JP2023034240A - Photovoltaic power generation system - Google Patents

Abstract

To insulate a power cable of a photovoltaic power generation system from a conductive roof surface.SOLUTION: A photovoltaic power generation system is equipped with solar cell panels laid on a conductive roof surface, power cables electrically connected to the solar cell panels, metal fittings which secure the solar cell panels to the roof surface and with which the power cables are secured using binders, and an insulating protective member interposed between the power cables and the metal fittings. The protective member is a member independent of the power cables and the metal fittings and is bound together with the power cables and the metal fittings by the binders.SELECTED DRAWING: Figure 3

Description

There is an application for the application of Article 30, Paragraph 2 of the Patent Law. Construction was completed at Welcia Susono Ojuku store and completed on July 20, 2021. Construction was carried out at Welcia Kamashiarai and was completed on July 21, 2021. It was constructed by Varius Works Co., Ltd. and completed on August 2, 2021.

The technology disclosed in this specification relates to a photovoltaic power generation system.

Patent Literature 1 describes a photovoltaic power generation system and its installation method. This photovoltaic power generation system includes a solar cell panel arranged on a roof surface. The solar panel is fixed to the roof using metal fittings, and power cables connected to the solar panel are routed along the roof.

JP 2020-172742 A

Since the solar cell panels and power cables laid on the roof surface are exposed to the elements, they need to be firmly fixed to the roof surface. At this time, when the roof surface is conductive, such as a folded roof, it is necessary to reliably insulate between the solar cell panel and the roof surface, especially between the power cable and the roof surface. Power cables are usually covered with an insulating coating and insulated from the roof surface. However, even if the insulation is secured at the initial stage, the insulation due to the insulation coating will be destroyed due to damage to the power cable during construction or the progression of deterioration over time due to the effects of ultraviolet rays and other factors. There is something.

Such problems tend to occur at positions where power cables are fixed to metal fittings, etc., or where they are in contact with the roof surface. end up In a normal power system, when a ground fault occurs, the power supply is cut off immediately by a breaker. On the other hand, in a photovoltaic power generation system, even if a ground fault occurs in a power cable laid on the roof surface, it cannot be interrupted by a breaker. And the solar panel will continue to supply power as long as it receives sunlight. In order to avoid such a ground fault in the power cable, it is conceivable to configure metal fittings and the like for fixing the power cable with an insulator such as a resin material. However, metal fittings made of an insulating material such as a resin material have a problem that they are inferior to general metal fittings in terms of strength and durability.

In view of the above, the present specification provides a technique for reliably insulating a solar cell panel and power cables from a roof surface in a photovoltaic power generation system installed on a conductive roof surface.

The technology disclosed in this specification is embodied in a first photovoltaic power generation system. This photovoltaic power generation system consists of solar panels laid on a conductive roof surface, power cables electrically connected to the solar panels, and binding materials that secure the solar panels to the roof surface and the power cables. and an insulating protective member interposed between the power cable and the metal fitting. The protective member is a member independent of the power cable and metal fittings, and is bound together with the power cable and metal fittings by a binding material.

In the above-described first photovoltaic power generation system, power cables are fixed to metal fittings that fix the solar panel to the roof surface. According to such a configuration, the number and types of metal fittings required can be reduced, and the installation of the photovoltaic power generation system can be easily performed. On the other hand, metal fittings for fixing the solar cell panel to the roof surface are required to have strength and durability, and are therefore often made of metal, and there is concern about the above-mentioned short circuit of the power cable. However, an insulating protective member is provided between the power cable and the fitting. With such a configuration, the insulation between the power cable and the fitting can be maintained for a long period of time.

In the first photovoltaic power generation system, the protection member may be made of a resin material or a rubber material. Although not particularly limited, the protection member may have the same structure as the insulation coating of the power cable. In this case, for example, an insulating coating removed from the end of the power cable can be used as a protective member. However, as another embodiment, the protective member may be another member prepared for that purpose, and may have a material and structure different from the insulating coating of the power cable.

In the first photovoltaic power generation system, the protection member may be arranged to surround the power cable and interposed between the power cable and the binding material. With such a configuration, the binding material does not come into direct contact with the power cable, so that a conductive member such as a wire can be used as the binding material. In this case, although not particularly limited, it may have a structure in which a conductive core wire is covered with an insulating coating such as a resin material, like a so-called binding wire.

In the first photovoltaic power generation system, the power cable may be fixed to metal fittings between the roof surface and the solar cell panel. According to such a configuration, the power cable is protected from sunlight (especially ultraviolet rays) and wind and rain, and age deterioration of the power cable (especially the insulation coating) is suppressed.

In the first photovoltaic power generation system, the binding material may be a resin binding band. According to such a configuration, it is possible to avoid short-circuiting of the power cable to the fitting through the binding material.

In the first photovoltaic power generation system, the roof surface may be a halved roof having ridges. In this case, the metal fittings may be fixed to the ridges of the folded roof. However, as another embodiment, the roof surface may be a folded roof with no ridges. In this case, there is no particular limitation on the position where the metal fitting is attached.

The technology disclosed in this specification is also embodied in the second photovoltaic power generation system. This photovoltaic power generation system includes a solar cell panel laid on a conductive roof surface, a power cable electrically connected to the solar cell panel, a cable rack accommodating the power cable, the power cable and the cable rack. and an insulating protective member interposed between. The protective member is a net-like (also referred to as mesh-like or net-like) sheet material, and is arranged over the bottom surface and a pair of inner side surfaces of the cable rack facing the power cables.

In the above-described second photovoltaic power generation system, power cables are held using cable racks. Since cable racks installed on roof surfaces are required to have strength and durability, they are often made of metal, and there is concern about short-circuiting of power cables. However, an insulating protective member is interposed between the power cable and the cable rack, and this protective member is provided over the bottom surface and a pair of inner side surfaces of the cable rack facing the power cables. . With such a configuration, insulation between the power cable and the cable rack can be maintained for a long period of time. In addition, since the protective member is a net-like sheet material, it is possible to prevent rainwater and dust from remaining on the cable rack.

In the second photovoltaic power generation system, the power cable may be fixed to the cable rack with a binding material together with the protective member. According to such a configuration, it is possible to maintain the positional relationship among the power cable, the protection member, and the cable rack over a long period of time. Note that the protective member may be fixed to the cable rack in advance, and then the power cable may be fixed to the cable rack together with the protective member using a binding material.

In the second photovoltaic system, the cable rack may be a ladder-shaped cable rack. According to such a configuration, it is possible to prevent rainwater and dust from remaining on the cable rack. However, in other embodiments, the cable rack may be a tray-type cable rack or a mesh-type cable rack. When a tray-type cable rack is used, it is preferable that an opening for draining water is provided on the bottom surface of the cable rack or the like.

In the second photovoltaic power generation system, the cable rack is usually arranged on the roof surface. However, in other embodiments the cable rack may be placed on the wall.

The technology disclosed in this specification is also embodied in the third photovoltaic power generation system. This photovoltaic power generation system includes a solar cell panel laid on a conductive roof surface, a power cable electrically connected to the solar cell panel, a plurality of metal fittings for fixing the solar cell panel to the roof surface, a plurality of and an insulating sheet material spanned between the metal fittings. The sheet material is a net-like sheet material and supports the power cable. Such a configuration can also prevent the power cable connected to the solar panel from coming into direct contact with the conductive roof surface or metal fittings. As a result, it is possible to effectively prevent the power cable from grounding on the conductive roof surface. Moreover, since the sheet material is lightweight, it is easy to install, and a large number of power cables can be arranged on the sheet material.

In the third photovoltaic system, the sheet material may be positioned between the roof surface and the solar panel. With such a configuration, the power cable and the sheet material can be protected from wind, rain and sunlight.

1 is a block diagram showing the configuration of a photovoltaic power generation system 10 of an embodiment; FIG. The figure which shows the solar panel 12 laid on the roof surface 4. FIG. FIG. 4 is a diagram showing a power cable 22 fixed to a metal fitting 20; FIG. 3 is a cross-sectional view showing how the protective member 24 surrounds the power cable 22; FIG. 2 shows a cable rack 30; A cable rack 30 arranged on the roof surface 4 and power cables 22 and protective members 32 in the cable rack 30 are shown. 7 shows a cross-sectional view along line VII-VII in FIG. 6. FIG. A sheet of material 40 spanned between two or more fittings 20 and a power cable 22 supported by the sheet of material are shown.

A photovoltaic power generation system 10 (hereinafter referred to as system 10) of an embodiment will be described with reference to the drawings. The system 10 of the present embodiment is installed at a demand destination 2 such as a general house or business establishment (for example, a store, an office, a factory, a hospital, etc.), and supplies power generated by sunlight to the demand destination 2 .

As shown in FIGS. 1 and 2 , system 10 includes a plurality of solar panels 12 , breakers 14 and power conditioners 16 . The solar cell panel 12 is laid on the roof surface 4 of the customer 2 . Each solar panel 12 is fixed to the roof surface 4 using a plurality of metal fittings 20 . Although it is an example, the roof surface 4 in this embodiment is a folded roof, is made of metal, and has electrical conductivity. A plurality of parallel ridges 6 are present on the roof surface 4 of the folded roof. Each metal fitting 20 is attached to the top of the protrusion 6 .

Each solar panel 12 has a plurality of solar cells, receives sunlight, and outputs DC power. A plurality of solar panels 12 are electrically connected to a power conditioner 16 . The power conditioner 16 is configured using a DC-DC converter or an inverter, and converts the DC power output from the solar cell panel 12 into AC power supplied to the demand destination 2 . Note that the AC power output by the power conditioner 16 may be supplied to a commercial power system (not shown) according to the power demand at the demand destination 2 . The breaker 14 is provided between the power conditioner 16 and the demand destination 2 . The breaker 14 electrically disconnects the solar panel 12 and the power conditioner 16 from the customer 2 and the commercial power system when an overcurrent exceeding a predetermined value is detected.

The photovoltaic system 10 further comprises a plurality of power cables 22 . A plurality of power cables 22 electrically connect between the plurality of solar panels 12 and the breakers 14 . Note that the power cable 22 here includes not only a cable that connects between the solar cell panel 12 and the breaker 14 but also a cable that connects between two solar cell panels 12 . Also, the power cable 22 may be a single-core cable or a multi-core cable.

Since the power cable 22 is exposed to the elements, it needs to be fixed to the roof surface 4 . Therefore, as shown in FIG. 3 , the power cable 22 is fixed to the fitting 20 using a binding material 26 . An insulating protection member 24 is interposed between the fitting 20 and the power cable 22 . The protective member 24 is a member independent of the metal fitting 20 and the power cable 22 , and is bound together with the metal fitting 20 and the power cable 22 by a binding material 26 . Although not particularly limited, the protective member 24 is a sheet-like member and is made of an insulator such as a resin material or a rubber material.

As described above, in the system 10 of this embodiment, the power cables 22 are fixed to the roof surface 4 using the metal fittings 20 for fixing the solar panel 12 . With such a configuration, the number and types of metal fittings 20 required can be reduced, and the system 10 can be easily installed. However, since the metal fittings 20 that fix the solar panel 12 are required to have strength and durability, they are made of metal. . If a short circuit were to occur between the power cable 22 and the fitting 20 , the solar panel 12 would be grounded against the conductive roof surface 4 . There is no breaker 14 on the path of this ground fault. Also, the solar panel 12 continues to supply power as long as it receives sunlight. As a result, the electric leakage from the solar cell panel 12 to the roof surface 4 may continue without being detected.

Regarding the above concerns, an insulating protective member 24 is provided between the power cable 22 and the fitting 20 . The protection member 24 can be made of, for example, a resin material or a rubber material. According to such a configuration, the insulation between the power cable 22 and the metal fitting 20 can be maintained for a long period of time even at the position of the metal fitting 20 where deterioration of the power cable 22 tends to progress over time. In particular, the insulation coating of power cable 22 may be unintentionally damaged during construction work to install system 10, thereby reducing durability. On the other hand, the protective member 24 is independent of the power cable 22 and the metal fittings 20, and is not a long member like the power cable 22. nor receive.

In the system 10 of this embodiment, the protective member 24 may have the same structure as the insulation coating of the power cable 22 . That is, the insulating coating removed from the end of the power cable 22 may be used as the protective member 24 . However, as another embodiment, the protective member 24 may be another member prepared for that purpose, and may have a material and structure different from the insulating coating of the power cable 22 .

In the system 10 of this embodiment, the protective member 24 is arranged to surround the power cable 22 (see FIG. 4). Thereby, the protective member 24 is interposed not only between the power cable 22 and the fitting 20 but also between the power cable 22 and the binding material 26 . With such a configuration, the binding material 26 does not come into direct contact with the power cable 22 , so a conductive member such as a wire can be used as the binding material 26 . In this case, although not particularly limited, it may have a structure in which a conductive core wire is covered with an insulating coating such as a resin material, like a so-called binding wire.

In the system 10 of this embodiment, the power cable 22 is fixed to the fitting 20 between the roof surface 4 and the solar panel 12 (see FIG. 3). According to such a configuration, the power cable 22 is protected from sunlight, wind and rain, and deterioration over time of the power cable 22 (especially the insulation coating) can be suppressed.

In the system 10 of this embodiment, the binding material 26 may be a plastic binding band. With such a configuration, it is possible to prevent the power cable 22 from being short-circuited to the fitting 20 through the binding material 26 . In addition, resin binding bands are widely used in various sizes, and appropriate ones can be obtained at low cost.

As shown in FIGS. 5-7, in the system 10 of the present embodiment, the power cables 22 may be secured to the roof surface 4 using cable racks 30. FIG. In this case, the cable rack 30 may be a ladder-shaped cable rack or a tray-shaped cable rack. The cable rack 30 installed on the roof surface 4 is preferably made of metal because strength and durability are required. However, if the cable rack 30 is made of metal and has electrical conductivity, the power cable 22 and the cable rack 30 must be reliably insulated.

Therefore, an insulating protection member 32 is provided between the power cable 22 and the cable rack 30 . In this case, the protective member 32 is a net-like sheet material such as Netron (registered trademark). As shown in FIG. 6, the protective member 32 may be arranged not only on the bottom surface 30a of the cable rack 30 facing the power cables 22, but also on a pair of inner side surfaces 30b facing the power cables 22 as well. With such a configuration, insulation between the power cable 22 and the cable rack 30 can be maintained for a long period of time. In addition, since the protective member 32 is a net-like sheet material, it is possible to prevent rainwater and dust from remaining on the cable rack 30 .

Although not particularly limited, the power cable 22 may be fixed to the cable rack 30 with the binding member 34 together with the protective member 32 . With such a configuration, the positional relationship among the power cable 22, the protection member 32, and the cable rack 30 can be maintained for a long period of time. The protective member 32 may be fixed to the cable rack 30 in advance, and then the power cable 22 may be fixed to the cable rack 30 together with the protective member 32 by the binding member 34 . The binding material 34 may be a resin binding band like the binding material 26 used for the fitting 20 .

As shown in FIG. 8, in the system 10 of the present embodiment, an insulating sheet material 40 may be bridged between two or more fittings 20, and the power cable 22 may be arranged on the sheet material 40. . In this case, the power cable 22 can be fixed to the sheet material 40 using a binding material 42 (for example, a resin binding band). According to such a configuration, the power cable 22 connected to the solar panel 12 can be prevented from directly contacting the conductive roof surface 4 and metal fittings 20 . Thereby, it is possible to effectively suppress the ground fault of the power cable 22 on the conductive roof surface 4 . In particular, since the sheet material 40 is lightweight, it is easy to install, and a large number of power cables can be arranged on the sheet material 40 rather than directly fixing the power cables 22 to the metal fittings 20. .

Netron (registered trademark), for example, can be used for the sheet material 40, although not particularly limited thereto. If the sheet material 40 is a net-like sheet material, it is possible to prevent rainwater and dust from remaining on the sheet material 40 . Moreover, the sheet material 40 may be positioned between the roof surface 4 and the solar panel 12, thereby protecting the power cable 22 and the sheet material 40 from wind, rain and sunlight.

The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or in the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims as filed. The techniques exemplified in this specification or drawings can achieve a plurality of purposes at the same time, and achieving only one of them has technical utility.

4: Roof surface (folded roof)
6: Protrusions on the roof surface 10: Solar power generation system 12: Solar panel 14: Breaker 16: Power conditioner 20: Metal fittings 22: Power cables 24, 32: Protective members 26, 34, 42: Binding material 30: Cable Rack 40: sheet material

Claims (12)

A solar power generation system,
a solar panel laid on a conductive roof surface;
a power cable electrically connected to the solar panel;
a fitting for fixing the solar panel to the roof surface and for fixing the power cable using a binding material;
an insulating protective member interposed between the power cable and the metal fitting;
with
The protective member is a member independent of the power cable and the metal fitting, and is bound together with the power cable and the metal fitting by the binding material.
Solar power system. The photovoltaic power generation system according to claim 1, wherein the protective member is made of a resin material or a rubber material. The photovoltaic power generation system according to claim 1 or 2, wherein the protection member is arranged to surround the power cable and is interposed between the power cable and the binding member. The solar power generation system according to any one of claims 1 to 3, wherein the power cable is fixed to the metal fitting between the roof surface and the solar cell panel. The solar power generation system according to any one of claims 1 to 4, wherein the binding material is a resin binding band. The roof surface is a folded roof having ridges,
The photovoltaic power generation system according to any one of claims 1 to 5, wherein the metal fitting is fixed to the ridge. A solar power generation system,
a solar panel laid on a conductive roof surface;
a power cable electrically connected to the solar panel;
a cable rack that houses the power cables;
an insulating protective member interposed between the power cable and the cable rack;
with
The protective member is a net-like sheet material, and is arranged over a bottom surface and a pair of inner side surfaces of the cable rack facing the power cables,
Solar power system. The photovoltaic power generation system according to claim 7, wherein the power cable is fixed to the cable rack together with the protective member by a binding material. The photovoltaic system according to claim 7 or 8, wherein the cable rack is a ladder-shaped cable rack. The photovoltaic power generation system according to any one of claims 7 to 9, wherein the cable rack is arranged on the roof surface. A solar power generation system,
a solar panel laid on a conductive roof surface;
a power cable electrically connected to the solar panel;
a plurality of metal fittings for fixing the solar panel to the roof surface;
an insulating sheet material bridged between the plurality of metal fittings;
with
The sheet material is a net-like sheet material and supports the power cable,
Solar power system. 12. The photovoltaic system of claim 11, wherein the sheet material is positioned between the roof surface and the solar panel.

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