CN210897304U

CN210897304U - Photovoltaic module

Info

Publication number: CN210897304U
Application number: CN201922355807.8U
Authority: CN
Inventors: 闫新春; 丁增千; 徐洁; 夏正月; 许涛; 邢国强
Original assignee: CSI Cells Co Ltd; Canadian Solar Manufacturing Changshu Inc
Current assignee: CSI Cells Co Ltd; Canadian Solar Manufacturing Changshu Inc; CSI Solar Technologies Inc
Priority date: 2019-12-25
Filing date: 2019-12-25
Publication date: 2020-06-30
Anticipated expiration: 2029-12-25

Abstract

The utility model provides a photovoltaic module, which comprises a plurality of battery strings arranged at intervals along a first direction, a plurality of bus bars arranged at intervals along a second direction, and a bypass diode, wherein the battery strings comprise a plurality of battery pieces which are overlapped and connected in series end to end along the second direction which is vertical to the first direction; the bus bar is including connecting in parallel a plurality of the first bus bar of the one end of battery cluster, parallelly connected a plurality of the second bus bar of battery cluster other end, parallelly connected a plurality of battery clusters equipotential battery piece and will the battery cluster divides into the middle bus bar of the equipotential battery piece of at least one interval bus bar of a plurality of substrings, a plurality of substrings of parallelly connected, the bypass diode including connect in first bus bar between the interval bus bar in every two adjacent bus bars of arranging along the second direction in the second bus bar. And the intermediate bus bar and the bypass diode degree battery plate form double protection.

Description

Photovoltaic module

Technical Field

The utility model relates to a photovoltaic field especially relates to a can effectively avoid photovoltaic module of hot spot effect.

Background

When the photovoltaic module is used outdoors, one or more battery pieces are shielded or hidden cracked inevitably, so that the resistance of the battery pieces is increased to generate a hot spot effect. In order to avoid the hot spot effect, the conventional photovoltaic module adopts 2-3 diodes to protect the battery pieces, wherein the number of the battery pieces protected by each diode is different from 16-24 battery pieces, and when a certain battery piece generates the hot spot effect due to external factors, the design can ensure that the battery piece protected by the conventional photovoltaic module avoids the hot spot effect.

The design that a certain number of battery pieces are connected in parallel by a diode is the most widely applied design scheme in the industry at present, but in the design scheme, the power consumed by the shielded battery pieces when the diode is started reaches a specific value, the diode cannot be started before the value is reached, and when the value is reached, the diode is started and other normal battery pieces protected by the diode are short-circuited, so that the generated energy of the assembly is seriously influenced.

In view of the above, there is a need for an improved photovoltaic module to solve the above technical problems.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a photovoltaic module with can effectively avoid hot spot effect.

In order to realize the purpose of the utility model, the utility model adopts the following technical scheme:

a photovoltaic module comprises a plurality of cell strings arranged at intervals along a first direction, a plurality of bus bars arranged at intervals along a second direction and a bypass diode, wherein each cell string comprises a plurality of cell pieces which are overlapped and connected in series end to end along the second direction perpendicular to the first direction; the bus bar is including connecting in parallel a plurality of the first bus bar of the one end of battery cluster, parallelly connected a plurality of the second bus bar of battery cluster other end, parallelly connected a plurality of battery clusters equipotential battery piece and will the battery cluster divides into the middle bus bar of the equipotential battery piece of at least one interval bus bar of a plurality of substrings, a plurality of substrings of parallelly connected, the bypass diode including connect in first bus bar between the interval bus bar in every two adjacent bus bars of arranging along the second direction in the second bus bar.

The utility model has the advantages that: when the hot spot effect is not obvious but the power of the component is influenced, the intermediate bus bar can greatly reduce the degree of power reduction and the temperature of a defective cell, and the intermediate bus bar is used as first layer protection; when the hot spot effect is serious, the diodes of the plurality of battery pieces can be used as a second layer for protection, and the defective battery pieces and the battery pieces nearby the defective battery pieces are directly protected and are completely short-circuited from the assembly circuit. Therefore, the topological structure of the utility model adds a protection on the basis of the original diode protection, and can protect the photovoltaic component under the condition of the less serious hot spot; the photovoltaic module is very suitable for being applied to roof projects, even if stains and bird droppings exist on the surface of the module and are shielded by the number, high power generation capacity can be still maintained, and meanwhile, the occurrence probability of fire disasters is reduced.

Drawings

Fig. 1 is a schematic view of a front surface of a solar cell according to a preferred embodiment of the present invention;

FIG. 2 is a schematic view of the back side of the solar cell sheet shown in FIG. 1;

fig. 3 is a schematic view of the back side of a solar cell sheet according to another preferred embodiment of the present invention;

fig. 4 is a schematic view of the back side of a solar cell sheet according to another preferred embodiment of the present invention;

FIG. 5 is a schematic diagram of a solar cell slice in any one of FIGS. 1-4 after laser dicing;

fig. 6 is a schematic front view of a photovoltaic module formed by a strip-shaped cell piece obtained by cutting any one of the solar cell pieces in fig. 1 to 4;

FIG. 7 is a schematic view of the back side of a photovoltaic module formed from the diced strip-shaped solar cell pieces of FIG. 2;

FIG. 8 is a schematic view of the back side of a photovoltaic module formed from the diced strip-shaped solar cell pieces of FIG. 3;

FIG. 9 is a schematic view of the back side of a photovoltaic module formed from the diced solar cell pieces of FIG. 4 in the form of strips

FIG. 10 is a schematic view of a buffering structure of the solder strip of the present invention;

fig. 11 is an equivalent circuit schematic diagram of a photovoltaic module.

Wherein 100-photovoltaic module, 1-cell string, 11-cell sheet, 111-front main grid, 112-front fine grid, 113-front anti-breaking grid, 114-back field, 115-back main grid, 116-welding electrode, 12-substring, 2-bus bar, 2 a-front electrode lead-out wire, 2 b-back electrode lead-out wire, 21-first bus bar, 211-i-shaped bus bar, 212-connection solder strip, 22-second bus bar, 23-interval bus bar, 24-middle bus bar, 25-long jumper, 26-short jumper, 27-solder strip, 271-buffer segment, 3-diode, 31-first diode, 32-second diode, 33-third diode, and 200-solar cell slice.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

The present invention will be described in detail below with reference to specific embodiments shown in the drawings. However, these embodiments are not intended to limit the present invention, and structural, methodical, or functional changes that may be made by one of ordinary skill in the art based on these embodiments are all included in the scope of the present invention.

In the various drawings of the present invention, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for ease of illustration, and thus, are used only to illustrate the basic structure of the subject matter of the present invention.

Referring to fig. 6 to 11, a photovoltaic module 100 according to a preferred embodiment of the present invention includes a plurality of battery strings 1 arranged at intervals along a first direction, a plurality of bus bars 2 connected in parallel to the plurality of battery strings 1, and a bypass diode 3 for protecting the battery strings 1.

Referring to fig. 1 to 10, specifically, the battery string 1 includes a plurality of battery pieces 11 arranged in a second direction, and connected in series with overlapping end to end, where the second direction is perpendicular to the first direction.

The battery pieces 11 can be strip-shaped battery pieces 11 obtained by dividing the whole single-piece single-crystal or polycrystalline solar battery piece 200 shown in fig. 1-5 into 6 pieces, for example, the solar battery piece 200 with 156mm × 156mm is divided into 6 strip-shaped battery pieces 11, and then the battery string 1 is formed by overlapping and serially connecting 48-84 strip-shaped battery pieces 11 end to end, and preferably, the number of the battery pieces 11 in the battery string 1 is an integral multiple of 6, that is, the battery pieces 11 formed by dividing a plurality of solar battery pieces 200 are serially connected to form one battery string 1, so that the layout operation is easy.

The front side of the battery piece 11 comprises a front side main grid 111 positioned at one long edge, a front side fine grid 112 positioned at one side of the front side main grid 111, and a front side breakage-proof grid 113 connected with the front side fine grid 112, wherein the front side fine grid 112 is perpendicular to the front side main grid 111. The back surface of the battery piece 11 comprises a back surface field 114 and a back surface main grid 115 positioned at the other long edge; the front main grid 111 and the back main grid 115 are respectively located at two long edges of the strip-shaped battery piece 11, so that the adjacent battery pieces 11 are connected in series in an overlapped mode in an end-to-end mode through conductive adhesive.

In a specific embodiment, the front main grid 111 is a solid or hollow structure, and the width of the front main grid 111 is 0.05mm to 1 mm; the back main grid 115 is a solid line or a segmented structure, the width of the back main grid 115 is greater than that of the front main grid 111, and the overlapping width of the adjacent battery pieces 11 along the second direction is generally set to be 0.5 mm-2 mm.

Referring to fig. 6 to 11, the plurality of bus bars 2 are disposed at intervals along the second direction, and the bus bars 2 include a first bus bar 21 connected in parallel to one end of the plurality of battery strings 1, a second bus bar 22 connected in parallel to the other end of the plurality of battery strings 1, at least one section bus bar 23 connected in parallel to the medium-potential battery pieces 11 in the plurality of battery strings 1, and at least one intermediate bus bar 24.

The front electrode lead wires 2a of the battery pieces 11 located at one end of the battery string 1 are welded to the first bus bar 21; the back electrode lead wire 2b of the cell piece 11 at the other end is welded to the second bus bar 22; the interval bus bar 23 is welded with the equipotential battery pieces 11 positioned in the middle of the battery string 1, the battery string 1 is divided into a plurality of sub strings 12, and the sub strings 12 comprise 16-24 battery pieces 11; the middle bus bar 24 is connected with the equipotential battery pieces 11 of the plurality of sub-strings 12 in parallel; all the bus bars 2 together form a special circuit topology.

Through interval busbar 23, middle busbar 24 connects a plurality of battery cluster 1 in parallel to when certain battery piece 11 appears the hot spot or other unusual and leads to the resistance increase, the electric current that flows through this battery piece 11 can shunt to other battery pieces 11 through busbar 2, can greatly reduce because of the subassembly power decline that shadow sheltered from or battery piece 11 hidden split causes, and the hot spot effect of defect battery piece 11 also greatly reduces simultaneously, improves subassembly reliability and outdoor generated energy.

Further, the sub-string 12 comprises 16 to 24 battery pieces 11, as shown in fig. 2 and 7, one battery piece 11 in every 6 battery pieces 11 in the sub-string 12 is connected in parallel with the equipotential battery pieces 11 of the other sub-strings 12 through the intermediate bus bar 24; or as shown in fig. 3 and 8, one cell 11 in every 3 cells 11 in the sub-strings 12 is connected in parallel with the equipotential cells 11 of the other sub-strings 12 through the intermediate bus bar 24; or as shown in fig. 4 and fig. 9, each cell 11 in the sub-strings 12 is connected in parallel with the equipotential cells 11 of the other sub-strings 12 through the intermediate bus bar 24. The more the number of the intermediate bus bars 24 is, the more complicated the topological structure is, the better the overall protection effect on the battery pieces 11 is, but the assembly cost and the product reject ratio are also increased correspondingly, so that preferably, none of the 3 battery pieces 11 is connected in parallel with the equipotential battery pieces 11 of the other sub-strings 12 through the intermediate bus bars 24.

Specifically, the back surface of at least part of the battery piece 11 is provided with a plurality of welding electrodes 116 arranged at intervals along a first direction; the inter-zone bus bar 23 and the intermediate bus bar 24 are electrically connected to the cell piece 11 having the welding electrode 116. The width of the welding electrode 116 along the first direction is 1mm to 5mm, and the width of the welding electrode 116 along the second direction is 3mm to 5mm, so that the welding electrode is suitable for various commonly used welding strips.

Preferably, along the first direction, a plurality of the battery strings 1 are aligned end to end, and the arrangement sequence of the battery pieces 11 with the welding electrodes 116 in any battery string 1 is the same, so that the equipotential battery pieces 11 in different battery strings 1 are connected in parallel through the linear bus bars 2. Taking the photovoltaic module 100 with 6 cell strings 1 as an example, in the extending direction from one end of the cell string 1 to the other end along the second straight line, the welding electrode 116 is disposed on the nth cell piece 11 in each cell string 1.

In an embodiment, the first bus bar 21 includes an i-shaped bus bar 211 electrically connected to each battery string 1, and a connection welding strip 212 for welding two adjacent i-shaped bus bars 211 between adjacent battery strings 1, so as to prevent the welded portion of the first bus bar 21 and the battery piece 11 from being separated when the adjacent battery strings 1 are relatively displaced. Wherein, the thickness of the I-shaped bus bar 211 is 0.07 mm-0.2 mm.

The second bus bar 22, the inter-zone bus bar 23, and the intermediate bus bar 24 are linear solder strips 27, such as tin-plated copper solder strips, which facilitate alignment welding with the battery cells 11. In addition, the solder ribbon 27 includes buffer sections 271 between the adjacent battery strings 1; in one embodiment, the buffering section 271 is V-shaped; preferably, the height of the buffer segment 271 is 0.3 mm-0.5 mm; the welding part of the welding strip 27 and the battery plate 11 is prevented from being separated when the adjacent battery strings 1 are relatively displaced.

The bypass diode 3 includes a diode 3 connected by a jumper wire between every two adjacent bus bars 2 arranged in the second direction among the first bus bar 21, the section bus bar 23, and the second bus bar 22.

Referring to fig. 6 to 11, in an embodiment, the bus bars 2 include a first bus bar 21, at least one intermediate bus bar 24, a first section bus bar 23, at least one intermediate bus bar 24, a second section bus bar 23, at least one intermediate bus bar 24, and a second bus bar 22, which are sequentially arranged along the second direction at intervals, and the first section bus bar 23 and the second section bus bar 23 divide each of the battery strings 1 into three sub strings 12.

The bus bar 2 further comprises a long jumper 25 and a short jumper 26, an insulating plate is arranged between the long jumper 25 and the short jumper 26 and the interval bus bar 23, one end of the long jumper 25 is connected to the first bus bar 21, the other end of the long jumper is connected to the second bus bar 22, and the position where the long jumper 25 meets the first interval bus bar 23 penetrates through an opening in the insulating plate to be electrically connected with the first interval bus bar 23; one end of the short jumper wire 26 is connected to the second bus bar 22, and the other end thereof passes through an opening formed in the insulating plate and is connected to the second section bus bar 23.

The bypass diode 3 comprises 3 diodes 3 connected to the bus bar 2 via long jumper wires 25 and short jumper wires 26, and the diodes are respectively: a first diode 31 connected between the first bus bar 21 and the first block bus bar 23 for protecting the substring 12 between the first bus bar 21 and the first block bus bar 23; a second diode 32 connected between the first block bus bar 23 and the second block bus bar 23 for protecting the substring 12 between the first block bus bar 23 and the second block bus bar 23; a third diode 33 connected between the second block bus bar 23 and the second bus bar 22 for protecting the substring 12 between the second block bus bar 23 and the second bus bar 22; wherein the first diode 31 is located in a junction box disposed at the first bus bar 21, and the second diode 32 and the third diode 33 are both disposed in a junction box disposed at the second bus bar 22.

In the circuit design of the conventional photovoltaic module 100, if a certain cell in the cell string 1 generates a hot spot effect, the current thereof can only flow from the tail of the string to the head of the string, and the hot spot effect is serious. On the basis of the existing circuit design of the photovoltaic module 100, the utility model additionally adds the middle bus bar 24 which connects the equipotential battery pieces 11 of the plurality of sub-strings 12 in parallel, if the hot spot effect does not occur, the middle bus bar 24 does not have current to pass through, so that the module power is not reduced, and the module power is slightly improved; if the module generates hot spot effect when generating electricity outdoors, the intermediate bus bar 24 provides more current paths for the current because the current follows the principle of the path with the lowest resistance, and ensures that the current has other feasible paths, thereby enabling the current to avoid the battery piece 11 generating the hot spot, reducing the hot spot effect and achieving the purpose of increasing the generated energy.

Meanwhile, when the hot spot effect is not obvious but the power of the assembly is affected, the intermediate bus bar 24 greatly reduces the degree of power reduction and the temperature of the defective cell 11, and serves as a first layer of protection; when the hot spot effect is serious, the diodes 3 of the plurality of battery pieces 11 can be used as a second layer for protection, and the defective battery pieces 11 and the battery pieces 11 nearby the defective battery pieces 11 are directly protected and completely short-circuited from the assembly circuit. Therefore, the topological structure of the utility model adds a protection on the basis of the original diode 3 protection, and can protect the photovoltaic module 100 under the condition of the less serious hot spot; the photovoltaic module 100 is very suitable for being applied to roof projects, and even if stains, bird droppings and the number of the components are covered on the surface of the module, high power generation can be maintained, and meanwhile, the occurrence probability of fire disasters is reduced.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above list of details is only for the practical implementation of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent implementations or modifications that do not depart from the technical spirit of the present invention should be included in the scope of the present invention.

Claims

1. A photovoltaic module, comprising:

the battery strings are arranged at intervals along a first direction and comprise a plurality of battery pieces which are overlapped and connected in series end to end along a second direction perpendicular to the first direction;

the bus bars comprise first bus bars connected with one ends of the battery strings in parallel, second bus bars connected with the other ends of the battery strings in parallel, and at least one interval bus bar connected with the equal-potential battery pieces in the battery strings in parallel, and the interval bus bar divides the battery strings into a plurality of sub-strings;

a bypass diode including a diode connected between every adjacent two of the first bus bar, the section bus bar, and the second bus bar arranged in the second direction;

the bus bar is characterized by further comprising a middle bus bar of the equipotential battery pieces, wherein the middle bus bar is connected with a plurality of substrings in parallel.

2. The photovoltaic module of claim 1, wherein: and each battery piece in the sub-string, or every 3 battery pieces, or every 6 battery pieces is connected with the equipotential battery pieces of other sub-strings in parallel through the middle bus bar.

3. The photovoltaic module of claim 1 or 2, wherein: and a plurality of welding electrodes arranged at intervals along a first direction are arranged on the back of part of the battery pieces, and the interval bus bar and the middle bus bar are electrically connected with the welding electrodes.

4. The photovoltaic module of claim 3, wherein: the battery strings are aligned end to end, and the arrangement sequence of the battery pieces with the welding electrodes in any battery string is the same.

5. The photovoltaic module of claim 3, wherein: the width of the welding electrode along the first direction is 1 mm-5 mm, and the width of the welding electrode along the second direction is 3 mm-5 mm.

6. The photovoltaic module of claim 1, wherein:

the bus bars comprise first bus bars, at least one middle bus bar, a first interval bus bar, at least one middle bus bar, a second interval bus bar, at least one middle bus bar and second bus bars which are sequentially arranged along a second direction at intervals;

the bypass diode includes a first diode connected between the first bus bar and the first section bus bar, a second diode connected between the first section bus bar and the second section bus bar, and a third diode connected between the second section bus bar and the second section bus bar.

7. The photovoltaic module of claim 6, wherein: the bus bar further includes:

the long jumper is provided with an insulating plate between the long jumper and the interval bus bar and between the long jumper and the intermediate bus bar, one end of the long jumper is connected to the first bus bar, the other end of the long jumper is connected to the second bus bar, and the position where the long jumper is intersected with the first interval bus bar penetrates through an opening in the insulating plate to be electrically connected with the first interval bus bar;

the short jumper wire with interval busbar have the insulation board between the middle busbar, short jumper wire one end connect in the second busbar, the other end pass set up the opening on the insulation board connect in the interval busbar of second.

8. The photovoltaic module of claim 1, wherein: the first bus bar comprises an I-shaped bus bar electrically connected with each battery string and a connecting welding strip for welding two adjacent I-shaped bus bars between the adjacent battery strings.

9. The photovoltaic module of claim 1, wherein: the interval bus bar the middle bus bar are welding strips, and the welding strips comprise buffer sections located between adjacent battery strings.

10. The photovoltaic module of claim 9, wherein: the buffer section is V-shaped; the height of the buffer section is 0.3 mm-0.5 mm.