A photovoltaic cell el detection system

Abstract

The application discloses a photovoltaic cell EL detection system, which comprises an EL detection device, the EL detection device comprises a detection chamber, an infrared camera and a probe group array arranged in the detection chamber, the lens of the infrared camera is directed to the photovoltaic cell corresponding to the probe group array; the probe group array comprises a base, a probe spacing adjusting mechanism and probes, the probes are movably arranged on the seat surface of the base in a linear array through the probe spacing adjusting mechanism, and a probe matrix is formed; and according to the size of the panel of the photovoltaic cell, the spacing between the individual probes is adjusted through the probe spacing adjusting mechanism, so that the probe matrix is diffused or shrunk to form a mode covering the panel of the photovoltaic cell, and the uniform distribution state of the probes relative to the panel of the photovoltaic cell is maintained. The probe spacing adjusting mechanism of the probe group array can adaptively cover and uniformly distribute the probes according to the size of the panel of the photovoltaic cell, so that the external current is uniformly injected into the photovoltaic cell, and the EL detection capacity and accuracy are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of photovoltaic cell EL detection, and in particular relates to a photovoltaic cell EL detection system. Background Art

[0002] EL testing utilizes near-infrared imaging in a darkroom designed to shield visible light. Within the darkroom, a CCD near-infrared camera captures images of photovoltaic cells connected to a constant DC source. Computer image processing produces complete, clear defect detection images, enabling the detection of defects such as black cores, dark spots, hidden cracks, and broken grids. In existing EL testing equipment, the probes on the probe assembly are fixedly mounted on a base. Due to the varying sizes of photovoltaic cells placed within the darkroom, the contact points between the probes and the cells lack sufficient coverage and uniformity relative to the cell surface. Consequently, the current injected into the cells is unevenly distributed, impacting EL testing capabilities and accuracy. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a photovoltaic cell EL detection system. The probe spacing adjustment mechanism of the probe array can adaptively matrix cover and evenly distribute the probes according to the panel size of the photovoltaic cell, so that the external current is evenly injected into the photovoltaic cell, ensuring the extensiveness and uniformity of the current distribution in the photovoltaic cell, and improving the EL detection capability and accuracy.

[0004] Technical solution: To achieve the above-mentioned purpose, a photovoltaic cell EL detection system of the present invention includes an EL detection device, which includes a detection chamber and an infrared camera and a probe group arranged in the detection chamber, the lens capture direction of the infrared camera is toward the photovoltaic cell corresponding to the probe group; the probe group includes a base, a probe spacing adjustment mechanism and probes, the probes are movably arranged in a linear array on the seat surface of the base through the probe spacing adjustment mechanism, forming a probe matrix; and according to the size of the panel surface of the photovoltaic cell, the spacing between the individual probes is adjusted by the probe spacing adjustment mechanism, so that the probe matrix is ​​expanded or contracted to form a shape covering the panel surface of the photovoltaic cell, keeping the probes evenly distributed relative to the panel surface of the photovoltaic cell.

[0005] Furthermore, the probe spacing adjustment mechanism allows the probes to have a spacing adjustment range within a horizontal plane enclosed by the seat surface of the base.

[0006] Further, the probe spacing adjustment mechanism comprises a rotating drive and a moving drive, the probe is connected to the rotating drive through the moving drive; the rotating drive provides a driving force for the circumferential fixed-point rotation of the probe, so as to adjust the circumferential orientation of the probe on the formed circumferential track circle; the moving drive provides a driving force for the radial movement of the probe along the circumferential track circle, so as to adjust the radial orientation of the probe.

[0007] Further, the probe group row further comprises a lifting support arranged on the base; in the distance adjustment state, the photovoltaic cell is in a suspended state relative to the probe through the supporting action of the lifting support; in the EL detection state, the photovoltaic cell is adjusted to the height of the contact head of the probe through the lowering of the lifting support.

[0008] Further, the lifting support is composed of a lifting part and a supporting part, the lifting part drives the supporting part supporting the photovoltaic cell to perform the lifting action; the supporting surface of the supporting part is a gas suction surface capable of adsorbing and positioning the photovoltaic cell, and in the lifting action, the photovoltaic cell is pressed against the contact head of the probe through the pulling action of the supporting part.

[0009] Further, the detection chamber comprises two light environment states of a bright room and a dark room, and the two light environment states are switchable; in the distance adjustment, the detection chamber is switched to the bright room state; in the EL detection, the detection chamber is switched to the dark room state.

[0010] Further, a current source is comprised; the probe is connected to the current source, and at least one fixed-value resistor is connected between the probe and the current source.

[0011] Further, a computer is comprised, the infrared camera is connected to the computer; in the distance adjustment, the image of the photovoltaic cell is captured through the infrared camera, the size information of the board is calculated through the computer, so as to control the probe spacing adjustment mechanism to perform the distance adjustment action on the probe; in the EL detection, the image of the photovoltaic cell connected to the current source is obtained through the infrared camera, and the defect detection image is generated through the image processing of the computer.

[0012] Beneficial effects: the photovoltaic cell EL detection system has the beneficial effects that: in the application, the probe spacing adjustment mechanism of the probe group row can adaptively matrix cover and uniformly distribute the probes according to the size of the board of the photovoltaic cell, so that the external current is uniformly injected into the photovoltaic cell, the universality and uniformity of the current distribution in the photovoltaic cell are ensured, the EL detection capability and accuracy are improved, and the application is suitable for large-scale popularization and application. BRIEF DESCRIPTION OF DRAWINGS

[0013] ATTACHED Figure 1 It is a structural schematic view of the EL detection device;

[0014] ATTACHED Figure 2Structure diagram of the probe group row;

[0015] Figure 2 is a structure diagram of the probe group row; Figure 3 Structure diagram of the probe spacing adjustment mechanism;

[0016] Figure 3 is a structure diagram of the probe spacing adjustment mechanism; Figure 4 Structure diagram of the lifting support;

[0017] Figure 4 is a structure diagram of the lifting support; Figure 5 Structure diagram of the electroluminescence principle; DETAILED DESCRIPTION

[0018] The application will be further described below with reference to the accompanying drawings.

[0019] In the existing EL detection equipment instrument, the probes on the probe group row are fixedly installed on the base, and the photovoltaic cell placed in the dark box has the problem of different sizes. The contact position of the probe and the photovoltaic cell is not enough in terms of the distribution coverage and uniformity of the board surface of the photovoltaic cell, so that the current distribution injected into the photovoltaic cell is also uneven, thereby affecting the EL detection capability and accuracy.

[0020] In order to solve the above problems, the technical scheme of the application is as follows: Figure 1 and Figure 2 is a structure diagram of the probe group row; Figure 2As shown, a photovoltaic cell EL detection system includes an EL detection device, which includes a detection chamber 1 and an infrared camera 2 and a probe group 3 arranged in the detection chamber 1, the lens capture direction of the infrared camera 2 is toward the photovoltaic cell 4 corresponding to the probe group 3; the probe group 3 includes a base 8, a probe spacing adjustment mechanism 9 and probes 10, the probes 10 are movably arranged in a linear array on the seat surface of the base 8 through the probe spacing adjustment mechanism 9, forming a probe matrix; and according to the size of the panel surface of the photovoltaic cell 4, the spacing between the individual probes 10 is adjusted by the probe spacing adjustment mechanism 9, so that the probe matrix is ​​expanded or contracted to form a shape covering the panel surface of the photovoltaic cell 4, and the probes 10 are kept uniformly distributed relative to the panel surface of the photovoltaic cell 4. More specifically, the present invention includes a computer, to which the infrared camera 2 is externally connected. During distance adjustment, the infrared camera 2 captures an image of the photovoltaic cell 4, and the computer calculates panel size information to control the probe spacing adjustment mechanism 9 to adjust the probes 10. During EL detection, the infrared camera 2 captures an image of the photovoltaic cell 4 connected to the current source 5, and after computer image processing, a defect detection image is generated, thereby detecting defects such as black cores, black spots, hidden cracks, and broken grids in the photovoltaic cell 4. Therefore, in the present invention, the probe spacing adjustment mechanism 9 of the probe array 3 can adaptively matrix-cover and evenly distribute the probes 10 according to the panel size of the photovoltaic cell 4, so that the external current is evenly injected into the photovoltaic cell 4, ensuring the extensive and uniform distribution of the current in the photovoltaic cell 4, thereby improving the EL detection capability and accuracy.

[0021] More specifically, the specific details of the probe movable distance adjustment are: the distance adjustment range of the probe 10 through the probe spacing adjustment mechanism 9 is within the horizontal plane enclosed by the seat surface of the base 8, and the distance adjustment activity of the probe 10 is to move within the horizontal plane.

[0022] As attached Figure 3As shown, the probe spacing adjustment mechanism 9 comprises a rotating drive and a moving drive, the probe 10 is connected to the rotating drive by the moving drive; the rotating drive provides a driving force for the circumferential fixed-point rotation of the probe 10, so as to adjust the circumferential orientation of the probe 10 on the formed circumferential track circle; the moving drive 95 provides a driving force for the radial movement of the probe 10 along the circumferential track circle, so as to adjust the radial orientation of the probe 10. During the adjustment, the circumferential orientation adjustment and the radial orientation adjustment of the probe 10 by the probe spacing adjustment mechanism 9 are completely controlled by the computer, so as to ensure the accuracy and efficiency of the adjustment. More specifically, the probe spacing adjustment mechanism 9 further comprises a mounting seat 91 and a probe mounting part 96; the rotating drive comprises a transverse support 93 mounted on the mounting seat 91 through a fixed-point rotating shaft 92 and a servo motor 94 drivingly connected to the fixed-point rotating shaft 92, and the moving drive is an electric guide rail horizontally mounted on the transverse support 93, and the probe 10 is mounted on the sliding block of the electric guide rail through the probe mounting part 96. The present application comprises a current source 5; the probe 10 is connected to the current source 5, and at least one fixed-value resistor 12 is connected between the probe 10 and the current source 5, and the resistance value of each fixed-value resistor 12 is the same, and the resistance value of the fixed-value resistor 12 is between 0.1-100Ω.

[0023] As shown in the accompanying drawings, Figure 2 Before performing the EL detection, the adjustment operation needs to be performed first, therefore, the probe group row 3 further comprises a lifting support 11 arranged on the base 8; in the adjustment state, the photovoltaic cell sheet 4 is in a suspended state relative to the probe 10 by the supporting action of the lifting support 11, at this time, the photovoltaic cell sheet 4 is not in contact with the probe 10; in the EL detection state, the photovoltaic cell sheet 4 is adjusted to the height of the contact head of the probe 10 by the lowering of the lifting support 11, and then the EL detection under the energized condition can be performed.

[0024] As shown in the accompanying drawings, Figure 4 As shown in the accompanying drawings, the lifting support 11 is composed of a lifting part 11.1 and a support part 11.2, the lifting part 11.1 drives the support part 11.2 to support the photovoltaic cell sheet 4 to perform the lifting action; the support surface of the support part 11.2 is an air suction surface 110 capable of adsorbing and positioning the photovoltaic cell sheet 4, and when the lifting part 11.1 is lowered, the photovoltaic cell sheet 4 is in contact with the contact head of the probe 10 by the pulling action of the support part 11.2. The lifting support 11 not only provides the supporting function, but also provides the function of adsorbing and positioning the photovoltaic cell sheet 4, so that the photovoltaic cell sheet 4 can keep the state of contacting the contact head of the probe 10 during the EL detection, and the poor contact can be avoided to affect the accuracy of the EL detection. The lifting part 11.1 can be an electric push rod. The support part 11.2 is specifically a structure with an air cavity in the inside and air holes distributed on the top surface, and the air cavity is connected to an air suction device 14 through an air pipe 13.

[0025] The detection chamber includes two light environment states of bright room and dark room, and the two light environment states are switchable, specifically, a light source 6 is arranged in the detection chamber, and the opening and closing of the light source is controlled by a computer; when the distance is adjusted, the detection chamber is switched to the bright room state, i.e. the light is on, to ensure the clarity and integrity of the board surface picture of the photovoltaic cell 4 captured by the infrared camera 2, so as to ensure the information acquisition and calculation of the computer on the board surface size of the photovoltaic cell 4; when the EL detection is performed, i.e. the light is off, the detection chamber is switched to the dark room state.

[0026] In order to more clearly understand the technical solution, the principle diagram of electroluminescence detection is as shown in the accompanying drawings. Figure 5 As shown, the process of EL test is that a forward bias voltage is applied to the photovoltaic cell 4, and a current source 5 injects a large number of non-equilibrium carriers into the photovoltaic cell 4, the photovoltaic cell 4 continuously recombines and emits light by a large number of non-equilibrium carriers injected from the diffusion zone, and emits photons, which is the reverse process of the photovoltaic effect; then the infrared camera 2 captures these photons, and the computer processes the captured photons to display them in the form of images, and the whole process is performed in the dark room.

[0027] The image brightness of the EL test is proportional to the minority carrier lifetime (or minority carrier diffusion length) and the current density of the photovoltaic cell 4, and the image brightness is darker when the minority carrier diffusion length is lower in the place with defects in the solar cell. Through the analysis of the EL test image, the hidden defects of the photovoltaic cell 4 and the assembly can be clearly found, and the defects include silicon material defects, diffusion defects, printing defects, sintering defects, and cracks in the assembly packaging process, etc.

[0028] The above only describes the preferred embodiments of the present application, and it should be noted that for ordinary skilled in the art, some improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A photovoltaic cell EL detection system characterized by: The application relates to an EL detection device, which comprises a detection chamber (1) and an infrared camera (2) and a probe group array (3) arranged in the detection chamber (1), the lens of the infrared camera (2) is directed towards a photovoltaic cell (4) corresponding to the probe group array (3); the probe group array (3) comprises a base (8), a probe spacing adjusting mechanism (9) and probes (10), the probes (10) are linearly arranged on the seat surface of the base (8) through the probe spacing adjusting mechanism (9) and form a probe matrix; and according to the size of the plate surface of the photovoltaic cell (4), the spacing between the probes (10) is adjusted through the probe spacing adjusting mechanism (9), so that the probe matrix is expanded or shrunk to form a mode covering the plate surface of the photovoltaic cell (4) and the probes (10) are uniformly distributed relative to the plate surface of the photovoltaic cell (4). The probe group array (3) further comprises a lifting support (11) arranged on the base (8); in the distance adjusting state, the photovoltaic cell (4) is in a suspended state relative to the probes (10) through the supporting action of the lifting support (11), and at this time, the photovoltaic cell (4) is not in contact with the probes (10). The application further relates to a computer, the infrared camera (2) is connected to the computer; in the distance adjusting process, the image of the photovoltaic cell (4) is captured through the infrared camera (2), the plate surface size information is calculated through the computer, and the probe spacing adjusting mechanism (9) is controlled to perform the distance adjusting action on the probes (10). The distance adjusting action range of the probes (10) through the probe spacing adjusting mechanism (9) is in the horizontal plane surrounded by the seat surface of the base (8). The probe spacing adjusting mechanism (9) comprises rotating driving and moving driving, the probes (10) are connected to the rotating driving through the moving driving; the rotating driving (93) provides a driving force for the circumferential fixed-point rotation of the probes (10), so as to adjust the circumferential direction of the probes (10) on the formed circumferential track circle; the moving part (95) provides a driving force for the radial movement of the probes (10) along the circumferential track circle, so as to adjust the radial direction of the probes (10).

2. A photovoltaic cell EL detection system according to claim 1, wherein: In the EL detection state, the photovoltaic cell (4) is adjusted to the height of the contact head of the probes (10) through the descending lifting support (11).

3. A photovoltaic cell EL detection system according to claim 1 or 2, wherein: The lifting support (11) is composed of a lifting part (11.1) and a supporting part (11.2), the lifting part (11.1) drives the supporting part (11.2) supporting the photovoltaic cell (4) to perform the lifting action; the supporting surface of the supporting part (11.2) is a gas suction surface (110) capable of adsorbing and positioning the photovoltaic cell (4), and in the lifting action, the photovoltaic cell (4) is pulled by the supporting part (11.2) to contact the contact head of the probes (10).

4. A photovoltaic cell EL detection system according to claim 1, wherein: The detection chamber comprises two light environment states of a bright room and a dark room, and the two light environment states are switchable; in the distance adjusting process, the detection chamber is switched to the bright room state; in the EL detection process, the detection chamber is switched to the dark room state.

5. A photovoltaic cell EL detection system according to claim 4, wherein: The current source (5) is connected with the probe (10), and at least one fixed resistance (12) is connected between the probe (10) and the current source (5).

6. A photovoltaic cell EL detection system according to claim 5, wherein: During the EL detection, the infrared camera (2) acquires the image of the photovoltaic cell (4) connected with the current source (5), and the computer image processing generates the defect detection image.

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