A crystalline silicon cell, a photovoltaic module and a photovoltaic power generation system

Abstract

The application discloses a crystalline silicon cell, a photovoltaic module and a photovoltaic power generation system, and belongs to the field of ground crystalline silicon solar modules. In view of the problem that, in the prior art, local current enrichment is caused by local connection failure of cell interconnection, local high temperature is generated, the power of the module is reduced, the power generation capacity is reduced, the module is seriously burned to cause a fire, and the consequences are very serious, the application provides a crystalline silicon cell, a photovoltaic module and a photovoltaic power generation system. The crystalline silicon cell comprises silver grid lines, a substrate, a doped region and a back field, the silver grid lines on the upper layer of the doped region are divided into a plurality of regions, and the design of the grid line division reduces current enrichment on the non-failed conductive interconnection material when part of the conductive interconnection material fails. The application reduces the problem of local current enrichment caused by local connection failure of cell interconnection in the crystalline silicon photovoltaic module, and improves the safety of the photovoltaic power generation system.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of crystalline silicon solar modules for ground use, more particularly to a crystalline silicon cell, a photovoltaic module and a photovoltaic power generation system. BACKGROUND

[0002] With the improvement of the efficiency of photovoltaic modules, high-power modules have become the mainstream of the market. While people are pursuing high-efficiency modules, they have not done a good job of protecting safety issues, and the safety problems of photovoltaic module power generation systems have become increasingly prominent. In recent years, there have been many reports of accidents in photovoltaic module power generation systems, especially in distributed power generation systems. Among the accidents in photovoltaic power generation systems, a class of accidents caused by partial connection failure of the internal cell pieces of the module accounts for a significant proportion, which is characterized by local backboard bulging, burning spots or burning.

[0003] The application is illustrated by taking the application of the current market mainstream P-type cell piece in a shingled module as an example. As shown in Figure 4 is the structure of the mainstream P-type cell piece, the upper layer of the P region base of the cell piece is sequentially the N-doped region and the silver grid line, and the lower layer of the P region base is sequentially the back field and the silver grid line. The silver grid line is divided into a main grid and a sub-grid. Each main grid is connected to a plurality of sub-grids on one side or both sides uniformly or non-uniformly.

[0004] As shown in Figure 5 is a shingled cell string, which includes a plurality of cell pieces. Each cell piece includes a main grid and a sub-grid. Each main grid is connected to a plurality of sub-grids on one side or both sides uniformly or non-uniformly. The shingled technology connects the cell pieces with conductive glue. The conductive glue is arranged on the silver grid line. The shingled technology eliminates the soldering of solder strips, reduces the shading area and line loss, and saves space.

[0005] If a cell piece in the shingled cell string has partial conductive glue connection failure, as shown in the left dashed box in Figure 6 , the current of the entire cell string will not be significantly reduced. As shown in Figure 7 , the carriers in the left cell piece can be transmitted through the N-doped layer interlayer and the P layer interlayer to the right side to be collected. As shown in Figure 6 and Figure 7 , the current collected by the silver grid line on the left side of the cell piece is transmitted to the non-failed part of the conductive glue on the right side through the silver grid line interconnection structure. In this way, the output current of the cell piece is approximately equal to the output current when there is no partial conductive glue connection failure, and the output current of the entire cell string is also approximately equal to the string output current when there is no partial conductive glue connection failure. Such a design is to enable the cell piece to still output higher power when there is local connection failure. However, such a design also brings safety risks. As shown in Figure 6 and Figure 7As shown, when the conductive glue on the left side of the battery piece fails, the conductive glue on the right side of the battery piece bears the current transmission of the whole battery piece, that is, the current density through the right side conductive glue increases. Assuming that a single battery piece has N conductive glue connection points, if N-1 conductive glue connection points fail, then the remaining intact conductive glue connection points will pass through approximately N times the current under normal circumstances. Due to the existence of a certain resistance in the main grid and the auxiliary grid interconnection structure, the current will be slightly lost. Such current enrichment will cause the battery piece to have a local backboard bulge, burning point or burnout, etc. safety risks. SUMMARY

[0006] 1. Technical problem to be solved

[0007] In view of the problem of local current enrichment caused by local connection failure of battery piece interconnection in the prior art, local high temperature is generated, which reduces the power of the assembly and reduces the power generation, and in severe cases, it will burn the assembly and cause a fire, etc. The consequences are very serious. The present application provides a crystalline silicon battery, a photovoltaic module and a photovoltaic power generation system, which can reduce the problem of local current enrichment caused by local connection failure of battery piece interconnection in the crystalline silicon photovoltaic module, improve safety, protect the safety of photovoltaic users' personal property, and promote the healthy development of photovoltaic power generation system.

[0008] 2. Technical solution

[0009] The purpose of the present application is achieved by the following technical solutions.

[0010] A crystalline silicon battery, comprising a grid line, a substrate, a doped region and a back field, the upper layer of the substrate is the doped region, the substrate and the doped region form a PN junction, the lower layer of the substrate is the back field, the upper layer of the doped region and the lower layer of the back field are the grid line, the grid line on the upper layer of the doped region is composed of a plurality of regions, and each region is arranged with a spacing. There is no connection between the separated grid lines, and the grid line is a very good conductor.

[0011] Further, the number of grid line regions arranged with a spacing is not less than two. The number of segmented regions of the grid line and the separation distance are not limited, the distance between the grid lines in the separation region is related to the sheet resistance of the doped layer, the smaller the sheet resistance of the doped layer, the greater the distance between the grid lines in the separation region, and the separation grid line pattern has no requirement, and need not be equally divided.

[0012] According to the analysis of a limited number of experiments:

[0013] If the width of the cut battery piece is about 40mm;

[0014] For a doped layer with a sheet resistance less than 60Ω / □, the distance between the grid lines in the separation region is about 10mm;

[0015] For a doped layer with a sheet resistance greater than or equal to 60Ω / □ and less than 120Ω / □, the distance between the grid lines in the separation region is about 6mm;

[0016] For the sheet resistance of the doped layer greater than or equal to 120 Ω / □, the distance between the grid lines of the separation area is about 4 mm.

[0017] If the width of the cut battery piece is about 80 mm;

[0018] For the sheet resistance of the doped layer less than 60 Ω / □, the distance between the grid lines of the separation area is about 20 mm;

[0019] For the sheet resistance of the doped layer greater than or equal to 60 Ω / □ and less than 120 Ω / □, the distance between the grid lines of the separation area is about 12 mm;

[0020] For the sheet resistance of the doped layer greater than or equal to 120 Ω / □, the distance between the grid lines of the separation area is about 8 mm.

[0021] Ω / □ is the unit of sheet resistance, 1 Ω / □ is 1 sheet resistance. If the battery piece is stacked with SE technology, the SE pattern needs to shield the separation area, the separation area does not need to be heavily doped, and if the battery piece uses a TCO film to collect carriers, such as a heterojunction battery, the separation area cannot use a TCO film.

[0022] Further, the battery includes a cut piece assembly. Because increasing the distance between the separation grid lines will cause a certain loss of battery efficiency, the present application is more suitable for an assembly using a cut small piece, and the loss of battery efficiency is caused by the reduction of the number of collected carriers due to the grid line distance at the battery grid line separation place. The efficiency loss caused by the present design is due to the increase of the grid line distance of the separation area and the lack of communication between the left and right, and the photo-generated carriers of the separation area cannot be effectively collected by the grid line, causing current loss. The present application is more suitable for a cut small piece assembly because the width of the cut small piece is small, and the separation area does not need too much distance to effectively block the current communication between the left and right parts. For a cut small piece assembly battery, the current loss has little effect.

[0023] Further, the battery is a shingled battery, a tiled battery, or a half-piece battery. The present application is suitable for all crystalline silicon solar cells that cause current local enrichment due to the local connection failure of the internal battery piece interconnection of the assembly.

[0024] Further, the grid lines are divided into main grid lines and auxiliary grid lines, and the main grid lines are provided with conductive interconnection materials. The main grid lines of the shingled battery are provided with conductive glue, and the main grid lines of the half-piece battery or the tiled battery are provided with solder strips.

[0025] Further, the substrate is a P-type or N-type substrate.

[0026] Further, the doped area is an N-type or P-type doped area. The substrate and the doped area form a PN junction, and the PN junction is conductive to form current.

[0027] A photovoltaic module, comprising the crystalline silicon cell, the cell is connected in series and parallel to form a photovoltaic module circuit.

[0028] Further, the photovoltaic module comprises a plurality of main grids, and each main grid is connected with a plurality of sub-grids on one side or both sides uniformly or non-uniformly.

[0029] A photovoltaic power generation system, comprising a photovoltaic module, a controller and a load, the photovoltaic module is connected with the controller to provide electric energy, and the controller controls the current flowing to the load.

[0030] Further, the load comprises a direct current load and an alternating current load.

[0031] 3. Beneficial effects

[0032] Compared with the prior art, the photovoltaic module has the following advantages:

[0033] The silver grid line connected with the doped region in the cell structure is designed to be divided into a plurality of regions, and the number of divisions is not limited. When the conductive interconnection material connected with the silver grid line is partially failed, only a small amount of current of the failed conductive interconnection material can pass through the unfailed conductive interconnection material. The current density passing through the unfailed conductive interconnection material is not much different from that when the conductive interconnection material is not failed. The current local enrichment caused by the partial connection failure of the interconnection between the cell pieces in the module can be reduced, the problems such as bulging and heating caused by current enrichment can be reduced, and the safety of the photovoltaic power generation system is improved. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 Equivalent simplified circuit for solar photovoltaic cell;

[0035] Figure 2 Equivalent simplified circuit for photovoltaic module comprising series-parallel structure;

[0036] Figure 3 Flowchart of output electric energy of photovoltaic power generation system circuit;

[0037] Figure 4 Main P-type cell structure diagram;

[0038] Figure 5 Imbricated cell string schematic diagram;

[0039] Figure 6 Imbricated cell string partial conductive glue connection failure schematic diagram;

[0040] Figure 7 Imbricated cell string partial conductive glue connection failure current flow schematic diagram;

[0041] Figure 8 Cell structure diagram of segmented main and sub-grid design of the present application;

[0042] Figure 9 For Figure 8 the detailed equivalent circuit diagram of the refinement;

[0043] Figure 10 For the schematic diagram of the imbricated cell string of the segmented main and auxiliary grid structure battery of the present application;

[0044] Figure 11 For the schematic diagram of the partial conductive glue connection failure in the imbricated cell string of the segmented main and auxiliary grid structure battery of the present application;

[0045] Figure 12 For the schematic diagram of the current flow after the partial conductive glue connection failure in the imbricated cell string of the segmented main and auxiliary grid structure battery of the present application;

[0046] Figure 13 For the detailed equivalent circuit diagram of the refinement after the partial conductive glue connection failure in the segmented main and auxiliary grid design battery of the present application;

[0047] Figure 14 For the schematic diagram of the half cell of the prior art;

[0048] Figure 15 For the schematic diagram of the partial solder strip failure of the half cell of the segmented grid line of the present application;

[0049] Figure 16 For the schematic diagram of the partial solder strip failure of the half cell string of the segmented grid line of the present application.

[0050] Explanation of the reference numerals in the drawing: 1, silver grid line; 2, N-doped region; 3, P region base; 4, back field; 5, main grid; 6, auxiliary grid; 7, cell piece; 8, conductive glue. DETAILED DESCRIPTION

[0051] The present application will be described in detail below in conjunction with the drawing and specific examples.

[0052] Examples

[0053] The equivalent simplified circuit diagram of the solar photovoltaic cell is shown in Figure 1 The battery circuit includes a battery parallel resistance Rsh, a series resistance Rs, an equivalent diode and a current source, the parallel resistance Rsh, the current source and the diode are all in parallel, and the series resistance Rs is in series with the parallel parallel resistance Rsh, the current source and the diode, Figure 1 is the equivalent circuit diagram of a standard cell piece 7, the resistance Rs here includes all the series resistances inside the battery, and in Figure 1In the circuit shown, the base resistance, the resistance of the doped region and the resistance of the gate line are all in series, and are collectively planned as Rs. In the current photovoltaic power generation system, when the local connection of the interconnection of the internal battery piece 7 of the assembly fails, the current of the battery string where the failure occurs does not decrease significantly compared with the current before the failure, at this time the current of the entire string flows through the non-failed connection, that is, the current density of the non-failed part increases, forming current enrichment, which can cause local overheating.

[0054] The present application is applicable to all crystalline silicon solar cells caused by the problem of local current enrichment caused by the local connection failure of the interconnection of the internal battery piece 7 of the assembly. The present embodiment takes the application of the current market mainstream P-type battery piece 7 in the shingled assembly as an example to illustrate the prior art battery piece 7 as shown in Figure 4 The mainstream P-type battery piece 7 structure is shown, the upper layer of the P region base 3 of the battery piece 7 is sequentially provided with an N doped region 2 and a silver gate line 1, the lower layer of the P region base 3 is sequentially provided with a back field 4 and a silver gate line 1, the silver gate line 1 is divided into a main grid 5 and a sub-grid 6, and each main grid 5 is uniformly or non-uniformly connected with a plurality of sub-grids 6 on one side or both sides.

[0055] As shown in Figure 5 The shingled battery string includes a plurality of battery pieces 7, the battery piece 7 includes a main grid 5 and a sub-grid 6, and the shingled technology interconnects the battery pieces 7 by using conductive glue 8, the conductive glue 8 is arranged on the silver gate line 1 connected with the N doped region 2, the shingled technology omits soldering of solder strips, reduces shading area and line loss, and saves space.

[0056] As shown in Figure 6 and Figure 7 When the left side part of the conductive glue 8 of the battery piece 7 is connected to fail, the carriers on the left side of the battery piece 7 are transmitted between the N doped layer 2 and the P layer base 3, and are collected on the right side, and are transmitted to the non-failed part of the conductive glue 8 on the right side; in this way, even if the conductive glue 8 fails, the output current of the battery is approximately the same as the current when the conductive glue 8 does not fail, and even if the conductive glue 8 fails, a higher power can still be output, but the non-failed conductive glue 8 passes through a current multiple of the normal value, and the current enrichment can cause the battery piece 7 to have a local back plate bulge, burning point or burnout and other safety risks, Figure 6 In the B of the sub-grid interconnection structure of the grid line, the sub-grid interconnection prevents the battery from being damaged by the broken grid, and the current can flow through the interconnection structure after the grid is broken, without affecting the use of the battery.

[0057] The present embodiment designs a battery for preventing local current enrichment of a crystalline silicon photovoltaic assembly, the battery piece 7 adopts a separated main and sub-grid design, and the problem of local current enrichment caused by the local connection failure of the interconnection of the internal battery piece 7 of the assembly is reduced.

[0058] As shown in Figure 8The battery structure is a segmented main and auxiliary grid design. The P region base 3 of the battery piece 7 has, in order, an N doped region 2 and a silver grid line 1 on the upper layer, and has, in order, a back field 4 and a silver grid line 1 on the lower layer. The silver grid line 1 is divided into a main grid 5 and an auxiliary grid 6. Each main grid 5 is connected to several auxiliary grids 6 on one side or both sides uniformly or non-uniformly. Figure 8 As shown in part A, part A represents the silver grid line 1 separation in the battery piece 7 of the embodiment, which is divided into left and right parts in this embodiment. The left and right silver grid lines 1 are not connected to each other. The separation shape and type of the silver grid line 1 are not limited by the present application. The separation distance and shape can be adjusted according to different situations.

[0059] The detailed equivalent circuit diagram of the embodiment is shown in Figure 9 The battery circuit after separation includes a left battery internal circuit, a right battery internal circuit, a separation zone N doped layer interlayer transmission resistance Rs1, a separation zone P layer interlayer transmission resistance Rs2, a left silver grid line interline transmission resistance Rs3, and a right silver grid line interline transmission resistance Rs4. The contact resistance and bulk resistance of the left conductive adhesive 8 are unified as Rs5, and the contact resistance and bulk resistance of the right conductive adhesive 8 are unified as Rs6. The left battery internal circuit and the right battery internal circuit have the same structure, both including a battery internal parallel resistance Rsh, an equivalent diode, and a current source. The battery internal parallel resistance Rsh, the equivalent diode, and the current source are connected in parallel. The left battery internal circuit and the right battery internal circuit are connected in parallel. The two ends of the separation zone N doped layer interlayer transmission resistance Rs1 are connected to the left battery internal circuit and the right battery internal circuit, respectively. The two ends of the separation zone P layer interlayer transmission resistance Rs2 are also connected to the left battery internal circuit and the right battery internal circuit, respectively. That is, the separation zone P layer interlayer transmission resistance Rs2 is connected in parallel with the separation zone N doped layer interlayer transmission resistance Rs1. The left silver grid line interline transmission resistance Rs3 is connected to the connection point of the left battery internal circuit, the separation zone N doped layer interlayer transmission resistance Rs1, and the separation zone P layer interlayer transmission resistance Rs2. The right silver grid line interline transmission resistance Rs4 is connected to the connection point of the right battery internal circuit, the separation zone N doped layer interlayer transmission resistance Rs1, and the separation zone P layer interlayer transmission resistance Rs2. The separation zone P layer interlayer transmission resistance Rs1 is much larger than the separation zone N doped layer transmission resistance Rs2, which is much larger than the left / right silver grid line interline transmission resistance Rs3 and Rs4, that is, Rs2>>Rs1>>Rs3=Rs4.

[0060] Figure 10 The shingled battery string of the battery with the separation design structure of the embodiment is shown in Figure 11 If the conductive adhesive 8 connection of a certain battery piece 7 in the battery string fails, as shown in the left dashed box in Figure 12The carriers in the left battery piece 7 shown can be transmitted through the N-doped layer interlayer and the P layer interlayer to the right side and collected, while the left silver grid line has lost its conductivity because of the connected conductive adhesive 8, and cannot be connected with the right silver grid line. The left carrier can only be transmitted through the N-doped layer interlayer and the P layer interlayer to the right side and collected, but the P layer interlayer transmission resistance is much greater than the N-doped layer transmission resistance, which is much greater than the left / right silver grid line transmission resistance, i.e. Rs2>>Rs1>>Rs3, as shown in Figure 13 As shown, the conductive adhesive 8 connected with Rs3 is invalid, and the circuit is disconnected at this point. At this time, only a very small part of the carrier on the left side of the battery piece 7 is collected, and the output current is approximately half of the output current when the partial conductive adhesive 8 connection failure does not occur. Therefore, the output current of the entire battery string is also approximately half of the string output current when the partial conductive adhesive 8 connection failure does not occur.

[0061] Such a design can ensure that when the battery piece 7 is locally connected, the output current of the battery piece 7 where the battery piece 7 is located is reduced. The carriers in the semiconductor drift in the direction of the internal electric field, and the electric field direction is vertical, so the carriers are difficult to flow horizontally. The main collection way of the carriers is collected by the grid line. As shown in Figure 11 Figure 12 As shown, when the left conductive adhesive 8 fails, the grid line separates, so the failed part cannot collect the carriers. Only a small number of the left current can be transmitted through the right conductive adhesive 8, and the current density through the right conductive adhesive 8 is not much different from that when it is not failed.

[0062] This embodiment illustrates an example of intermediate separation. As an improvement of this embodiment, if there are N conductive adhesive 8 connection points for a single battery piece 7, and each conductive adhesive 8 connection point corresponds to a separated battery grid line, then if N-1 conductive adhesive 8 connection points fail, the current of the battery string is approximately 1 / N of the original current. Therefore, the current local enrichment problem caused by the local connection failure of the internal battery piece 7 interconnection of the component can be reduced. Figure 11 The middle B part is the same as Figure 6 The middle B part is the same as the auxiliary grid interconnection structure of the grid line. The auxiliary grid interconnection prevents the battery from being damaged by the auxiliary grid disconnection. After the disconnection, the current can flow through the interconnection structure, without affecting the use of the battery.

[0063] When the battery is a half battery, as shown in Figure 14 ​As shown, the half-cell battery uses a solder strip welding technology to complete the interconnection between the battery pieces 7, and in batch production, welding defects such as virtual welding, welding off, and overwelding may occur. The detection equipment EL (Electroluminescent) can detect most of the defects to avoid the flow of defective products into the power station. However, EL is through the transmission of a certain current to each battery piece 7 in the internal circuit of the module, and detects the quality of the battery piece 7 and the solder strip connection by using the electroluminescence principle. If part of the solder strip connection itself is not firm and only meets the current transmission requirements when the current is passed, or the contact resistance between the solder strip and the battery piece 7 increases or even breaks in the subsequent use due to the influence of the use environment, current enrichment will occur, causing adverse consequences.

[0064] The present application adopts a separation grid line design for the half-cell battery, as shown in the accompanying drawings. Figure 15 As shown, part C is the separation area of the half-cell battery string. In the half-cell battery string of the separation grid line, the principle of reducing current enrichment is the same as that of the shingle battery string, and the equivalent circuit diagram is the same as that of the shingle battery string. When some of the battery pieces 7 and part of the solder strip connection fail, as shown in the accompanying drawings, the current of the whole string will decrease to approximately half of the original current, and then the failed solder strip only bears approximately half of the original current. Figure 16

[0065] The interlayer resistance of the P layer can be ignored, but the interlayer of the N doped layer will transmit a small part of the carrier. At present, the mainstream PERC battery is superimposed with SE technology, that is, high-concentration doping is performed at the contact part and near the silver grid line 1 and the silicon wafer, and low-concentration doping is performed in the area outside the electrode. In this way, the contact resistance between the silicon wafer and the electrode is reduced, and the surface recombination is also reduced, thereby improving the short-circuit current and open-circuit voltage. Laser doping can reduce the square resistance of the local N doped area 2. The square resistance is only related to the thickness of the conductive film and other factors. As shown in the accompanying drawings, the SE pattern is optimized when the embodiment is used, and the separation area is avoided to be laser doped. Figure 12

[0066] The interlayer transmission resistance of the N doped layer is determined by the following points:

[0067] 1. The doping concentration of the N doped area 2 in the separation area determines the resistivity p of the N doped area 2;

[0068] 2. The doping depth h of the N doped area 2 in the separation area;

[0069] 3. The width W of the battery piece 7;

[0070] 4. The separation area distance S; the separation area distance S refers to the distance between the left and right grid lines in the separation area, and there is no connection between the grid lines in the left and right areas within this distance;

[0071] ​​5. The interlayer transport resistance Rs1 of N-doped region 2 is (ρ*S) / (h*W);

[0072] To achieve the function of reducing current enrichment in this invention, it is necessary to increase the sheet resistance of the N-doped region 2 in the separator region. From the formula for the transmission resistance of the N-doped region 2, it can be seen that to increase the sheet resistance of the N-doped region 2 in the separator region, it is necessary to reduce the width W of the cell 7 and increase the separator distance S. Therefore, this embodiment is more suitable for shingled, multi-cell, or half-cell components that use cut small pieces. Increasing the distance between the separator grid lines has little impact on the battery.

[0073] A photovoltaic module consists of solar cells 7, which are connected in series and parallel to form a photovoltaic module circuit, which outputs electrical energy. Solar cells 7 cannot be used directly for power generation. Unencapsulated solar cells 7 are susceptible to corrosion from the external environment, such as oxidation and failure of electrodes and conductive interconnect materials, and cell breakage. Furthermore, the output voltage of a single solar cell 7 is limited; for example, a single M2 solar cell 7 has a working current of around 10A but a relatively low working voltage of only about 0.6V. In practical applications, a certain number of solar cells 7 are typically first arranged into strings, and then these strings are interconnected and sealed with encapsulation materials such as glass, encapsulating film (EVA / POE), and a backsheet through lamination to form a photovoltaic module.

[0074] The internal circuit connection methods of photovoltaic modules include series, parallel, or a combination of series and parallel connections. For example, traditional modules only use series connections, while half-cell and shingled modules include both series and parallel connections. Figure 2 The diagram shows an equivalent simplified circuit of a photovoltaic module with series and parallel structures according to this embodiment. The separation of the battery grid lines in this invention is applicable to any photovoltaic module layout mode; this is just one example.

[0075] Photovoltaic module power generation system such as Figure 3 As shown, the system includes a photovoltaic (PV) module matrix, a controller, a battery, a DC load, an inverter, and an AC load / national grid. The PV module matrix provides electrical energy, which is then controlled by the controller to be output to the DC load via the battery, or the controller controls the electrical energy to be output to the AC load / national grid via the inverter. The PV module matrix is ​​composed of PV modules connected in series and parallel, and the system outputs electrical energy through the PV module matrix circuit.

[0076] The above description of the application and its embodiments is illustrative and not restrictive, and the application can be practiced in other specific forms without departing from the spirit or essential character thereof. The drawings described herein are only one of the many embodiments of the application and are not limiting, and any reference signs in the claims should not be construed as limiting the claims to the figure in which the reference signs are used. Therefore, if a person skilled in the art is inspired by the disclosure, and without departing from the spirit of the application, he can design similar structural forms and embodiments without creativity, which should also be within the scope of protection of the patent. In addition, the word "comprising" does not exclude other elements or steps, and the word "one" before an element does not exclude the inclusion of "multiple" such elements. The multiple elements stated in the product claims can also be implemented by one element through software or hardware. The words "first", "second" and the like are used to indicate names, and not to indicate any particular order.

Claims

1. A crystalline silicon cell comprising a grid line, a substrate, a doped region and a back field, the upper layer of the substrate being the doped region, the substrate and the doped region forming a PN junction, the lower layer of the substrate being the back field, the upper layer of the doped region and the lower layer of the back field both being the grid line, characterized in that, The gate line above the doped region is composed of several regions, each region is arranged at intervals, and the number of the gate line regions arranged at intervals is not less than two; the cell is a shingled cell, a tiled cell or a half-cell; the gate line above the doped region is divided into several regions, and the interval distance S between each region satisfies: ​ S=f(cell width W, sheet resistance of doped layer ρ), wherein: When W=40mm and ρ<60Ω / □, S≈10mm; When W=40mm and 60≤ρ<120Ω / □, S≈6mm; When W=40mm and ρ≥120Ω / □, S≈4mm; And the separation area needs to shield the SE heavy doping pattern, or the separation area cannot use the TCO film.

2. A crystalline silicon solar cell according to claim 1, wherein The cell comprises a slice assembly.

3. A crystalline silicon solar cell according to claim 1, wherein The gate line is divided into a main gate and a sub gate, and the main gate is provided with a conductive interconnection material.

4. The crystalline silicon solar cell of claim 1, wherein The substrate is a P-type or N-type substrate.

5. A crystalline silicon solar cell according to claim 4, wherein The doped region is an N-type or P-type doped region.

6. A photovoltaic module comprising a crystalline silicon cell according to any one of claims 1 to 5, characterized in that The cells are connected in series or in parallel to form a photovoltaic module circuit.

7. A photovoltaic module according to claim 6, wherein, The photovoltaic module comprises a plurality of main gates, and each main gate is connected with a plurality of sub gates on one side or both sides uniformly or non-uniformly.

8. A photovoltaic power system comprising a matrix of photovoltaic modules consisting of photovoltaic modules according to any one of claims 6-7, characterized in that, It also includes a controller and a load, the photovoltaic module is connected with the controller to provide electric energy, and the controller controls the current flowing to the load.

9. A photovoltaic power system according to claim 8, wherein, The load includes a direct current load and an alternating current load.

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