Branch-type power generation connection panel and power system

Abstract

To provide a branch-type power generation connection panel and a power system to achieve "capacity expansion" or the like by externally attaching a housing of a power generation connection panel, which incorporates a vacuum circuit breaker, to a side of a housing of a grid interconnection panel with its bottom edge higher than that of the housing of the grid interconnection panel or the like.SOLUTION: A power generation connection panel 1, which connects a power generation device P to a grid interconnection panel C and a load L, includes a branch electrical path 2 branched from a bus electrical path M and connected to the power generation device P, and a vacuum circuit breaker 3 provided in the branch electrical path 2 in a panel housing 10 thereof, the panel housing 10 is mounted externally on a side surface of a panel housing C' of the grid interconnection panel C, and the bottom end is higher than the bottom end of the panel housing C' of the grid interconnection panel C. Furthermore, the branch electrical path 2 may be arranged internally between an upper panel housing 10A and a lower panel housing 10B, and the vacuum circuit breaker 3 may be arranged within the upper panel housing 10A or the lower panel housing 10B, or a disconnector 4, current transformer 5, overcurrent relay 6, or the like may also be included. A power system 50 having the grid interconnection panel C, the load L, and the power generation device P may also include the branch electrical path 2, the vacuum circuit breaker 3, or the like.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a grid interconnection panel that connects to a grid, a power generation connection panel that connects a power generation device to a load connected to the grid interconnection panel, and a power system. [Background technology]

[0002] BACKGROUND ART Conventionally, a system interconnected with a power system having a commercial power source is known (see Patent Document 1). This grid-connected system includes a storage battery installed in a parking lot, an AC / DC power conversion device for the storage battery, a charging / discharging stand for an electric vehicle, and a grid-connected control device, and in the event of an emergency in the power grid, the grid-connected control device supplies power to a first load from at least one of the charging / discharging stand or the AC / DC power conversion device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2020-010442 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the grid-connected system of Patent Document 1 does not describe or disclose any power generation devices such as solar power generation devices, and does not anticipate adding such power generation devices to this grid-connected system. If a power generation device is added to increase the load (for example, a charging / discharging stand, general lighting load, power load, etc.), the capacity required for the added power generation device will naturally increase, but this cannot be handled using a high-voltage AC load switch, which is equipment with a low upper capacity limit. Furthermore, in the grid interconnection system of Patent Document 1, consumers cannot use electricity while work to add the power generation device is being carried out, so if a separate foundation is created to install equipment such as a high-voltage AC load switch or the level of the created foundation is adjusted to that of the existing foundation, costs increase and the construction period is extended, which results in a longer period during which consumers are unable to use electricity.

[0005] In view of these points, the present invention aims to provide a power generation connection panel and a power system that can "accommodate increased capacity" and "reduce costs, construction time, and power outage periods" by externally attaching the panel housing of the power generation connection panel, which has a built-in vacuum circuit breaker, to the side of the panel housing of the grid interconnection panel and making its bottom end higher than the bottom end of the panel housing of the grid interconnection panel. [Means for solving the problem]

[0006] The power generation connection panel 1 of the present invention is a power generation connection panel that connects a power generation device P to a system interconnection panel C that is system-connected to a system G and a load L connected to the system interconnection panel C, and has a panel housing 10 of the power generation connection panel inside which is located a branch circuit 2 that branches off from a bus circuit M between the system G and the load L and is connected to the power generation device P, and a vacuum circuit breaker 3 provided on the branch circuit 2, and the panel housing 10 of the power generation connection panel is attached from the outside to the side of the panel housing C' of the system interconnection panel C, and a first feature is that the lower end of the panel housing 10 of the power generation connection panel is located at a higher position than the lower end of the panel housing C' of the system interconnection panel C.

[0007] A second feature of the power generation connection panel 1 of the present invention is that, in addition to the first feature described above, the panel housing 10 of the power generation connection panel includes an upper panel housing 10A and a lower panel housing 10B, the branch circuit 2 is arranged inside the upper panel housing 10A and the lower panel housing 10B, and the vacuum circuit breaker 3 is arranged inside one of the upper panel housing 10A and the lower panel housing 10B.

[0008] A third feature of the power generation connection panel 1 of the present invention is that, in addition to the first or second feature described above, the panel housing 10 of the power generation connection panel contains a circuit breaker 4 provided in the branch circuit 2, a current transformer 5 provided in the branch circuit 2, an overcurrent relay 6 connected to the current transformer 5, and a cable head 7 provided in the branch circuit 2, and the cable head 7 is grounded.

[0009] Due to these features, the panel housing 10 of the power generation connection panel 1, which incorporates a vacuum circuit breaker 3 provided in a branch circuit 2 branching off from the bus circuit M, is attached externally to the side of the panel housing C' of the grid interconnection panel C, and its lower end is made higher than the lower end of the panel housing C' of the grid interconnection panel C. Thus, even when a large-capacity power generation device P is added to the power system 50, the use of the vacuum circuit breaker 3, which is a device with a higher capacity upper limit than when a high-voltage AC load switch is used, makes it possible to accommodate an increase in the capacity of the load L and the power generation device P ("accommodating increased capacity"). At the same time, when adding a power generation device P, there is no need to create a separate foundation for installing the power generation connection panel 1 incorporating equipment such as a vacuum circuit breaker 3, or to align the level of the created foundation with the existing foundation B, which reduces expenses, the construction period for adding the power generation device P, and the period during which electricity use by consumers is suspended ("Reducing expenses, construction period, and power suspension period"). In addition, since such a power generation connection board 1 incorporates the branch electric circuit 2 branched from the bus electric circuit M, it can also be said to be a "branch-type power generation connection board."

[0010] Furthermore, by arranging the branch circuit 2 inside the upper panel housing 10A and the lower panel housing 10B and arranging the vacuum circuit breaker 3 inside the upper panel housing 10A or the lower panel housing 10B, the weight of the vacuum circuit breaker 3 tends to be heavy due to the high upper capacity limit, but if one of the upper panel housing 10A and the lower panel housing 10B that has the vacuum circuit breaker 3 built in is transported and installed separately from the other panel housing, the workload and work time can be reduced, resulting in a ``reduction in expenses, construction period and power outage period.''

[0011] Furthermore, by grounding the disconnector 4, current transformer 5, overcurrent relay 6, and cable head 7 inside the panel housing 10 of the power generation connection panel 1, it becomes possible to simultaneously install the equipment required to add a power generation unit P by simply attaching the power generation connection panel 1 to the grid interconnection panel C, thereby further reducing costs, construction time, and power outage periods.

[0012] The power system 50 of the present invention is a power system having a system interconnection panel C that is interconnected to a system G, a load L connected to the system interconnection panel C, and a power generation device P connected to the system interconnection panel C and the load L, and has a first feature in that it has a branch circuit 2 that branches off from a bus circuit M between the system G and the load L and is connected to the power generation device P, and a vacuum circuit breaker 3 provided on the branch circuit 2.

[0013] A second feature of the power system 50 according to the present invention is that, in addition to the first feature described above, the branch circuit 2 and vacuum circuit breaker 3 are located inside a panel housing 10 of the power generation connection panel 1 that is separate from the panel housing C' of the system interconnection panel C, the panel housing 10 of the power generation connection panel 1 is attached externally to the side of the panel housing C' of the system interconnection panel C, and the lower end of the panel housing 10 of the power generation connection panel 1 is located at a higher position than the lower end of the panel housing C' of the system interconnection panel C.

[0014] Due to these features, by having a vacuum circuit breaker 3 installed in the branch circuit 2 branching off from the bus circuit M, even when a large-capacity power generating device P is added to the power system 50, the use of the vacuum circuit breaker 3, which is equipment with a higher capacity upper limit than when a high-voltage AC load switch is used, makes it possible to accommodate an increase in the capacity of the load L and the power generating device P ("accommodating increased capacity"). In addition, since the power system 50 has the branch electric circuit 2 branched from the bus electric circuit M built in, it can also be said to be a "branch-type power system."

[0015] Furthermore, by attaching the panel housing 10 of the power generation connection panel 1, which incorporates the vacuum circuit breaker 3 provided in the branch circuit 2, from the outside to the side of the panel housing C' of the grid interconnection panel C and making its bottom end higher than the bottom end of the panel housing C' of the grid interconnection panel C, even when adding a power generation device P, there is no need to create a separate foundation for installing the power generation connection panel 1, which incorporates equipment such as the vacuum circuit breaker 3, or to align the level of the created foundation with the existing foundation B, thereby reducing expenses, the construction period for adding the power generation device P, and the period during which electricity use by consumers is suspended ("Reducing expenses, construction period, and power suspension period"). [Effects of the Invention]

[0016] According to the power generation connection panel and power system of the present invention, the panel housing of the power generation connection panel, which has a built-in vacuum circuit breaker, can be attached externally to the side of the panel housing of the grid interconnection panel, and its bottom end can be made higher than the bottom end of the panel housing of the grid interconnection panel, thereby making it possible to ``accommodate increased capacity''. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing a power generation connection panel and a power system according to the present invention; [Figure 2] FIG. [Figure 3] 3 is a side view of the power generation connection board taken along the line AA' in FIG. 2. FIG. [Figure 4] FIG. 2 is a front view showing the exterior of the power generation connection panel. [Figure 5] FIG. 4 is a side view showing the exterior of the power generation connection panel. [Figure 6] 1 is a photograph substituted for a drawing illustrating a schematic front view of a power generation connection panel attached from the outside to the side of a panel housing of a grid interconnection panel. [Figure 7] This is a photograph used as a substitute for a drawing, illustrating a vacuum circuit breaker and other components inside the upper panel housing of a grid interconnection panel. [Figure 8] 1 is a photograph in place of a drawing illustrating a perspective view of a power generation connection panel attached from the outside to the side of a panel housing of a grid interconnection panel. [Figure 9]10 is a photograph in place of a drawing illustrating a side view of a power generation connection panel attached from the outside to the side of a panel housing of a grid interconnection panel. [Figure 10] This is a photograph used as a substitute for a drawing, illustrating a current sensor unit attached to the secondary circuit between an instrument current transformer (beyond a bulkhead, etc.) installed on a bus circuit and an overcurrent relay inside the panel housing of a grid interconnection panel, as well as a sensor cable and shield connected to the current sensor unit. [Figure 11] This is a circuit diagram showing a grid interconnection panel. In Fig. 11, symbol M (C) indicates connection to the busbar circuit of the grid interconnection panel, symbol P indicates connection to a power generation device outside the panel housing of the power generation connection panel, symbol C (C') indicates connection to the panel housing of the grid interconnection panel (grounding busbar), and the section between EA and ET in the lower left diagram in Fig. 11 is a Class A grounding busbar. [Figure 12] 12 is a schematic circuit diagram showing a power generation connection panel and a power system according to the present invention. In Fig. 12, the power distribution transformer (reference symbol P33) and the zero-phase voltage detector (reference symbol P34) in the power generation device distribution panel are drawn outside the distribution panel housing (reference symbol P31), but in reality they may be built into the distribution panel housing. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. <Generator connection panel 1> 1 to 12 show a power generation connection board 1 according to the present invention. This power generation connection board 1 is a board that connects a power generation device P (to be described later) to a grid interconnection board C (to be described later) and a load L (to be described later). Inside the panel housing 10 of the power generation connection panel 1, there are branch electric circuits 2, which will be described later, and vacuum circuit breakers 3, which will also be described later. Additionally, the panel housing 10 of the power generation connection panel 1 may contain a disconnector 4, a current transformer 5, an overcurrent relay 6, and a cable head 7, which will be described later.

[0019] Here, the current, voltage, power, and capacity in the present invention may be values ​​within a rated range, in which case they can be referred to as rated current, rated voltage, rated power, and rated capacity. These rated currents, etc. can also be referred to as limit values ​​of current, etc. guaranteed by manufacturers to ensure the safe use of electrical appliances, and further, ratings can also be referred to as usage limits or conditions that guarantee the safe and proper operation of devices (electrical and electronic devices) and equipment. When the current in the present invention is an AC current, the current value (current value), voltage value (voltage value), power value (power value), and capacitance value (capacity value) may be effective values. In addition, the term "electrical circuit" in this invention refers to a circuit that allows electricity (current) to flow, and is made of a conductor such as copper, aluminum, silver, gold, or nichrome covered with an insulating coating, and includes common cables and electric wires. Below, we will first describe the system G, the system interconnection panel C (and its panel housing C', etc.), the load L, the power generation device P, and the bus line M, which are related to the power generation connection panel 1 described above.

[0020] <System G> As shown in Figures 1 and 9, the system G transmits (receives) electricity to the power generation connection panel 1 and the power system 50, and refers to the entire system through which electric power companies and others supply electricity to consumers, and can also be called a power system. Specifically, the system G includes facilities such as substations, transmission lines, and distribution lines, and may also include power plants. The system G may also include pole air switches (PAS) 50a, which will be described later, as well as a utility transformer, a power purchase watt-hour meter, a power sale watt-hour meter, and protective relay devices. The power handled by such a system G may be either AC or DC, but the following description will be given assuming that it is AC. In System G, most of the electricity transmitted is AC, so it is transmitted using three-phase, three-wire (3φ3W) transmission lines. In order to reduce transmission losses during this process, the main long-distance transmission sections transmit electricity at as high a voltage as possible (for example, 6600V or 22000V). The electricity transmitted by system G is transformed (stepped down) in several stages near the point of consumption, and after the pole-mounted transformer, it is distributed via single-phase two-wire (1φ2W) or similar. System G may be a system such as a power company system (commercial power system), a system independently owned by an organization such as a company or a local government, or a system within a plant (independent power system).

[0021] <Grid connection panel C> As shown in Figures 1, 6 to 10, and 12, the grid interconnection panel C is a panel that is interconnected to the above-mentioned system G, and can be said to be the only one that exists in one power system 50 described below, and equipment that is interconnected to the above-mentioned system G is provided on the grid interconnection panel C. The specific configuration of the equipment provided on the grid interconnection panel C (strictly speaking, the panel case C') is not particularly limited, but may include, for example, a combined voltage and current transformer (VCT) C1 for commerce, a disconnecting switch (also called a service breaker, which is different from the disconnecting switch 4 of the power generation connection panel 1 described later) C2, a voltage transformer (VT, i.e., a high-voltage transformer) C3, a circuit breaker such as a vacuum circuit breaker (which can be called a system breaker or a high-voltage breaker, which is different from the vacuum circuit breaker 3 of the power generation connection panel 1 described later) C4, a current transformer (also called a high-voltage current transformer, which is different from the current transformer 5 of the power generation connection panel 1 described later) C5, an overcurrent relay C6, a high-voltage AC load break switch (LBS, Load Breaker The power supply may include a switch C7, a transformer (if it is a transformer for a general lighting load L1 described later, it can be said to be a lighting transformer, and if it is a transformer for a general power load L2 described later, it can be said to be a power transformer) C8, a molded case circuit breaker (MCCB) C9, a standby circuit breaker C10, etc. The equipment provided on the grid interconnection panel C may also include a current sensor P43 connected to a digital multi-relay P42 in a control box P4 of the power generation device P (described later) via a sensor cable P44 of a predetermined length. The sensor cable P44 may be covered with a shield P45. The rated capacity of the high-voltage AC load switch C7 (or a general high-voltage AC load switch) is not particularly limited and may be, for example, 10 kVA to less than 2000 kVA, preferably 100 kVA to 1500 kVA, and more preferably 500 kVA to 1000 kVA. The weight of the high-voltage AC load switch C7 (or a general high-voltage AC load switch) is also not particularly limited and may be, for example, 1 kg to less than 15 kg, preferably 2 kg to 12 kg, and more preferably 3 kg to 10 kg. Other equipment installed on the system interconnection panel C may include a zero-phase voltage detector, a zero-phase current transformer, a load switch, an undervoltage relay, an overcurrent relay, a power supply circuit breaker, a voltmeter, an ammeter, a single-phase transformer, a single-phase transformer circuit breaker, a grounding resistor, a circuit protector, a voltage test terminal, a current test terminal, etc., and may also include a circuit for suppressing inrush current, a lightning arrester, an undervoltage relay, an overvoltage relay, an underfrequency relay (also called an underfrequency relay), an overfrequency relay, an electricity meter, etc.

[0022] <Grid connection panel C enclosure (grid connection panel enclosure) C', etc.> 1, 6 to 10, and 12, the panel housing C' of the above-described grid interconnection panel C can also be referred to as the grid interconnection panel housing C', and it can be said that this grid interconnection panel housing C' houses at least some of the devices provided in the above-described grid interconnection panel C. Among the devices provided in the grid interconnection panel C, the transformer C8 does not have to be housed in the grid interconnection panel housing C', and the transformer C8 may be attached to the grid interconnection panel housing C' from the outside or installed outside the grid interconnection panel housing C'. Conversely, the transformer C8 may be housed in the grid interconnection panel housing C'. The specific configuration of the system interconnection panel housing C' is not particularly limited, but for example, it may be formed in an approximately rectangular shape overall, and the volume (volume of the outer surface) and capacity (volume of the inner surface) of the system interconnection panel housing C' may be larger than the volume and capacity of the panel housing 10 (also referred to as the power generation connection panel housing 10) of the power generation connection panel 1 described below. When the entire system interconnection panel housing C' is substantially rectangular, the system interconnection panel housing C' may have an openable and closable door (front door, etc.) on each of its side members (front member, rear member, left member, right member, etc.). Furthermore, the system interconnection panel housing C' may have a ceiling member, a bottom member, etc. in addition to the side members. In addition, the "front and back" of the roughly rectangular parallelepiped system interconnection panel housing C' refers to the side with the door as the "front" and the side opposite the door as the "rear" (if there are doors at the front and back, the side with either door is referred to as the "front"). Furthermore, the "left and right" of the system interconnection panel housing C' refers to the left-hand side when a user enters the system interconnection panel housing C' and faces from the "rear" to the "front" of the system interconnection panel housing C', and the right-hand side when facing from the "rear" to the "front" of the system interconnection panel housing C'.

[0023] The side surface materials and ceiling surface materials of the system interconnection panel housing C' may have rear through holes 10Aa in the rear surface material of the panel housing 10 of the power generation connection panel 1 described later, and through holes Ca' and rear openings corresponding to (approximately the same number, size, and shape) the rear openings in the rear surface material. Naturally, these through holes Ca' and rear openings are not provided in the existing system interconnection panel housing C', but when installing the power generation connection panel housing 10, they may be provided according to the rear through holes 10Aa and rear openings of the power generation connection panel housing 10 to be installed, or they may be made as small as possible. A power generation connection panel housing 10 (particularly its rear side), which will be described later, is attached to the side members (front member, rear member, left member, right member, etc.) of the grid interconnection panel housing C', and at least one of the side members (front member, rear member, left member, right member, etc.) may be wider than the rear member of the power generation connection panel housing 10, which will be described later. Even if the volume or capacity of the grid interconnection panel housing C' is smaller than the volume or capacity of the power generation connection panel housing 10, which will be described later, at least one of the side members of the grid interconnection panel housing C' may be wider than the rear member of the power generation connection panel housing 10, which will be described later. Only one power generation connection panel case 10, which will be described later, may be attached to one grid interconnection panel case C', or multiple power generation connection panel cases 10 may be attached to one grid interconnection panel case C'.

[0024] A lifting device Cb' that can be lifted by a crane or the like may be provided on the outer surface of the ceiling surface material of the system interconnection panel housing C', and the entire system interconnection panel housing C' lifted via this lifting device Cb' may be installed (mounted) on a foundation (base) B that has been constructed in advance. The specific material of this foundation B is not particularly limited, and may be made of, for example, concrete or steel (H-beam), and its specific configuration may be a mat foundation with a uniform thickness, a girder foundation with a recess or the like to form a space below the bottom material of the grid interconnection panel casing C', or a plurality of pile members driven into the installation location, which may also be the foundation B. Furthermore, if the foundation B of the grid interconnection panel casing C' is made up of a plurality of pile members, the grid interconnection panel casing C' will be installed on the upper end surfaces of the plurality of pile members, which can also be said to reduce construction costs. The location (installation location) where these foundations B and the grid interconnection panel housing C' (grid interconnection panel C) itself are installed is not particularly limited, and may be, for example, the outdoors of a building such as a store, or the indoors or outdoors of a factory, etc. The installation surface S at this installation location may be approximately horizontal or inclined, and the surface of the installation surface S may be approximately flat or may have irregularities.

[0025] <Load L> 1 and 12, the load L is a load (load equipment) that consumes at least the power received from the above-mentioned system G (hereinafter also referred to as "received power"). In other words, the value of the power consumption (capacity) of the load L may be greater than the value of the received power received from the system G (only a part of the power consumption of the load L may be covered by the received power). The load L may be, for example, a car dealership or a gas station, a rental car store (rental car shop), a charger in a factory or workshop, or may include electrical equipment and facilities that use electricity such as electrical and electronic devices (general lighting loads L1 such as incandescent lamps, fluorescent lamps, and mercury lamps (lighting fixtures), and general power loads L2 such as air conditioners, motors, and pumps), or it may even include the factory or workshop itself. Furthermore, the load L may include electrical equipment that uses electricity, such as electrical and electronic devices in corporate bodies, organizations, individuals, government offices, unions, and other offices, homes, stores, warehouses, garages, car parks, bicycle parking lots, school buildings, auditoriums, gymnasiums, research facilities, hospitals, clinics, inns, hotels, theaters, movie theaters, stadiums, baseball stadiums, etc., as well as the company offices themselves, or it may include a combination of these.

[0026] <Generator P> As shown in Figures 1 and 12, the power generation device P is a device connected to the above-mentioned grid interconnection panel C and the above-mentioned load L via a power generation connection panel 1 described later, and has a power generation section P1 and a conversion section P2 described later. Additionally, the power generation device P may include a switchboard P3 and a control box (also called a control panel) P4.

[0027] As shown in FIG. 12, the power generation section P1 is a section that generates electricity and may have any configuration, such as solar power generation, wind power generation, hydroelectric power generation, geothermal power generation, solar thermal power generation, power generation using atmospheric heat or other heat present in nature, or power generation using biomass (organic matter derived from plants and animals that can be used as an energy source). Alternatively, the power generating unit P1 may generate power using ocean temperature difference, wave power, tidal currents (ocean currents), or tides. The number of power generation units P1 in one power generation device P is not particularly limited, but may be, for example, one or more, and the power generation power (capacity) of the power generation unit P1 is also not particularly limited, but may be, for example, 100 kW or more and 30,000 kW or less, preferably 300 kW or more and 20,000 kW or less, and more preferably 500 kW or more and 10,000 kW or less. The following will particularly describe the solar power generation unit P1 that generates solar power. The solar power generation unit P1 includes a solar cell P1a in the form of a panel or the like. In addition, the solar power generation unit P1 may have a pyranometer that measures solar radiation intensity, a current collector that collects DC current from the solar cells P1a, a junction box, etc., and sends it to the conversion unit P2 (described later), etc. The solar power generation unit P1 may have a plurality of solar cells P1a, and these plurality of solar cells P1a may be connected in series to form a solar cell string. The solar power generation unit P1 may have a junction box to which a plurality of solar cell strings are connected in parallel, and there may be a plurality of such junction boxes.

[0028] As shown in FIG. 12, the conversion unit P2 is a part that converts the DC current or AC current from the power generation unit P1 described above into a low-voltage AC current. The conversion unit P2 may include an inverter that converts DC current from the solar cell P1a into AC current, and may also include a controller that controls the voltage and frequency of the AC converted by the inverter, an air circuit breaker, etc. The conversion unit P2 is also called a power conditioner. The number of conversion units P2 in one power generation device P is not particularly limited, but may be, for example, multiple (for example, four or five) or just one, and the conversion power (capacity) that can be converted by the conversion unit P2 is also not particularly limited, but may be, for example, 30 kW to 10,000 kW, preferably 50 kW to 5,000 kW, and more preferably 100 kW to 2,000 kW (250 kW, 500 kW, etc.). Note that the conversion power of the conversion unit P2 may be smaller than the power generation power of the above-mentioned solar power generation unit P1 (in other words, the power generation capacity may be greater than the conversion power), and in this case, it can be said that the solar cell P1a is overloaded with respect to the conversion unit P2. In addition, the conversion unit P2 may have an undervoltage relay, an overvoltage relay, an underfrequency relay, an overfrequency relay, or a passive or active islanding protection device.

[0029] As shown in Figure 12, the distribution board P3 is a board that distributes the electricity generated from the power generation unit P1 via the conversion unit P2 to the grid interconnection board C side, and it can be said that there are one or more of these in one power system 50 described below, and the distribution board P3 has components that distribute electricity to the grid interconnection board C side. The specific configuration of the components of the distribution board P3 is not particularly limited, but may include, for example, a board housing P31 that incorporates equipment that distributes power to the system interconnection board C, a transformer P32, etc., and a control box P4, which will be described later, may be attached to the board housing P31 of the distribution board P3 (in other words, the distribution board housing) P31. The specific configuration of the devices housed in the panel housing P31 of the distribution panel P3 is not particularly limited, but may include, for example, a voltage transformer (VT, which can be considered a distribution transformer and is different from the high-voltage transformer C3 of the grid interconnection panel C) P33, a zero-phase potential device (ZPD) P34, a voltmeter, a low-voltage circuit breaker, a circuit protector, and even (a part of) the branch electric circuit 2 described below. Note that the output from the distribution transformer P33 may be output to a digital multi-relay P42 housed in a control box P4 described below, and the output from the zero-phase voltage detector P34 may be output to an earth fault overvoltage relay housed in the control box P4. The transformer (i.e., distribution transformer) P32 of the switchboard P3 is a device that transforms (steps up) low-voltage AC current from outside the switchboard housing P31 (from the power generation unit P1 through the conversion unit P2) to higher voltage AC current. The word "transformer" is an abbreviation for "transformer." The switchboard housing P31 may be attached above the distribution transformer P32. This means that the distribution transformer P32 is installed outside the switchboard housing P31, eliminating the need for a ventilation fan or auxiliary power supply for the ventilation fan inside the switchboard housing P31. This allows for easy repair and painting of the distribution transformer P32 (main body), allows for long-term maintenance (e.g., 20 years or more), and eliminates the need for assembly work at the installation site by shipping the unit as a single unit.

[0030] As shown in Figure 12, the control box P4 may be attached to the above-mentioned distribution board P3 (distribution board housing P31), or may be attached to a stand supporting the above-mentioned solar power generation unit P1 (panel-shaped solar cell P1a). The devices housed in the control box P4 are not particularly limited, and may include, for example, a control device P41 or a digital multi-relay (DMR) P42, which will be described later, an uninterruptible power supply, a watt-hour meter, a ground fault overcurrent relay, an overcurrent relay 6, which will be described later, an autotransformer, a socket, an undervoltage relay, a capacitor tripping power supply, a monitoring device (a device that monitors the amount of power generated (amount of power) by the power generation unit P1 described above, the amount of power converted by the conversion unit P2, etc.), etc. The current sensor unit P43 housed in the grid interconnection panel C described above can also be considered a device on the control box P4 side. The control device P41 is a device that controls the above-mentioned conversion unit P2 and the grid interconnection panel C. For example, the control device P41 controls the output of the conversion unit P2 (by providing an output target value to the conversion unit P2) based on the power (received power) received from the grid G ​​to the grid interconnection panel C, the power generated by the power generation device P (conversion unit P2), and the power consumption of the load L. The control device P41 is connected to a ground fault overvoltage relay and receives a stop signal from the ground fault overvoltage relay to stop the conversion of the above-mentioned conversion unit P2. The control device P41 may be a smart logger, a sequencer, a computer, etc. One power generation device P may have one or more control devices P41. The power supply for the control device P41 is connected to the above-mentioned uninterruptible power supply and receives power from the uninterruptible power supply. The control device P41 may be monitored, configured, and operated by a user directly or remotely via the Internet, telephone lines, etc. The digital multi-relay P42 is a device that receives as input a transformed output current (a smaller current (smaller current value) transformed output current corresponding to the high-voltage AC current (its current value) flowing in the bus circuit M described below) output from a current sensor unit P43 built into the above-mentioned system interconnection panel C (provided inside the system interconnection panel housing C'), and is also connected to a distribution transformer P33 built into the above-mentioned distribution panel housing P31, and receives as input a transformed output current (a transformed output current obtained by transforming (stepping down) the high-voltage AC current flowing in the branch circuit 2 (or bus circuit M) described below to a lower voltage) output from the distribution transformer P33. As its name suggests, the digital multi-relay P42 also functions as a relay, and when the input transformed output current or transformed output current exceeds a certain value (operating voltage value) for a certain period of time (such as an operating time of approximately 1 second), it may output a stop signal to stop the conversion of the above-mentioned conversion unit P2, but it is not necessary to output a stop signal. In addition, the digital multi-relay P42 may calculate the current and voltage values ​​of the high-voltage AC current flowing through the bus circuit M based on the transformed output current and the transformed output current, or may multiply these values ​​to calculate power values ​​and energy values, and output these values. This allows the power generation device P to confirm the power value of the power received from the grid G ​​(i.e., purchased power). While the output signals from the digital multi-relay P42 are not input to the control device P41 of the conversion unit P2, they may be input to the control device P41. Alternatively, the values ​​may be output to a remote terminal such as a computer via the Internet or a telephone line. When outputting a stop signal to the conversion unit P2, the digital multi-relay P42 may input the signal directly to the conversion unit P2 or to a low-voltage circuit breaker built into the distribution board P3 (distribution board housing P31) to interrupt the electrical path (i.e., the low-voltage path) between the distribution transformer P32 and the conversion unit P2. The current sensor unit P43 is a sensor attached to the output electric path (i.e., the secondary side) of the high-voltage current transformer C5 inside the grid interconnection panel C (grid interconnection panel housing C') and detects the current flowing through the output electric path. The specific configuration of the current sensor unit P43 is not particularly limited, and it may be configured to be attachable to the output electric path without disconnecting the specified electric path (i.e., capable of opening and closing itself without disconnecting the output electric path to be detected). If the current sensor unit P43 is a fluxgate type or a Hall element type, it can also be considered to be a part that includes the fluxgate or Hall element itself. If the output electric path of the high-voltage current transformer C5 is three-phase three-wire (3φ3W), the current sensor unit P43 may be attached to two of the wires (i.e., two current sensors on one grid interconnection panel C).

[0031] <Bus line M> As shown in FIGS. 1 and 12, the bus electric circuit M is an electric circuit (such as a three-phase three-wire (3φ3W)) between the above-mentioned system G and the above-mentioned load L. Here, the "bus electric circuit M between the system G and the load L" in the present invention includes not only the case where the entire electric circuit between the system G and the load L is the bus electric circuit M, but also the case where at least a part of the electric circuits between the system G and the load L (for example, the electric circuit from the system G to the transformer C8 of the system interconnection panel C) is the bus electric circuit M, and it can be said that the electric circuit between the system G and the load L is the bus electric circuit M. Note that, among the electric circuits between the system G and the load L, if the electric circuit from the above-mentioned system G to the transformer C8 of the system interconnection panel C is the bus electric circuit M, the remaining electric circuit from the transformer C8 to the load L can also be said to be a system low-voltage circuit. Furthermore, the entire electrical circuit between the system G and the load L is a bus electrical circuit M, for example, when the load L, which has (built-in) a transformer (step-down transformer), and the system G are directly connected by a bus electrical circuit M. The potential in this bus circuit M may be the same as the potential in system G (6600V, 22000V, etc.), and if a transformer C8 (which can also be called a step-down transformer, specifically the lighting transformer or power transformer mentioned above) of the system interconnection panel C is provided between each load L and the bus circuit M, the circuit connecting this transformer C8 (its high-voltage side) and system G can be said to be the bus circuit M. The bus circuit M is provided with the equipment of the system interconnection panel C described above, and to explain each piece of equipment in detail, the bus circuit M may be provided with, in order from the system G to the load L, a supply transformer current C1, an incoming switch C2, a high-voltage transformer C3 (strictly speaking, provided on a circuit branching off from the bus circuit M), a system circuit breaker C4, a high-voltage current transformer C5, an overcurrent relay C6 (strictly speaking, provided on the output circuit of the high-voltage current transformer C5), a high-voltage AC load switch C7, a transformer C8, etc. The bus electric circuit M described above may be connected to devices (particularly the branch electric circuit 2) housed in the generator connection board 1 described later.

[0032] <Branch Circuit 2> As shown in Figures 1 to 3, 11, and 12, the branch electric circuit 2 is an electric circuit (such as a three-phase three-wire (3φ3W)) branched from the above-mentioned bus electric circuit M, and is an electric circuit that connects the above-mentioned power generation device P to the above-mentioned grid interconnection panel C and load L. The branch electric circuit 2 may be connectable to the bus electric circuit M, in which case the potential in the branch electric circuit 2 will be the same high voltage as the potential in the bus electric circuit M and the system G (that is, the branch electric circuit 2 will have approximately the same potential as the bus electric circuit M, such as 6600V or 22000V). Therefore, even if the distance between the system interconnection panel C or the load L and the power generation device P becomes long (even if it becomes a long distance), the branch electric circuit 2 will be at a high voltage, which reduces cable loss and allows the power generation device P to be installed anywhere (increasing the number of installation location options). One end of the branch electric circuit 2 may be connected to a bus electric circuit M (an electric circuit at any point between the equipment provided on the system interconnection panel C and the load L (for example, between the high-voltage current transformer C5 and the high-voltage AC load switch C7), and the other end of the branch electric circuit 2 may be connected to the output side of the power generation device P (the output side (high-voltage side) of the distribution transformer P32). Therefore, the branch circuit 2 may have not only a portion provided inside the panel housing (power generation connection panel housing) 10 of the power generation connection panel 1 described later, but also a portion protruding from the power generation connection panel housing 10, and this protruding portion may be the portion between the power generation connection panel 1 (power generation connection panel housing 10) and the distribution panel P3 in the power generation device P described above, or a portion provided inside the distribution panel P3. As described above, the branch circuit 2 is provided with the equipment described below that is built into the power generation connection panel 1 and the equipment of the power generation device P described above. To explain each piece of equipment in detail, the branch circuit 2 may be provided, in order from the bus circuit M to the distribution panel P3 of the power generation device P, with a circuit breaker 4 described below, a vacuum circuit breaker 3 described below (which may include a current transformer 5 and an overcurrent relay 6 described below), a cable head 7 described below, and equipment built into the distribution panel housing P31 of the distribution panel P3 described above (such as a distribution transformer P33 and a zero-phase voltage detector P34).

[0033] <Vacuum circuit breaker 3> As shown in Figures 1 to 3, 7, 11, and 12, a vacuum circuit breaker (VCB) 3 is provided in the branch electric circuit 2 described above, and is a device that opens and closes the branch electric circuit 2 (three-phase, three-wire all at once) when high-voltage AC current is flowing, and extinguishes the arc within the vacuum valve. The vacuum circuit breaker 3 may be built into a panel housing 10 of the power generation connection panel 1, which will be described later. It should be noted that this vacuum circuit breaker 3 is different from the system circuit breaker C4 provided in the system interconnection panel C described above. The vacuum circuit breaker 3 may include a current transformer 5 and an overcurrent relay 6, which will be described later. The vacuum circuit breaker 3 may also be of an electric spring operation (capacitor trip) type. The rated capacity of the vacuum circuit breaker 3 is not particularly limited, but may be, for example, 2000 kVA to 100,000 kVA, preferably 2500 kVA to 50,000 kVA, and more preferably 3000 kVA to 10,000 kVA (such as 4,320 kVA). The weight of the vacuum circuit breaker 3 is not particularly limited either, but may be, for example, 15 kg to 1000 kg, preferably 20 kg to 500 kg, and more preferably 25 kg to 100 kg (eg, 32 kg). The number of vacuum circuit breakers 3 in one power generation connection panel 1 may be one or more.

[0034] <Disconnector 4> As shown in Figures 1 to 3, 7, 11, and 12, a disconnecting switch (DS) 4 is also provided in the branch electric circuit 2 described above, and is a device that opens and closes the branch electric circuit 2 when high-voltage AC current is not flowing. The disconnecting switch 4 does not have the function of interrupting current, and opens and closes the disconnecting switch 4 after the current is interrupted by another circuit breaker. The disconnector 4 may also be built into a panel housing 10 of the power generation connection panel 1, which will be described later. The disconnector 4 may also be opened and closed by operating a hook. The number of disconnectors 4 in one power generation connection panel 1 may be one or more.

[0035] <Current transformer 5> As shown in FIG. 11, the current transformer (CT) 5 is a device included in the vacuum circuit breaker 3 described above, and is provided in the branch circuit 2 described above. The current transformer 5 transforms the high-voltage AC current (its current value) flowing through the branch circuit 2 into a smaller current (smaller current value) transformed output current. The electrical circuit that outputs the transformed output current from the current transformer 5 may be connected to the overcurrent relay 6 described later, and the above-mentioned current sensor unit P43 may be provided on this output electrical circuit. The current transformer 5 can be said to be built into the panel housing 10 of the power generation connection panel 1, which will be described later, and may also be provided inside the above-mentioned vacuum circuit breaker 3 (its housing) or attached to the housing of the vacuum circuit breaker 3 from the outside. The number of current transformers 5 in one power generation connection panel 1 may be one or more.

[0036] <Overcurrent relay 6> As shown in FIG. 11, the overcurrent relay (OCR) 6 is a device that receives the transformed output current from the current transformer 5 (i.e., the overcurrent relay 6 is connected to the circuit that outputs the transformed output current from the current transformer 5), and outputs a stop signal to stop the conversion of the conversion unit P2 when the transformed output current exceeds a certain value (value of the operating voltage) for a certain time (e.g., an operating time of approximately 1 second). The output signal from the overcurrent relay 6 may be input to the control device P41 of the conversion unit P2, or may be input directly to the conversion unit P2, or may be input to a low-voltage circuit breaker built into the above-mentioned distribution board P3 (distribution board housing P31) to cut off the low-voltage circuit between the distribution transformer P32 and the conversion unit P2. The overcurrent relay 6 can also be said to be built into the panel housing 10 of the power generation connection panel 1, which will be described later, and may further be provided inside the above-mentioned vacuum circuit breaker 3 (its housing) or attached from the outside to the housing of the vacuum circuit breaker 3. Alternatively, the overcurrent relay 6 may be provided outside the panel housing 10 of the power generation connection panel 1, in which case it may be built into the above-mentioned control box P4, for example. The number of overcurrent relays 6 in one power generation connection panel 1 may be one or more.

[0037] <Cable head 7, other equipment> As shown in Figures 2, 3, and 11, the cable head 7 is provided on the above-mentioned branch electric circuit 2 and is a part that has been subjected to terminal processing in order to connect the branch electric circuit 2 to high-voltage equipment such as the above-mentioned vacuum circuit breaker 3 and disconnector 4. The specific configuration of the cable head 7 is not particularly limited, but for example, the coating of the ends of the cables or wires that make up the branch circuit 2 is stripped off, wrapped with insulating tape or semi-conductive tape, and a branch pipe is used to branch the branch circuit 2 into three branches if it is a three-phase, three-wire circuit, or if it is a single-phase, two-wire circuit, it is branched into two branches. The cable head 7 may be grounded, and the type of grounding is not particularly limited, but may be, for example, a type A grounding. The cable head 7 may also be built into a panel housing 10 of the power generation connection panel 1, which will be described later. The number of cable heads 7 in one power generation connection board 1 may be one or more.

[0038] Other devices built into the panel housing 10 of the power generation connection panel 1 may include, for example, an ammeter 8, which receives the transformed output current output from the current transformer 5 described above (i.e., the overcurrent relay 6 is connected to the circuit that outputs the transformed output current from the current transformer 5), and measures the current value of the high-voltage AC current flowing through the branch circuit 2 based on the transformed output current. The ammeter 8 may measure the current value of any of the three phases of the branch electric circuit 2, for example, the current value of the R phase, or alternatively, the current values ​​of any two of the three phases or all three phases. The ammeter 8 may also be provided with an ammeter changeover switch (AS, Ammeter change over Switch, normal angle). Other devices built into the panel housing 10 of the power generation connection panel 1 may include insulators 9, a reverse power relay (RPR), and a power meter (such as a power generation meter or a power receiving meter).

[0039] <Power generation connection panel 1 panel case (power generation connection panel case) 10> As shown in Figures 1 to 12, the panel housing 10 of the power generation connection panel 1 described so far can also be called the power generation connection panel housing 10, and is attached externally to the side of the panel housing (system interconnection panel housing) C' of the above-mentioned system interconnection panel C, and the lower end of the power generation connection panel housing 10 is located at a higher position than the lower end of the system interconnection panel housing C'. In other words, the difference in height ΔH between the bottom end of the power generation connection panel housing 10 and the bottom end of the system interconnection panel housing C' (difference in bottom end height) is greater than 0 cm, and the specific value of this difference in bottom end height ΔH is not particularly limited, but may be, for example, 5 cm or more and 100 cm or less, preferably 10 cm or more and 70 cm or less, and even more preferably 15 cm or more and 50 cm or less. When attaching the power generation connection panel housing 10 to the side of the grid interconnection panel housing C', a foundation for the power generation connection panel housing 10 is not required, and the bottom surface material of the power generation connection panel housing 10 may be floating (separate) from the foundation B of the grid interconnection panel C (grid interconnection panel housing C') or the installation surface S. The specific configuration of the power generation connection panel housing 10 is not particularly limited, but for example, it may be formed in an approximately rectangular shape overall, and the volume (volume of the outer surface) and capacity (volume of the inner surface) of the power generation connection panel housing 10 may be smaller than the volume and capacity of the above-mentioned system interconnection panel housing C'. The power generation connection panel housing 10 may include an upper panel housing 10A, which will be described later, and a lower panel housing 10B, which will be described later, and may further include other panel housings and boxes. The upper and lower panel casings 10A and 10B will be described in detail below.

[0040] <Upper panel enclosure 10A> As shown in FIGS. 2 to 10, the upper panel housing 10A is a panel housing that constitutes the upper side of the power generation connection panel housing 10 described above, and can be said to be a part of the power generation connection panel housing 10. The upper panel housing 10A is also attached externally to the side of the panel housing (system interconnection panel housing) C' of the above-mentioned system interconnection panel C, and naturally, the lower end of the upper panel housing 10A is located higher than the lower end of the system interconnection panel housing C'. The specific configuration of the upper panel housing 10A is not particularly limited, but for example, it may be formed in an approximately rectangular parallelepiped shape as a whole, and the volume and capacity of the upper panel housing 10A may naturally be smaller than the volume and capacity of the system interconnection panel housing C' described above. When the entire upper panel housing 10A is substantially rectangular, the side members (front member, rear member, left member, right member, etc., particularly the front member) of the upper panel housing 10A may be provided with an openable / closable door (front door, etc.) 10A', or the front member, etc. may be detachable, or no openable / closable door may be provided, or the front member, etc. may not be detachable. A handle (a lever handle, a flush handle, etc.) may be attached to the door 10A', and, for example, the handle may be used to move a stopper (a rod-shaped (bar-shaped) made of stainless steel (SUS), etc.) fixed at three points to lock and unlock the door 10A'. The upper panel housing 10A may have a ceiling surface material (top surface material), a bottom surface material (lower surface material), and the like in addition to the side surface material.

[0041] In addition, the "front and back" of the approximately rectangular parallelepiped upper panel housing 10A refers to the side where the above-mentioned equipment such as the vacuum circuit breaker 3 and the circuit breaker 4 are exposed (or the side where the door 10A' is located), and the opposite side refers to the "rear." Furthermore, the "left and right" of the upper panel housing 10A are defined as the left-hand side when a user enters the upper panel housing 10A and faces from the "rear" to the "front" of the power generation connection panel housing 10, and the right-hand side when facing from the "rear" to the "front" of the power generation connection panel housing 10. The rear material of the upper panel housing 10A may be provided with rear through-holes 10Aa or rear openings corresponding to (having substantially the same number, size, and shape as) the through-holes Ca' and openings of the above-mentioned grid interconnection panel housing C'. The rear openings are openings in the rear surface of the upper panel housing 10A itself, and may communicate with the interior of the grid interconnection panel housing C' through these rear openings. The specific configuration of the rear through-hole 10Aa and the rear opening is not particularly limited, but may be configured to allow the above-mentioned branch circuit 2 to be inserted therethrough, or the sensor cable P44 between the above-mentioned digital multi-relay P42 and the current sensor unit P43 to be inserted therethrough, and the number, size, and shape of the rear through-hole 10Aa and the rear opening are not particularly important. The upper panel housing 10A (particularly its rear side) is attached to at least one of the side members (front member, rear member, left member, right member, etc.) of the grid interconnection panel housing C' described above. It can be said that the lower panel housing 10B, which will be described later, is also attached to the same surface member as the upper panel housing 10A.

[0042] The rear surface material of the upper panel housing 10A may be narrower than the side surface materials (at least one of the front surface material, rear surface material, left surface material, right surface material, etc.) attached to the system interconnection panel housing C'. The specific configuration of the mounting means for the upper panel housing 10A to the grid interconnection panel housing C' is not particularly limited, but for example, the power generation connection panel housing 10 may be mounted to the grid interconnection panel housing C' by a mounting means using fasteners (bolts, nuts, etc.), welding (such as welding mounting brackets all around), adhesive, fitting, etc. The lower surface material of the upper panel housing 10A may be provided with a lower surface through-hole (upper-lower surface through-hole) 10Ab that passes through the lower panel housing 10B (described later) or a lower surface opening. The lower surface opening is an opening in the lower surface of the upper panel housing 10A itself, and the upper panel housing 10A may communicate with the interior of the lower panel housing 10B via this lower surface opening. The specific configuration of the bottom surface through-hole 10Ab and the bottom surface opening is not particularly limited, but for example, it may be configured to allow the above-mentioned branch electric circuit 2 to be inserted therethrough, or the sensor cable P44 between the above-mentioned digital multi-relay P42 and the current sensor unit P43 to be inserted therethrough, and the number, size, and shape of the bottom surface through-hole 10Ab and the bottom surface opening are not particularly important. The size of the upper panel housing 10A is not particularly limited, but when the entire upper panel housing 10A is approximately rectangular, for example, the width may be 300 mm or more and 900 mm or less, preferably 400 mm or more and 800 mm or less, and more preferably 500 mm or more and 700 mm or less (e.g., 600 mm), the height may be 650 mm or more and 1250 mm or less, preferably 750 mm or more and 1150 mm or less, and more preferably 850 mm or more and 1050 mm or less (e.g., 950 mm), and the depth may be 300 mm or more and 900 mm or less, preferably 400 mm or more and 800 mm or less, and more preferably 500 mm or more and 700 mm or less (e.g., 615 mm).

[0043] <Lower panel chassis 10B> As shown in FIGS. 2 to 10, the lower panel casing 10B is a panel casing that constitutes the lower side of the power generation connection panel casing 10 described above, and can be said to be a part of the power generation connection panel casing 10. The lower panel housing 10B is also attached externally to the side surface of the panel housing (system interconnection panel housing) C' of the above-mentioned grid interconnection panel C, and the lower end of the lower panel housing 10B is naturally located higher than the lower end of the grid interconnection panel housing C'. It can also be said that the difference in height between the lower end of the lower panel housing 10B and the lower end of the grid interconnection panel housing C' is the difference in bottom height ΔH, which is the difference in height between the lower end of the above-mentioned power generation connection panel housing 10 and the lower end of the grid interconnection panel housing C'. The specific configuration of the lower panel housing 10B is not particularly limited, but for example, it may be formed in an approximately rectangular parallelepiped shape overall, and the volume and capacity of the lower panel housing 10B may naturally be smaller than the volume and capacity of the system interconnection panel housing C' described above. When the entire lower panel housing 10B is approximately rectangular, the lower panel housing 10B may have one of its side members (e.g., the front member among the front member, rear member, left member, right member, etc., particularly the front member) configured to be removable, and may also have an openable / closable door (e.g., a front door), or conversely, may not have an openable / closable door. The lower panel housing 10B may have a ceiling surface material (upper surface material), a bottom surface material (lower surface material), and the like in addition to the side surface material.

[0044] Furthermore, the "front and back" of the approximately rectangular parallelepiped lower panel housing 10B refers to the side where the above-mentioned equipment such as the cable head 7 is exposed (or the side where the door is located), and the opposite side refers to the "rear." Furthermore, the "left and right" of the lower panel housing 10B are defined as the left-hand side when a user enters the lower panel housing 10B and faces from the "rear" to the "front" of the power generation connection panel housing 10, and the right-hand side when facing from the "rear" to the "front". The upper surface material of the lower panel-shaped housing 10B may be provided with upper-bottom through-holes 10Ab and upper surface through-holes 10Ba corresponding to the lower surface through-holes 10Ab and the lower surface through-holes 10Ba (which have substantially the same number, size, and shape) of the upper panel-shaped housing 10A. The upper surface through-holes 10Ba are openings in the upper surface of the lower panel-shaped housing 10B, and the lower panel-shaped housing 10B may be connected to the interior of the upper panel-shaped housing 10A through the upper surface through-holes 10Ab. The specific configuration of the top surface through hole 10Ba and the top surface opening is not particularly limited, but for example, it may be configured to allow the above-mentioned branch electric circuit 2 to be inserted therethrough, or the sensor cable P44 between the above-mentioned digital multi-relay P42 and the current sensor unit P43 to be inserted therethrough, and the number, size, and shape of the top surface through hole 10Ba and the top surface opening are not particularly important. The lower panel housing 10B (particularly, its rear side) is also attached to at least one of the side members (front member, rear member, left member, right member, etc.) of the above-mentioned system interconnection panel housing C'. It can be said that the above-mentioned upper panel housing 10A is also attached to the same surface member as the lower panel housing 10B.

[0045] The rear surface material of the lower panel casing 10B may also be narrower than the side surface materials (at least one of the front surface material, rear surface material, left surface material, right surface material, etc.) attached to the system interconnection panel casing C'. The specific configuration of the mounting means for the lower panel housing 10B to the grid interconnection panel housing C' is not particularly limited, but for example, the power generation connection panel housing 10 may be mounted to the grid interconnection panel housing C' by a mounting means using fasteners (bolts, nuts, etc.), welding (such as welding mounting brackets all around), adhesive, fitting, etc. Furthermore, the lower surface material of the lower panel casing 10B may be provided with a lower surface through-hole (lower lower surface through-hole) 10Bb or the like that passes through to the outside of the lower panel casing 10B (that is, the outside of the power generation connection panel casing 10). The specific configuration of the bottom surface through-holes 10Bb, etc. is not particularly limited, and may be configured to allow the aforementioned branch electric circuit 2 to be inserted therethrough, or the sensor cable P44 between the aforementioned digital multi-relay P42 and current sensor unit P43 to be inserted therethrough, and there are no particular restrictions on the number, size, or shape of the bottom surface through-holes 10Bb, etc. Note that in the bottom surface through-holes 10Bb, etc., the gap between the branch electric circuit 2, etc. inserted therethrough and the bottom surface material of the lower panel casing 10B may be blocked with a plate of a predetermined material (for example, hot-rolled mild steel plate (SPHC, Steel Plate Hot Commercial)), and this plate may be attached to the bottom surface through-holes 10Bb, etc. with fasteners such as screws. The size of the lower panel housing 10B is not particularly limited, but when the entire lower panel housing 10B is approximately rectangular, for example, the width may be 300 mm or more and 900 mm or less, preferably 400 mm or more and 800 mm or less, and more preferably 500 mm or more and 700 mm or less (600 mm, etc.), the height may be 350 mm or more and 950 mm or less, preferably 450 mm or more and 850 mm or less, and more preferably 550 mm or more and 750 mm or less (650 mm, etc.), and the depth may be 150 mm or more and 750 mm or less, preferably 250 mm or more and 650 mm or less, and more preferably 350 mm or more and 550 mm or less (430 mm, etc.).

[0046] Regarding the volumes and capacities of the upper panel housing 10A and the lower panel housing 10B described above, one (for example, the upper panel housing 10A) may be larger, or the other (for example, the lower panel housing 10B) may be larger, or they may be approximately the same. Moreover, in the upper panel casing 10A and the lower panel casing 10B, the branch electric circuit 2 can be said to be arranged (provided) inside the upper panel casing 10A and the lower panel casing 10B. Furthermore, when the power generation connection panel housing 10 is divided into an upper panel housing 10A and a lower panel housing 10B, it can also be said that the upper panel housing 10A and the lower panel housing 10B are separated by the bottom surface material of the upper panel housing 10A and the top surface material of the lower panel housing 10B. The above-mentioned vacuum circuit breaker 3 may be arranged inside one of the upper panel housing 10A and the lower panel housing 10B (for example, the upper panel housing 10A).In this case, if the vacuum circuit breaker 3 has a current transformer 5 or an overcurrent relay 6 built in, the current transformer 5 and the overcurrent relay 6 will also be arranged inside one of the upper panel housing 10A and the lower panel housing 10B (for example, the upper panel housing 10A). Furthermore, the disconnector 4 may also be disposed inside one of the upper panel housing 10A and the lower panel housing 10B (for example, the upper panel housing 10A). Alternatively, the cable head 7 may be disposed inside the other of the upper panel housing 10A and the lower panel housing 10B (for example, the lower panel housing 10B), and the ammeter 8 may be disposed inside either the upper panel housing 10A or the lower panel housing 10B (for example, the upper panel housing 10A) (for example, on the back side of the door 10A' of the upper panel housing 10A). The insulator 9 may also be disposed inside the other of the upper panel housing 10A and the lower panel housing 10B (for example, the lower panel housing 10B). Additionally, at least one of the upper panel housing 10A and the lower panel housing 10B may be provided with an earth terminal (ET) and a cable bracket.

[0047] <Power System 50> As shown in FIGS. 1 and 12, the power system 50 includes the above-mentioned grid interconnection panel C, load L, power generation device P, etc., as well as a bus line M, branch lines 2, and a vacuum circuit breaker 3. The power system 50 may include the power generation connection panel 1 described above, and in this case, the branch electric circuits 2 and vacuum circuit breakers 3 included in the power system 50 will be provided inside the power generation connection panel 1 (power generation connection panel housing 10). In this case, the panel housing 10 of the power generation connection panel 1 may be attached to the top surface (top plate or roof) of the panel housing C' of the grid interconnection panel C, or may be attached from the inside to the top surface or side surface of the panel housing C' of the grid interconnection panel C (i.e., it does not have to be attached from the outside to the side surface of the panel housing C' of the grid interconnection panel C), and the bottom end of the panel housing 10 of the power generation connection panel 1 may be at approximately the same height as the bottom end of the panel housing C' of the grid interconnection panel C (it does not have to be higher than the bottom end of the panel housing C' of the grid interconnection panel C). In addition, the power system 50 may have the branch circuit 2 and the vacuum circuit breaker 3 inside the panel housing C' of the grid interconnection panel C (i.e., they do not have to be inside the panel housing 10 of the power generation connection panel 1 separate from the panel housing C' of the grid interconnection panel C). Furthermore, the power system 50 may have the above-mentioned pole-mounted air switch 50a between the system interconnection panel housing C' and the system G in the busbar circuit M, and may also have other devices such as a commercial transformer, a power purchase meter, a power sale meter, and a protective relay device.

[0048] <Other> The present invention is not limited to the above-described embodiment. The individual components of the power generation connection board 1, the power system 50, etc., or the overall structure, shape, dimensions, etc., can be modified as appropriate in accordance with the spirit of the present invention. The panel housing 10 of the power generation connection board 1 does not have to include an upper panel housing 10A and a lower panel housing 10B, or any other panel housings or boxes; in this case, the power generation connection board 1 can be said to be composed of a single panel housing 10. At least one of the disconnector 4, current transformer 5, overcurrent relay 6, and cable head 7 may not be provided inside the panel housing 10 of the power generation connection panel 1. The openable doors of the power generation connection panel 1 (such as the upper panel housing 10A and the lower panel housing 10B) may be provided with door stoppers (made of stainless steel, for example), and the openable doors of the power generation connection panel 1 and the detachable front members may be provided with gaskets at their openings. The vacuum circuit breaker 3 and the disconnecting switch 4 may be grounded, and the type of grounding is not particularly limited, but may be, for example, a type A grounding. The power system 50 may include a power storage device (not shown), which will be described below.

[0049] <Electricity storage device> The storage device is a device that stores electricity (received power) from the system K and electricity (generated power) from the above-mentioned power generation device P, and may be provided outside the panel housing of the above-mentioned system interconnection panel C, power generation connection panel 1, distribution panel P3 of the power generation device P, etc. The power storage device may be, for example, a storage battery such as a lead acid battery, lithium ion battery, nickel-metal hydride battery, or nickel-cadmium battery; it may store hydrogen produced by electrolysis of water using the power generated by the power generation device P, and extract electricity when needed using a fuel cell, or it may be a device that stores electricity as kinetic energy using a flywheel, stores electricity as potential energy using pumped water, or stores electricity directly as electrical energy using a capacitor, etc. Such a power storage device may be connected to the bus line M, and the stored power from this power storage device will be consumed by the load L described above. Furthermore, since the storage of electricity in the storage device and the discharge of electricity from the storage device are performed using direct current, a conversion unit may be connected between the storage device and the bus line M to convert alternating current into direct current or to convert the direct current from the storage device into alternating current to the bus line M. [Industrial Applicability]

[0050] The power generation connection panel and power system of the present invention can be used for grid interconnection panels and loads, regardless of whether they are existing or new installations. Regardless of the amount of power generated or its scale, the power generation device can be used as a solar power generation plant, etc. In addition to solar power generation plants, it can also be used as a plant that generates power using a generator (such as an AC motor) rotated by wind power, water power, wave power, geothermal power, etc., and can be used both indoors and outdoors. [Explanation of symbols]

[0051] 1 Power generation connection panel 2 Branch lines 3. Vacuum circuit breaker 4 Disconnector 5 Current transformers 6 Overcurrent relay 7 Cable Head 10 Power generation connection panel enclosure 10A power generation connection panel upper panel housing 10B Lower panel housing of power generation connection panel 50 Power Systems G system C Grid connection panel C' Grid connection panel case L load P Power Generation Equipment M Bus line

Claims

1. A power generation connection panel that connects a power generation device (P) to a system interconnection panel (C) that is connected to a system (G) and a load (L) connected to the system interconnection panel (C), The power generation connection panel has a panel housing (10) therein which includes a branch circuit (2) branched from a bus circuit (M) between the system (G) and the load (L) and connected to the power generation device (P), and a vacuum circuit breaker (3) provided in the branch circuit (2); The panel housing (10) of the power generation connection panel is attached from the outside to a side surface of the panel housing (C') of the grid interconnection panel (C), The power generation connection panel is characterized in that the lower end of the panel housing (10) of the power generation connection panel is located at a higher position than the lower end of the panel housing (C') of the grid interconnection panel (C).

2. The panel housing (10) of the power generation connection panel includes an upper panel housing (10A) and a lower panel housing (10B), The branch electric circuit (2) is arranged inside the upper panel housing (10A) and the lower panel housing (10B), 2. The power generation connection panel according to claim 1, wherein the vacuum circuit breaker (3) is disposed inside one of the upper panel housing (10A) and the lower panel housing (10B).

3. The power generation connection panel has a panel housing (10) therein, a disconnector (4) provided in the branch electric circuit (2), a current transformer (5) provided in the branch electric circuit (2), an overcurrent relay (6) connected to the current transformer (5), and a cable head (7) provided in the branch electric circuit (2), 3. The generator connection board according to claim 1 or 2, characterized in that the cable head (7) is earthed.

4. A power system including a grid interconnection panel (C) connected to a grid (G), a load (L) connected to the grid interconnection panel (C), and a power generation device (P) connected to the grid interconnection panel (C) and the load (L), A power system comprising: a branch circuit (2) branching from a bus circuit (M) between the system (G) and a load (L) and connected to the power generation device (P); and a vacuum circuit breaker (3) provided in the branch circuit (2).

5. The branch circuit (2) and the vacuum circuit breaker (3) are provided inside a panel housing (10) of a power generation connection panel (1) separate from a panel housing (C') of the grid interconnection panel (C), The panel housing (10) of the power generation connection panel (1) is attached from the outside to a side surface of the panel housing (C') of the grid interconnection panel (C), The power system according to claim 4, characterized in that the lower end of the panel housing (10) of the power generation connection panel (1) is located higher than the lower end of the panel housing (C') of the grid interconnection panel (C).

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