Uninterruptible Power Supply System

Abstract

To provide an uninterruptible power supply system capable of supplying sufficient power to a load having high importance (priority) even when an AC power supply fails.SOLUTION: An uninterruptible power supply system 100 comprises: a plurality of regular-use uninterruptible power supply devices 10 each including a converter 11, an inverter 12, a bypass circuit 14 and a switch 15; a standby uninterruptible power supply device 20 for supplying standby power to each of the plurality of regular-use uninterruptible power supply devices 10; and a control device (control unit). When an AC power supply fails, the control device 30 performs power supply control that determines a regular-use uninterruptible power supply device 10 to which standby power is supplied from the standby uninterruptible power supply device 20 among the plurality of regular-use uninterruptible power supply devices 10 connected to the failed AC power supply 101 on the basis of priority set in advance for each of at least the plurality of regular-use uninterruptible power supply devices 10.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to an uninterruptible power supply system, and more particularly to an uninterruptible power supply system including a plurality of regular uninterruptible power supply devices. [Background technology]

[0002] BACKGROUND ART Conventionally, an uninterruptible power supply system including a plurality of regular uninterruptible power supply devices is known (see, for example, Patent Document 1).

[0003] The uninterruptible power supply system described in Patent Document 1 includes a plurality of regular UPSs (regular uninterruptible power supplies), each connected to a load, and a backup UPS that supplies backup power to the regular UPSs in the event of a power outage of the regular UPS. In the uninterruptible power supply system described in Patent Document 1, when a power outage occurs in the commercial power supply (AC power supply) connected to the multiple regular UPSs, backup power is supplied from the backup UPS to all of the multiple regular UPSs. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-271074 Summary of the Invention [Problem to be solved by the invention]

[0005] In the uninterruptible power supply system described in Patent Document 1, when a commercial power supply (AC power supply) connected to multiple regular UPSs experiences a power outage, backup power is supplied from a backup UPS to all of the multiple regular UPSs. As a result, the power output from the backup UPS to one regular UPS may be reduced, and sufficient backup power may not be supplied to the regular UPSs connected to loads with high importance (priority). In this case, there is a problem in that it may be difficult to supply sufficient power to loads with high importance (priority).

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an uninterruptible power supply system that can supply sufficient power to loads of high importance (priority) even in the event of a power outage in the AC power supply. [Means for solving the problem]

[0007] In order to achieve the above object, an uninterruptible power supply system according to one aspect of the present invention comprises a plurality of normal uninterruptible power supplies that are supplied with power from an AC power source and that supply power to a first load connected to each of the plurality of normal uninterruptible power supplies; a backup uninterruptible power supply that supplies backup power to each of the plurality of normal uninterruptible power supplies; and a control unit, wherein each of the plurality of normal uninterruptible power supplies includes a power conversion circuit that converts power input from the AC power source and outputs the converted power to the first load, a bypass circuit that supplies power from the AC power source or the backup uninterruptible power supply to the first load without passing through the power conversion circuit, and a switching circuit that is instructed to open or close by the control unit and switches between a state in which the AC power source and the bypass circuit are connected and a state in which the backup uninterruptible power supply and the bypass circuit are connected, and the control unit performs power supply control to determine, in the event of an AC power power outage, which normal uninterruptible power supply will be supplied with backup power from the backup uninterruptible power supply, of the plurality of normal uninterruptible power supplies connected to the AC power source that has suffered a power outage, based on a priority order that is preset for at least each of the plurality of normal uninterruptible power supplies.

[0008] In an uninterruptible power supply system according to one aspect of the present invention, as described above, when an AC power supply power outage occurs, the control unit performs power supply control to determine, among multiple normal uninterruptible power supplies connected to the AC power supply experiencing the power outage, which normal uninterruptible power supply will receive backup power from the backup uninterruptible power supply, based on a predetermined priority level for each of at least the multiple normal uninterruptible power supplies. This allows backup power from the backup uninterruptible power supply to be preferentially supplied to the normal uninterruptible power supply determined based on the priority level. As a result, it is easy to preferentially supply backup power from the backup uninterruptible power supply to the normal uninterruptible power supply connected to a load with high importance (priority). This allows sufficient power to be supplied to loads with high importance (priority) even when the AC power supply power outage occurs.

[0009] In the uninterruptible power supply system according to the above aspect, the control unit preferably controls the power supply based on the priority and the state of each of the plurality of normal uninterruptible power supplies connected to the AC power supply in the power outage state. With this configuration, it is possible to perform appropriate power supply control according to the state of the normal uninterruptible power supplies, compared to when power supply control is performed based only on the priority.

[0010] In this case, the control unit preferably controls the power supply based on the priority order, the capacity of the first load corresponding to the main uninterruptible power supply connected to the AC power supply in the power outage state, and the available output capacity of the backup uninterruptible power supply. With this configuration, the power supply control can be performed taking into account the capacity of the first load and the available output capacity of the backup uninterruptible power supply, compared to when power supply control is performed based only on the priority order, thereby enabling more appropriate power supply control.

[0011] In the uninterruptible power supply system that controls the power supply based on the priority order, the capacity of the first load, and the available output capacity of the standby uninterruptible power supply, the control unit preferably controls the power supply based on the priority order, the capacity of the first load corresponding to the main uninterruptible power supply connected to the AC power source in the power outage state, the available output capacity of the standby uninterruptible power supply, and also the capacity of the second load connected to the standby uninterruptible power supply. With this configuration, the power supply control can be performed taking into account the capacity of the second load, compared to when power supply control is performed based only on the priority order, the capacity of the first load, and the available output capacity of the standby uninterruptible power supply, thereby enabling more appropriate power supply control.

[0012] In this case, preferably, in the power supply control, the control unit determines the main uninterruptible power supply to which power is to be supplied from the standby uninterruptible power supply based on the priority order so that the total value of the capacities of the first loads corresponding to the main uninterruptible power supplies to which power is to be supplied from the standby uninterruptible power supply is equal to or less than the difference between the available output capacity of the standby uninterruptible power supply and the capacity of the second load. With this configuration, it is possible to determine the main uninterruptible power supply to which power is to be supplied from the standby uninterruptible power supply based on the priority order while preventing the capacity output (consumed) by the standby uninterruptible power supply from exceeding the available output capacity of the standby uninterruptible power supply.

[0013] In an uninterruptible power supply system that controls power supply based on the priority order, the capacity of the first load, and the available output capacity of the backup uninterruptible power supply, the available output capacity of the backup uninterruptible power supply is preferably equal to or greater than the available output capacity of each of the plurality of main uninterruptible power supplies. With this configuration, the available output capacity of the backup uninterruptible power supply becomes relatively large, so that backup power from the backup uninterruptible power supply can be simultaneously supplied to a larger number of main uninterruptible power supplies with higher priority.

[0014] In the uninterruptible power supply system according to the above aspect, the control unit is preferably configured to perform the power supply control when the AC power supply fails based on the priority order of multiple normal uninterruptible power supplies, among the multiple normal uninterruptible power supplies connected to the failed AC power supply, other than the normal uninterruptible power supply that is already supplying power from the backup uninterruptible power supply to the first load. With this configuration, it is possible to continue supplying backup power to a normal uninterruptible power supply that is already supplying backup power from the backup uninterruptible power supply to the first load due to a failure or the like, without stopping the supply of backup power.

[0015] In the uninterruptible power supply system according to the above aspect, the control unit preferably determines, based at least on the priority, in the power supply control, which main uninterruptible power supply has its standby uninterruptible power supply connected to the bypass circuit by the switching circuit, and which main uninterruptible power supply has its AC power supply connected to the bypass circuit by the switching circuit. With this configuration, by switching the switching circuit, it is possible to easily switch whether or not the standby power from the standby uninterruptible power supply is supplied to the load via the bypass circuit.

[0016] In the uninterruptible power supply system according to the above aspect, the control unit preferably determines, in the power supply control, the plurality of main uninterruptible power supplies in descending order of priority as the main uninterruptible power supplies to which backup power is to be supplied from the backup uninterruptible power supply. With this configuration, backup power can be easily supplied from the backup uninterruptible power supply to the plurality of main uninterruptible power supplies with high priority. [Effects of the Invention]

[0017] According to the present invention, as described above, even if the AC power supply fails, sufficient power can be supplied to loads with high importance (priority). [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a diagram illustrating a configuration of an uninterruptible power supply system according to an embodiment during normal operation. [Figure 2] 3 is a diagram showing the priorities of a main uninterruptible power supply and a standby uninterruptible power supply according to an embodiment; FIG. [Figure 3] FIG. 2 illustrates the power supply status in multiple states of an uninterruptible power supply system according to one embodiment. [Figure 4] 1 is a diagram showing a state when a continuous uninterruptible power supply 10c of an uninterruptible power supply system according to an embodiment fails (is undergoing maintenance). FIG. [Figure 5] FIG. 2 is a diagram illustrating a state of an uninterruptible power supply system according to an embodiment during a power outage. [Figure 6] 1 is a diagram showing a state of an uninterruptible power supply system according to an embodiment at the time of a power outage and a failure (maintenance) of a continuous uninterruptible power supply 10c. [Figure 7] 1 is a diagram showing a state of an uninterruptible power supply system according to an embodiment at the time of a power outage and a failure (maintenance) of a continuous uninterruptible power supply 10d. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0020] (Uninterruptible Power Supply System Configuration) The configuration of an uninterruptible power supply system 100 according to this embodiment will be described with reference to FIGS.

[0021] 1, the uninterruptible power supply system 100 includes a plurality of (four in this embodiment) main uninterruptible power supply devices 10, a backup uninterruptible power supply device 20, and a control device 30. The control device 30 is an example of the "control unit" in the claims.

[0022] The multiple normal uninterruptible power supplies 10 include normal uninterruptible power supplies 10a, 10b, 10c, and 10d. The normal uninterruptible power supplies 10a to 10d have a common configuration. Therefore, in the following description, matters described as "normal uninterruptible power supplies 10" are matters common to each of the normal uninterruptible power supplies 10a to 10d.

[0023] The standby uninterruptible power supply 20 supplies standby power to each of the multiple normal uninterruptible power supplies 10. Specifically, as will be described later, the standby uninterruptible power supply 20 is provided to supply standby power to the normal uninterruptible power supplies 10 in the event of a failure (maintenance) of the normal uninterruptible power supply 10 or in the event of a power outage of the AC power supply 101.

[0024] The control device 30 is configured to control the operation of each of the regular uninterruptible power supply 10 and the standby uninterruptible power supply 20. The control device 30 is provided separately from the regular uninterruptible power supply 10 and the standby uninterruptible power supply 20. The control device 30 is configured, for example, by a PLC (programmable logic controller).

[0025] Each of the regular uninterruptible power supplies 10 and the standby uninterruptible power supplies 20 is supplied with power from a commercial AC power supply 101, which is a power source of a common power system. During normal operation of the uninterruptible power supply system 100 shown in Figure 1, each of the multiple regular uninterruptible power supplies 10 and standby uninterruptible power supplies 20 supplies power from the AC power supply 101 to loads (102 to 106) connected to each of them, which will be described later.

[0026] Regular uninterruptible power supply 10a, regular uninterruptible power supply 10b, regular uninterruptible power supply 10c, and regular uninterruptible power supply 10d supply power to load 102, load 103, load 104, and load 105, respectively. Also, standby uninterruptible power supply 20 supplies power to load 106. Each of loads 102 to 105 is an example of a "first load" in the claims. Also, load 106 is an example of a "second load" in the claims.

[0027] The continuous uninterruptible power supply 10 includes a converter 11, an inverter 12, a battery 13, a bypass circuit 14, a selector 15, and a switch 16. The converter 11 and the inverter 12 are an example of a "power conversion circuit" in the claims. The selector 15 is an example of a "switching circuit" in the claims.

[0028] Converter 11 converts AC power input from AC power supply 101 into DC power. A part of the DC power converted by converter 11 is sent to inverter 12. The remaining part of the DC power converted by converter 11 is charged into battery 13.

[0029] The inverter 12 converts the DC power sent from the converter 11 into AC power. Then, the AC power from the inverter 12 is output to the loads (102 to 105).

[0030] Furthermore, the battery 13 supplies power to the loads (102 to 105) when power from the AC power supply 101 is not supplied to the loads (102 to 105). Specifically, the battery 13 supplies power to the loads (102 to 105) when a power outage occurs in the AC power supply 101. The battery 13 is connected between the converter 11 and the inverter 12.

[0031] The bypass circuit 14 is provided to supply power from the AC power supply 101 or the standby uninterruptible power supply 20 to the loads (102 to 105) without passing through the converter 11 and the inverter 12. In other words, the bypass circuit 14 is provided to bypass the converter 11 and the inverter 12.

[0032] The switch 15 is configured to switch between a state in which the AC power supply 101 and the bypass circuit 14 are connected and a state in which the standby uninterruptible power supply 20 and the bypass circuit 14 are connected. The switch 15 is, for example, a double throw magnetic contactor (DTMC). No switch is provided between the AC power supply 101 and the converter 11.

[0033] The switch 16 is provided in the bypass circuit 14. When the switch 16 is closed, the power input to the bypass circuit 14 is supplied to the loads (102 to 105). On the other hand, when the switch 16 is open, the power input to the bypass circuit 14 is not supplied to the loads (102 to 105). In this case, the power input to the bypass circuit 14 is not supplied to the loads (102 to 105). In FIG. 1 (and FIGS. 4 to 7), the flow of current is indicated by dashed arrows.

[0034] The standby uninterruptible power supply 20 includes a converter 21, an inverter 22, and a battery 23. The converter 21, the inverter 22, and the battery 23 are similar to the converter 11, the inverter 12, and the battery 13 of the main uninterruptible power supply 10, respectively, and therefore detailed description thereof will be omitted.

[0035] The standby uninterruptible power supply 20 supplies standby power to each of the plurality of normal uninterruptible power supplies 10 via wiring 24 connected to the switch 15 of each of the plurality of normal uninterruptible power supplies 10. During normal operation of the uninterruptible power supply system 100 shown in Figure 1, the switch 16 of each of the plurality of normal uninterruptible power supplies 10 is open, and therefore the standby power from the standby uninterruptible power supply 20 is not supplied to the loads (102 to 105).

[0036] 2, as will be described later, each of the normal uninterruptible power supplies 10a to 10d has a preset priority order for supplying backup power from the backup uninterruptible power supply 20 in the event of a power outage. Specifically, the priorities of the normal uninterruptible power supply 10a, the normal uninterruptible power supply 10b, the normal uninterruptible power supply 10c, and the normal uninterruptible power supply 10d are set to 1st, 2nd, 3rd, and 4th, respectively.

[0037] The output capacity (possible output capacity) of each of the plurality of normal uninterruptible power supplies 10 (10a to 10d) is 500 kVA.

[0038] In this embodiment, the available output capacity of the standby uninterruptible power supply 20 is equal to or greater than the available output capacity of each of the plurality of regular uninterruptible power supplies 10. Specifically, the available output capacity of the standby uninterruptible power supply 20 is 1000 kVA, which is twice the available output capacity of each of the plurality of regular uninterruptible power supplies 10.

[0039] In addition, the load capacities of load 102 connected to normal uninterruptible power supply 10a, load 103 connected to normal uninterruptible power supply 10b, load 104 connected to normal uninterruptible power supply 10c, and load 105 connected to normal uninterruptible power supply 10d are 300kVA, 400kVA, 300kVA, and 200kVA, respectively.

[0040] Furthermore, the load capacity of the load 106 connected to the standby uninterruptible power supply 20 is smaller than the load capacity of the loads (102 to 105) connected to each of the multiple main uninterruptible power supplies 10. Specifically, the load capacity of the load 106 is 100 kVA, which is half or less the load capacity of each of the loads (102 to 105).

[0041] (Uninterruptible power supply system operation) The operation of the uninterruptible power supply system 100 will be described below with reference to FIGS.

[0042] (during normal operation) As shown in FIG. 1, during normal operation of the uninterruptible power supply system 100, AC power from an AC power source 101 is converted into DC power by a converter 11 of a main uninterruptible power supply 10, and the DC power from the converter 11 is converted into AC power by an inverter 12. The AC power converted by the inverter 12 is then supplied to loads (102 to 105). At this time, a switch 15 of each of the multiple main uninterruptible power supplies 10 connects a standby uninterruptible power supply 20 to a bypass circuit 14 of the main uninterruptible power supply 10 (see the "Normal Operation" column in FIG. 3). Note that in FIG. 3, the unhatched "standby system" indicates a state in which the standby uninterruptible power supply 20 and the bypass circuit 14 are connected by the switch 15, and the switch 16 is open, so that the standby power of the standby uninterruptible power supply 20 is not supplied to the loads (102 to 105).

[0043] (During failure / maintenance) Next, with reference to FIGS. 4 and 3 (see the column "Upon Failure (Maintenance) of 10c"), the operation of the uninterruptible power supply system 100 when the normal uninterruptible power supply 10c fails (or undergoes maintenance) will be described. In this case, as shown in FIG. 4, the switch 16 of the normal uninterruptible power supply 10c is closed, and power from the standby uninterruptible power supply 20 is supplied to the load 104 via the bypass circuit 14 of the normal uninterruptible power supply 10c. The operation of the other normal uninterruptible power supplies 10 (10a, 10b, and 10d) is the same as during normal operation (see FIG. 1). Note that the normal uninterruptible power supply 10c transmits a signal (see dashed line) to the control device 30 indicating that power is being supplied from the standby uninterruptible power supply 20. This allows the control device 30 to detect that the normal uninterruptible power supply 10c is receiving power from the standby uninterruptible power supply 20.

[0044] (During a power outage) In this embodiment, when the AC power supply 101 experiences a power outage, the control device 30 performs power supply control to determine, from among the plurality of normal uninterruptible power supplies 10 connected to the AC power supply 101 in the power outage state, a normal uninterruptible power supply 10 to which backup power is supplied from the backup uninterruptible power supply 20, based at least on the priority order preset for each of the plurality of normal uninterruptible power supplies 10. Specifically, in the power supply control, the control device 30 determines, based at least on the priority order, the normal uninterruptible power supply 10 to which the backup uninterruptible power supply 20 and the bypass circuit 14 are connected by the switch 15, and the normal uninterruptible power supply 10 to which the AC power supply 101 and the bypass circuit 14 are connected by the switch 15.

[0045] 5, the main uninterruptible power supply 10 transmits a power outage operation signal (see dashed line) to the control device 30 based on a power outage of the AC power supply 101. Based on receiving the power outage operation signal, the control device 30 transmits a switching signal (see dashed line) to switch the switch 15 to the main uninterruptible power supply 10 that has been determined not to supply the backup power of the backup uninterruptible power supply 20. Upon receiving the switching signal, the main uninterruptible power supply 10 connects the AC power supply 101 and the bypass circuit 14 via the switch 15. Based on the power outage of the AC power supply 101, the main uninterruptible power supply 10 starts control to supply DC power from the battery 13 to the loads (102 to 105) via the inverter 12.

[0046] When the switch 15 connects the AC power supply 101 and the bypass circuit 14, the standby uninterruptible power supply 20 and the AC power supply 101 are disconnected. Therefore, there is no need for adjustments to prevent interference between the constant voltage control of the standby uninterruptible power supply 20 (inverter 22) and the constant voltage control of the AC power supply 101. As a result, it is possible to simplify the control of the uninterruptible power supply system 100.

[0047] Furthermore, in this embodiment, the control device 30 performs the power supply control based on the priority order, the capacity of the loads (102 to 105) corresponding to the main uninterruptible power supply 10 connected to the AC power supply 101 in a power outage state, the available output capacity of the standby uninterruptible power supply 20, and the capacity of the load 106 connected to the standby uninterruptible power supply 20. Information on the capacities of the loads (102 to 106) and the available output capacity of the standby uninterruptible power supply 20 is stored in advance in the control device 30. Information on the (available) output capacity of the main uninterruptible power supply 10 is also stored in advance in the control device 30. Furthermore, the main uninterruptible power supply 10 being connected to loads (102 to 105) with predetermined load capacities is an example of "the state of each of the plurality of main uninterruptible power supplies" in the claims.

[0048] Specifically, in the above-mentioned power supply control, the control device 30 determines the normal uninterruptible power supply 10 to which power is supplied from the standby uninterruptible power supply 20 based on priority so that the total capacity of the loads (102 to 105) corresponding to the normal uninterruptible power supply 10 to which power is supplied from the standby uninterruptible power supply 20 is less than or equal to the difference between the output capacity of the standby uninterruptible power supply 20 and the capacity of the load 106.

[0049] 5 and 3 (see the "Power Outage" column), the control device 30 determines that the first-priority regular uninterruptible power supply 10a and the second-priority regular uninterruptible power supply 10b are the regular uninterruptible power supplies 10 to which backup power is supplied from the backup uninterruptible power supply 20. As a result, the sum (700 kVA) of the capacity (300 kVA) of the load 102 corresponding to the regular uninterruptible power supply 10a and the capacity (400 kVA) of the load 103 corresponding to the regular uninterruptible power supply 10b becomes equal to or less than the difference (900 kVA) between the available output capacity (1000 kVA) of the backup uninterruptible power supply 20 and the capacity (100 kVA) of the load 106. Note that "own system" in FIG. 3 refers to a state in which the AC power supply 101 and the bypass circuit 14 are connected by the switch 15. In addition, the hatched "standby system" in Figure 3 means that the standby uninterruptible power supply 20 and the bypass circuit 14 are connected by a switch 15, and the standby power of the standby uninterruptible power supply 20 is supplied to the loads (102 to 105) via the bypass circuit 14.

[0050] If the main uninterruptible power supply 10c, which has the third highest priority, is also determined to be the main uninterruptible power supply 10 to be supplied with backup power from the backup uninterruptible power supply 20, the total capacity of the loads (102 to 104) (300 + 400 + 300 = 1000 kVA) would be greater than the difference (900 kVA). Therefore, the control device 30 does not select the main uninterruptible power supplies 10 (10c, 10d) with priorities third or lower as the main uninterruptible power supplies 10 to be supplied with backup power from the backup uninterruptible power supply 20. If the main uninterruptible power supply 10d, which has the fourth highest priority, is selected in addition to the main uninterruptible power supply 10a and the main uninterruptible power supply 10b as the main uninterruptible power supply 10 to be supplied with backup power from the backup uninterruptible power supply 20, the total capacity of the loads (102, 103, 105) (900 kVA) would be equal to the difference (900 kVA). Therefore, in addition to the normal uninterruptible power supply 10a and the normal uninterruptible power supply 10b, the control device 30 may select the normal uninterruptible power supply 10d, which has the fourth priority, instead of selecting the normal uninterruptible power supply 10c, which has the third priority, as the normal uninterruptible power supply 10 to which backup power is supplied from the backup uninterruptible power supply 20.

[0051] 5, the main uninterruptible power supply 10 continues to supply power from the battery 13 to the loads (102 to 105) even after the supply of backup power from the backup uninterruptible power supply 20 has begun. Then, after the charge in the battery 13 runs out, the main uninterruptible power supply 10, to which backup power is being supplied from the backup uninterruptible power supply 20, supplies only the backup power from the backup uninterruptible power supply 20 to the loads (102 to 105).

[0052] 6 and 7, in this embodiment, the control device 30 is configured to perform power supply control when the AC power supply 101 experiences a power outage, based on the priority order of multiple normal uninterruptible power supplies 10 connected to the powered-down AC power supply 101, other than the normal uninterruptible power supply 10 that is already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105). In other words, the control device 30 is configured to exclude from the power supply control, when the AC power supply 101 experiences a power outage, the normal uninterruptible power supplies 10 that are already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105) among the multiple normal uninterruptible power supplies 10 connected to the powered-down AC power supply 101.

[0053] For example, as shown in Figures 6 and 3 (see the column "Power outage + 10c failure (maintenance)"), assume that due to a failure (maintenance) or the like, regular uninterruptible power supply 10c is already supplying power from standby uninterruptible power supply 20 to load 104. In this case, control device 30 determines which regular uninterruptible power supply 10 will supply backup power from standby uninterruptible power supply 20 from regular uninterruptible power supply 10a, regular uninterruptible power supply 10b, and regular uninterruptible power supply 10d.

[0054] Specifically, the control device 30 determines the main uninterruptible power supply 10 to be supplied with power from the standby uninterruptible power supply 20 based on the priority order so that the total capacity of the loads (102, 103, 105) corresponding to the main uninterruptible power supplies 10 to be supplied with backup power from the standby uninterruptible power supply 20 is equal to or less than the value obtained by subtracting the capacity of the load 106 (100 kVA) and the load capacity of the main uninterruptible power supply 10c (300 kVA) from the available output capacity (1000 kVA) of the standby uninterruptible power supply 20 (1000 - 100 - 300 = 600 kVA). In this case, the control device 30 determines only the main uninterruptible power supply 10a, which has the highest priority order, as the main uninterruptible power supply 10 to be supplied with power from the standby uninterruptible power supply 20. Even if, in addition to regular uninterruptible power supply 10a, regular uninterruptible power supply 10d, which has the fourth highest priority, is determined as the regular uninterruptible power supply 10 to be supplied with power from standby uninterruptible power supply 20, the total capacity of the loads (102, 105) (300 + 200 = 500 kVA) will be smaller than the above-mentioned subtracted value (600 kVA). Therefore, the control device 30 may select regular uninterruptible power supply 10d, which has the fourth highest priority, as the regular uninterruptible power supply 10 to be supplied with power from standby uninterruptible power supply 20, instead of selecting regular uninterruptible power supply 10b, which has the second highest priority, in addition to regular uninterruptible power supply 10a.

[0055] 7 and 3 (see the column "Power outage + 10d failure (maintenance)"), assume that normal uninterruptible power supply 10d is already supplying backup power from standby uninterruptible power supply 20 to load 105 due to a failure (maintenance) or the like. In this case, control device 30 determines the normal uninterruptible power supply 10 that will supply backup power from standby uninterruptible power supply 20 from normal uninterruptible power supply 10a, normal uninterruptible power supply 10b, and normal uninterruptible power supply 10c.

[0056] Specifically, the control device 30 determines the main uninterruptible power supply 10 to be supplied with power from the standby uninterruptible power supply 20 based on the priority order so that the total capacity of the loads (102, 103, 104) corresponding to the main uninterruptible power supplies 10 to be supplied with backup power from the standby uninterruptible power supply 20 is equal to or less than the value obtained by subtracting the capacity of the load 106 (100 kVA) and the load capacity of the main uninterruptible power supply 10d (200 kVA) from the available output capacity (1000 kVA) of the standby uninterruptible power supply 20 (1000 - 100 - 200 = 700 kVA). In this case, the control device 30 determines the main uninterruptible power supply 10a, which has the first priority order, and the main uninterruptible power supply 10b, which has the second priority order, as the main uninterruptible power supplies 10 to be supplied with power from the standby uninterruptible power supply 20.

[0057] The example shown in Figure 5 (see the "During power outage" column in Figure 3) and the example shown in Figure 7 (see the "During power outage + 10d failure (maintenance)" column in Figure 3) are examples in which the control device 30 determines, in power supply control, multiple regular uninterruptible power supplies 10 in descending order of priority as regular uninterruptible power supplies 10 to which backup power is supplied from the backup uninterruptible power supply 20.

[0058] Furthermore, when the AC power supply 101 is restored after the above-described power supply control, the uninterruptible power supply system 100 performs the normal operation shown in FIG.

[0059] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0060] In this embodiment, as described above, the uninterruptible power supply system 100 is configured to include a control device 30 that performs power supply control to determine, when the AC power supply 101 experiences a power outage, which of the multiple normal uninterruptible power supplies 10 connected to the AC power supply 101 that is to receive backup power from the backup uninterruptible power supply 20, based on at least a predetermined priority order set for each of the multiple normal uninterruptible power supplies 10. This allows backup power from the backup uninterruptible power supply 20 to be preferentially supplied to the normal uninterruptible power supply 10 determined based on the priority order. As a result, it is easy to preferentially supply backup power from the backup uninterruptible power supply 20 to the normal uninterruptible power supplies 10 connected to loads (102 to 105) with high importance (priority). This allows sufficient power to be supplied to the loads (102 to 105) with high importance (priority), even when the AC power supply 101 experiences a power outage.

[0061] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the control device 30 controls the power supply based on the priority and the state of each of the multiple continuous uninterruptible power supplies 10 connected to the AC power supply 101 in a power outage. This makes it possible to perform appropriate power supply control according to the state of the continuous uninterruptible power supply 10, compared to when power supply control is performed based only on the priority.

[0062] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the control device 30 controls the power supply based on the priority order, the capacity of the loads (102 to 105) corresponding to the main uninterruptible power supply 10 connected to the AC power supply 101 in a power outage, and the available output capacity of the standby uninterruptible power supply 20. This allows the power supply control to be performed taking into consideration the capacity of the loads (102 to 105) and the available output capacity of the standby uninterruptible power supply 20, compared to when the power supply control is performed based only on the priority order, thereby enabling more appropriate power supply control.

[0063] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the control device 30 controls the power supply based on the capacity of the load 106 connected to the standby uninterruptible power supply 20 in addition to the priority order, the capacity of the loads (102 to 105) corresponding to the main uninterruptible power supplies 10 connected to the AC power supply 101 in a power outage, and the available output capacity of the standby uninterruptible power supply 20. This allows the power supply control to be performed taking into account the capacity of the load 106, compared to when power supply control is performed based only on the priority order, the capacity of the loads (102 to 105), and the available output capacity of the standby uninterruptible power supply 20, thereby enabling more appropriate power supply control.

[0064] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that, in power supply control, the control device 30 determines the main uninterruptible power supply 10 to be supplied with power from the standby uninterruptible power supply 20 based on the priority order so that the total value of the capacities of the loads (102 to 105) corresponding to the main uninterruptible power supplies 10 to be supplied with power from the standby uninterruptible power supply 20 is equal to or less than the difference between the available output capacity of the standby uninterruptible power supply 20 and the capacity of the load 106. In this way, it is possible to determine the main uninterruptible power supply 10 to be supplied with power from the standby uninterruptible power supply 20 based on the priority order while preventing the capacity output (consumption) of the standby uninterruptible power supply 20 from exceeding the available output capacity of the standby uninterruptible power supply 20.

[0065] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the available output capacity of the standby uninterruptible power supply 20 is equal to or greater than the available output capacity of each of the plurality of regular uninterruptible power supplies 10. This makes the available output capacity of the standby uninterruptible power supply 20 relatively large, so that backup power from the standby uninterruptible power supply 20 can be simultaneously supplied to a greater number of regular uninterruptible power supplies 10 with higher priority.

[0066] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that, when the AC power supply 101 experiences a power outage, the control device 30 controls the power supply based on the priority order of the multiple normal uninterruptible power supplies 10 connected to the powered-down AC power supply 101, other than the normal uninterruptible power supply 10 that is already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105). This makes it possible to continue supplying backup power to a normal uninterruptible power supply 10 that is already supplying backup power from the standby uninterruptible power supply 20 to the loads (102 to 105) due to a failure or the like, without stopping the supply of backup power.

[0067] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the control device 30, in power supply control, determines, based at least on the priority, the normal uninterruptible power supply 10 to which the standby uninterruptible power supply 20 and the bypass circuit 14 are connected by the switch 15, and the normal uninterruptible power supply 10 to which the AC power source 101 and the bypass circuit 14 are connected by the switch 15. This makes it possible to easily switch, by switching the switch 15, whether or not the standby power from the standby uninterruptible power supply 20 is supplied to the loads (102 to 105) via the bypass circuit 14.

[0068] Furthermore, in this embodiment, as described above, the uninterruptible power supply system 100 is configured so that the control device 30 determines, in power supply control, the multiple regular uninterruptible power supplies 10 in descending order of priority as the regular uninterruptible power supplies 10 to which backup power is supplied from the backup uninterruptible power supply 20. This makes it possible to easily supply backup power from the backup uninterruptible power supply 20 to the multiple regular uninterruptible power supplies 10 with high priority.

[0069] (Variation) The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0070] For example, in the above embodiment, the control device 30 (controller) controls the power supply based on the priority order preset for the multiple main uninterruptible power supplies 10, the available output capacity of the standby uninterruptible power supply 20, the load capacity of the loads (102 to 105) (first loads), and the load capacity of the load 106 (second load). However, the present invention is not limited to this. For example, the control device 30 may control the power supply based only on the priority order. Alternatively, the control device 30 may control the power supply based on the priority order and at least one of the available output capacity of the standby uninterruptible power supply 20, the load capacity of the loads (102 to 105), and the load capacity of the load 106. Alternatively, the control device 30 may control the power supply based on the priority order and predetermined information other than the available output capacity of the standby uninterruptible power supply 20, the load capacity of the loads (102 to 105), and the load capacity of the load 106 (for example, the remaining capacity of the battery 13).

[0071] In the above embodiment, an example has been shown in which the standby uninterruptible power supply 20 supplies power to the load 106 (second load), but the present invention is not limited to this. The standby uninterruptible power supply 20 does not have to supply power to loads other than the loads (102 to 105) corresponding to the main uninterruptible power supply 10.

[0072] In the above embodiment, the available output capacity of the standby uninterruptible power supply 20 is equal to or greater than the available output capacity of each of the plurality of main uninterruptible power supplies 10, but the present invention is not limited to this. The available output capacity of the standby uninterruptible power supply 20 may be smaller than the available output capacity of each of the plurality of main uninterruptible power supplies 10.

[0073] In the above embodiment, an example was shown in which the load capacity of the load 106 (second load) corresponding to the standby uninterruptible power supply 20 was smaller than the load capacity of the loads (102 to 105) (first loads) corresponding to each of the multiple main uninterruptible power supplies 10, but the present invention is not limited to this. The load capacity of the load 106 may be equal to or greater than the load capacity of the loads (102 to 105).

[0074] Furthermore, in the above embodiment, an example has been shown in which the main uninterruptible power supply 10 selected by power supply control supplies the backup power supplied from the backup uninterruptible power supply 20 to the loads (102 to 105) via the bypass circuit 14, but the present invention is not limited to this. The backup power of the backup uninterruptible power supply 20 may be supplied to the loads (102 to 105) without going through the bypass circuit 14 (for example, directly from the backup uninterruptible power supply 20).

[0075] Furthermore, in the above embodiment, an example was shown in which power supply control was performed based on the priority of multiple normal uninterruptible power supplies 10, among the multiple normal uninterruptible power supplies 10 connected to the AC power supply 101 that has experienced a power outage, other than the normal uninterruptible power supply 10 that is already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105) (first loads). However, the present invention is not limited to this. Power conversion control may also be performed taking into consideration the priority of the normal uninterruptible power supplies 10 that are already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105). In other words, normal uninterruptible power supplies 10 that are already supplying power from the standby uninterruptible power supply 20 to the loads (102 to 105) may also be subject to power supply control.

[0076] In the above embodiment, the control device 30 (control unit) is provided separately from the plurality of regular uninterruptible power supplies 10 and the backup uninterruptible power supply 20, but the present invention is not limited to this. For example, the control unit may be provided in the backup uninterruptible power supply 20.

[0077] Furthermore, in the above embodiment, an example has been shown in which the regular uninterruptible power supply 10 (standby uninterruptible power supply 20) includes the battery 13 (battery 23), but the present invention is not limited to this. The regular uninterruptible power supply 10 (standby uninterruptible power supply 20) may include a DC power source other than a battery. Furthermore, the regular uninterruptible power supply 10 (standby uninterruptible power supply 20) may not include a battery (DC power source).

[0078] Furthermore, in the above embodiment, an example has been shown in which each of the multiple normal uninterruptible power supplies 10 is supplied with power from an AC power supply 101 of a common system, but the present invention is not limited to this. Each of the multiple normal uninterruptible power supplies 10 does not have to be supplied with power from an AC power supply 101 of a common system. For example, some of the four normal uninterruptible power supplies 10 may be supplied with power from an AC power supply of a first system, and the remaining some may be supplied with power from an AC power supply of a second system different from the first system. Furthermore, the standby uninterruptible power supply 20 may be supplied with power from an AC power supply of a system different from the AC power supplies 101 connected to the multiple normal uninterruptible power supplies 10. [Explanation of symbols]

[0079] 10, 10a, 10b, 10c, 10d regular uninterruptible power supply 11 Converter (power conversion circuit) 12 Inverter (power conversion circuit) 14 Bypass circuit 15 Switch (switching circuit) 20 Standby uninterruptible power supply 30 Control device (control unit) 100 Uninterruptible Power Supply System 101 AC power supply 102, 103, 104, 105 load (1st load) 106 load (second load)

Claims

1. a plurality of continuous uninterruptible power supplies each receiving power from an AC power supply and supplying power to a first load connected to each of the continuous uninterruptible power supplies; a standby uninterruptible power supply unit that supplies standby power to each of the plurality of normal uninterruptible power supplies; a control unit, Each of the plurality of normal uninterruptible power supplies includes a power conversion circuit that converts power input from the AC power supply and outputs the converted power to the first load, a bypass circuit that supplies power from the AC power supply or the standby uninterruptible power supply to the first load without passing through the power conversion circuit, and a switching circuit that is instructed to be opened or closed by the control unit and switches between a state in which the AC power supply and the bypass circuit are connected and a state in which the standby uninterruptible power supply and the bypass circuit are connected, In an uninterruptible power supply system, when the AC power supply experiences a power outage, the control unit performs power supply control to determine, among the plurality of normal uninterruptible power supplies connected to the AC power supply in the power outage state, which normal uninterruptible power supply will be supplied with backup power from the backup uninterruptible power supply, based at least on a priority order preset for each of the plurality of normal uninterruptible power supplies.

2. 2. The uninterruptible power supply system according to claim 1, wherein the control unit performs the power supply control based on the priority and the state of each of the plurality of normal uninterruptible power supply devices connected to the AC power supply in a power outage state.

3. 3. The uninterruptible power supply system according to claim 2, wherein the control unit performs the power supply control based on the priority, the capacity of the first load corresponding to the normal uninterruptible power supply connected to the AC power supply in a power outage state, and the output capacity of the standby uninterruptible power supply.

4. 4. The uninterruptible power supply system according to claim 3, wherein the control unit controls the power supply based on the priority, the capacity of the first load corresponding to the normal uninterruptible power supply connected to the AC power source in a power outage state, the available output capacity of the standby uninterruptible power supply, and the capacity of the second load connected to the standby uninterruptible power supply.

5. 5. The uninterruptible power supply system of claim 4, wherein the control unit, in the power supply control, determines the normal uninterruptible power supply to which power is supplied from the standby uninterruptible power supply based on the priority order so that the total value of the capacities of the first loads corresponding to the normal uninterruptible power supplies to which power is supplied from the standby uninterruptible power supply is less than or equal to the difference between the output capacity of the standby uninterruptible power supply and the capacity of the second load.

6. 6. The uninterruptible power supply system according to claim 3, wherein the available output capacity of the standby uninterruptible power supply is equal to or greater than the available output capacity of each of the plurality of main uninterruptible power supplies.

7. The uninterruptible power supply system according to any one of claims 1 to 6, wherein the control unit is configured to perform the power supply control when the AC power supply is powered down based on the priority order of the plurality of normal uninterruptible power supplies connected to the AC power supply that has been powered down, other than the normal uninterruptible power supply that is already supplying power from the backup uninterruptible power supply to the first load.

8. 8. The uninterruptible power supply system according to claim 1, wherein the control unit, in the power supply control, determines, based at least on the priority, the normal uninterruptible power supply to which the standby uninterruptible power supply and the bypass circuit are connected by the switching circuit, and the normal uninterruptible power supply to which the AC power supply and the bypass circuit are connected by the switching circuit.

9. An uninterruptible power supply system according to any one of claims 1 to 8, wherein the control unit, in the power supply control, determines the plurality of regular uninterruptible power supplies in descending order of priority as the regular uninterruptible power supplies to which backup power is supplied from the backup uninterruptible power supply.

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