power consumer. The modular UPS 10 including a plurality of UPS modules 11A to 11D is configured such that the storage batteries 12A to 12D are respectively connected to the UPS modules 11A to 11D. That is, the storage battery 12A is connected to the UPS module 11A, the storage battery 12B is connected to the UPS module 11B, the storage battery 12C is connected to the UPS module 11C, and the storage battery 12D is connected to the UPS module 11D.

[0018] The number of UPS modules included in the modular UPS 10 is variable, and the number of storage batteries is also variable accordingly. Also, the number of UPS modules and storage batteries does not have to be 1:1, and the corresponding quantities may be different, such as 1:N.

[0019] Here, the functions of the UPS modules 11A to 11D will be described taking the UPS module 11A as an example. The UPS module 11A has a converter function for charging the battery 12A from the commercial power supply 13 and an inverter function for supplying power from the battery 12A to the load 15.

[0020] When an abnormality occurs in the UPS module 11A having such functions, if the abnormality occurs in the converter function part of the UPS module 11A, charging from the commercial power supply 13 to the battery 12A cannot be performed. However, power supply from the battery 12 to the load 15 via the inverter function is possible.

[0021] Also, if the abnormality occurring in the UPS module 11A is an abnormality in the inverter function part, power supply from the battery 12A to the load 15 via the inverter function cannot be performed. However, charging from the commercial power supply to the battery 12A via the converter function is possible.

[0022] From this, when an abnormality occurs in the UPS modules 11A to 11D, the control unit 14 is notified via the control line 16 of which functional part the abnormality has occurred in. The control unit 14 determines which of the UPS modules 11A to 11D the abnormality notified via the control line 16 is in, and which function of the module the abnormality has occurred in.

[0023] As a result of the determination, if it is only in either the converter function or the inverter function of any of the UPS modules 11A to 11D, it is possible to operate using other functions without operating only the abnormal function of the UPS module 11A to 11D in which the abnormality has been detected. Therefore, the control device 14 transmits signals for controlling the functions to be operated for each of the UPS modules 11A to 11D via the control line 16 and the amount of power supplied to the load 15.

[0024] Each of the UPS modules 11A to 11D operates by determining its function and the amount of power to supply based on the received control signal as described below.

[0025] The UPS modules 11A to 11D have the role of stably supplying the power supplied from the commercial power supply 13 to the load 15. In the embodiment, as shown in FIG. 2, the UPS modules 11A to 11D each output 20 kVA of the 80 kVA of power supplied from the commercial power supply 13.

[0026] The storage batteries 12A to 12D are so-called emergency batteries and can perform so-called assist discharge, which discharges the power charged when the peak shift function is exerted. In the embodiment, as shown in FIG. 2, the amount of power for assist discharge is 5 kVA for each of the storage batteries 12A to 12D. The power used for these assist discharges is, for example, the power charged at night when the power demand is low (when the electricity rate is low), and by using this power during the day, the power consumption from the commercial power supply 13 during the day when the power demand is high (when the electricity rate is high) can be reduced (the electricity rate can be reduced).

[0027] The commercial power supply 13 in the embodiment is a so-called power plant, which shows the power generation equipment that supplies power to the grid. The power generation method is not limited as long as it is equipment capable of supplying power. Also, it may be equipment capable of supplying power even if it is not a so-called power plant.

[0028] Next, the control unit 14 will be described with reference to FIGS. 2 and 3 to 5. Even if any abnormality occurs in the UPS modules 11A to 11D, the control unit 14 can continue the peak shift function by controlling the optimal power supply state according to the abnormality.

[0029] Here, FIG. 2 shows the power supply state in which the peak shift function is exerted in the modular UPS 10. Of the 100 kVA of power required by the load 15, 80 kVA is supplied from the commercial power supply 13. The power supplied from the commercial power supply 13 is distributed by the control unit 14 to each of the UPS modules 11A to 11D. In this embodiment, it is distributed to each of the UPS modules 11A to 11D at 20 kVA each.

[0030] Furthermore, the remaining 20 kVA of the power required by the load 15 is supplied from the storage batteries 12A to 12D at 5 kVA each. The amount of power supplied from the storage batteries 12A to 12D is also controlled by the control unit 14.

[0031] From the above, rather than purchasing all 100 kVA originally required by the load 15 from the commercial power supply 13, by using the power stored in the storage batteries 12A to 12D as surplus power, the power to be purchased can be reduced to 80 kVA. This means that the original power demand of 100 kVA is reduced to 80 kVA, and the peak shift function is being exerted.

[0032] FIG. 3 shows the power supply state in which the peak shift function according to the embodiment is exerted when an abnormality occurs in the UPS module 11A and has no effect on the input / output of the UPS module 11A (power supply from the commercial power supply 13 to the load 15).

[0033] When any abnormality occurs in the UPS module 11A in a state where the peak shift function is exerted in the modular UPS 10, the control unit 14 determines the type of the abnormality. When the type of the abnormality has no effect on the input / output of the UPS module 11A, the control unit 14 instructs to continue the same peak shift function as before the occurrence of the abnormality.

[0034] Next, FIG. 4 shows a power supply state in which the peak shift function according to an embodiment is exhibited when an abnormality occurs in the UPS module 11A, which affects the input / output of the UPS module 11A (power supply from the commercial power supply 13 to the load 15), but does not affect the power supply from the storage battery 12A to the load 15.

[0035] When the above abnormality is detected by the control unit 14, the control unit 14 controls to stop the power supply from the commercial power supply 13 to the UPS module 11A. At the same time, in order to continue the peak shift function, the power from the commercial power supply 13 supplied to the UPS module 11A is distributed to the other UPS modules 11B to 11D. For example, in the embodiment, the calculation method regarding the distribution is as follows.

[0036] The value obtained by dividing the number of healthy UPS modules before the occurrence of the abnormality by the difference between the number of healthy UPS modules before the occurrence of the abnormality and the number of the UPS module in which the abnormality has occurred, and the amount of power supplied by each healthy UPS module before the occurrence of the abnormality are integrated and calculated.

[0037] That is, assuming that the number of healthy UPS modules before the occurrence of the abnormality is X and the number of the UPS module in which the abnormality has occurred is Y, the amount of power that is the product of the amount of power supplied by each of the UPS modules 11A to 11D before the occurrence of the abnormality and X / (X - Y) is the amount of power supplied from the healthy UPS modules 11B to 11D calculated by the control unit 14 in order to continue the peak shift function.

[0038] In the embodiment, when there is an impact on the input / output of the UPS module 11A but no impact on the power supply from the storage battery 12A to the load 15, as shown in FIG. 4, the control unit 14 controls so that an amount of power of 20 kVA×4 / (4 - 1)=26.7 kVA is supplied from the UPS modules 11B to 11D to the load 15. Note that this calculation method is an example, and other calculation methods may also be used.

[0039] In addition, the control unit 14 also controls so that the power supply from the storage batteries 12A to 12D is not stopped. By this control, it becomes possible to continue the power supply by the storage batteries 12A to 12D without stopping.

[0040] FIG. 5 shows a power supply state in which the peak shift function according to an embodiment is exhibited when an abnormality occurring in the UPS module 11A affects the input / output of the UPS module and the power supply from the storage battery.

[0041] When the above abnormality is detected by the control unit 14, the control unit 14 stops the power supply from the commercial power supply 13 to the UPS module 11A and controls to stop the power supply from the storage battery 12A. At the same time, in order to continue the peak shift function, the power from the commercial power supply 13 supplied to the UPS module 11A is distributed to the other UPS modules 11B to 11D, and the power supply by the storage batteries 12B to 12D is increased.

[0042] The above-described distribution and increase methods are the same as the methods described above in the embodiment, and other calculation methods may also be used.

[0043] Next, a method for continuing the peak shift function will be described using the flowchart of the peak shift function continuation system in FIG. 6.

[0044] In the modular UPS 10 in which the peak shift function is continuing, an abnormality of Y (Y = 1 in the embodiment) UPS modules is detected by the control unit 14 (S101).

[0045] Next, the control unit 14 determines whether the abnormality affects the input / output of the target UPS module or is an abnormality (S102).

[0046] When it is determined that the abnormality does not affect the input / output of the UPS module (No in S102), the control unit 14 instructs to continue the same peak shift function as before the occurrence of the abnormality, and the peak shift function is continued (S103).

[0047] When it is determined that the abnormality affects the input / output of the UPS module (Yes in S102), next, the control unit 14 determines whether or not the abnormality is an abnormality that affects the power supply from the storage battery (S104).

[0048] When it is determined that the abnormality does not affect the power supply from the storage battery (No in S104), assuming that X (in the embodiment, X = 4) healthy UPS modules 11A to 11D were operating before the above abnormality occurred, the control unit 14 performs the calculation of X - Y. When X - Y = 0 (Yes in S105), that is, when the above abnormality has occurred in all of the UPS modules 11A to 11D, the control unit 14 stops the peak shift function (S111), and the flowchart in the embodiment ends.

[0049] When X - Y is not 0 (No in S105), that is, when it is 4 - 1 = 3 in the embodiment, the control unit 14 instructs the UPS modules 11B to 11D to supply X / (X - Y) times the amount of power that was being supplied to each of the healthy UPS modules 11A to 11D, that is, 4 / (4 - 1) = 4 / 3 times the amount of power in the embodiment (S106).

[0050] In the embodiment, according to the instruction from the control unit 14, the power supply from the UPS modules 11B to 11D is changed from 20 kVA to 26.7 kVA. At this time, since the power supply from each of the storage batteries 12A to 12D is not stopped, while maintaining the power supply amount of 80 kVA from the commercial power supply 13, the power supply of 100 kVA to the load 15 is maintained, and the peak shift function of the modular UPS 10 continues (S107).

[0051] When it is determined that the abnormality affects the power supply from the storage battery (Yes in S104), the control unit 14 performs the X-Y calculation as described above. When X-Y = 0 (Yes in S108), that is, when the above abnormality has occurred in all of the UPS modules 11A to 11D, the control unit 14 stops the peak shift function (S111), and the flowchart in the embodiment ends.

[0052] When X-Y is not 0 (No in S108), that is, when it is 4-1 = 3 in the embodiment, the control unit 14 instructs the UPS modules 11B to 11D, which were operating normally, to supply X / (X-Y) times the amount of power supplied to each of them, that is, 4 / (4-1)=4 / 3 times the amount of power in the embodiment, and also instructs the storage batteries 12B to 12D to supply X / (X-Y) times the amount of power, that is, 4 / (4-1)=4 / 3 times the amount of power in the embodiment (S109).

[0053] In the embodiment, according to the instruction from the control unit 14 described above, the power supply from the UPS modules 11B to 11D is changed from 20 kVA to 26.7 kVA. At the same time, the power supply amount from each of the storage batteries 12B to 12D is also changed from 5 kVA to 6.7 kVA. Therefore, while maintaining the power supply amount of 80 kVA from the commercial power supply 13, the 100 kVA power supply to the load 15 is maintained, and the peak shift function of the modular UPS 10 continues (S110).

[0054] As described above, according to the embodiment, the following effects can be obtained.

[0055] Even if an abnormality occurs in the UPS module while the peak shift function is being exhibited in the modular UPS, it is possible to appropriately continue the peak shift function according to the type of the abnormality, avoid the tightness of the daytime power demand, and suppress the increase in the purchased power amount and the increase in the electricity bill.

[0056] As described above, the embodiments of the present invention have been explained. However, these embodiments are presented as examples and are not intended to limit the scope of the invention. This novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0057] 10…Modular UPS, 11A~11D…UPS Modules, 12A~12D…Batteries, 13…Commercial Power Supply, 14…Control Unit, 15…Load, 16…Control Line

Claims

1. In the in-facility electrical system of a power consumer using a commercial power supply, a storage battery capable of supplying the charged power to the in-facility electrical system; a UPS module to which the storage battery is connected; a modular UPS including a plurality of the UPS modules; a control unit that detects an abnormality of the UPS module and controls an optimal power supply state according to the detected abnormality to continue the peak shifting function; A peak shifting function continuation system comprising the same.

2. The peak shifting function continuation system according to claim 1, wherein the UPS module has a converter function for charging the storage battery from the commercial power supply and an inverter function for supplying power from the storage battery to the in-facility electrical system.

3. The peak shifting function continuation system according to claim 1 or claim 2, wherein the control unit continues the same peak shifting function as before the occurrence of the abnormality when the abnormality has no influence on the input / output of the UPS module.

4. The peak shifting function continuation system according to claim 1 or claim 2, wherein when the abnormality has an influence on the input / output of the UPS module but has no influence on the power supply from the storage battery, the control unit stops the power supply from the commercial power supply to the UPS module in which the abnormality is detected, distributes and supplies the power supplied to the UPS module in which the power supply is stopped to other healthy UPS modules, and continues the peak shifting function.

5. The peak shifting function continuation system according to claim 1 or claim 2, wherein when the abnormality has an influence on the input / output of the UPS module and the power supply from the storage battery, the control unit stops the power supply to the UPS module in which the abnormality is detected and the power supply from the storage battery connected to the UPS module in which the abnormality is detected, distributes and supplies the power supplied to the UPS module in which the power supply is stopped and the power supplied from the storage battery to other healthy UPS modules, and additionally distributes and supplies the power supplied from the storage battery connected to the UPS module in which the abnormality is detected from the storage battery connected to the healthy UPS module, and continues the peak shifting function.

6. A control unit that calculates the amount of power to be distributed by integrating a value obtained by dividing the number of all the UPS modules included in the modular UPS by the difference between the number of all the UPS modules included in the modular UPS and the number of UPS modules whose power supply from the commercial power supply has stopped, and the amount of power supplied by the UPS modules. The peak shift function continuation system according to claim 4.

7. A control unit that calculates the amount of power to be distributed by integrating a value obtained by dividing the number of all the UPS modules included in the modular UPS by the difference between the number of all the UPS modules included in the modular UPS and the number of UPS modules whose power supply from the commercial power supply has stopped, and the amount of power supplied by the UPS modules. The peak shift function continuation system according to claim 5.

8. In a modular UPS including a storage battery capable of supplying charged power to an in-facility electrical system of an electricity consumer, a UPS module to which the storage battery is connected, and a plurality of the UPS modules, one or more of the UPS modules are stopped, and the power supplied to the stopped UPS module is distributed to other operating UPS modules to maintain the power supply from the storage battery. Peak shift function continuation method.

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