JPH0212878A - Photocell module - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a photovoltaic module, and more particularly to a junction box integrally formed with a frame of a photovoltaic module.

A photovoltaic module is a device that generates electricity using sunlight. A solar cell panel is an example of a photovoltaic module. Typically, photovoltaic modules convert sunlight energy directly into electricity using multiple solar cells mounted on a frame.

Solar cells can be connected in a variety of configurations based on system requirements and the design requirements of the solar panels and the solar cells themselves.

Photovoltaic modules typically have one or more junction boxes for connecting each to the electrical system. These junction boxes are placed on the back side of the photovoltaic module and cover a portion of the back side. An example of this configuration is the solar panel manufactured by Arco Solar Inc., model number M55.

In this configuration, the junction box is permanently affixed to the backside of the solar panel and sealed from the surrounding environment to maintain the electrical integrity of the solar panel, a time-consuming and expensive practice.

For example, a module that uses two glass plates, one for the top plate and one for the bottom plate, requires holes to be drilled in the bottom plate for electrical connection. Another problem with installing the junction box on the back side of the panel is that it can easily break when assembling and handling the module.Since the junction box is located on the back side of the panel, it is difficult to move the junction box when moving the panel. While convenient to grip, this can easily destroy the adhesive seal that holds the junction box to the back of the panel, destroying the electrical and environmental sealing integrity of the panel.

Another problem when attaching a junction box to the back side of a photovoltaic module is that the junction box covers a portion of the back side. This is particularly important for solar panels using bifacial solar cells, which are cells that are excited by light hitting both their front and back sides, i.e., generate a direct current voltage and current. When using a six-sided solar cell in a photovoltaic module, it is important that the back side of the solar cell is not covered.

It is an object of the present invention to provide photovoltaic modules and junction boxes with improved structural, electrical and environmental integrity and with minimal or no shielding of the backside of the module.

The present invention includes a solar cell stack for power generation, a plurality of frame members that support the solar cell stack, and a connection box that connects the solar cell stack to an electrical system, and the connection box includes at least one frame member and a plurality of frame members that support the solar cell stack. The present invention relates to an integrally formed photovoltaic module. The shape and size of the frame metal body constituted by the frame member can be arbitrarily selected, but it is preferably rectangular. Similarly, the frame member formed integrally with the junction box may be of any shape, but Preferably, it is one of the shorter frame members.

The present invention is particularly useful in photovoltaic modules using double-sided solar cells where shielding of the backside of the module must be minimized or preferably eliminated. By forming the junction box integrally with the frame.

The back side of the photovoltaic module is not covered and therefore none of the solar cells are shielded.

This results in an increase in the efficiency of the photovoltaic module.

The present invention integrates a junction box and a frame, which is not limited to photovoltaic modules having single-sided solar cells as it has the effect of improving the structural, electrical and environmental integrity of the photovoltaic module. Another advantage of the present invention is that.

The overall cost of the photovoltaic module is reduced because the number of junction boxes is reduced to one instead of two.

Since the junction box is not attached to the back side of the photovoltaic module, the structural, electrical and environmental integrity of the module is improved. Because the junction box is not attached to the backside of the module, there is a very low chance that someone handling the photovoltaic module will inadvertently break the environmental seal and compromise the electrical integrity of the module.

The junction box integrated with the frame of the invention facilitates the parallel and series connection of photovoltaic modules and their connection to the electrical system. In addition, there is no need to drill holes into the bottom plate of the solar cell stack; instead, electrical connections to the solar cells can be made at the edges of the solar cell stack. The frame-integrated junction box of the present invention also allows for a reduction in the overall cost of photovoltaic modules by using uniform standard formwork components for all modules.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Broadly speaking, the photovoltaic module 1 of the present invention comprises a first
As shown in the figure, the solar cell stack consists of a 2° frame 3 and a connection box 4 integrally formed with the frame 3. The frame 3 is preferably rectangular and consists of four frame members 5. The frame 3 is typically made from a strong, lightweight material such as anodized 204 etched aluminum, but it can also be formed from any other material that functions as a frame.

FIG. 1 is a view of the photovoltaic module 1 seen from the front side. No junction box is arranged on the back side of the photovoltaic module 1; instead, the junction box 4 is preferably formed integrally with one frame member 5 at the top or bottom of the photovoltaic module 1.

By forming the junction box 4 integrally with the shorter frame member, the amount of material used for the junction box can be reduced.

However, the junction box 4 can be integrally formed as one unit with any frame member. The junction box 4 preferably extends over the entire width of the photovoltaic module 1;
This is not a requirement.

The junction box 4 is formed with at least one first opening 8 for passing electrical connection means that allow the photovoltaic module l to be connected to an electrical system. The 7rL electrical connection means is a wire or cable 7 that passes through the first opening 6 at the bottom of the junction box 4 and connects to the terminal strip 8 on the terminal block 9. The wire or cable 7 may be housed within the pipe or conduit, but this is not a requirement; the first opening 6 is sized to receive a cable or conduit coupling member consisting of a threaded sleeve and a nut; 0 to ensure that the first opening B is sealed from the surrounding environment;
Typically, two such first openings 6 are used, one for the positive connection to the electrical system and one for the negative connection. The unused first opening 8 is filled with a plug, preferably made of plastic, to seal the junction box 4 from the surrounding environment. First opening 6
is preferably located at the bottom of the integral junction box so that the front side of the module is not covered and is easily accessible when the module is configured as a solar array.

The terminal block 9 extends over the entire length of the junction box 4, but preferably along part of its length. The terminal block 8 is made of a non-conductive material such as Bakelite,
The integral frame member 5 and the inner wall of the junction box 4 are fixed with an adhesive.

A part of the junction box 4 is removed and a transparent cover 10 located below the terminal strip 8 and the terminal block 9 is attached. The transparent cover IO allows the state of electrical connections on the terminal block 8 to be visually checked from below the module without removing the cover. Preferably, a rubber locking gasket 11 is used to seal the transparent cover 10 to the junction box 4 from the surrounding environment, thereby preventing the ingress of water or other foreign matter that could adversely affect the electrical connection. prevent. The transparent cover IO has locking screws to avoid accidental loss during installation and inspection in the field, taking into account its installation location.

FIG. 2 is a side view showing a part of the photovoltaic module 1 in cross section taken along the line AA' in FIG. Frame member 5
The junction box 4 integrated with the casing 4 is rectangular and preferably has four sides. The four sides of junction box 4 are preferably extruded as one unit, but may also be formed by assembling four separately extruded members so long as they form a chamber that is sealed from the surrounding environment. If separately extruded parts are used, corner key locking is sufficient.

Preferably, the terminal block 3 has a shape as shown in FIG. 2, so that the terminal strip 8 has an angled shape so that it can be easily accessed from below when the transparent cover 10 is removed. This configuration allows the terminal block 3 to fit snugly into the interior of the integral frame member/junction box. As shown in FIG. 2, the terminal strip 8 is attached to the terminal block 3.
A plurality of holes 12 are drilled at the top. Hole 12 allows electrical connection to solar cell 18 . An insulating insert 13, such as high-density rubber, is placed inside the hole 12 to provide sealing from the surrounding environment and prevent solar cell stack connection means, such as conductors 14, from coming into contact with the terminal block 9. do.

This is necessary because the conductor 14 is normally not insulated from the frame 3 and must be electrically isolated. One end of the conductor 14 is connected to the terminal strip 8, and the other end is connected to the solar cell 18.

At least one S2 aperture 15 is formed in the frame member 5 to allow electrical connection to the solar cell 18.

The second opening 15 is preferably provided in the same wall of the frame member 5 as the first opening 6. Further, the second opening 15 is preferably smaller than the hole 12, and two vertical protrusions 16 and 17 are formed on the frame member 5.
It extends from the wall above and below the second opening 15 . These protrusions together with the walls of the frame member 5 form a C-shaped groove in which the edge of the solar cell stack 2 is received. As shown in FIG. 2, the solar cell stack 2 is a portion of a photovoltaic module 1 consisting of a solar cell 18 sandwiched between two glass layers 19. As shown in FIG.

These layers are preferably glass, but other transparent materials can also be used.

The edge of the solar cell aM body 2 is brought into contact with the wall of the frame member 5 so that the conductor 14 is placed above the second opening 15. The advantage of using this configuration is that the conductor 14 can be easily pulled out from the end of the solar cell carcass 2 without drilling holes in the glass 19. Preferably, two conductors 14 are used, one for the positive connection to the solar cell 18 and one for the negative connection.

Similarly, two second openings 15 are provided, one for the positive connection and one for the negative connection. A gas scale 20 is provided between the solar cell stack 2 and the protrusion 1617 so that the solar cell stack and the second opening 15 are sealed from the surrounding environment. The gasket can also be used as a cushion for solar cell stacks. The gasket 20 is preferably an EPDM gas gasket 1. It is.

The conductor 14 can be secured to the terminal strip 8 by any known method, such as by soldering, as long as a good electrical connection is possible. Similarly, the cable 7 can be secured to the terminal strip 8 by various known methods, including screws 21.

If necessary, a terminal strip 8 may be provided on the terminal block 8 to allow further electrical connections.

For example, depending on the configuration of the system, it may be necessary to provide some type of protection circuitry, such as a neutral terminal or a diode connected to the solar cell 18.

These further terminal strips 8 provide flexibility.

According to one embodiment of the invention, the integral frame member 5/junction box 4 measures 43.18 cm x 3.175 am x 5.
08cm (17″! 1.25” x 2.0”), terminal block 9 is 12.7cm x 2.69cm!
4.80cm (5.0" x 1.08"z 1.8
1") and the top is 0.97cm (0,38")
There is a range of Transparent cover 10 is 15.24c++!
2.54 cm (8.0" x 1.0"), these dimensions are an example of the size of the integral frame member 5/junction box 4 used in a photovoltaic module of 43.18 cm x 101.8 crs. It's nothing more than that.

In the double-sided photovoltaic module of the present invention, the enclosing area increases by 4z, so the efficiency decreases by 4z, but the net efficiency increases because the junction box does not shield the back side of the module. In existing photovoltaic modules, the back side of several solar cells is shielded in order to attach two junction boxes and their associated bus connection means to the back side of the photovoltaic module. usually,
The total area of these parts is about 150 cm' or about 3.5z of module envelope area. Shielding these areas reduces power output and efficiency; however, this reduction in efficiency is greater than the area that is shielded. If we make a conservative prediction, it will decrease to 1/1.5.

In the example where an area of 3.5z is shielded, this reduces the efficiency by 5.3z, which is greater than the loss of 4z due to the increased encircling area of the photovoltaic module of the present invention, which is greater than the efficiency due to not shielding the back side of the module. This increase in is particularly important because in many instances the area surrounded by the photovoltaic module is not as important as its power output. As a result, a module that generates 5.3z or more power with the same number of solar cells is preferable to a smaller module with lower power output.

Although preferred embodiments of the invention have been described in detail above, various modifications can be made to the invention without departing from the scope of the appended claims.

[Brief explanation of the drawing]

FIG. 1 shows a photovoltaic module according to the invention in which a junction box is integrally formed with a frame. FIG. 2 is a side view of a portion of the photovoltaic module taken along line AA' in FIG. l ... Photovoltaic module 2 ... Solar cell laminate 3 - Frame 4 - Connection box 8 - 10 - 18 - 18 - Terminal block, transparent cover, solar cell, glass layer Applicant: Westing House φ Electric Corporation Agent: Hirokazu Kato (and 1 other person)

Claims (5)

[Claims] (1) A photovoltaic module having a solar cell stack for power generation, a plurality of frame members supporting the solar cell stack, and a connection box, wherein the connection box is integrally formed with one of the frame members, and the connection box is integrally formed with one of the frame members. A terminal block made of an insulating material has an opening aligned with the opening provided in the frame member, a conductive terminal strip is provided on the terminal block adjacent to the opening, and a conductor is provided in the solar cell stack. Connected to the terminal strip, an electrically insulating encapsulant material filled to seal the opening and insulate the conductor from the frame, and a cable to connect the terminal strip to a system utilizing electricity from the photovoltaic module. A photovoltaic module characterized in that it is electrically connected. (2) The photovoltaic module according to claim 1, wherein the connection box is provided with an opening for a cable in the one frame member, and a space between the opening and the cable is sealed. . (3) The junction box is provided with a transparent cover that is sealed so that the terminal strip can be visually recognized at all times without impairing the sealed state of the junction box. photovoltaic module. (4) The photovoltaic cell according to claim 1, characterized in that the solar cell laminate is a double-sided type that generates power from sunlight hitting both surfaces, and the junction box does not cover either surface. module. (5) The photovoltaic module according to claim 1, wherein the frame member has a rectangular shape, and the connection box is integrally formed with one of the shorter frame members.