Photovoltaic module el detection apparatus

Abstract

The utility model relates to EL detection device technical field, and disclose photovoltaic module EL detection device, include: light storage direct current coupling mechanism, the light storage direct current coupling mechanism includes photovoltaic group string, energy storage equipment, direct current bus, photovoltaic group string inverter and reverse power supply control assembly, the photovoltaic group string passes through photovoltaic side connection branch and direct current bus electric connection, is equipped with anti -reverse flow device and bypass switch in proper order on photovoltaic side connection branch, the input of photovoltaic group string inverter and the one end away from direct current bus of photovoltaic group string electric connection, the energy storage equipment passes through energy storage side connection branch and direct current bus electric connection, is equipped with energy storage inverter setting device on energy storage side connection branch, energy storage inverter setting device and energy storage equipment electric connection. The utility model discloses through light storage direct current collaborative power supply and reverse control, anti -reverse flow device blocks reverse flow, bypass switch keeps power supply continuous, solves power supply instability and power grid hidden danger, promotes EL detection reliability and security.

Description

Technical Field

[0001] This utility model relates to the technical field of EL testing devices, specifically to a photovoltaic module EL testing device. Background Technology

[0002] In the photovoltaic industry, the quality of photovoltaic modules directly affects the power generation efficiency and lifespan of photovoltaic systems. EL testing, as a key means of assessing the internal quality of photovoltaic modules, must be carried out under a stable power supply environment.

[0003] Existing EL testing devices have significant limitations in their power supply methods: some devices rely directly on the power grid, but due to geographical location, standard power supply voltages are often lacking at actual photovoltaic sites, limiting the applicability of these devices; some devices use independent energy storage equipment for power supply, but due to the lack of coordinated control with the photovoltaic strings, insufficient energy storage capacity or power supply redundancy often occurs, leading to testing interruptions or energy waste; in addition, photovoltaic strings may generate unstable power due to changes in sunlight during the testing process. If directly connected to the power supply circuit, this can easily lead to backflow into the grid, affecting grid security and exacerbating power supply fluctuations. Furthermore, existing devices lack targeted backflow protection and dynamic power supply adjustment mechanisms, severely restricting the efficiency and reliability of EL testing. Therefore, a photovoltaic module EL testing device is proposed. Utility Model Content

[0004] In view of the shortcomings of the prior art, this utility model provides a photovoltaic module EL testing device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a photovoltaic module EL testing device, comprising:

[0006] A photovoltaic-storage DC coupling mechanism, comprising a photovoltaic string, an energy storage device, a DC bus, a photovoltaic string inverter, and a reverse power supply control component;

[0007] The photovoltaic string is electrically connected to the DC bus through a photovoltaic side connection branch. An anti-reverse current device and a bypass switch are sequentially installed on the photovoltaic side connection branch, and the bypass switch and the anti-reverse current device are connected in parallel.

[0008] The input terminal of the photovoltaic string inverter is electrically connected to the end of the photovoltaic string away from the DC bus, and the output terminal of the photovoltaic string inverter is electrically connected to the external power grid.

[0009] The energy storage device is electrically connected to the DC bus via an energy storage side connection branch. An energy storage inverter is provided on the energy storage side connection branch, and the energy storage inverter is electrically connected to the energy storage device.

[0010] The reverse power supply control component is connected to the bypass switch, the photovoltaic string inverter, and the energy storage inverter setting device. In reverse power supply mode, the reverse power supply control component controls the bypass switch to close, controls the photovoltaic string inverter to adjust the grid output active power to zero, and simultaneously controls the energy storage inverter setting device to put the energy storage device into constant current working mode. The energy storage device backflows current into the photovoltaic string through the DC bus and the closed bypass switch. In normal power generation mode, the energy storage device is connected to the external grid through the energy storage inverter setting device, the DC bus, and the photovoltaic string inverter. It charges and discharges according to the photovoltaic operation status. The reverse power supply control component controls the bypass switch to open, and the anti-reverse current device is in working state to prevent the energy storage device from supplying reverse power to the photovoltaic string.

[0011] By achieving complementary power supply through DC coupling between photovoltaic strings and energy storage devices, the stable power supply for testing is ensured through the coordinated regulation of reverse power supply control components, the anti-reverse current device avoids the risk of power reverse flow, and the bypass switch ensures the continuity of power supply, thus improving the overall safety and accuracy of EL testing.

[0012] Preferably, the anti-reverse current device includes an anti-reverse current diode and an overcurrent protection module. The anti-reverse current diode and the overcurrent protection module are connected in series on the photovoltaic side connection branch, and the forward conduction direction of the anti-reverse current diode is consistent with the current direction of the photovoltaic string supplying power to the DC bus.

[0013] Preferably, the bypass switch includes an electromagnetic contactor and a switch control module. The main contacts of the electromagnetic contactor are connected in parallel across the two ends of the anti-reverse current device. The switch control module is electrically connected to the coil of the electromagnetic contactor and is signal-connected to the reverse power supply control component.

[0014] Preferably, the energy storage side connection branch further includes a DC / DC converter, which is connected in series between the energy storage device and the DC bus, and is electrically connected to the energy storage device, the DC bus and the energy storage inverter respectively.

[0015] Preferably, the photovoltaic string inverter includes a power regulation module, the input terminal of which is electrically connected to the photovoltaic string, the output terminal of which is electrically connected to the external power grid, and the power regulation module is signal-connected to the reverse power supply control component for adjusting the output active power to zero in reverse power supply mode.

[0016] Preferably, it also includes a current monitoring module, which is connected in series on the photovoltaic side connection branch and is signal-connected to the reverse power supply control component for real-time monitoring of the current of the photovoltaic string and feedback to the reverse power supply control component.

[0017] Preferably, the DC bus includes a main bus and a branch bus. One end of the branch bus is electrically connected to the main bus, and the other end of the branch bus is electrically connected to the photovoltaic string through a photovoltaic side connection branch. A bus protection switch is provided on the branch bus.

[0018] Preferably, the energy storage device includes a battery pack and a constant current control module. The constant current control module is electrically connected to the battery pack and signal-connected to the energy storage inverter, and is used to adjust the output current according to the instructions of the energy storage inverter in reverse power supply mode.

[0019] Preferably, a freewheeling diode is connected in parallel across the two ends of the main contacts of the electromagnetic contactor, and the forward conduction direction of the freewheeling diode is opposite to the current direction when the main contacts of the electromagnetic contactor are closed.

[0020] Preferably, the photovoltaic string includes multiple photovoltaic modules connected in series, and the output end of the photovoltaic string is provided with a string combiner box. The input end of the string combiner box is electrically connected to the photovoltaic modules, and the output end of the string combiner box is electrically connected to the DC bus through a photovoltaic side connection branch.

[0021] Compared with the prior art, the present invention provides a photovoltaic module EL testing device, which has the following beneficial effects:

[0022] This invention achieves dynamic balance of power supply for detection by using DC collaborative power supply from photovoltaic strings and energy storage devices, combined with precise regulation of the bypass switch, photovoltaic string inverter, and energy storage inverter by a reverse power supply control component. The anti-reverse current device effectively blocks the reverse power flow path of the photovoltaic strings, solving potential grid safety hazards. The parallel connection of the bypass switch and the anti-reverse current device ensures the continuity of energy storage power supply by switching when photovoltaic power supply is insufficient, and stores electricity through the energy storage device when photovoltaic power is limited, solving the problem of instability of a single power supply method. It has the benefits of improving power supply stability, avoiding reverse current risks, and promoting photovoltaic power consumption, thereby improving the reliability, economy, and convenience of EL detection. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of the photovoltaic module EL testing device of this utility model;

[0024] Figure 2 This is a schematic diagram of the photovoltaic-side connection branch structure of this utility model;

[0025] Figure 3 This is a schematic diagram of the energy storage side connection branch structure of this utility model;

[0026] Figure 4 This is a schematic diagram of the photovoltaic string and string combiner box structure of this utility model.

[0027] In the diagram: 1. Photovoltaic string; 2. Energy storage device; 3. DC bus; 4. Photovoltaic string inverter; 5. Reverse power supply control component; 6. Photovoltaic side connection branch; 7. Anti-reverse current device; 8. Bypass switch; 9. Energy storage side connection branch; 10. Energy storage inverter setter; 11. Anti-reverse current diode; 12. Overcurrent protection module; 13. Electromagnetic contactor; 14. Switch control module; 15. DC / DC converter; 16. Power regulation module; 17. Current monitoring module; 18. Main bus; 19. Branch bus; 20. Bus protection switch; 21. Battery pack; 22. Constant current control module; 23. Freewheeling diode; 24. Photovoltaic module; 25. String combiner box. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] This utility model provides a technical solution: a photovoltaic module EL testing device. Please refer to [link / reference]. Figure 1 , Figure 2 , Figure 3 and Figure 4 ,include:

[0030] The photovoltaic-storage DC coupling mechanism includes a photovoltaic string 1, an energy storage device 2, a DC bus 3, a photovoltaic string inverter 4, and a reverse power supply control component 5.

[0031] The photovoltaic string 1 is electrically connected to the DC bus 3 through the photovoltaic side connection branch 6. The photovoltaic side connection branch 6 is equipped with an anti-reverse current device 7 and a bypass switch 8 in sequence, and the bypass switch 8 and the anti-reverse current device 7 are connected in parallel.

[0032] The input terminal of the photovoltaic string inverter 4 is electrically connected to the end of the photovoltaic string 1 that is furthest from the DC bus 3, and the output terminal of the photovoltaic string inverter 4 is electrically connected to the external power grid.

[0033] The energy storage device 2 is electrically connected to the DC bus 3 through the energy storage side connection branch 9. The energy storage side connection branch 9 is equipped with an energy storage inverter 10, which is electrically connected to the energy storage device 2.

[0034] The reverse power supply control component 5 is connected to the bypass switch 8, the photovoltaic string inverter 4, and the energy storage inverter setter 10. In reverse power supply mode, the reverse power supply control component 5 controls the bypass switch 8 to close, controls the photovoltaic string inverter 4 to adjust the grid output active power to zero, and simultaneously controls the energy storage inverter setter 10 to make the energy storage device 2 enter constant current working mode. The energy storage device 2 backflows current to the photovoltaic string 1 through the DC bus 3 and the closed bypass switch 8. In normal power generation mode, the energy storage device 2 is connected to the external grid through the energy storage inverter setter 10, the DC bus 3, and the photovoltaic string inverter 4. It charges and discharges according to the photovoltaic operation status. The reverse power supply control component 5 controls the bypass switch 8 to open, and the anti-reverse current device 7 is in working state to prevent the energy storage device 2 from backflowing power to the photovoltaic string 1.

[0035] Please see Figure 1 and Figure 2 The anti-reverse current device 7 includes an anti-reverse current diode 11 and an overcurrent protection module 12. The anti-reverse current diode 11 and the overcurrent protection module 12 are connected in series on the photovoltaic side connection branch 6, and the forward conduction direction of the anti-reverse current diode 11 is consistent with the current direction of the photovoltaic string 1 supplying power to the DC bus 3.

[0036] Please see Figure 1 and Figure 2 The bypass switch 8 includes an electromagnetic contactor 13 and a switch control module 14. The main contacts of the electromagnetic contactor 13 are connected in parallel across the two ends of the anti-reverse current device 7. The switch control module 14 is electrically connected to the coil of the electromagnetic contactor 13 and is signal-connected to the reverse power supply control component 5.

[0037] Please see Figure 1 and Figure 3 The energy storage side connection branch 9 also includes a DC / DC converter 15, which is connected in series between the energy storage device 2 and the DC bus 3, and is electrically connected to the energy storage device 2, the DC bus 3 and the energy storage inverter 10 respectively.

[0038] Please see Figure 1 The photovoltaic string inverter 4 includes a power regulation module 16. The input terminal of the power regulation module 16 is electrically connected to the photovoltaic string 1, the output terminal of the power regulation module 16 is electrically connected to the external power grid, and the power regulation module 16 is signal-connected to the reverse power supply control component 5 for adjusting the output active power to zero in reverse power supply mode.

[0039] Please see Figure 1 It also includes a current monitoring module 17, which is connected in series on the photovoltaic side connection branch 6 and is signal-connected to the reverse power supply control component 5. It is used to monitor the current of the photovoltaic string 1 in real time and feed it back to the reverse power supply control component 5.

[0040] Please see Figure 1 The DC bus 3 includes a main bus 18 and a branch bus 19. One end of the branch bus 19 is electrically connected to the main bus 18, and the other end of the branch bus 19 is electrically connected to the photovoltaic string 1 through the photovoltaic side connection branch 6. The branch bus 19 is equipped with a bus protection switch 20.

[0041] Please see Figure 1 , Figure 2 and Figure 3 The energy storage device 2 includes a battery pack 21 and a constant current control module 22. The constant current control module 22 is electrically connected to the battery pack 21 and is signal-connected to the energy storage inverter 10. It is used to adjust the output current according to the instructions of the energy storage inverter 10 in reverse power supply mode.

[0042] Please see Figure 1 and Figure 2 A freewheeling diode 23 is connected in parallel across the main contacts of the electromagnetic contactor 13. The forward conduction direction of the freewheeling diode 23 is opposite to the current direction when the main contacts of the electromagnetic contactor 13 are closed.

[0043] Please see Figure 4 The photovoltaic string 1 includes multiple photovoltaic modules 24 connected in series, and the output end of the photovoltaic string 1 is provided with a string combiner box 25. The input end of the string combiner box 25 is electrically connected to the photovoltaic modules 24, and the output end of the string combiner box 25 is electrically connected to the DC bus 3 through the photovoltaic side connection branch 6.

[0044] In this scheme: Photovoltaic string 1 (including photovoltaic modules 24 and string combiner box 25) is connected to DC bus 3 (including main bus 18, branch bus 19, and bus protection switch 20) via photovoltaic side connection branch 6 (including anti-reverse current device 7, bypass switch 8, and current monitoring module 17); during normal power generation, the reverse power supply control component 5 controls the bypass switch 8 to open, the anti-reverse current device 7 (anti-reverse current diode 11 and overcurrent protection module 12) works to block the energy storage device 2 from reversing the power supply, and photovoltaic string 1 supplies power to the grid through photovoltaic string inverter 4 (power regulation module 16); during reverse power supply, the reverse power supply control component 5 controls the bypass switch 8 to open. The magnetic contactor 13 closes (assisted by the freewheeling diode 23), causing the active power output of the photovoltaic string inverter 4 to be zero. At the same time, the energy storage device 2 (battery pack 21, constant current control module 22) enters constant current mode through the energy storage side connection branch 9 (energy storage inverter setter 10, DC / DC converter 15), and reverse current flows to the photovoltaic string 1 through the DC bus 3 and the closed bypass switch 8. The current monitoring module 17 monitors the current of the photovoltaic string 1 in real time and feeds it back to the reverse power supply control component 5. The energy storage inverter setter 10 instructs the constant current control module 22 to adjust the output current, and the bus protection switch 20 of the branch bus 19 ensures the safety of the bus.

[0045] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0046] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A photovoltaic module EL testing device, characterized in that, include: A photovoltaic-storage DC coupling mechanism, comprising a photovoltaic string (1), an energy storage device (2), a DC bus (3), a photovoltaic string inverter (4), and a reverse power supply control component (5); The photovoltaic string (1) is electrically connected to the DC bus (3) through the photovoltaic side connection branch (6). The photovoltaic side connection branch (6) is provided with an anti-reverse current device (7) and a bypass switch (8) in sequence, and the bypass switch (8) and the anti-reverse current device (7) are connected in parallel. The input terminal of the photovoltaic string inverter (4) is electrically connected to the end of the photovoltaic string (1) away from the DC bus (3); The energy storage device (2) is electrically connected to the DC bus (3) through the energy storage side connection branch (9). The energy storage side connection branch (9) is equipped with an energy storage inverter (10), and the energy storage inverter (10) is electrically connected to the energy storage device (2). The reverse power supply control component (5) is connected to the bypass switch (8), the photovoltaic string inverter (4), and the energy storage inverter setter (10) respectively.

2. The photovoltaic module EL testing device according to claim 1, characterized in that: The anti-reverse current device (7) includes an anti-reverse current diode (11) and an overcurrent protection module (12). The anti-reverse current diode (11) and the overcurrent protection module (12) are connected in series on the photovoltaic side connection branch (6), and the forward conduction direction of the anti-reverse current diode (11) is consistent with the current direction of the photovoltaic string (1) supplying power to the DC bus (3).

3. The photovoltaic module EL testing device according to claim 2, characterized in that: The bypass switch (8) includes an electromagnetic contactor (13) and a switch control module (14). The main contacts of the electromagnetic contactor (13) are connected in parallel to the two ends of the anti-reverse current device (7). The switch control module (14) is electrically connected to the coil of the electromagnetic contactor (13) and is signal-connected to the reverse power supply control component (5).

4. The photovoltaic module EL testing device according to claim 1, characterized in that: The energy storage side connection branch (9) also includes a DC / DC converter (15), which is connected in series between the energy storage device (2) and the DC bus (3), and is electrically connected to the energy storage device (2), the DC bus (3) and the energy storage inverter (10) respectively.

5. The photovoltaic module EL testing device according to claim 1, characterized in that: The photovoltaic string inverter (4) includes a power regulation module (16), the input terminal of which is electrically connected to the photovoltaic string (1), and the power regulation module (16) is signal-connected to the reverse power supply control component (5).

6. The photovoltaic module EL testing device according to claim 1, characterized in that: It also includes a current monitoring module (17), which is connected in series on the photovoltaic side connection branch (6) and is signal-connected to the reverse power supply control component (5).

7. The photovoltaic module EL testing device according to claim 1, characterized in that: The DC bus (3) includes a main bus (18) and a branch bus (19). One end of the branch bus (19) is electrically connected to the main bus (18), and the other end of the branch bus (19) is electrically connected to the photovoltaic string (1) through the photovoltaic side connection branch (6). A bus protection switch (20) is provided on the branch bus (19).

8. The photovoltaic module EL testing device according to claim 1, characterized in that: The energy storage device (2) includes a battery pack (21) and a constant current control module (22). The constant current control module (22) is electrically connected to the battery pack (21) and is signal-connected to the energy storage inverter (10).

9. The photovoltaic module EL testing device according to claim 3, characterized in that: A freewheeling diode (23) is connected in parallel across the two ends of the main contacts of the electromagnetic contactor (13). The forward conduction direction of the freewheeling diode (23) is opposite to the current direction when the main contacts of the electromagnetic contactor (13) are closed.

10. The photovoltaic module EL testing device according to claim 1, characterized in that: The photovoltaic string (1) includes multiple photovoltaic modules (24) connected in series, and the output end of the photovoltaic string (1) is provided with a string combiner box (25). The input end of the string combiner box (25) is electrically connected to the photovoltaic module (24), and the output end of the string combiner box (25) is electrically connected to the DC bus (3) through the photovoltaic side connection branch (6).

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