Power system

Abstract

To provide a technique capable of simplifying maintenance work in a power system including an uninterruptible power supply device.SOLUTION: A power system 10 for supplying power from a power supply system 1 to a load, the power supply system 1 including a plurality of uninterruptible power supplies 3, a power supply switching unit 5 for switching between a first state in which a path connected to a system power supply 2 via the uninterruptible power supplies 3 and a path connected to the load are connected, and a second state in which a path connected to the system power supply 2 not via the uninterruptible power supplies 3 and the path connected to the load are connected, and a relay unit 6 capable of outputting power from the uninterruptible power supplies 3, the relay unit 6 includes a first connection unit 11, a second connection unit 12, and a first disconnect switch 13 that disconnects electrical connection between the first connection unit 11 and the second connection unit 12, and the first disconnect switch 13 is a switch that disconnects electrical connection between the first connection unit 11 and the second connection unit 12 by a manual operation.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 periodic maintenance work on the output panel, it is necessary to temporarily 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, it is not possible to cut off the power supply to the load, which creates a problem that makes it difficult to perform periodic maintenance work on the output panel.

[0006] The present invention has been made in view of the above-mentioned problems, and has an object to provide a technique that can simplify maintenance work 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 disclosure 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 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 and a path connected to the load are connected; a relay unit capable of outputting power from the plurality of uninterruptible power supply devices to the power supply switching unit, the relay unit includes a first connection unit connected to the uninterruptible power supply, a second connection unit connected to the power supply switching unit, and a disconnection switch that disconnects the electrical connection between the first connection unit and the second connection unit, The disconnecting switch is a manual switch that is manually operated to disconnect the electrical connection between the first connection part and the second connection part.

[0008] According to the above characteristic configuration, the power supply system selects the first state in normal cases where the power supply from the grid power source is normal, and supplies power 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, the power supply system can supply power to the load from multiple uninterruptible power supply devices (for example, storage batteries of the uninterruptible power supply devices). Furthermore, even if a problem occurs in the path via the uninterruptible power supply devices, the power supply system can select the second state and supply power 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 the disconnecting switch of the relay unit is a manual switch that does not require maintenance, unlike an automatic switch, i.e., a switch that automatically disconnects the electrical connection between the first connection unit and the second connection unit, periodic maintenance work on the relay unit is not required, thereby simplifying maintenance work in the power system.

[0009] Another characteristic feature of the power system according to the present invention is that the uninterruptible power supply includes a cutoff switch that cuts off the power output from the uninterruptible power supply.

[0010] According to the above characteristic configuration, each uninterruptible power supply is provided with a cutoff switch that cuts off the power output from itself. Therefore, even if a malfunction such as a short circuit occurs in a path downstream (on the load side) of the uninterruptible power supply, the cutoff switch can cut off the electrical connection between the uninterruptible power supply and the path further downstream. Therefore, each uninterruptible power supply can be protected from malfunctions such as short circuits as needed. Furthermore, by providing a sequence that can cut off the electrical connection using the cutoff switch in the event of a malfunction in the uninterruptible power supply itself, it is possible to prevent the malfunction occurring in the uninterruptible power supply from affecting downstream paths or other uninterruptible power supplies.

[0011] Another characteristic configuration of the power system according to the present invention is that the power supply system includes: a third state in which a path connected to the relay 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 relay unit without passing through the power supply switching unit and a path connected to the load are connected, the relay unit includes a third connection unit connected to the uninterruptible power supply direct connection selection unit, The path changeover switch is a manual switch that is manually operated to selectively switch between the third state and the fourth state.

[0012] According to the above characteristic configuration, by transitioning from the third state to the fourth state using the relay unit and the uninterruptible power supply direct transfer selection unit without stopping the power supply to the load, maintenance work can be performed 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 disconnect switch of the relay unit and the path switching switch that selectively switches between the third state and the fourth state are manual switches that do not require maintenance, regular maintenance of the relay unit and the uninterruptible power supply direct connection selection unit is not required.

[0013] 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.

[0014] 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 work on the power circuit breaker and on the distribution board connected downstream can be performed without affecting other loads connected to the output system of the power supply system.

[0015] 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.

[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, 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.

[0017] Another characteristic configuration of the power system according to the present invention is that 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 uninterruptible power supply direct supply selection unit is a first uninterruptible power supply direct supply selection unit, the path changeover switch is a first path changeover switch, and the power supply changeover unit is a first power supply changeover 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 plurality of second uninterruptible power supplies; 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 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 and a path connected to the load are connected; a second relay 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 at least one second path changeover switch that selectively switches between a seventh state in which the second relay unit is connected to a path connected to the load via the second power supply changeover unit, and an eighth state in which the second relay unit is connected to a path connected to the load without the second power supply changeover unit, The second path changeover switch is a manual switch that is manually operated to selectively switch between the seventh state and the eighth state.

[0018] According to the above characteristic configuration, a load that can receive power from multiple power sources can receive 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. Conversely, for a load that can receive power from multiple power sources, the first power supply system can maintain a state in which the first power supply system can continuously supply power to the load, even if a malfunction occurs in the second power supply system or maintenance work is performed on the second power supply system. Therefore, even when a second power supply system is provided in addition to the first power supply system, the size of the power system can be reduced and costs can be reduced compared to when multiple first power supply systems are provided. Furthermore, for a load that cannot receive power from only a single power source, the power supply system to be 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 without stopping the power supply to the load by the second relay unit and the second uninterruptible power supply direct supply selection unit, maintenance work on the second power supply switching unit can be performed 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, periodic maintenance work on the second uninterruptible power supply direct supply selection unit is not required. Therefore, management of the second power supply system can be made easier.

[0019] 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.

[0020] 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.

[0021] 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 relay unit that is disposed between the uninterruptible power supply and the load and is capable of outputting power from the uninterruptible power supply to the load, the relay unit includes a first connection unit connected to the uninterruptible power supply, a second connection unit connected to the load, and a disconnection switch that disconnects the electrical connection between the first connection unit and the second connection unit, The disconnecting switch is a manual switch that is manually operated to disconnect the electrical connection between the first connection part and the second connection part.

[0022] According to the above characteristic configuration, since the disconnecting switch is a manual switch that does not require maintenance, periodic maintenance work on the relay unit is not required, compared to when the disconnecting switch is an automatic switch, i.e., a switch that automatically disconnects the electrical connection between the first connection unit and the second connection unit, thereby simplifying maintenance work in the power system.

[0023] Another characteristic feature of the power system according to the present invention is that the uninterruptible power supply includes a cutoff switch that cuts off the power output from the uninterruptible power supply.

[0024] According to the above characteristic configuration, each uninterruptible power supply is provided with a cutoff switch that cuts off the power output from itself. Therefore, even if a malfunction such as a short circuit occurs in a path downstream (on the load side) of the uninterruptible power supply, the cutoff switch can cut off the electrical connection between the uninterruptible power supply and the path further downstream. Therefore, each uninterruptible power supply can be protected from malfunctions such as short circuits as needed. Furthermore, by providing a sequence that can cut off the electrical connection using the cutoff switch in the event of a malfunction in the uninterruptible power supply itself, it is possible to prevent the malfunction of the uninterruptible power supply from affecting downstream paths or other uninterruptible power supplies.

[0025] 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.

[0026] 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 work on the power circuit breaker and on the distribution board connected downstream can be performed without affecting other loads connected to the output system of the power supply system. [Brief explanation of the drawings]

[0027] [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

[0028] [First embodiment] A first embodiment of a power system 10 will be described with reference to the drawings.

[0029] 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, and a relay unit 6. 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. If the uninterruptible power supply 3 is unable to supply power to the load 41 due to an overload or cascading failure of the uninterruptible power supply 3, power is supplied from the grid power supply 2 instead of the uninterruptible power supply 3.

[0030] In this embodiment, the uninterruptible power supply 3 includes an input terminal connected to the system power supply 2, an output terminal connected to the cutoff switch 14, a power conversion unit (inverter and converter), and a storage battery, a capacitor, etc. (hereinafter, these may be collectively referred to as the storage battery, etc.). 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, etc. are 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, etc. to the load 41 via the inverter. In this embodiment, the multiple uninterruptible power supplies 3 are arranged so as to be connected in parallel to the load 41. As a result, in the power supply system 1, if some of the multiple uninterruptible power supplies 3 become unavailable due to maintenance, a malfunction, etc., the remaining uninterruptible power supplies 3 can supply power to the load 41.

[0031] 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.

[0032] As shown in FIG. 1 , the relay unit 6 can output power from multiple uninterruptible power supplies 3 to the power supply switching unit 5. In this example, a single relay unit 6 is provided. The relay unit 6 includes a first connection unit 11 connected to the uninterruptible power supply 3, a second connection unit 12 connected to the power supply switching unit 5, and a first disconnection switch 13 that disconnects the electrical connection between the first connection unit 11 and the second connection unit 12. The relay unit 6 also includes a third connection unit 66 connected to the uninterruptible power supply direct supply selection unit 8, a second disconnection switch 15, and a third disconnection switch 67. Here, the first disconnection switch 13 corresponds to the "disconnection switch." Note that the second disconnection switch 15 and the third disconnection switch 67 may also be included in the "disconnection switch."

[0033] The multiple uninterruptible power supplies 3 are connected in parallel at the first connection unit 11 via the first disconnection switch 13. The first connection unit 11 has multiple connection terminals corresponding to the multiple (here, three) uninterruptible power supplies 3. The second connection unit 12 has a connection terminal connected to the power supply switching unit 5. The third connection unit 66 has a connection terminal connected to the uninterruptible power supply direct supply selection unit 8.

[0034] The first disconnecting switch 13 is a manual switch that is manually operated to disconnect the electrical connection between the first connection part 11 and the second connection part 12. The second disconnecting switch 15 is also a manual switch that is manually operated to disconnect the electrical connection between the first connection part 11 and the second connection part 12. By turning on the first disconnecting switch 13 and the second disconnecting switch 15, the first connection part 11 and the second connection part 12 are electrically connected. This allows the power supplied via the uninterruptible power supply 3 to be output to the power supply switching unit 5. In this example, a plurality of first disconnecting switches 13 are arranged to correspond to the respective connection terminals of the first connection part 11, i.e., to correspond to each of the multiple uninterruptible power supplies 3. In addition, one second disconnecting switch 15 is arranged downstream of the multiple first disconnecting switches 13. In the illustrated example, by turning off the second disconnection switch 15, the electrical connection between the first connection part 11 and the second connection part 12 is cut off, and power cannot be supplied to the power supply switching part 5. Here, "power supplied via the uninterruptible power supply 3" includes power from the system power supply 2 supplied via the uninterruptible power supply 3 and power supplied from the storage battery of the uninterruptible power supply 3, etc.

[0035] In this example, the first disconnecting switch 13 is further configured to be able to disconnect the electrical connection between the first connection part 11 and the third connection part 66. The third disconnecting switch 67 is a manual switch that is manually operated to disconnect the electrical connection between the first connection part 11 and the third connection part 66. By turning on the first disconnecting switch 13 and the third disconnecting switch 67, the first connection part 11 and the third connection part 66 are electrically connected. This allows power supplied via the uninterruptible power supply 3 to be directly output to the uninterruptible power supply direct supply selection part 8. One third disconnecting switch 67 is disposed downstream of the multiple first disconnecting switches 13. In the example shown in the figure, by turning off the third disconnecting switch 67, the electrical connection between the first connection part 11 and the third connection part 66 is interrupted, and power cannot be supplied to the uninterruptible power supply direct supply selection part 8. Therefore, for example, when the power supplied via the uninterruptible power supply 3 is to be output to the power supply switching unit 5 and not to the uninterruptible power supply direct delivery selection unit 8, the switches are manually operated to turn on the second disconnection switch 15 and turn off the third disconnection switch 67. In this manner, by operating the third disconnection switch 67 and the second disconnection switch 15, it is possible to select whether the power supplied via the uninterruptible power supply 3 is to be output to the power supply switching unit 5 or the uninterruptible power supply direct delivery selection unit 8. In this embodiment, the first disconnection switch 13, the second disconnection switch 15, and the third disconnection switch 67 are manual switches that do not require maintenance, thereby eliminating the need for periodic maintenance work on the relay unit 6. Note that when the uninterruptible power supply direct delivery selection unit 8 is provided as described above, it is necessary to provide the second disconnection switch 15 (or an overlap-type double-throw switch instead of the second disconnection switch 15 and the third disconnection switch 67) to select the output destination of the power from the relay unit 6. On the other hand, if the uninterruptible power supply direct connection selection unit 8 is not provided, the second disconnection switch 15 and the third disconnection switch 67 do not need to be provided.

[0036] Here, a cutoff switch 14 that cuts off the power output from the uninterruptible power supply 3 is provided between the uninterruptible power supply 3 and the relay unit 6. The cutoff switch 14 is provided adjacent to the main body of the uninterruptible power supply 3 on the downstream side (load side). Here, the cutoff switch 14 is an automatic switch that automatically switches between an on state and an off state. As a result, when a failure such as an overload or short circuit occurs downstream, the cutoff switch 14 can isolate the failed part from the uninterruptible power supply 3, thereby protecting the uninterruptible power supply 3. Furthermore, by providing a sequence that opens the cutoff switch 14 in response to a failure in one of the uninterruptible power supplies 3, only the failed uninterruptible power supply 3 can be isolated from the relay unit 6, and the remaining uninterruptible power supplies 3 can continue to supply power to the load 41. Furthermore, when performing maintenance on the uninterruptible power supply 3, it is possible to eliminate the external power supply connection to the uninterruptible power supply 3 by opening the cut-off switch 14 or the first disconnect switch 13 to which the uninterruptible power supply 3 is connected, and the distribution switch 130 installed between the system power supply 2 and the uninterruptible power supply 3.This makes it possible to perform maintenance on the uninterruptible power supply 3 in a state where there is no external power supply while the remaining uninterruptible power supplies 3 continue to supply power to the load 41.

[0037] In this embodiment, the uninterruptible power supply direct supply selection unit 8 has at least one path switching switch 18 that selectively switches between a third state in which a path connected to the relay unit 6 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 relay unit 6 without the power supply switching unit 5 and a path connected to the load 41 are connected. In this example, in order to perform maintenance work on the power supply switching unit 5 while maintaining power supply to the load 41, the third state and the fourth state can be switched by the second disconnecting switch 15 and the third disconnecting switch 67, which are arranged immediately upstream of the second connection unit 12, and the path switching switch 18. 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. Therefore, when performing maintenance work on the power supply switching unit 5, a worker or the like manually operates the path switching switch 18 to set the state of the power supply system 1 to the fourth state (a specific switching procedure will be described later in this paragraph). Furthermore, by using a maintenance-free manual switch for the path selector switch 18, periodic maintenance work on the UPS direct supply selection unit 8 is not required. In this specification, maintenance work may include any of inspection, maintenance, and repair work on equipment, etc. When performing maintenance work on the power supply switching unit 5, the power supply switching unit 5 must be placed in a no-voltage state. Specifically, when the second disconnection switch 15 in the relay unit 6 and the path selector switch 18 connected to the power supply switching unit 5 are in the on state (third state), the third disconnection switch 67 and the path selector switch 18 directly connected to the relay unit 6 are placed in the on state (fourth state), and then the second disconnection switch 15 and the path selector switch 18 connected to the power supply switching unit 5 are placed in the off state. Furthermore, the power distribution switch 130 directly connected to the power supply switching unit 5 from the system power source 2 is also placed in the off state. This allows the power supply switching unit 5 to be placed in a no-voltage state while continuing to supply power from the UPS 3 to the load 41.

[0038] 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 delivery selection unit 8 and the load 41. Here, the power circuit breaker 81 is a circuit breaker. An example of the load 41 is a power consuming device connected to a distribution board 4, as shown in FIG. 2 . In the example of FIG. 1 , the disconnecting switch 9 is disposed adjacent to the upstream side (the uninterruptible power supply direct delivery selection unit 8 side) of the power circuit breaker 81. This allows the power supplied to the power circuit breaker 81 to be cut off on the upstream side (upstream side) of the power circuit breaker 81, so that maintenance work on the distribution board 4 and other devices connected downstream of the power circuit breaker 81 can be performed without affecting other loads 41 connected to the output system 111 of the power supply system 1. Here, the disconnecting switch 9 is a manual switch that is manually operated. By making the disconnecting switch 9 a manual switch that does not require maintenance, periodic maintenance work on the disconnecting switch 9 becomes unnecessary.

[0039] In this example, as shown in FIG. 1 , the power supply system 1 further includes a path interruption unit 21. The path interruption unit 21 is disposed on a path connecting the third connection unit 66 of the relay unit 6 and the UPS direct supply selection unit 8 (i.e., a path that does not pass through the power supply switching unit 5). The path interruption unit 21 includes a path interruption switch 22. The path interruption switch 22 is configured to disconnect the electrical connection between the third connection unit 66 of the relay unit 6 and the UPS direct supply selection unit 8. Here, the path interruption switch 22 is an automatic switch that can automatically switch between an ON state and an OFF state. For example, in the fourth state, the path interruption unit 21 cuts off the power supply to the downstream side when, for example, a current exceeding the total rated current of multiple UPSs 3 or a fault current such as a short circuit flows through the UPS direct supply selection unit 8 and downstream sides thereof (load 41 side), thereby protecting the UPSs 3 and the output system 111 (cables, bus ducts, etc.). In this example, it is assumed that multiple uninterruptible power supplies 3 are installed, but it is also assumed that a new uninterruptible power supply 3 will be added to the power supply system 1 at a later date in addition to a single uninterruptible power supply 3.

[0040] 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.

[0041] 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.

[0042] 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, so that even if one power supply system 1 malfunctions or is replaced, power supply by the uninterruptible power supply 3 can continue. Also, an appropriate number of power supply systems 1 can be installed depending on the scale of the load 41. The first power supply system 1a and the second power supply system 1b can have different configurations.

[0043] Third Embodiment A third embodiment of the power supply system 1 will be described with reference to FIG. 3. The following description of the power supply system 1 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 the first power supply system 1a, the uninterruptible power supply 3 will be referred to as the first uninterruptible power supply 3a, the relay unit 6 will be referred to as the first relay unit 6a, the uninterruptible power supply direct supply selection unit 8 will be referred to as the first uninterruptible power supply direct supply selection unit 8a, the path selector switch 18 will be referred to as the first path selector switch 18a, and the power supply switching unit 5 will be referred to as the first power supply switching unit 5a.

[0044] 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 second relay unit 6b, and a second uninterruptible power supply direct supply selection unit 8b. In this example, the second power supply system 1b includes a plurality of (here, two) second uninterruptible power supplies 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.

[0045] 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 switch 51b and a semiconductor switch 51S. In this example, the second power supply switch 51b and the semiconductor switch 51S are switches that automatically switch between a fifth state and a sixth state.

[0046] In this embodiment, the second power supply system 1b includes a single second relay unit 6b. The second relay unit 6b outputs power from the second uninterruptible power supply device 3b to the second power supply switching unit 5b. In this example, the second relay unit 6b can output power from each of the multiple (here, two) second uninterruptible power supply devices 3b to either the second power supply switching unit 5b or the second uninterruptible power supply direct supply selector 8b.

[0047] In this embodiment, the second relay unit 6b includes an output switch 61. The output switch 61 is configured to be able to switch between outputting power from the second uninterruptible power supply 3b to the second power supply switching unit 5b and outputting power from the second uninterruptible power supply 3b to the second uninterruptible power supply direct supply selection unit 8b (outputting power 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 and the second uninterruptible power supply direct supply selection unit 8b. Here, the output switch 61 is configured as an automatic switch that automatically switches between an on state and an off state, but it can also be configured as a manual switch.

[0048] The second uninterruptible power supply direct supply selection unit 8b has at least one second path selector switch 18b that selectively switches between a seventh state in which a path connected to the second relay unit 6b via the second power supply switching unit 5b is connected to a path connected to the load 41, and an eighth state in which a path connected to the second relay unit 6b without the second power supply switching unit 5b is connected to a path connected to the load 41. In this example, the output switch 61 and the second path selector switch 18b are capable of switching between the seventh state and the eighth state so that maintenance work on the second power supply switching unit 5b can be performed while maintaining power supply to the load 41. In this embodiment, the second path selector 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 selector switch 18b in parallel with switching the power output destination by the output switch 61, thereby setting the state of the second power supply system 1b to the eighth state. Furthermore, by using a manual switch for the second path selector switch 18b, periodic maintenance work on the second UPS direct supply selector 8b is unnecessary. The load 41 connected to the first power supply system 1a and the load 41 connected to the second power supply system 1b may be the same or different. By providing a second power supply system 1b different from the first power supply system 1a, power can be supplied from multiple power supply systems 1 to the load 41 that can receive power from multiple power sources. This allows the uninterruptible power supply 3 to continue supplying power even if one of the power supply systems 1 malfunctions or is replaced. Furthermore, even when maintenance work is performed on the second power supply system 1b, the first power supply system 1a can maintain a state in which power can be continuously supplied to the load 41. Therefore, even when the second power supply system 1b is provided in addition to the first power supply system 1a, the power system 10 can be prevented from becoming larger and costs can be reduced compared to the second embodiment.Furthermore, for a load 41 that cannot receive power from only a single power source, the power supply system 1 to be connected can be selected depending on the reliability required by the load 41. The configuration of the second power supply system 1b is not limited to the above, and may be configured differently from this embodiment, for example, without the second uninterruptible power supply direct supply selection unit 8b or without the second power supply switching unit 5b.

[0049] [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.

[0050] As shown in FIG. 4 , in this embodiment, the power supply system 1 and a path that directly connects the grid power supply 2 and the load 41 are 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 the path that directly connects 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) that is arranged in the power supply system 1. As a result, 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 power supply system 1 can continuously supply power to the load 41. This makes it possible to improve the reliability of the entire power system 10 compared to the first embodiment, and also to reduce costs by simplifying the power system 10 compared to the second and third embodiments.

[0051] 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.

[0052] As shown in FIG. 5 , in this embodiment, the power supply system 1 includes a plurality of uninterruptible power supply devices 3 and a relay unit 6 disposed between the uninterruptible power supply devices 3 and a load 41, capable of outputting power from the uninterruptible power supply devices 3 to the load 41. In this power supply system 1, a path is provided for supplying power from the uninterruptible power supply devices 3 to the load 41. However, unlike the first embodiment, a path is not provided for supplying power directly from the grid power supply 2 to the load 41 without passing through the uninterruptible power supply devices 3. That is, in this embodiment, the power supply system 1 does not include a power supply switching unit 5. Normally, power is supplied from the grid power supply 2 to the load 41 via the uninterruptible power supply devices 3. In the event of a power outage or the like in the grid power supply 2, power is supplied to the load 41 from a storage battery or the like via an inverter. The relay unit 6 includes a first connection unit 11 connected to the uninterruptible power supply devices 3, a second connection unit 12 connected to the load 41, and a first disconnection switch 13 for disconnecting the electrical connection between the first connection unit 11 and the second connection unit 12. The first disconnecting switch 13 is a manual switch that manually disconnects the electrical connection between the first connection part 11 and the second connection part 12. By turning on the first disconnecting switch 13, the first connection part 11 and the second connection part 12 are electrically connected. This allows power supplied via multiple uninterruptible power supplies 3 to be output to the power supply switching unit 5. In this embodiment, the first disconnecting switch 13 is a manual switch that does not require maintenance, which eliminates the need for periodic maintenance work on the relay unit 6. A disconnecting switch 14 that cuts off the power output from the uninterruptible power supply 3 is provided between the uninterruptible power supply 3 and the relay unit 6. The disconnecting switch 14 is provided adjacent to the main body of the uninterruptible power supply 3 on the downstream side (load side) (FIG. 1). Here, the disconnecting switch 14 is an automatic switch that automatically switches between an on state and an off state.

[0053] 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 delivery 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 111 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.

[0054] <Another embodiment> While the first to fifth embodiments specifically describe the configuration of the power system 10, 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 first disconnecting switch 13, 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.

[0055] In the first embodiment described above, a path blocking unit 21 is provided, but if a current that exceeds the total rated current value of multiple uninterruptible power supplies 3 flows downstream of the third connection part 66 in the fourth state, or if a malfunction such as a short circuit occurs, it is possible for each of the multiple uninterruptible power supplies 3 to detect these malfunctioning states and cut off the power supply to the malfunctioning part and protect the uninterruptible power supply 3, making the path blocking unit 21 unnecessary.

[0056] In the first and fifth embodiments, the relay unit 6 includes a single second connection unit 12. However, the present invention is not limited to this. The relay unit 6 may include multiple second connection units 12. In the first and fifth embodiments, the multiple uninterruptible power supplies 3 each include a cutoff switch 14 that cuts off the power output from the uninterruptible power supply 3. However, the present invention is not limited to this. If the uninterruptible power supply 3 includes a function (such as a circuit breaker, load switch, or gate block function) that can cut off the power supply to the downstream side when a failure such as an overload or short circuit occurs on the downstream side (load side), and if overload protection of the uninterruptible power supply 3 is possible, the cutoff switch 14 may be omitted. In this case, the cutoff switch 14 may be installed to reliably disconnect the power supply connection of the uninterruptible power supply 3 during maintenance, etc. Alternatively, instead of connecting the cutoff switch 14 downstream of the uninterruptible power supply 3, a function equivalent to the cutoff switch 14 may be built into the uninterruptible power supply 3.

[0057] 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.

[0058] In the third embodiment described above, a representative example is given as the second power supply system 1b, but there does not need to be a plurality of uninterruptible power supplies 3. Also, although the output switch 61 of the second relay unit 6b is described as an automatic switch that automatically switches between an on state and an off state, it may be a manual switch similar to the first disconnecting switch 13. Also, in FIG. 3, the configuration may be such that the output switch 61 that outputs power to the second uninterruptible power supply direct delivery selection unit 8b is not provided.

[0059] 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.

[0060] In the second to fourth embodiments described above, an example has been described in which only highly important loads 41 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 may also be used in which all loads 41 are connected to both distribution boards 4 regardless of the relative importance of each of the multiple loads 41. Furthermore, in the fifth embodiment described above, a single power supply system 1 has been described, but it is also possible to use multiple power supply systems 1 or use direct power supply units 94 in parallel, as in the second, third, and fourth embodiments described above.

[0061] 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]

[0062] The present invention can be used in power systems. [Explanation of symbols]

[0063] 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 section 5a: First power supply switching unit 5b: Second power supply switching unit 6: Relay section 6a: First relay section 6b: Second relay section 8: Uninterruptible power supply direct supply selection section 8a: First uninterruptible power supply direct supply selection section 8b: Second uninterruptible power supply direct supply selection section 9: Disconnecting switch (a manual switch between the power supply system and the power breaker that can be manually operated to disconnect the power supply to the load) 10: Power Systems 11: First connection part 12: Second connection part 13: First disconnect switch (disconnect switch) 14:Shut-off switch 18: Route change switch 18a: 1st route changeover switch 18b: Second route changeover switch 41: Load 66: Third connection part

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 relay unit capable of outputting power from the plurality of uninterruptible power supply devices to the power supply switching unit, the relay unit includes a first connection unit connected to the uninterruptible power supply, a second connection unit connected to the power supply switching unit, and a disconnection switch that disconnects the electrical connection between the first connection unit and the second connection unit, The power system, wherein the disconnecting switch is a manual switch that is manually operated to disconnect the electrical connection between the first connection portion and the second connection portion.

2. The power system according to claim 1 , wherein the uninterruptible power supply comprises a cutoff switch that cuts off power output from the uninterruptible power supply.

3. The power supply system includes: a third state in which a path connected to the relay 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 relay unit without passing through the power supply switching unit and a path connected to the load are connected, the relay unit includes a third connection unit connected to the uninterruptible power supply direct connection selection unit, 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.

4. The power supply system includes: a third state in which a path connected to the relay 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 relay unit without passing through the power supply switching unit and a path connected to the load are connected, The power system according to claim 2 , wherein the path changeover switch is a manual switch that is manually operated to selectively switch between the third state and the fourth state.

5. 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.

6. 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.

7. 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 3 , 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.

8. 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 4 , 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.

9. 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.

10. 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 uninterruptible power supply direct supply selection unit is a first uninterruptible power supply direct supply selection unit, the path changeover switch is a first path changeover switch, and the power supply changeover unit is a first power supply changeover 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 plurality of second uninterruptible power supplies; 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 second relay 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 at least one second path changeover switch that selectively switches between a seventh state in which a path connected to the second relay unit via the second power supply changeover unit and a path connected to the load are connected to the second relay unit, and an eighth state in which a path connected to the second relay unit without going through the second power supply changeover unit and a path connected to the load are connected to the second relay unit, The power system according to claim 3 , 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.

11. 9. 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.

12. 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 relay unit that is disposed between the uninterruptible power supply and the load and is capable of outputting power from the uninterruptible power supply to the load, the relay unit includes a first connection unit connected to the uninterruptible power supply, a second connection unit connected to the load, and a disconnection switch that disconnects an electrical connection between the first connection unit and the second connection unit, The power system, wherein the disconnecting switch is a manual switch that is manually operated to disconnect the electrical connection between the first connection portion and the second connection portion.

13. The power system according to claim 12 , wherein the uninterruptible power supply includes a cutoff switch that cuts off power output from the uninterruptible power supply.

14. 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 12 or 13, 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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