Back contact solar cell module structure with low hot spot temperature

Abstract

The utility model discloses a back contact solar cell module structure with low hot spot temperature, which is characterized by comprising an even number of back contact solar cells without main grids or with symmetrically distributed main grids, and the back contact solar cells are centrally cut into two half cells along the direction vertical to fine grids. The half cells are welded in series to form a cell string along the long edge direction of the half cells through interconnecting strips, and the cell string is arranged in a laminated manner and packaged to form the solar cell module. According to the utility model, by changing the arrangement and series connection structure of the battery assembly, the heating value of the hot spot battery is nearly halved, the hot spot temperature and the packaging failure risk are greatly reduced, and the used interconnecting strip can be widened according to the series connection length of the half-piece battery so as to reduce the power loss caused by the current stroke increased by vertically cutting the half-piece series connection; and the front power is not influenced.

Description

TECHNICAL FIELD

[0001] The utility model relates to solar cell technical field especially relates to a low heat spot temperature's back contact solar cell module structure. BACKGROUND

[0002] The heat spot resistance is the key index for measuring the safety of the module product. The heat spot is that the photovoltaic module is caused by the quality problem of the cell piece breaking, hidden crack, welding or the local shielding reason such as shadow, bird dropping, dust, and the problematic cell piece is taken as the load to consume the energy generated by the other cell pieces in series, thereby making the local temperature rise. The occurrence of the heat spot not only will influence the power generation performance and service life of the module, but also will make the packaging material melt and deform or burn out, and even will cause fire, seriously threatening the stability and safety of the photovoltaic power generation system.

[0003] In the prior art of the back contact solar cell module, the back contact solar cell is cut into half solar cell by laser scribing in the direction of parallel fine grid line, and then is series connected into a cell string along the vertical cutting direction, and then is stacked and arranged, and finally is packaged into a solar cell module. Figures 1-3 According to the conventional half solar cell module electrical schematic diagram, the number of cell pieces connected in parallel with one diode is the number of cell pieces of two cell strings, and the number of cell pieces connected in parallel with one diode is 24 pieces for the 144 half solar cell version (72 version) and is 26 pieces for the 156 half solar cell version (78 version).

[0004] Specifically, the actual heat spot temperature of the module has little to do with the current size, and is mainly related to the number of bypass diode parallel cell pieces and the leakage current, the more the number of bypass diode parallel cell pieces, the greater the cell leakage current, and the higher the temperature of the shaded cell, and the greater the risk of heat spot. INVENTION CONTENTS

[0005] In view of the above problems, the utility model provides a low heat spot temperature back contact solar cell module structure, which reduces the heat spot temperature and the packaging failure risk by nearly halving the heat generation of the heat spot cell.

[0006] To solve the above technical problems, the utility model adopts the technical scheme, a low heat spot temperature's back contact solar cell module structure, including the back contact solar cell of even number of main grid or main grid symmetry distribution and quantity, the back contact solar cell is cut into two half piece cells along the vertical fine grid direction in the middle, the half piece cell is connected in series along the half piece cell long side direction by interconnecting strip and is arranged in laminated, and is packed into solar cell module.

[0007] Further, the interconnecting strip is arranged on the back of the half piece cell, and the width of the interconnecting strip is set according to the series length of the half piece cell.

[0008] Further, the number of pieces of the solar cell module in parallel connection with a diode is half of the number of pieces of the conventional half piece cell module structure in parallel connection with a single diode.

[0009] From the above description of the structure of the utility model, compared with the prior art, the utility model has the following advantages:

[0010] The utility model changes the arrangement and series connection structure of the battery module, the heat generation of the hot spot battery is close to halving, the hot spot temperature and the packaging failure risk are greatly reduced, the interconnecting strip used can be widened according to the series length of the half piece cell to reduce the power loss caused by the increase of the current stroke of the vertical cutting half piece series connection, and the front power is not affected. BRIEF DESCRIPTION OF DRAWINGS

[0011] The drawings that form a part of this application are used to provide further understanding of the utility model, and the illustrative embodiment of the utility model and its description are used to explain the utility model, and do not constitute improper limitation on the utility model. In the drawings:

[0012] Figure 1 It is the half piece cell series structure schematic diagram of the prior art back contact solar cell module;

[0013] Figure 2 It is the electrical schematic diagram of the prior art back contact solar cell module;

[0014] Figure 3 It is the structure schematic diagram of the prior art back contact solar cell module;

[0015] Figure 4 It is the half piece cell series structure schematic diagram of the embodiment of the utility model;

[0016] Figure 5 It is the electrical schematic diagram of the embodiment of the utility model;

[0017] Figure 6 It is the module structure schematic diagram of the embodiment of the utility model. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical scheme and advantages of the utility model clearer and more apparent, the utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0019] Embodiment

[0020] Reference Figures 1-6 A low hot spot temperature back contact solar cell module structure, the back contact solar cell 1 is cut into half piece battery 12 in the vertical fine grid 2 direction, the fine grid is disconnected in the middle position of the battery, leaving the space of cutting half piece, preventing cutting from being continuous or short circuit. The main grid 3 is symmetrically distributed, the number is even, that is, there is no main grid 3 at the cutting position. Or the battery finished product itself is half piece battery 12, the long side of half piece battery 12 is perpendicular to the fine grid 2 direction and parallel to the main grid 3 direction, if the battery is designed without main grid, the main grid 3 is ignored, the half piece battery is connected in series along the long side direction of the battery using the interconnection strip 4 to form the battery string 6, and finally encapsulated into the back contact solar cell module of the patent structure.

[0021] The interconnection strip is arranged on the back of the half piece battery, the back interconnection strip is widened without affecting the front power, and the width of the interconnection strip is set according to the series length of the half piece battery, so as to reduce the power loss caused by the current journey of the vertical cutting half piece series.

[0022] The number of the half piece battery module structure is half of the number of the single diode parallel piece in the conventional half piece battery module structure, and the number of the battery piece connected in parallel by one diode of the solar cell module technology is 12 pieces.

[0023] The theoretical formula of the heat generation of the hot spot battery is: total heat generation of the hot spot battery P=Vrev·Iph+Vrev·Irev = (n-1) Vcell·Iph+ (n-1) Vcell·Irev

[0024] n is the number of parallel pieces of bypass diodes; V rev V is the reverse bias voltage of the shaded battery; I rev I is the reverse bias leakage current; I ph V is the photo-generated current of the shaded battery; V cell V is the working voltage of the single battery piece.

[0025] According to the comparison between the electrical schematic diagram of the embodiment and the conventional half piece battery module, the number of the half piece battery module structure is half of the number of the single diode parallel piece in the conventional half piece battery module structure, which greatly reduces the reverse bias voltage V rev of the battery when the hot spot is generated. revThe heat quantity of the hot spot battery is close to halving, according to the heat quantity formula of the hot spot and theory, V rev The heat quantity is halved, the temperature of the hot spot is greatly reduced, the reliability of the module is improved, the service life of the module is prolonged, the risk of the battery reverse bias breakdown is greatly reduced after the reverse bias voltage Vrev is greatly reduced, the local breakdown and burning risk are reduced.

[0026] The utility model discloses a battery module and a battery module manufacturing method, and the heat quantity of the hot spot battery is close to halving through changing the arrangement and series structure of the battery module, the temperature of the hot spot and the packaging failure risk are greatly reduced, the interconnection strip used can be widened according to the series length of the half battery to reduce the power loss caused by the current journey of the vertical cutting half piece series, and the front power is not affected.

[0027] The above only is the preferred embodiment of the utility model, and does not use to limit the utility model, and any modification, equivalent replacement and improvement etc. that are made within the spirit and principle of the utility model should be included in the protection scope of the utility model.

Claims

1. A back contact solar cell module structure with low hot spot temperature, characterized by: The back contact solar cell includes no main grid or main grid symmetrically distributed and even number, the back contact solar cell is cut into two half cells along the vertical fine grid direction, the half cells are series connected by interconnecting strips along the half cell long edge direction, and are stacked and arranged to encapsulate a solar cell module.

2. The low hot-spot temperature back contact solar cell module structure of claim 1, wherein: The interconnecting strips are arranged on the back surface of the half cells, and the width of the interconnecting strips is arranged according to the series length of the half cells.

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