CN210724686U

CN210724686U - Photovoltaic junction box with novel structure

Info

Publication number: CN210724686U
Application number: CN201922266195.5U
Authority: CN
Inventors: 余如龙; 彭祁军; 李艳群; 郑朋朋
Original assignee: Zhejiang Xinhui Photovoltaic Technology Co ltd
Current assignee: Zhejiang Zhengtai Xinhui Photovoltaic Co ltd
Priority date: 2019-12-17
Filing date: 2019-12-17
Publication date: 2020-06-09
Anticipated expiration: 2029-12-17

Abstract

The utility model discloses a photovoltaic terminal box of new construction belongs to photovoltaic terminal box structural design field. The junction box comprises a junction box base, a junction box body and a bus bar guide through hole, wherein the junction box base is provided with a bus bar guide through hole in the middle of the bottom of the junction box base, the bus bar guide through hole is used for guiding a bus bar and is convenient to mount in a narrow space, one side of the bus bar guide through hole is provided with a through groove, or two sides of the bus bar guide through hole are respectively provided with a through groove, the through grooves penetrate through the top surface and the bottom surface of the base, and the length of the through grooves is larger than that of the bus bar guide through hole, so that the creepage distance; in addition, the length of the pin of the diode is set, the long pin enables the contact surface of the pin of the diode and the terminal copper sheet to be longer by lengthening the length of the terminal sheet, and the heat of the diode can be quickly conducted to the copper sheet for heat dissipation; the terminal tail is reversely folded, the area is increased downwards, the radiating surface of the terminal is larger, the radiating performance is better, meanwhile, the length of the box body does not need to be increased, and the cost is saved.

Description

Photovoltaic junction box with novel structure

Technical Field

The utility model belongs to the structural design field of photovoltaic terminal box, concretely relates to photovoltaic terminal box of new construction.

Background

The photovoltaic junction box is an important component of a solar power generation system for connecting a photovoltaic back sheet and an inverter. Through the development of many years, the performance and reliability of the photovoltaic junction box have been improved greatly, but the current photovoltaic junction box on the market has the following defects:

1. and (4) heat dissipation. A large number of heating elements exist in the photovoltaic junction box, and the long-term thermal structure enables the box body to deform, so that a product fails, or the sealant generates cracks in the box body.

2. The problem of volume. Because the smaller the effective utilization area of the photovoltaic junction box and the back surface of the cell, namely the narrower the junction box is arranged, the more remarkable the cost benefit is, and the lower the cost of the photovoltaic panel is. The creepage distance from the bus bar belt to the outside needs to be ensured in the design of the junction box, in order to increase the creepage distance, the creepage distance between the bus bar belt and the outside, namely the creepage distance on the base of the junction box, is increased by adding a plurality of circles of grooves on the base of the junction box at present, and the volume of the junction box is increased.

3. The welding problem of the bus bar. Because the area of converging needs to weld the assigned position at the terminal piece, and the terminal box space is narrow and small, and the area of converging is difficult accurate when inserting the terminal box and is aimed at to the terminal piece is unstable when the welding or even can bounce-back, influences welded quality.

4. Installation of different busbar assemblies. In practical application, the photovoltaic junction box is suitable for two components of a double-sided component bus belt and a single-sided component bus belt, the existing photovoltaic junction box structure cannot meet multiple application occasions simultaneously, different junction box structures need to be designed for different bus belt components of customers, and cost pressure is high.

5. Reliability issues. The photovoltaic junction box works in a severe environment for a long time, and the junction box is easy to deform after working for a long time due to the high temperature inside the junction box and the external impact.

Therefore, the photovoltaic junction box solves the problems, achieves miniaturization of the junction box, improves heat dissipation, increases creepage distance, improves strength, ensures stability of the junction box performance, and reduces cost, and is a target to be achieved in the design of the photovoltaic junction box at present.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a photovoltaic terminal box of new construction to solve the problem that the present photovoltaic terminal box that proposes exists in the above-mentioned background art.

The technical scheme of the utility model as follows:

a photovoltaic junction box with a new structure comprises a cover and a base which are buckled with each other, wherein a diode and a terminal block which is electrically connected through the diode are arranged in the base, a bus bar is connected onto the terminal block, the diode and the bus bar are installed in the base, a wire pressing buckle is arranged at the tail of the base, and a leading-out end of a photovoltaic cable penetrates through the middle of the base and the wire pressing buckle and then is connected with a terminal piece; filling pouring sealant in the base to cover the diode; a bus bar guide through hole is formed in the bottom of the base, a bus bar penetrates through the bus bar guide through hole and then is connected to an internal terminal block, a through groove is formed in one side of the bus bar guide through hole, or a through groove is formed in each of the two sides of the bus bar guide through hole, the through grooves penetrate through the top surface and the bottom surface of the base, and the length of each through groove is larger than that of the bus bar guide through hole; the terminal block comprises a first metal sheet, a second metal sheet, a third metal sheet and a connecting strip, the first metal sheet and the third metal sheet are connected through the connecting strip, the first metal sheet is located at one end close to the photovoltaic cable, and the third metal sheet is located at one end far away from the photovoltaic cable; the second metal sheet is positioned between the first metal sheet and the third metal sheet, and a bus bar is welded on the first metal sheet and the second metal sheet; two pins of the diode are long and short, the short pin is welded below the second metal sheet, the long pin is welded below the third metal sheet, and the number of welding points between the long pin and the third metal sheet is one or more; the length of the third metal sheet is larger than that of the second metal sheet, and the tail of the third metal sheet is vertically bent to form a terminal reverse-bending lengthened surface.

Preferably, the first metal sheet and the second metal sheet of the terminal block are respectively provided with a single-side assembly bus bar mounting jack, and the single-side assembly bus bar is inserted into the single-side assembly bus bar mounting jacks on the first metal sheet and the second metal sheet and is welded with the surfaces of the first metal sheet and the second metal sheet.

Preferably, the two-sided assembly bus bar is inserted between the first metal sheet and the second metal sheet and is welded with the surfaces of the first metal sheet and the second metal sheet respectively.

Preferably, a bus bar insertion guide rib is arranged in the junction box base and is located between the first metal sheet and the second metal sheet of the terminal block.

Preferably, the two sides of the junction box base are provided with uniformly distributed supporting rib positions.

The utility model has the beneficial technical effects that:

1. the pins of the diode are directly welded below the terminal copper sheet welded with the bus bar, so that the heat of the diode can be quickly conducted out through the bus bar;

2. the two pins of the diode are long on one side and short on the other side, the long-end pin enables the contact surface of the diode pin and the terminal copper sheet to be longer by lengthening the length of the terminal sheet, the connecting surface which can be welded in resistance welding is larger, welding spots can be increased, more than two welding spots can be provided, therefore, the heat of the diode is quickly conducted to the copper sheet for heat dissipation, and the possibility of thermal failure of the diode is reduced;

3. the tail part of the terminal is reversely folded and downwards extended to increase the area, so that the radiating surface of the terminal is larger, the radiating performance is better, meanwhile, the length of the box body does not need to be lengthened, the radiating surface of the terminal is increased, and the cost is saved;

4. the box body is provided with a through groove to increase the creepage distance from the bus belt to the outside, and the creepage distance from the bus belt to the outside is increased by increasing the groove and designing the through groove, so that the width of the box body can be narrower;

5. the junction box is suitable for mounting single-sided components and double-sided components, and one junction box is suitable for mounting various components;

6. the bus bar insertion guide ribs are arranged, so that the bus bar can be quickly guided into the insertion holes when the bus bar is installed, and the bus bar can be tightly fixed without rebounding when the bus bar is welded, so that the welding quality is ensured;

7. the design of box body both sides has even support rib position, both can guarantee box body intensity and can guarantee that the terminal box is indeformable in long-term operation again.

Advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

Drawings

Fig. 1 is an overall exploded view of the embodiment of the tri-body junction box of the present invention.

Fig. 2 is an installation view of the terminal block, bus bar, and diode.

Fig. 3 is an installation view of the terminal block, bus bar, diode in the base.

Fig. 4 is a back view of fig. 3.

Fig. 5 is a view of the base and cover.

Fig. 6 is a through slot and groove view of the base bottom.

Fig. 7 is a cross-sectional view of fig. 6.

Fig. 8 is a view showing two types of mounting methods of the bus bar.

Fig. 9 is a view of the bus bar insertion guide rib.

FIG. 10 is a view of the supporting rib of the case.

Fig. 11 is a cross-sectional view of fig. 10.

Detailed Description

The following describes the embodiments of the present invention with reference to the accompanying drawings.

The utility model discloses a structural design of photovoltaic terminal box, following embodiment uses the components of a whole that can function independently formula terminal box as the example to explain. The split junction box decomposes the junction box into a positive junction box, a negative junction box and a plurality of intermediate junction boxes. The split junction box can minimize the connection length, disperse the heat of the diode, meanwhile, the electric parts in the middle junction box can be sealed well in advance, and only the positive junction box and the negative junction box need to be sealed during field installation, so that the field workload is reduced, and the wiring reliability is improved. The structure design of the utility model is also suitable for a single junction box, a bipartite junction box or a junction box with more split bodies.

Fig. 1 shows a disassembled structure of an embodiment of the three-split junction box of the present invention, which includes a positive junction box, a negative junction box and an intermediate junction box. The positive terminal box comprises a cover 101 and a positive base 102 which are buckled with each other, the negative terminal box comprises a cover 201 and a negative base 202 which are buckled with each other, and the middle terminal box comprises a cover 301 and a middle base 302 which are buckled with each other. The positive base 102, the negative base 202, and the intermediate base 302 are respectively provided with

diodes

103, 203, 303 and

terminal blocks

104, 204, 304 electrically connected by the

diodes

103, 203, 303, and bus bars are respectively connected to the terminal blocks 104, 204, 304. The tail part of the positive terminal box and the tail part of the negative terminal box are respectively provided with a wire pressing buckle 105 and a wire pressing buckle 205, the leading-out end of the positive photovoltaic cable 106 passes through the middle of the positive base 102 and the wire pressing buckle 105 and then is connected with the terminal piece 104, and the leading-out end of the negative photovoltaic cable 206 passes through the middle of the negative base 202 and the wire pressing buckle 205 and then is connected with the terminal piece 204. The box bodies in the diode lower areas of the anode base 102, the cathode base 202 and the middle base 302 are all filled with the potting adhesive in a hollow manner.

The utility model discloses in, the subassembly mounting structure of subassembly is the same in anodal box body 1, negative pole box body 2 and the middle box body 3. One of the cartridges will now be described as an example.

See fig. 2 and 3. Fig. 2 shows the structure of the terminal block and the mounting structure of the diode and the bus bar on the terminal block. The terminal block comprises a first metal sheet 1, a second metal sheet 2, a third metal sheet 3 and a connecting strip 4. Referring to fig. 3, when the terminal block is mounted in the junction box, the first metal sheet 1 is located near the cable end, i.e., the end of the photovoltaic cable 11 connected to the terminal block, and the third metal sheet 3 is located far from the cable end. Referring to fig. 2, the first metal sheet 1, the second metal sheet 2, and the third metal sheet 3 are not in contact with each other, the first metal sheet 1 and the third metal sheet 3 are connected together by a connecting strip 4, and the second metal sheet 2 is located between the first metal sheet 1 and the third metal sheet 3. Referring to fig. 2, a bus bar connecting stopper face 5 is formed by vertically bending the side of the second metal sheet 2 facing the first metal sheet 1, a diode connecting stopper face 6 is formed by vertically bending the side of the second metal sheet 2 facing the third metal sheet 3, and a diode connecting stopper face 7 is formed by vertically bending the side of the third metal sheet 3 facing the second metal sheet 2. Referring to fig. 2, the length of the third metal sheet 3 is longer than that of the second metal sheet 2, and the tail of the third metal sheet 3 is vertically bent to form a terminal reverse-bending elongated surface 8.

Referring to fig. 2 and 3, the bus bars 9 are welded to the first metal sheet 1 and the second metal sheet 2, and since the welding ends of the bus bars 9 are close to the cable ends and are close to each other, the generated heat can be rapidly conducted out through the photovoltaic cables 11. Referring to fig. 2, two sides of a main body of a diode 10 are respectively abutted against two diode

connection blocking surfaces

6 and 7, two pins of the diode 10 are long and short, and the short pins are directly welded below a second metal sheet 2 welded with a bus bar 9, so that heat of the diode 10 can be quickly conducted out through the bus bar 9; the long pin of the diode 10 is welded below the third metal sheet 3, the connectable area during resistance welding is large, and more than one welding point can be realized; by lengthening the length of the third metal sheet 3, the contact surface between the long pin of the diode 10 and the third metal sheet 3 is longer, so that the heat of the diode 10 can be quickly conducted to the third metal sheet 3 for heat dissipation, and the possibility of thermal failure of the diode is reduced. Referring to fig. 2, the tail of the third metal sheet 3 is bent back to extend the area and increase the heat dissipation surface of the terminal block, so that the heat dissipation surface of the terminal block is larger and better, meanwhile, the length of the box body does not need to be increased, the heat dissipation surface of the terminal block is increased, and the cost is saved.

Referring to fig. 4 and 5, the base of the terminal box in the area below the diode 10 is completely hollowed out 13 and filled with the potting adhesive 12, the diode 10 is covered by the potting adhesive 12, and the heat of the diode and the heat of the terminal block can be quickly conducted to the photovoltaic module back plate through the potting adhesive 12 below for heat dissipation; the surface of the pouring sealant 12 and the bottom surface of the junction box cover 14 are designed to be suspended, and heat emitted from the surface of the pouring sealant is dissipated by air convection at the suspended position.

Referring to fig. 6 and 7, a bus bar guide through hole 22 is formed in the middle of the bottom of the junction box base, the bus bar guide through hole 22 is used for guiding the bus bar, so that the junction box is convenient to mount in a narrow space, the bus bar 9 penetrates through the bus bar guide through hole 22 and then is connected to an internal terminal block, three circles of grooves 20 are formed in one side, on the bus bar guide through hole 22, of the junction box base, and the creepage distance from the bus bar 9 to the outside is increased by adding the three circles of grooves, which is a traditional method; in the embodiment, a through groove 21 is formed on the other side of the bus bar guide through hole 22 instead, and the creepage distance from the bus bar 9 to the outside is also increased; by adding the grooves 20 and the through grooves 21, the creepage distance of the bus bars 9 to the outside is increased. In other embodiments, the through grooves 21 can be machined on both sides of the bottom, which is more effective. The through groove 21 is a groove penetrating the top and bottom surfaces of the base, and has a length much greater than its width. Here, the through groove 21 and the bus bar guide groove 22 are independent grooves and do not communicate with each other. The advantage of providing the through grooves 21 is that on the one hand the through grooves 21 are better for the increase of the creepage distance than the grooves 20, and as can be seen from a comparison of fig. 6 and 7, the box width on the side of the through grooves 21 is smaller than the box width on the side of the three-turn grooves 20, and the through grooves 21 can make the box width narrower than several turns of the grooves 20.

Referring to fig. 8, the junction box is suitable for single-sided assembly installation and double-sided assembly installation, and one junction box is suitable for multiple assembly installation. Respectively arranging a single-side assembly bus bar mounting jack 30 on a first metal sheet 1 and a second metal sheet 2 of a terminal block, inserting two single-side assembly bus bars 31 into the single-side assembly bus bar mounting jacks 30 on the first metal sheet 1 and the second metal sheet 2 when the single-side assembly bus bars need to be mounted, and then respectively bending and welding the single-side assembly bus bars with the surfaces of the first metal sheet 1 and the second metal sheet 2; and when the double-sided assembly bus strips need to be installed, the two double-sided assembly bus strips 32 are inserted between the first metal sheet 1 and the second metal sheet 2 and then are respectively bent to be welded with the surfaces of the first metal sheet 1 and the second metal sheet 2. In fig. 8, the bus bar is inserted only and is not bent, and a bending and welding diagram can be seen in fig. 9.

Referring to fig. 9, a bus bar insertion guide rib 40 is provided in the terminal block base, and when the terminal block is mounted in the terminal block, the bus bar insertion guide rib 40 is located between the first metal piece 1 and the second metal piece 2 of the terminal block and does not contact the first metal piece 1 and the second metal piece 2. When the bus bar 9 (in this case, a double-sided assembly bus bar) is mounted, the bus bar is inserted into the guide ribs 40 so that the bus bar 9 can be quickly guided into the insertion holes, for example, the insertion holes between the bus bar connection blocking surface on the terminal block and the guide ribs; and when the bus bar 9 is welded, the bus bar 9 can be tightly abutted and fixed, so that the bus bar 9 is not rebounded, and the welding quality is ensured.

Referring to fig. 10 and 11, the two sides of the base of the junction box are designed with uniformly distributed support rib positions 50, and the support rib positions 50 can ensure the strength of the box body and also ensure that the junction box does not deform during long-term operation.

What has been described above is only a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is to be understood that other modifications and variations directly derivable or suggested by those skilled in the art without departing from the spirit and scope of the present invention are to be considered as included within the scope of the present invention.

Claims

1. A photovoltaic junction box with a new structure comprises a cover and a base which are buckled with each other, wherein a diode and a terminal block which is electrically connected through the diode are arranged in the base, a bus bar is connected onto the terminal block, the diode and the bus bar are installed in the base, a wire pressing buckle is arranged at the tail of the base, and a leading-out end of a photovoltaic cable penetrates through the middle of the base and the wire pressing buckle and then is connected with a terminal piece; filling pouring sealant in the base to cover the diode; the method is characterized in that: a bus bar guide through hole is formed in the bottom of the base, a bus bar penetrates through the bus bar guide through hole and then is connected to an internal terminal block, a through groove is formed in one side of the bus bar guide through hole, or a through groove is formed in each of the two sides of the bus bar guide through hole, the through grooves penetrate through the top surface and the bottom surface of the base, and the length of each through groove is larger than that of the bus bar guide through hole; the terminal block comprises a first metal sheet, a second metal sheet, a third metal sheet and a connecting strip, the first metal sheet and the third metal sheet are connected through the connecting strip, the first metal sheet is located at one end close to the photovoltaic cable, and the third metal sheet is located at one end far away from the photovoltaic cable; the second metal sheet is positioned between the first metal sheet and the third metal sheet, and a bus bar is welded on the first metal sheet and the second metal sheet; two pins of the diode are long and short, the short pin is welded below the second metal sheet, the long pin is welded below the third metal sheet, and the number of welding points between the long pin and the third metal sheet is one or more; the length of the third metal sheet is larger than that of the second metal sheet, and the tail of the third metal sheet is vertically bent to form a terminal reverse-bending lengthened surface.

2. The photovoltaic junction box with a new structure as claimed in claim 1, wherein: the terminal block is characterized in that a first metal sheet and a second metal sheet of the terminal block are respectively provided with a single-side assembly bus bar mounting jack, and a single-side assembly bus bar is inserted into the single-side assembly bus bar mounting jacks on the first metal sheet and the second metal sheet and is welded with the surfaces of the first metal sheet and the second metal sheet.

3. The photovoltaic junction box with a new structure as claimed in claim 1, wherein: the double-sided assembly bus bar is inserted between the first metal sheet and the second metal sheet and is respectively welded with the surfaces of the first metal sheet and the second metal sheet.

4. The photovoltaic junction box with a new structure as claimed in claim 1, wherein: be provided with in the terminal box base and converge the area and insert the direction muscle, it is located between the first sheetmetal and the second sheetmetal of terminal block to converge the area and insert the direction muscle.

5. The photovoltaic junction box with a new structure as claimed in claim 1, wherein: and supporting rib positions which are uniformly distributed are arranged on two sides of the base of the junction box.