A device and detection method for testing LETID of photovoltaic modules

Abstract

The invention discloses a device and a detection method for testing the LETID of a photovoltaic module, and relates to the field of photovoltaic module testing. The device comprises an environmental chamber, a movable structure, a temperature adjustment structure and a movable contact test structure, wherein the movable structure is arranged on the side of the environmental chamber, the temperature adjustment structure is arranged on the side of the outer wall of the environmental chamber, and the movable contact test structure is arranged inside the environmental chamber. By arranging the movable structure, when a photovoltaic panel is placed in the environmental chamber, it can stably enter the environmental chamber. By arranging the temperature adjustment structure, the power of an electric heating tube can be adjusted according to demand by changing the position of a sliding electrode on a resistance coil, so as to facilitate the adjustment of a test environment. By arranging the movable contact test structure, the test can be realized by placing a sliding conductive plate on different fixed conductive plates and performing continuity detection of the current through a current detector.

Description

Technical Field

[0001] The present invention relates to the field of photovoltaic component testing, and in particular to a device and a detection method for testing LETID of a photovoltaic component. Background Art

[0002] Light and high temperature induced P-type crystal degradation (LETID) effect on PERC cells can cause field power loss, affecting both multicrystalline and monocrystalline technologies;

[0003] The standard high temperature "ignition" of PERC technology solar cells may cause hydrogen to diffuse into the bulk wafer, which, combined with the defects / impurities in the wafer, may lead to LETID. However, it is difficult to eliminate these wafer defects / impurities without significantly increasing the cost. Therefore, it is necessary to design a device and detection method for testing the LETID of photovoltaic modules after testing the photovoltaic panels. Summary of the invention

[0004] The object of the present invention is to provide a device and a detection method for testing the LETID of a photovoltaic module, which can test wafers with defects / impurities.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A device for testing photovoltaic module LETID, comprising an environmental chamber, a movable structure, a temperature adjustment structure and a movable contact test structure, wherein the movable structure is arranged on the side of the environmental chamber, the temperature adjustment structure is arranged on the side of the outer wall of the environmental chamber, and the movable contact test structure is arranged inside the environmental chamber;

[0007] The movable structure includes a load-bearing plate, a slide plate, a slide groove, a sealed box door, a push screw, a positioning plate, an asynchronous motor and a matching push rod, the slide groove is opened inside the box wall on the bottom side of the inner cavity of the environmental box, the slide plate is arranged inside the slide groove, the bottom side of one end of the load-bearing plate is connected to the top side of the slide plate by welding, the sealed box door is vertically welded and fixed to the end face of one end of the load-bearing plate, the matching push rod is horizontally welded and fixed to the top side of the sealed box door, the positioning plate is fixed to one end of the top side of the environmental box, the asynchronous motor is mounted on one side of the positioning plate by bolts, a screw hole is opened inside the matching push rod, the push screw is mounted on the output end of the asynchronous motor, and the other end of the push screw is mounted inside the matching push rod by threaded fitting;

[0008] The temperature control structure includes an electric heating tube, an adjusting motor, an adjusting screw, a sliding electrode, a sliding block, a fixing frame and a resistance coil. The electric heating tube is mounted on the top side wall of the inner cavity of the environmental box, the fixing frame is fixed to one side of the outer wall of the environmental box by welding, a resistance coil is installed between the upper and lower side walls of the fixing frame, the sliding electrode is sleeved on the outside of the resistance coil, the sliding block is fixed to the outer circumferential surface of the sliding electrode, the adjusting motor is installed on the top side of the fixing frame by bolts, the two ends of the adjusting screw are respectively penetrated between the upper and lower beams of the fixing frame, the top end of the adjusting screw is installed on the output end of the adjusting motor, the adjusting screw penetrates the inside of the sliding block by threaded cooperation, and an electronic thermometer is arranged inside the environmental box.

[0009] As a further solution of the present invention: the movable contact test structure includes a conductive sheet, an extrusion spring, a support plate, a fixed conductive plate, a sliding conductive plate, a slider, a current detector and a limiting slot plate, the support plate horizontally penetrates the interior of the box wall of the environmental box, the conductive sheet is arranged on the bottom side of the support plate, a conductive sheet is arranged between the top side of the conductive sheet and the bottom side of the support plate, the limiting slot plate is fixedly connected to one end of the top side of the support plate, a plurality of the fixed conductive plates are arranged in parallel inside the limiting slot plate, the slider is buckled on a slot plate on one side of the limiting slot plate, the sliding conductive plate is fixed on one side of the slider, and the current detector is vertically installed on the top surface of the side of the support plate.

[0010] As a further solution of the present invention: the electric heating tube, the sliding electrode and the resistance coil form a series circuit with the power supply through a wire.

[0011] As a further solution of the present invention: a plurality of groups of conductive sheets are arranged on the bottom side of the support plate, and each of the conductive sheets is connected to each corresponding fixed conductive plate via a wire.

[0012] As a further solution of the present invention: the bottom side of the sliding conductive plate is tangent to the top side of the fixed conductive plate.

[0013] As a further solution of the present invention: two sliding conductive plates are arranged on the top side of the inner wall of the limiting slot plate, and the sliding conductive plates are connected to the current detector through wires.

[0014] A detection method for testing the LETID of a photovoltaic module, the operation steps are as follows:

[0015] S1: Initial curve measurement under STC conditions according to IEC 60904-1;

[0016] S2: Place the test module in the environmental chamber, adjust the motor to drive the adjusting screw to rotate, change the position of the sliding block, change the position of the sliding electrode on the resistance coil, and adjust the environmental chamber environment to 75°C;

[0017] S3: Stabilize the temperature of the environmental chamber at 75°C for 1 hour;

[0018] S4: After the temperature is less than 20%, each current line is connected to remove the load after different time intervals, and then the current continuity is detected by the current detector by changing the position of the slider and placing the sliding conductive plate on different fixed conductive plates to obtain the result;

[0019] S5: By adjusting the motor operation, the adjusting screw is driven to rotate, the position of the sliding block is changed, the position of the sliding electrode on the resistance coil is changed, and the component temperature is reduced to 25°C at a rate not exceeding 100°C / hour. By changing the position of the slider, the sliding conductive plate is placed on different fixed conductive plates, and the current continuity is detected by the current detector to obtain the result;

[0020] S6: Carry out the final IV test according to IEC60904-1 and draw conclusions based on the comprehensive test results.

[0021] Beneficial effects of the present invention:

[0022] During the test, by setting up an active structure, the photovoltaic panel can be stably placed in the environmental chamber; by setting up a temperature control structure, the power of the electric heating tube can be adjusted according to needs by changing the position of the sliding electrode on the resistance coil, which is convenient for adjusting the test environment; by setting up an active contact test structure, the sliding conductive plate can be placed on different fixed conductive plates, and the current continuity can be detected by the current detector to achieve testing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to facilitate understanding by those skilled in the art, the present invention is further described below with reference to the accompanying drawings.

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0025] Figure 2 This is a structural diagram of the active contact test of the present invention;

[0026] Figure 3 This is a schematic diagram of the temperature adjustment structure of the present invention;

[0027] In the figure: 1. environmental chamber; 2. movable structure; 3. temperature adjustment structure; 4. movable contact test structure; 21. load-bearing plate; 22. slide plate; 23. slide groove; 24. sealed box door; 25. push screw; 26. positioning plate; 27. asynchronous motor; 28. matching push rod; 31. electric heating tube; 32. adjustment motor; 33. adjustment screw; 34. sliding electrode; 35. sliding block; 36. fixed frame; 37. resistance coil; 41. conductive sheet; 42. extrusion spring; 43. support plate; 44. fixed conductive plate; 45. sliding conductive plate; 46. slide buckle; 47. current detector; 48. limit slot plate. DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] like Figure 1-3 As shown, the present invention provides a technical solution: a device and a detection method for testing the LETID of a photovoltaic module:

[0030] Embodiment 1:

[0031] A device for testing photovoltaic module LETID, comprising an environmental chamber 1, an active structure 2, a temperature adjustment structure 3 and an active contact test structure 4, wherein the active structure 2 is arranged on the side of the environmental chamber 1, the temperature adjustment structure 3 is arranged on the side of the outer wall of the environmental chamber 1, and the active contact test structure 4 is arranged inside the environmental chamber 1;

[0032] The movable structure 2 includes a load-bearing plate 21, a slide plate 22, a slide groove 23, a sealed box door 24, a push screw 25, a positioning plate 26, an asynchronous motor 27 and a matching push rod 28. The slide groove 23 is opened inside the box wall on the bottom side of the inner cavity of the environmental box 1, and the slide plate 22 is arranged inside the slide groove 23. The bottom side of one end of the load-bearing plate 21 is connected to the top side of the slide plate 22 by welding. The sealed box door 24 is vertically welded and fixed to the end face of one end of the load-bearing plate 21. The matching push rod 28 is horizontally welded and fixed to the top side of the sealed box door 24. The positioning plate 26 is fixed to one end of the top side of the environmental box 1. The asynchronous motor 27 is installed on one side of the positioning plate 26 by bolts. A screw hole is opened inside the matching push rod 28. The push screw 25 is installed on the output end of the asynchronous motor 27, and the other end of the push screw 25 is installed inside the matching push rod 28 by threaded fitting.

[0033] The temperature control structure 3 includes an electric heating tube 31, an adjusting motor 32, an adjusting screw rod 33, a sliding electrode 34, a sliding block 35, a fixing frame 36 and a resistance coil 37. The electric heating tube 31 is mounted on the top side of the inner cavity of the environmental box 1. The fixing frame 36 is fixed to one side of the outer wall of the environmental box 1 by welding. A resistance coil 37 is installed between the upper and lower side walls of the fixing frame 36. The sliding electrode 34 is sleeved on the outer side of the resistance coil 37. The sliding block 35 is fixed to the outer circumferential surface of the sliding electrode 34. The adjusting motor 32 is installed on the top side of the fixing frame 36 by bolts. The two ends of the adjusting screw rod 33 are respectively penetrated between the upper and lower beams of the fixing frame 36. The top end of the adjusting screw rod 33 is installed on the output end of the adjusting motor 32. The adjusting screw rod 33 penetrates the inside of the sliding block 35 by threaded cooperation. An electronic thermometer is arranged inside the environmental box 1.

[0034] The movable contact test structure 4 includes a conductive sheet 41, an extrusion spring 42, a support plate 43, a fixed conductive plate 44, a sliding conductive plate 45, a slide buckle 46, a current detector 47 and a limit slot plate 48. The support plate 43 horizontally penetrates the interior of the box wall of the environmental box 1. The conductive sheet 41 is arranged on the bottom side of the support plate 43. The conductive sheet 41 is arranged between the top side of the conductive sheet 41 and the bottom side of the support plate 43. The limit slot plate 48 is fixedly connected to one end of the top side of the support plate 43. A plurality of fixed conductive plates 44 are arranged in parallel inside the limit slot plate 48. The slide buckle 46 is buckled on a side slot plate of the limit slot plate 48. The sliding conductive plate 45 is fixed on one side of the slide buckle 46. The current detector 47 is vertically installed on the side top surface of the support plate 43.

[0035] The electric heating tube 31, the sliding electrode 34 and the resistance coil 37 form a series circuit with the power supply through the wire;

[0036] A plurality of conductive sheets 41 are disposed on the bottom side of the support plate 43, and each conductive sheet 41 is connected to each fixed conductive plate 44 via a wire.

[0037] The bottom side of the sliding conductive plate 45 is tangent to the top side of the fixed conductive plate 44;

[0038] Two sliding conductive plates 45 are provided on the top side of the inner wall of the limiting slot plate 48 , and the sliding conductive plates 45 are connected to the current detector 47 through wires.

[0039] Working principle: When testing, the photovoltaic component is placed on the load-bearing plate 21, and the asynchronous motor 27 is operated to drive the push screw 25 to rotate. Under the cooperation with the thread in the push rod 28 and the sliding cooperation of the slide plate 22 along the slide groove 23, the sealed box door 24 is in close contact with the environmental box 1, and the sealing of the environmental box 1 is achieved. After sealing, when setting the temperature adjustment, the adjustment motor 32 is operated to drive the adjustment screw 33 to rotate, change the position of the sliding block 35, change the position of the sliding electrode 34 on the resistance coil 37, change the resistance, adjust the output power of the electric heating tube 31, and achieve the adjustment of different temperatures. At the same time, it can perform stable cooling operations. When cooling, the extrusion spring 42 can realize the connection test of the photovoltaic component with the cooperation of the conductive sheet 41. By changing the position of the slider 46 and placing the sliding conductive plate 45 on different fixed conductive plates 44, the current continuity is detected by the current detector 47 to achieve the test.

[0040] A detection method for testing the LETID of a photovoltaic module, the operation steps are as follows:

[0041] S1: Initial curve measurement under STC conditions according to IEC 60904-1;

[0042] S2: Place the test module in the environmental chamber 1, and adjust the motor 32 to drive the adjusting screw 33 to rotate, change the position of the sliding block 35, change the position of the sliding electrode 34 on the resistance coil 37, and adjust the environment of the environmental chamber 1 to 75°C;

[0043] S3: by stabilizing the temperature of environmental chamber 1 at 75°C for 1 hour, the temperature is less than 20%;

[0044] S4: After the temperature is less than 20%, each current line is connected to remove the load after different time intervals, and then the current continuity is detected by changing the position of the slider 46, by placing the sliding conductive plate 45 on different fixed conductive plates 44, and the current is detected by the current detector 47 to obtain the result;

[0045] S5: by adjusting the motor 32 to drive the adjusting screw 33 to rotate, the position of the sliding block 35 is changed, the position of the sliding electrode 34 on the resistance coil 37 is changed, the temperature of the component is reduced to 25°C at a rate not exceeding 100°C / hour, and the position of the slider 46 is changed, and the sliding conductive plate 45 is placed on different fixed conductive plates 44, and the current is tested for continuity through the current detector 47 to obtain the result;

[0046] S6: Carry out the final IV test according to IEC60904-1 and draw conclusions based on the comprehensive test results.

[0047] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A device for testing the LETID of a photovoltaic module, characterized in that: The invention comprises an environmental chamber (1), a movable structure (2), a temperature adjustment structure (3) and a movable contact test structure (4), wherein the movable structure (2) is arranged on the side of the environmental chamber (1), the temperature adjustment structure (3) is arranged on the side of the outer wall of the environmental chamber (1), and the movable contact test structure (4) is arranged inside the environmental chamber (1); The movable structure (2) comprises a bearing plate (21), a slide plate (22), a slide groove (23), a sealed box door (24), a push screw (25), a positioning plate (26), an asynchronous motor (27) and a matching push rod (28); the slide groove (23) is arranged inside the box wall at the bottom side of the inner cavity of the environmental box (1); the slide plate (22) is arranged inside the slide groove (23); the bottom side of one end of the bearing plate (21) is connected to the top side of the slide plate (22) by welding; the sealed box door (24) is vertically welded and fixed to the bearing plate (21); 21), the mating push rod (28) is horizontally welded and fixed on the top side of the sealed box door (24), the positioning plate (26) is fixed to one end of the top side of the environmental box (1), the asynchronous motor (27) is mounted on one side of the positioning plate (26) by bolts, a screw hole is provided inside the mating push rod (28), the push screw (25) is mounted on the output end of the asynchronous motor (27), and the other end of the push screw (25) is mounted inside the mating push rod (28) by threaded fitting; The temperature adjustment structure (3) comprises an electric heating tube (31), an adjustment motor (32), an adjustment screw (33), a sliding electrode (34), a sliding block (35), a fixing frame (36) and a resistance coil (37); the electric heating tube (31) is mounted on the top wall of the inner cavity of the environmental box (1); the fixing frame (36) is fixed to one side of the outer wall of the environmental box (1) by welding; a resistance coil (37) is installed between the upper and lower side walls of the fixing frame (36); the sliding electrode (34) is sleeved on the resistance coil (37); On the outside, the sliding block (35) is fixedly connected to the outer circumferential surface of the sliding electrode (34), the adjusting motor (32) is mounted on the top side of the fixing frame (36) by means of bolts, the two ends of the adjusting screw rod (33) are respectively penetrated between the upper and lower beams of the fixing frame (36), the top end of the adjusting screw rod (33) is mounted on the output end of the adjusting motor (32), the adjusting screw rod (33) penetrates the inside of the sliding block (35) by means of threads, and an electronic thermometer is arranged inside the environmental chamber (1); The movable contact test structure (4) comprises a conductive sheet (41), a compression spring (42), a support plate (43), a fixed conductive plate (44), a sliding conductive plate (45), a slide buckle (46), a current detector (47) and a limit slot plate (48); the support plate (43) extends transversely through the interior of the box wall of the environmental box (1); the conductive sheet (41) is arranged on the bottom side of the support plate (43); a conductive sheet (41) is arranged between the top side of the conductive sheet (41) and the bottom side of the support plate (43); the limit slot plate (48) is fixedly connected to one end of the top side of the support plate (43); a plurality of fixed conductive plates (44) are arranged in parallel inside the limit slot plate (48); the slide buckle (46) is buckled on a side slot plate of the limit slot plate (48); the sliding conductive plate (45) is fixed on one side of the slide buckle (46); and the current detector (47) is vertically mounted on the top surface of the side of the support plate (43).

2. The device for testing photovoltaic module LETID according to claim 1, characterized in that: The electric heating tube (31), the sliding electrode (34) and the resistance coil (37) form a series circuit with a power source via a conducting wire.

3. The device for testing photovoltaic module LETID according to claim 1, characterized in that: A plurality of groups of conductive sheets (41) are arranged on the bottom side of the support plate (43), and each conductive sheet (41) is correspondingly connected to each fixed conductive plate (44) via a wire.

4. The device for testing photovoltaic module LETID according to claim 1, characterized in that: The bottom side of the sliding conductive plate (45) is tangent to the top side of the fixed conductive plate (44).

5. The device for testing photovoltaic module LETID according to claim 1, characterized in that: Two sliding conductive plates (45) are provided on the top side of the inner wall of the limiting slot plate (48), and the sliding conductive plates (45) are connected to the current detector (47) via a wire.

6. A method for testing the LETID of a photovoltaic module, characterized in that: Using the device for testing the LETID of a photovoltaic module according to any one of claims 1 to 5, the operating steps are as follows: S1: Initial curve measurement under STC conditions according to IEC 60904-1; S2: Place the test module in the environmental chamber (1), operate the adjusting motor (32), drive the adjusting screw (33) to rotate, change the position of the sliding block (35), change the position of the sliding electrode (34) on the resistance coil (37), and adjust the environment of the environmental chamber (1) to 75°C; S3: Stabilize the temperature of the environmental chamber (1) at 75°C for 1 hour; S4: After the temperature is less than 20%, each current line is connected to remove the load after different time intervals, and then the current continuity is detected by changing the position of the slider (46) and placing the sliding conductive plate (45) on different fixed conductive plates (44) through the current detector (47) to obtain the result; S5: by adjusting the motor (32), driving the adjusting screw (33) to rotate, changing the position of the sliding block (35), changing the position of the sliding electrode (34) on the resistance coil (37), reducing the component temperature to 25°C at a rate not exceeding 100°C / hour, changing the position of the slider (46), placing the sliding conductive plate (45) on different fixed conductive plates (44), and performing a continuity test on the current through the current detector (47), and obtaining a result; S6: Carry out the final IV test according to IEC60904-1 and draw conclusions based on the comprehensive test results.

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