Power system

Abstract

To provide a technique capable of appropriately performing maintenance work in a power system including an uninterruptible power supply device.SOLUTION: This power supply system 10 supplies power from a power supply system 1 connected to a system power source 2 to a load, and the power supply system 1 is provided with a power source switching part 5 for selectively switching a first state where a path connected to the system power source 2 through an uninterruptible power supply device 3 and a path connected to the load 41 are connected and a second state where the path connected to the system power source 2 through the uninterruptible power supply device 3 and the path connected to the load 41 are not connected, a relay part 6 having a plurality of output parts 16 for outputting power from the uninterruptible power supply device 3 to the power source switching part 5, and an output selection part 7 for selectively connecting each of the plurality of output parts 16 to the uninterruptible power supply device 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to power systems. [Background technology]

[0002] For example, Japanese Patent Laid-Open Publication No. 2015-180136 (Patent Document 1) discloses a technology related to a power system. In the following description of the background art, the reference numerals in parentheses refer to those in Patent Document 1.

[0003] The power system of Patent Document 1 includes a plurality of uninterruptible power supplies (U1 to U3), a plurality of batteries (B1 to B3), and an output panel (7). The plurality of batteries (B1 to B3) are connected to corresponding uninterruptible power supplies (U1 to U3). The uninterruptible power supplies (U1 to U3) are configured to output power supplied from a system power supply to the output panel (7), and to output power supplied from the batteries to the output panel (7) when power is not normally supplied from the system power supply. The output panel (7) outputs power from each of the uninterruptible power supplies (U1 to U3) to a load. The output panel (7) includes a plurality of breakers (switches S11 to S13) corresponding to each of the plurality of uninterruptible power supplies (U1 to U3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-180136 Summary of the Invention [Problem to be solved by the invention]

[0005] In the power system of Patent Document 1, an output panel is placed between multiple uninterruptible power supplies and a load, and the power output from the uninterruptible power supplies is aggregated in the output panel and supplied to the load via the output panel. Therefore, when performing maintenance work on the output panel, it is necessary to cut off the power supply to the load. However, if the load includes a device or the like that does not allow the power supply to be cut off, the power supply to the load cannot be cut off, which creates a problem in that maintenance on the output panel cannot be performed.

[0006] The present invention has been made in view of the above-mentioned problems, and aims to provide a technique that enables maintenance work to be performed appropriately in a power system equipped with an uninterruptible power supply. [Means for solving the problem]

[0007] A characteristic configuration of a power system according to the present invention is a power system that supplies power to a load from a power supply system connected to a grid power source, The power supply system includes: a plurality of uninterruptible power supplies; a power supply switching unit that selectively switches between a first state in which a path connected to the system power supply via the uninterruptible power supply device and a path connected to the load are connected, and a second state in which a path connected to the system power supply without via the uninterruptible power supply device and a path connected to the load are connected; a plurality of relay units capable of outputting power from the plurality of uninterruptible power supply devices to the power supply switching unit; an output selection unit that selectively connects each of the plurality of uninterruptible power supply units to each of the plurality of relay units.

[0008] According to the above characteristic configuration, the power supply system normally selects the first state, and in the normal case where the power supply from the grid power source is normal, power is supplied to the load from the grid power source via multiple uninterruptible power supply devices. Even if a problem occurs in the power supply from the grid power source, power can be supplied to the load from multiple uninterruptible power supply devices (for example, storage batteries of the uninterruptible power supply devices). Furthermore, if a problem occurs in the path via the uninterruptible power supply devices, the power supply system selects the second state, and power can be supplied to the load from the grid power source without passing through the uninterruptible power supply devices. Therefore, it is possible to avoid interruption of the power supply to the load. Furthermore, since multiple relay units are provided, in the first state, at least one of these relay units can be used to output power from the uninterruptible power supply to the power supply switching unit. The remaining relay units that are not outputting power to the power supply switching unit can be electrically disconnected by the output selection unit and the power supply switching unit. This allows maintenance to be performed on any relay unit by placing the relay unit to be maintained in a no-voltage state. When performing maintenance on a relay unit that is currently supplying power to the power supply switching unit, the power supply switching unit is first supplied with power from another relay unit, and then the relay unit to be maintained is placed in a no-voltage state. This allows maintenance to be performed on the relay unit without stopping the power supply from the uninterruptible power supply to the load.

[0009] Another characteristic configuration of the power system according to the present invention is each of the plurality of relay units includes at least one output unit capable of outputting power from the uninterruptible power supply to the power supply switching unit; The power supply system includes: At least one of the plurality of output units is set as a target output unit, a third state in which a path connected to the target output unit via the power supply switching unit and a path connected to the load are connected, and a fourth state in which a path connected to the target output unit without going through the power supply switching unit and a path connected to the load are connected, The path changeover switch is a manual switch that is manually operated to selectively switch between the third state and the fourth state.

[0010] According to the above characteristic configuration, by transitioning from the third state to the fourth state without stopping the power supply to the load using the output unit including the target output unit and the uninterruptible power supply direct transfer selection unit, it is possible to perform maintenance work on the power supply switching unit while maintaining a state in which power can be continuously supplied from the uninterruptible power supply device to the load. Furthermore, since the path switching switch that selectively switches between the third state and the fourth state is a manual switch that does not require maintenance, regular maintenance of the uninterruptible power supply direct connection selection unit is not required.

[0011] Another characteristic configuration of the power system according to the present invention is that a power breaker that cuts off power supply to the load is disposed on a path connecting the power supply system and the load, A manual switch is disposed between the power supply system and the power breaker, and is manually operated to cut off the power supply to the load.

[0012] According to the above characteristic configuration, a maintenance-free manual switch is provided upstream of the power circuit breaker (on the power supply system side), so that when maintenance of the power circuit breaker is required, the power supplied to the power circuit breaker can be cut off upstream of the power circuit breaker. Therefore, maintenance of the power circuit breaker and distribution boards and the like connected downstream can be performed without affecting other loads connected to the output system of the power supply system.

[0013] Another characteristic feature of the power system according to the present invention is that a plurality of the power supply systems are connected in parallel between the system power supply and the load.

[0014] According to the above characteristic configuration, a load that can receive power from multiple power sources can be supplied with power from multiple power supply systems, so that even if a problem occurs in one power supply system, power supply from the uninterruptible power supply can continue. Furthermore, an appropriate number of power supply systems can be installed depending on the scale of the load.

[0015] Another characteristic configuration of the power system according to the present invention is The power supply system is a first power supply system, the uninterruptible power supply device is a first uninterruptible power supply device, the relay unit is a first relay unit, the output unit is a first output unit, the path changeover switch is a first path changeover switch, the uninterruptible power supply direct supply selection unit is a first uninterruptible power supply direct supply selection unit, and the power supply switching unit is a first power supply switching unit, further comprising a second power supply system different from the first power supply system; the first power supply system and the second power supply system are connected in parallel between the system power supply and the load; The second power supply system a second uninterruptible power supply; a second power supply switching unit that selectively switches between a fifth state in which a path connected to the system power supply via the second uninterruptible power supply device and a path connected to the load are connected, and a sixth state in which a path connected to the system power supply without via the second uninterruptible power supply device and a path connected to the load are connected; a single second relay unit having at least one second output unit capable of outputting power from the second uninterruptible power supply to the second power supply switching unit, a second uninterruptible power supply direct connection selection unit having a second path changeover switch that selectively switches between a seventh state in which a path connected to the second output unit via the second power supply changeover unit and a path connected to the load are connected, and an eighth state in which a path connected to the second output unit not via the second power supply changeover unit and a path connected to the load are connected, The second path changeover switch is a manual switch that is manually operated to selectively switch between the seventh state and the eighth state.

[0016] According to the above characteristic configuration, a load that can receive power from multiple power sources can be supplied with power from multiple power supply systems. Therefore, even if the power supply from the first power supply system is interrupted due to an accident downstream of the first UPS direct delivery selection unit, the second power supply system can maintain a state in which the second UPS can continuously supply power to the load. Furthermore, unlike the first UPS, the second relay unit in the second power supply system has a single second output unit. Therefore, even if maintenance work on the second output unit is required or the power supply from the second power supply system is interrupted due to an accident downstream of the second UPS direct delivery selection unit, the first power supply system can maintain a state in which the first UPS can continuously supply power to the load. Therefore, for a load that can receive power from multiple power sources, compared to installing multiple first power supply systems, it is possible to maintain the reliability of the power supply while suppressing the size of the power system and reducing costs. Furthermore, for a load that cannot receive power from only a single power source, the power supply system to which the load is connected can be selected depending on the reliability required by the load. In the second power supply system, by transitioning from the seventh state to the eighth state by the second relay unit and the second uninterruptible power supply direct supply selection unit without stopping the power supply to the load, it is possible to perform maintenance work on the second power supply switching unit while maintaining a state in which power can be continuously supplied from the second uninterruptible power supply to the load. Here, because the second path switching switch is a manual switch that does not require maintenance, it is possible to eliminate the need for periodic maintenance work on the second uninterruptible power supply direct supply selection unit.

[0017] Another characteristic configuration of the power system according to the present invention is that the power supply system and a path directly connecting the grid power supply and the load are connected in parallel between the grid power supply and the load.

[0018] According to the above characteristic configuration, in the event of a malfunction in the power supply system, for a load that can receive power from multiple power sources, power can be continuously supplied to the load via a path that is connected in parallel to the power supply system and directly connects the load to the grid power source.This makes it possible to simplify the power system compared to a case where multiple power supply systems each equipped with an uninterruptible power supply are provided, while increasing the reliability of the entire power system compared to a case where a single power supply system is provided.

[0019] Another characteristic configuration of the power system according to the present invention is a power system that supplies power to a load from a power supply system connected to a grid power source, comprising: The power supply system includes: a plurality of uninterruptible power supplies; a plurality of relay units arranged in parallel with each other between the uninterruptible power supply and the load, and configured to output power from the uninterruptible power supply to the load; an output selection unit that selectively connects the uninterruptible power supply to each of the plurality of relay units.

[0020] According to the above characteristic configuration, the uninterruptible power supply includes an output selection unit that selectively connects the uninterruptible power supply to each of the multiple relay units. Therefore, a load that can receive power from multiple power sources can be supplied with power from multiple output systems. Therefore, at least one of these relay units can be used to supply power from the uninterruptible power supply to the load. The output selection unit can then cut off electrical connection to the remaining relay units. This allows the remaining relay units to be placed in a no-voltage state. Therefore, maintenance work on the relay units can be performed while maintaining a state in which the uninterruptible power supply can continuously supply power to the load.

[0021] Another characteristic configuration of the power system according to the present invention is that the power supply system includes an uninterruptible power supply direct supply selection unit having a path switching switch that selectively connects the load to each of the plurality of relay units by manual operation, and the path switching switch is a manual switch that selectively switches the relay units to be connected by manual operation.

[0022] According to the above characteristic configuration, by selecting a relay unit that connects the uninterruptible power supply and the load using the target output unit and the uninterruptible power supply direct delivery selection unit, it is possible to perform maintenance work on the power supply switching unit while maintaining a state in which power can be continuously supplied from the uninterruptible power supply to the load. Furthermore, since the path switching switches that selectively connect to each relay unit are manual switches that do not require maintenance, periodic maintenance of the uninterruptible power supply direct delivery selection unit is not required.

[0023] Another characteristic configuration of the power system according to the present invention is that a power breaker that cuts off power supply to the load is disposed on a path connecting the power supply system and the load, A manual switch is disposed between the power supply system and the power breaker, and is manually operated to cut off the power supply to the load.

[0024] According to the above characteristic configuration, a maintenance-free manual switch is provided upstream of the power circuit breaker (on the power supply system side), so that when maintenance of the power circuit breaker is required, the power supplied to the power circuit breaker can be cut off upstream of the power circuit breaker. Therefore, maintenance of the power circuit breaker and distribution boards and the like connected downstream can be performed without affecting other loads connected to the output system of the power supply system. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a schematic diagram of a power supply system according to an embodiment. [Figure 2] FIG. 10 is a schematic diagram of a power supply system according to another embodiment. [Figure 3] FIG. 10 is a schematic diagram of a power supply system according to another embodiment. [Figure 4] FIG. 10 is a schematic diagram of a power supply system according to another embodiment. [Figure 5] FIG. 10 is a schematic diagram of a power supply system according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0026] [First embodiment] A first embodiment of a power system 10 will be described with reference to the drawings.

[0027] As shown in FIG. 1, a power system 10 is configured to supply power to a load 41 from a power supply system 1 connected to a grid power supply 2. The power supply system 1 includes a plurality of uninterruptible power supplies 3, a power supply switching unit 5, a plurality of relay units 6, and an output selection unit 7. In this embodiment, the power supply system 1 further includes an uninterruptible power supply direct supply selection unit 8. The power supply system 1 is provided with a path for supplying power from the uninterruptible power supply 3 to the load 41, and a path for supplying power from the grid power supply 2 without passing through the uninterruptible power supply 3. If the uninterruptible power supply 3 is unable to supply power to the load 41 due to an overload, a cascading failure, or the like, power is supplied from the grid power supply 2 instead of the uninterruptible power supply 3.

[0028] In this embodiment, each of the multiple uninterruptible power supplies 3 includes an input terminal connected to the system power supply 2, an output terminal connected to the output selection unit 7, a power conversion unit (inverter and converter), and a storage battery, a capacitor, or the like (hereinafter, may be collectively referred to as the storage battery, or the like). When the system power supply 2 is normal, power is supplied from the system power supply 2 to the load 41 via the uninterruptible power supply 3, and the storage battery, or the like, is configured to be rechargeable by the power supply from the system power supply 2. On the other hand, when a power outage or the like occurs in the system power supply 2, power is supplied from the storage battery, or the like, to the load 41 via the inverter. In this example, the power supply system 1 is provided with multiple (here, three) uninterruptible power supplies 3. Specifically, the multiple uninterruptible power supplies 3 are arranged so as to be connected in parallel via the relay unit 6. As a result, in the power supply system 1, if some of the multiple uninterruptible power supplies 3 become unusable due to a failure or the like, the remaining uninterruptible power supplies 3 can supply power to the load 41.

[0029] The power supply switching unit 5 is configured to selectively switch between a first state in which a path connected to the system power supply 2 via the uninterruptible power supply 3 and a path connected to the load 41 are connected, and a second state in which a path connected to the system power supply 2 without the uninterruptible power supply 3 and a path connected to the load 41 are connected. Normally, the power supply switching unit 5 selects the first state. This allows power to be supplied from the system power supply 2 to the load 41 via the uninterruptible power supply 3. The power supply switching unit 5 maintains the first state even if a power outage or other problem occurs in the system power supply 2. If the uninterruptible power supply 3 is unable to supply power to the load 41 via the uninterruptible power supply 3 due to an overload, a cascading failure, or the like, the power supply switching unit 5 selects the second state and can supply power from the system power supply 2 to the load 41 without the uninterruptible power supply 3. This prevents the power supply to the load 41 from being interrupted. As shown in FIG. 1 , the power supply switching unit 5 includes a power supply switching switch 51 and an input switch 121. In this example, the power supply changeover switch 51 is an automatic switch that automatically switches between a first state and a second state. In the illustrated example, reference numeral 51S denotes a semiconductor switch (for example, a thyristor or an IGBT), and while the system power supply 2 is normal, the semiconductor switch 51S is kept in the OFF state while the uninterruptible power supply 3 is operated in synchronous with the system power supply 2, and if power supply from the uninterruptible power supply 3 becomes impossible, the semiconductor switch 51S is instantly turned ON and the input switch 121 is turned OFF, thereby preventing power supply to the load 41 from being cut off.

[0030] As shown in FIG. 1 , the multiple relay units 6 are connected to the multiple uninterruptible power supply devices 3 via the output selection unit 7. The multiple relay units 6 are connected in parallel between the uninterruptible power supply devices 3 and the power supply switching unit 5. In this embodiment, the multiple relay units 6 each include at least one output unit 16 that can output power from the uninterruptible power supply device 3 to the power supply switching unit 5. The relay unit 6 outputs power from the multiple uninterruptible power supply devices 3 to the power supply switching unit 5 via the output unit 16. Some of the multiple relay units 6 can output power from the multiple uninterruptible power supply devices 3 directly to the UPS direct supply selection unit 8 via the output unit 16 without going through the power supply switching unit 5. In this example, each of the multiple relay units 6 further includes an input unit 26 that receives power from the uninterruptible power supply device 3. The power from the uninterruptible power supply device 3 supplied to the input unit 26 is parallelized by the input unit 26 and then output to the output unit 16. As shown in FIG. 1, the input unit 26 includes a switch, which is different from an output switch 61 described later, for each uninterruptible power supply 3.

[0031] In this embodiment, each of the multiple output units 16 includes an output switch 61. Here, when the output switch 61 is turned on, power is supplied from the output unit 16 to the power supply switching unit 5. Each of the multiple relay units 6 is connected to the output selection unit 7 at the input unit 26 and connected to the power supply switching unit 5 on the downstream side (load side). At least one output unit 16 of the multiple output units 16 is designated as a target output unit 161, and the target output unit 161 is connected directly to the uninterruptible power supply direct supply selection unit 8 on the downstream side without going through the power supply switching unit 5. In contrast, the output units 16 other than the target output unit 161 are connected to the uninterruptible power supply direct supply selection unit 8 via the power supply switching unit 5, but are not directly connected to the uninterruptible power supply direct supply selection unit 8. Furthermore, the target output unit 161 is provided with a changeover switch 62 for outputting power directly to the uninterruptible power supply direct supply selection unit 8. When the changeover switch 62 is turned on, power is output from the target output unit 161 to the uninterruptible power supply direct supply selection unit 8.

[0032] As shown in FIG. 1 , the output selection unit 7 selectively connects the uninterruptible power supply 3 to each of the multiple relay units 6. In this embodiment, the power supply system 1 is provided with multiple output selection units 7. One output selection unit 7 is provided for each uninterruptible power supply 3. The output selection unit 7 is also provided downstream of the uninterruptible power supply 3. Here, the output selection unit 7 is connected to each of the multiple output units 16 and is provided with a selection switch 71. This allows power from the uninterruptible power supply 3 to be selectively output to the multiple output units 16. In the example shown in the figure, the selection switch 71 is an automatic switch, but it may also be a manual switch.

[0033] When performing maintenance work on a relay unit 6, it is necessary to set the relay unit 6 to be subjected to the maintenance work to a no-voltage state. In this embodiment, when power is supplied to the load 41 via a relay unit 6 that is not the target of the maintenance work, power is not supplied from the uninterruptible power supply 3 to the relay unit 6 to be subjected to the maintenance work, and power is not supplied from downstream to the output unit 16. That is, the selection switch 71 of the output selection unit 7, which is the power supply source to the input unit 26 of the relay unit 6 to be subjected to the maintenance work, is turned off, and the input switch 121 of the power supply switching unit 5 connected to the relay unit 6 to be subjected to the maintenance work, or the path switching switch 18 and the power distribution switch 130 connected to the power supply switching unit 5, are turned off, thereby preventing power from being supplied to the relay unit 6 to be subjected to the maintenance work via the power supply switching unit 5. Here, when the relay unit 6 having the target output unit 161 directly connected to the uninterruptible power supply direct transfer selection unit 8 is to be subjected to maintenance work, the selection switch 71 of the output selection unit 7 which is the power supply source to the input unit 26 of the relay unit 6 to be subjected to maintenance work is turned off, and in addition to the input switch 121 of the power supply switching unit 5 connected to the relay unit 6 to be subjected to maintenance work, the path switching switch 18 connected to the target output unit 161 is also turned off. Note that the maintenance work in this specification may include any of inspection, maintenance, and repair work on equipment, etc.

[0034] In this embodiment, the UPS direct supply selection unit 8 has a path switching switch 18 that selectively switches between a third state in which a path connected to the output unit 16 via the power supply switching unit 5 and a path connected to the load 41 are connected, and a fourth state in which a path connected to the target output unit 161 without the power supply switching unit 5 and a path connected to the load 41 are connected. In this example, the path switching switch 18 can switch between the third state and the fourth state so that maintenance work can be performed on the power supply switching unit 5 while maintaining power supply from the UPS 3 to the load 41. In this embodiment, the path switching switch 18 is a manual switch that selectively switches between the third state and the fourth state by manual operation. Here, when maintenance work is performed on the power supply switching unit 5, the power supply switching unit 5 needs to be placed in a no-voltage state. Therefore, when performing maintenance work on the power supply switching unit 5, first, in the third state in which the path connected to the output unit 16 via the power supply switching unit 5 and the path connected to the load 41 are connected, power is supplied from the uninterruptible power supply 3 to the target output unit 161, and then the switching switch 62 is turned on. At the same time, an operator manually turns on the path switching switch 18 connected to the target output unit 161, temporarily placing the power supply system 1 in a state in which the third state and the fourth state coexist. Then, the output switch 61 of the relay unit 6 is turned off. The path switching switch 18 connected to the power supply switching unit 5 is also turned off. Furthermore, the power distribution switch 130 connected to the power supply switching unit 5 is turned off. This allows the power supply switching unit 5 to be placed in a no-voltage state (fourth state) while continuing to supply power from the uninterruptible power supply 3 to the load 41. Note that by using the path switching switch 18 as a manual switch that does not require maintenance, periodic maintenance work on the uninterruptible power supply direct supply selection unit 8 is not required.

[0035] When switching from the fourth state to the third state, the path changeover switch 18 connected to the power supply changeover unit 5 is turned on, and the output switch 61, which is in a state where power is supplied from the uninterruptible power supply 3, is turned on to make the third state and the fourth state coexist, and then the path changeover switch 18 connected to the target output unit 161 is turned off, thereby making it possible to enter the third state while continuing the supply of power from the uninterruptible power supply 3 to the load 41. At this time, the changeover switch 62 may be turned off.

[0036] As shown in FIG. 1 , in this embodiment, a power circuit breaker 81 that cuts off the power supply to the load 41 is disposed on a path connecting the power supply system 1 and the load 41, and a manual switch (disconnecting switch 9) that manually disconnects the power supply to the load 41 is disposed between the power supply system 1 and the power circuit breaker 81. In this example, the power circuit breaker 81 is disposed on a path connecting the uninterruptible power supply direct supply selection unit 8 and the load 41. The load 41 is disposed downstream of the power circuit breaker 81. Here, the power circuit breaker 81 is a circuit breaker. An example of the load 41 is a power consuming device connected to the distribution board 4, as shown in FIG. 2 . In this embodiment, the disconnecting switch 9 is disposed between the power circuit breaker 81 and the output system 11 of the power supply system 1. In the example of FIG. 1 , the disconnecting switch 9 is disposed adjacent to the power circuit breaker 81 on the upstream side (the output system 11 side). This allows the power supplied to the power circuit breaker 81 to be cut off before (upstream of) the power circuit breaker 81, facilitating maintenance work on the power circuit breaker 81 and the distribution boards and other devices connected downstream thereof. Here, the disconnecting switch 9 is a manual switch that is operated manually. By making the disconnecting switch 9 a manual switch that does not require maintenance, regular maintenance work on the disconnecting switch 9 is no longer necessary. With this configuration, maintenance can be performed on the power circuit breaker 81 and the distribution boards 4 and other devices connected downstream thereof without affecting other loads 41 connected to the output system 11 of the power supply system 1. Note that while this example assumes that multiple uninterruptible power supplies 3 are provided, it also assumes the case that a new uninterruptible power supply 3 is added to the power supply system 1 at a later date in addition to a single uninterruptible power supply 3.

[0037] Second Embodiment A second embodiment of the power system 10 will be described with reference to FIG. 2. The following description of the power system 10 of this embodiment will focus on the differences from the first embodiment. Points that are not specifically mentioned are the same as those of the first embodiment, and the same reference numerals will be used to omit detailed description. In the following description, the power supply system 1 will be referred to as a first power supply system 1a, and the load 41 connected to the first power supply system 1a will be referred to as a first load 41a.

[0038] As shown in Fig. 2, the power system 10 further includes a second power supply system 1b. The second power supply system 1b is disposed between the system power supply 2 and a second load 41b that is different from the first load 41a. In this example, the first power supply system 1a and the second power supply system 1b have the same configuration. Therefore, a detailed description of the second power supply system 1b will be omitted.

[0039] In the present embodiment, each of the first load 41a and the second load 41b includes a plurality of loads 41. In the example of FIG. 2, in each of the first power supply system 1a and the second power supply system 1b, the distribution board 4 is connected downstream of the power circuit breaker 81 (on the opposite side of the uninterruptible power supply direct supply selection unit 8). The loads 41 are connected to the distribution board 4. In the present embodiment, the plurality of loads 41 are configured to be able to receive power from the first power supply system 1a or the second power supply system 1b, and in this example, a load 41 that is relatively important among the plurality of loads 41 and can receive power from a plurality of power sources (hereinafter simply referred to as a "highly important load 41") is connected to both the distribution board 4 of the first power supply system 1a (first distribution board 4a) and the distribution board 4 of the second power supply system 1b (second distribution board 4b). According to this configuration, a load 41 that can receive power from a plurality of power sources can be supplied with power from a plurality of power supply systems 1 (here, a first power supply system 1a and a second power supply system 1b), so that even if one power supply system 1 malfunctions or is replaced, the other normal power supply systems 1 can continue to supply power from the uninterruptible power supply 3. Furthermore, an appropriate number of power supply systems 1 can be installed depending on the scale of the load 41.

[0040] Third Embodiment A third embodiment of a power system 10 will be described with reference to FIG. 3 . The following description of the power supply system 1 of this embodiment will focus on differences from the first embodiment. Unless otherwise specified, the same components are the same as those of the first embodiment, and the same reference numerals are used, and detailed description will be omitted. In the following description, the power supply system 1 will be referred to as the first power supply system 1a, the uninterruptible power supply 3 will be referred to as the first uninterruptible power supply 3a, the power supply switching unit 5 will be referred to as the first power supply switching unit 5a, the relay unit 6 will be referred to as the first relay unit 6a, the output unit 16 will be referred to as the first output unit 16a, the input unit 26 will be referred to as the first input unit 26a, the path switching switch 18 will be referred to as the first path switching switch 18a, and the uninterruptible power supply direct supply selector 8 will be referred to as the first uninterruptible power supply direct supply selector 8a. In the following description, the power supply switching switch 51 will be referred to as the first power supply switching switch 51a, the output switch 61 will be referred to as the first output switch 61a, and the selector switch 62 will be referred to as the first selector switch 62a.

[0041] As shown in FIG. 3, in this embodiment, the power system 10 further includes a second power supply system 1b that is different from the first power supply system 1a. The first power supply system 1a and the second power supply system 1b are connected in parallel to a power grid 2. Here, the first power supply system 1a and the second power supply system 1b are each connected to the same power grid 2. The second power supply system 1b includes a second uninterruptible power supply 3b, a second power supply switching unit 5b, a single second relay unit 6b, and a second uninterruptible power supply direct supply selecting unit 8b. In this example, the second power supply system 1b includes a plurality of (here, two) second uninterruptible power supply units 3b. In this example, the second uninterruptible power supply 3b has the same structure as the first uninterruptible power supply 3a, and therefore description thereof will be omitted.

[0042] The second power supply switching unit 5b is configured to selectively switch between a fifth state in which a path connected to the system power supply 2 via the second uninterruptible power supply 3b and a path connected to the load 41 are connected, and a sixth state in which a path connected to the system power supply 2 without the second uninterruptible power supply 3b and a path connected to the load 41 are connected. Normally, the second power supply switching unit 5b switches to the fifth state. This allows power to be supplied from the system power supply 2 to the load 41 via the second uninterruptible power supply 3b. The second power supply switching unit 5b maintains the fifth state even if a power outage or the like occurs in the system power supply 2. If power cannot be supplied to the load 41 via the second uninterruptible power supply 3b due to a simultaneous failure of the second uninterruptible power supply 3b or the like, the second power supply switching unit 5b selects the sixth state and can supply power to the load 41 from the system power supply 2 without the second uninterruptible power supply 3b. This prevents the power supply to the load 41 from being interrupted. 3, the second power supply switching unit 5b includes a second power supply switching switch 51b and a semiconductor switch 51S. In this example, the second power supply switching switch 51b and the semiconductor switch 51S are switches that automatically switch between a fifth state and a sixth state.

[0043] The second relay unit 6b has at least one second output unit 16b that can output power from the second uninterruptible power supply 3b to the second power supply switching unit 5b. The second relay unit 6b can output power from multiple (here, two) second uninterruptible power supplies 3b to either the second power supply switching unit 5b or the second uninterruptible power supply direct supply selector 8b via the second output unit 16b. In this embodiment, the second power supply system 1b does not have an output selector 7 like the first power supply system 1a. The second relay unit 6b also has a second input unit 26b that inputs power from the second uninterruptible power supply 3b.

[0044] In this embodiment, the second output unit 16b includes a second output switch 61b. When the second output switch 61b is turned on, power is supplied from the second output unit 16b to the second power supply switching unit 5b. The second output unit 16b also includes a second switching switch 62b for outputting power directly to the second uninterruptible power supply direct supply selection unit 8b without going through the second power supply switching unit 5b. This allows the second relay unit 6b to selectively output power to the second power supply switching unit 5b or the second uninterruptible power supply direct supply selection unit 8b.

[0045] The second uninterruptible power supply direct supply selection unit 8b has a second path selection switch 18b that selectively switches between a seventh state in which the path connected to the second output unit 16b via the second power supply switching unit 5b and the path connected to the load 41 are connected, and an eighth state in which the path connected to the second output unit 16b without the second power supply switching unit 5b and the path connected to the load 41 are connected. In this example, in order to enable maintenance work on the second power supply switching unit 5b to be performed while maintaining power supply to the load 41, the second output unit 16b and the second path selection switch 18b can switch between the seventh state and the eighth state without momentary interruption. In this embodiment, the second path selection switch 18b is a manual switch that selectively switches between the seventh state and the eighth state by manual operation. Therefore, when performing maintenance work on the second power supply switching unit 5b, a worker or the like manually operates the second path switching switch 18b in parallel with switching the output destination using the second output switch 61b and the second switching switch 62b. This temporarily creates a state in which the seventh and eighth states coexist in the second power supply system 1b, and then transitions to only the eighth state. This places the second power supply switching unit 5b in a no-voltage state, transitioning to a state where work can be performed safely while continuing to supply power from the uninterruptible power supply 3 to the load 41. Furthermore, by making the second path switching switch 18b a manual switch that does not require maintenance, periodic maintenance work on the second uninterruptible power supply direct delivery selection unit 8b is not required. With this configuration, power can be supplied from multiple power supply systems 1 (here, the first power supply system 1a and the second power supply system 1b) to a load 41 that can receive power from multiple power sources. Therefore, even if maintenance work is required on the second relay unit 6b in the second power supply system 1b, the first power supply system 1a can maintain a state in which the first uninterruptible power supply 3a can supply power to the load 41. Furthermore, even if a problem occurs in one power supply system 1 or it is replaced, it is possible to continue power supply from the uninterruptible power supply 3 in another normal power supply system 1.Therefore, for a load 41 that can receive power from multiple power sources, compared to the second embodiment, it is possible to prevent the power system 10 from becoming larger and reduce costs while maintaining the reliability of the power supply. Furthermore, for a load 41 that cannot receive power from only a single power source, it is possible to select the power supply system 1 to be connected to depending on the reliability required by the load 41. Note that the configuration of the second power supply system 1b is not limited to the above-described form, and it may have a configuration different from this embodiment, such as a configuration that does not include the second uninterruptible power supply direct supply selection unit 8b or a configuration that does not include the second power supply switching unit 5b.

[0046] [Fourth embodiment] A fourth embodiment of the power system 10 will be described with reference to Fig. 4. The following description of the power system 10 of this embodiment will focus on the differences from the first embodiment. Points that are not specifically mentioned are the same as those of the first embodiment, and the same reference numerals will be used to omit detailed description.

[0047] As shown in FIG. 4 , in this embodiment, a path directly connecting the power supply system 1, the grid power supply 2, and the load 41 is connected in parallel to the grid power supply 2. In this example, the power system 10 includes a direct power supply unit 94. The direct power supply unit 94 serves as a path directly connecting the grid power supply 2 and the load 41. The direct power supply unit 94 does not include each device (e.g., an uninterruptible power supply 3) arranged in the power supply system 1. According to this configuration, for a load 41 that can receive power from multiple power sources, if a malfunction occurs in the power supply system 1, the direct power supply unit 94 connected in parallel to the load 41 can continuously supply power to the load 41. This improves the overall reliability of the power system 10 compared to the first embodiment, and also reduces costs compared to the second and third embodiments by simplifying the power system 10.

[0048] Fifth Embodiment A fifth embodiment of the power system 10 will be described with reference to FIG. 5. The following description of the power system 10 of this embodiment will focus on the differences from the first embodiment. Points that are not specifically mentioned are the same as those of the first embodiment, and the same reference numerals will be used and detailed description will be omitted. The power system 10 supplies power to a load 41 from a power supply system 1 connected to a grid power source 2.

[0049] As shown in FIG. 5 , in this embodiment, the power supply system 1 includes an uninterruptible power supply 3 (here, multiple uninterruptible power supply devices 3), multiple relay units 6 arranged in parallel between the uninterruptible power supply 3 and a load 41 and outputting power from the uninterruptible power supply 3 to the load 41, and an output selection unit 7 selectively connecting the uninterruptible power supply 3 to each of the multiple relay units 6. The power supply system 1 also includes an uninterruptible power supply direct supply selection unit 8 having a path changeover switch 18 that selectively connects the load 41 to each of the multiple relay units 6 by manual operation. In this power supply system 1, a path is provided for supplying power from the uninterruptible power supply 3 to the load 41, but unlike the first embodiment, no path is provided for supplying power directly from the system power supply 2 to the load 41 without going through the uninterruptible power supply 3. That is, in this embodiment, the power supply system 1 does not include a power supply changeover unit 5. Normally, power is supplied from the system power supply 2 to the load 41 via the uninterruptible power supply 3, but in the event of a power outage or the like in the system power supply 2, power is supplied to the load 41 from a storage battery or the like via an inverter. As shown in FIG. 5 , each of the multiple relay units 6 has an output unit 16 that outputs power from the uninterruptible power supply 3 to the uninterruptible power supply direct supply selection unit 8. The output selection unit 7 supplies power from the uninterruptible power supply 3 to a random relay unit 6 by turning on any of the selection switches 71, and the relay unit 6 outputs the power from the uninterruptible power supply 3 to the uninterruptible power supply direct supply selection unit 8 via the output unit 16. Each of the multiple output units 16 has an output switch 61. Here, when the output switch 61 of a relay unit 6 that receives power from multiple uninterruptible power supplies 3 is turned on, power is supplied from the output unit 16 to the uninterruptible power supply direct supply selection unit 8.

[0050] In this example, in order to perform maintenance work on the relay unit 6 while maintaining power supply to the load 41, the path changeover switch 18 can select a path that passes through one of the multiple (here, two) relay units 6 and electrically connect the selected path to the path that is connected to the load 41. Therefore, when performing maintenance work on the relay unit 6, in parallel with the operation of the selection switch 71 and the output switch 61 of the output selection unit 7 that is the power supply source to the relay unit 6, a worker or the like manually operates the path changeover switch 18 to electrically connect one of the multiple relay units 6 to the load 41, and the relay unit 6 to be maintained is electrically disconnected from the uninterruptible power supply 3 and the load 41, and the maintenance work is performed on the relay unit 6 that is in a power outage state. Naturally, in order to put the relay unit 6 into an uninterruptible state when maintenance work is performed without stopping the power supply from the uninterruptible power supply 3 to the load 41, it is necessary to temporarily configure a state in which power is supplied from the uninterruptible power supply 3 to the load 41 from multiple relay units 6 via the uninterruptible power supply direct transmission selection unit 8 when the selection switch 71, output switch 61, and path switching switch 18 are operated.

[0051] As shown in FIG. 5 , in this embodiment, a power circuit breaker 81 that cuts off the power supply to the load 41 is disposed on a path connecting the power supply system 1 and the load 41, and a manual switch (disconnecting switch 9) that manually disconnects the power supply to the load 41 is disposed between the power supply system 1 and the power circuit breaker 81. Here, the power circuit breaker 81 is a circuit breaker. An example of the load 41 is a power consuming device connected to the distribution board 4. In the example of FIG. 5 , the disconnecting switch 9 is disposed adjacent to the power circuit breaker 81 on the upstream side (the UPS direct supply selection unit 8 side). This allows the power supplied to the power circuit breaker 81 to be cut off before (upstream from) the power circuit breaker 81, so that maintenance work on the power circuit breaker 81 and the distribution board 4 connected downstream thereof can be performed without affecting other loads 41 connected to the output system 11 of the power supply system 1. Here, the disconnecting switch 9 is a manually operated manual switch. By using a manual switch as the disconnecting switch 9, periodic maintenance work on the disconnecting switch 9 becomes unnecessary.

[0052] <Another embodiment> In the first to fifth embodiments, the configuration of the power system 10 has been specifically described, but the configuration can be modified as appropriate. For example, each uninterruptible power supply 3 may be configured to include a storage battery or the like, or multiple uninterruptible power supplies 3 may share one or more storage batteries or the like. Furthermore, for example, the path selector switch 18 (first path selector switch 18a), the second path selector switch 18b, and the disconnecting switch 9 provided between the power supply system 1 and the power circuit breaker 81 are configured as non-trip breakers as manual switches. However, any known manual switch that can be turned on and off manually and does not require maintenance can be used. Furthermore, in the first to fifth embodiments, the uninterruptible power supply direct supply selector 8 includes two path selector switches 18 as disconnecting switches that open and close a single circuit. However, instead, the path selector switch 18 may be a single manual overlapping double-throw switch.

[0053] In the above first and fifth embodiments, a configuration in which one or two output units 16 are arranged for each of a plurality of relay units 6 has been described as an example, but the number of output units 16 arranged can be changed as appropriate.

[0054] In the above second and third embodiments, a configuration in which each of the multiple power supply systems 1 is connected to a common power system 2 has been described as an example, but each of the multiple power supply systems 1 may also be connected to a different power system 2.

[0055] In the third embodiment described above, a representative example is given as the second power supply system 1b, but the number of uninterruptible power supplies 3 does not need to be multiple. Also, although the second output unit 16b has been described as including the second changeover switch 62b in addition to the second output switch 61b, the second changeover switch 62b may be an automatic switch that automatically switches between an on state and an off state, or may be a manual switch. Furthermore, the second changeover switch 62b may not be included.

[0056] In the above fourth embodiment, an example has been described in which the power supply system 1 and the direct power supply unit 94 are connected to a common power grid 2, but they may also be connected to different power grids 2.

[0057] In the above second to fourth embodiments, an example has been described in which only the loads 41 of high importance are connected to both the distribution board 4 of the first power supply system 1a and the distribution board 4 of the second power supply system 1b or the distribution board 4 of the direct power supply unit 94, but a configuration in which all of the loads 41 are connected to both distribution boards 4 regardless of the relative importance of each of the multiple loads 41 may also be used.

[0058] In the above fifth embodiment, a single power supply system 1 has been described, but as in the above second, third and fourth embodiments, it is also possible to use multiple power supply systems 1 or to use multiple direct power supply units 94 in parallel.

[0059] The configurations disclosed in the above embodiments (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, as long as no contradictions arise. Furthermore, the embodiments disclosed in this specification are examples, and the embodiments of the present invention are not limited to these and can be modified as appropriate within the scope that does not deviate from the purpose of the present invention. [Industrial Applicability]

[0060] The present invention can be used in power systems. [Explanation of symbols]

[0061] 1: Power supply system 1a: First power supply system 1b: Second power supply system 2: Grid power supply 3: Uninterruptible power supply 3a: 1st uninterruptible power supply 3b:Second uninterruptible power supply 4: Distribution board 4a: 1st load 4b: 2nd load 5: Power switch 5b: Second power supply switching unit 6: Relay section 6a: First relay section 6b: Second relay section 7: Output selection section 8: Uninterruptible power supply direct supply selection section 8b: Second uninterruptible power supply direct supply selection section 9: Disconnection switch (manual switch) 10: Power Systems 16: Output section 16a: First output section 16b: 2nd output section 18: Route change switch 18b: Second path selector switch 41: Load 81: Power circuit breaker 161: Target output section

Claims

1. A power system that supplies power to a load from a power supply system connected to a grid power source, The power supply system includes: a plurality of uninterruptible power supplies; a power supply switching unit that selectively switches between a first state in which a path connected to the system power supply via the uninterruptible power supply device and a path connected to the load are connected, and a second state in which a path connected to the system power supply without via the uninterruptible power supply device and a path connected to the load are connected; a plurality of relay units capable of outputting power from the plurality of uninterruptible power supply devices to the power supply switching unit; an output selection unit that selectively connects each of the plurality of uninterruptible power supply devices to each of the plurality of relay units.

2. each of the plurality of relay units includes at least one output unit capable of outputting power from the uninterruptible power supply to the power supply switching unit; The power supply system includes: At least one of the plurality of output units is set as a target output unit, a third state in which a path connected to the output unit via the power supply switching unit and a path connected to the load are connected, and a fourth state in which a path connected to the target output unit without passing through the power supply switching unit and a path connected to the load are connected, The power system according to claim 1 , wherein the path changeover switch is a manual switch that is manually operated to selectively switch between the third state and the fourth state.

3. a power breaker that cuts off power supply to the load is disposed on a path connecting the power supply system and the load; The power system according to claim 1 , further comprising a manual switch disposed between the power supply system and the power breaker, the manual switch being manually operated to cut off the power supply to the load.

4. a power breaker that cuts off power supply to the load is disposed on a path connecting the power supply system and the load; The power system according to claim 2 , further comprising a manual switch disposed between the power supply system and the power breaker, the manual switch being manually operated to cut off the power supply to the load.

5. The power system according to claim 1 , wherein a plurality of the power supply systems are connected in parallel between the grid power supply and the load.

6. The power supply system is a first power supply system, the uninterruptible power supply device is a first uninterruptible power supply device, the relay unit is a first relay unit, the output unit is a first output unit, the path changeover switch is a first path changeover switch, the uninterruptible power supply direct supply selection unit is a first uninterruptible power supply direct supply selection unit, and the power supply switching unit is a first power supply switching unit, further comprising a second power supply system different from the first power supply system; the first power supply system and the second power supply system are connected in parallel between the system power supply and the load; The second power supply system a second uninterruptible power supply; a second power supply switching unit that selectively switches between a fifth state in which a path connected to the system power supply via the second uninterruptible power supply device and a path connected to the load are connected, and a sixth state in which a path connected to the system power supply without via the second uninterruptible power supply device and a path connected to the load are connected; a single second relay unit having at least one second output unit capable of outputting power from the second uninterruptible power supply to the second power supply switching unit, a second uninterruptible power supply direct supply selection unit having a second path changeover switch that selectively switches between a seventh state in which a path connected to the second output unit via the second power supply changeover unit and a path connected to the load are connected, and an eighth state in which a path connected to the second output unit not via the second power supply changeover unit and a path connected to the load are connected, The power system according to claim 2 or 4, wherein the second path changeover switch is a manual switch that is manually operated to selectively switch between the seventh state and the eighth state.

7. 5. The power system according to claim 1, wherein the power supply system and a path that directly connects the grid power supply and the load are connected in parallel between the grid power supply and the load.

8. A power system that supplies power to a load from a power supply system connected to a grid power source, The power supply system includes: a plurality of uninterruptible power supplies; a plurality of relay units arranged in parallel with each other between the uninterruptible power supply and the load, and capable of outputting power from the uninterruptible power supply to the load; an output selection unit that selectively connects each of the plurality of uninterruptible power supply devices to each of the plurality of relay units.

9. the power supply system includes an uninterruptible power supply direct supply selection unit having a path changeover switch that selectively connects the load to each of the plurality of relay units by manual operation; The power system according to claim 8 , wherein the path changeover switch is a manual switch that selectively switches the relay unit to be connected by manual operation.

10. a power breaker that cuts off power supply to the load is disposed on a path connecting the power supply system and the load; The power system according to claim 8 or 9, further comprising a manual switch disposed between the power supply system and the power breaker, the manual switch being manually operated to cut off the power supply to the load.

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