Dynamic string assembling device for photovoltaic modules of photovoltaic cells

Abstract

The utility model provides a dynamic string assembling device for a photovoltaic module of a photovoltaic cell, and the device comprises a master controller which is electrically connected with a combiner box; the plurality of sub-controllers are electrically connected with the master controller, each sub-controller is at least electrically connected with the photovoltaic modules on the two photovoltaic group strings, and the plurality of sub-controllers are arranged in series; the sub-controller at least comprises a voltage detection assembly, a switching circuit and a microcontroller, the voltage detection assembly is electrically connected with the photovoltaic assembly, the switching circuit is electrically connected with the microcontroller, and the voltage detection assembly is electrically connected with the microcontroller. The dynamic stringing device for the photovoltaic module of the photovoltaic cell can effectively solve the problem of shading caused by a fixed stringing mode of an existing photovoltaic power station and string voltage deviation caused by the problems of module aging and the like, dynamic stringing of the photovoltaic module is achieved, and the power generation efficiency and reliability of a photovoltaic system are improved.

Description

Technical Field

[0001] This utility model relates to the field of photovoltaic power station technology, and in particular to a dynamic stringing device for photovoltaic cells and photovoltaic modules. Background Technology

[0002] Photovoltaic modules are the core power generation units of solar photovoltaic (PV) power generation, and their operating status directly affects the power generation efficiency of the entire PV power plant. However, in practical applications, PV power plants typically use fixed strings, and factors such as shading and module aging severely restrict the performance of the PV modules. When some PV modules are shaded by trees, buildings, or other structures, or gradually age due to long-term exposure to complex natural environments, string voltage deviation occurs. This deviation disrupts the electrical balance within the PV system, significantly reducing power generation efficiency. Utility Model Content

[0003] The technical problem this invention aims to solve is that the existing photovoltaic power station uses fixed strings, which leads to problems such as shading and component aging, causing string voltage deviation and resulting in electrical imbalance within the photovoltaic system.

[0004] To address the aforementioned problems, this utility model provides a dynamic stringing device for photovoltaic cells and photovoltaic modules, comprising: a main controller electrically connected to a combiner box; a plurality of sub-controllers electrically connected to the main controller, each sub-controller being electrically connected to photovoltaic modules on at least two photovoltaic strings, the plurality of sub-controllers being arranged in series; each sub-controller comprising at least a voltage detection component, a switching circuit, and a microcontroller, the voltage detection component being electrically connected to the photovoltaic modules, the switching circuit being electrically connected to the microcontroller, and the voltage detection component being electrically connected to the microcontroller.

[0005] According to the above-described dynamic stringing device for photovoltaic cells and photovoltaic modules of this utility model, the sub-controller includes at least two voltage detection components, and each voltage detection component is connected to a single photovoltaic module.

[0006] According to the above-mentioned dynamic stringing device for photovoltaic cells and photovoltaic modules of this utility model, the sub-controller includes at least two switching circuits, the switching circuits include a first switching circuit and a second switching circuit, a single first switching circuit is connected in series between two photovoltaic modules, the second switching circuit is connected on the main line, and the second switching circuit is arranged in parallel with the first switching circuit.

[0007] Furthermore, the switching circuit also includes a third switching circuit, which is connected to the photovoltaic modules on the two photovoltaic strings.

[0008] According to the above-described dynamic stringing device for photovoltaic cells and photovoltaic modules of this utility model, the sub-controller further includes a communication module, which is electrically connected to the microcontroller.

[0009] According to the above-described dynamic stringing device for photovoltaic cells and photovoltaic modules of this utility model, the communication module is at least one of a wireless communication module or a wired communication module.

[0010] The technical advantages of this utility model are as follows:

[0011] In the dynamic stringing device for photovoltaic cells and modules provided by this utility model, the main controller receives information from each sub-controller and controls the operation of the entire device according to a preset threshold, ensuring that each photovoltaic string can be combined in an optimal manner to achieve electrical balance within the photovoltaic system. Several sub-controllers are electrically connected to the main controller, and each sub-controller is electrically connected to photovoltaic modules on at least two photovoltaic strings. A voltage detection component acquires the voltage value of each photovoltaic module and transmits the detected voltage signal to the microcontroller. By monitoring the voltage in real time, voltage deviations caused by shading problems or module aging can be detected promptly. When an abnormal voltage is detected in a photovoltaic module, the main controller controls the microcontroller to control the switching circuit to separate the abnormal photovoltaic module from the current string or reassemble it into another suitable string. This effectively solves the string voltage deviations caused by shading problems and module aging in existing fixed stringing methods of photovoltaic power plants, realizing dynamic stringing of photovoltaic modules and improving the power generation efficiency and reliability of the photovoltaic system. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the installation of the dynamic stringing device for photovoltaic cells and photovoltaic modules provided in this embodiment of the present invention in a photovoltaic power station;

[0013] Figure 2 This is a schematic diagram of the circuit structure connection of the sub-controller provided in this embodiment of the utility model;

[0014] Figure 3 This is a schematic diagram of the connection of the switching circuit in an embodiment of this utility model;

[0015] Figure 4 This is a schematic diagram of removing low-voltage photovoltaic module strings in an embodiment of this utility model;

[0016] Figure 5 This is a schematic diagram of another stringing method provided by an embodiment of the present utility model;

[0017] Figure 6 This is a schematic diagram of another stringing method provided by an embodiment of this utility model; Explanation of reference numerals:

[0018] 1. Main controller; 2. Sub-controllers; 21. Voltage detection component; 22. Switching circuit; 221. First switching circuit; 222. Second switching circuit; 223. Third switching circuit; 23. Microcontroller; 24. Communication module;

[0019] 200. Combiner box;

[0020] 300. Photovoltaic string; 301. Photovoltaic module. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0022] The technical problem this invention aims to solve is that the existing photovoltaic power station uses fixed strings, which leads to problems such as shading and component aging, causing string voltage deviation and resulting in electrical imbalance within the photovoltaic system.

[0023] To address the aforementioned problems, this invention provides a dynamic stringing device for photovoltaic cells and modules, such as... Figures 1-3 This diagram illustrates the setup of a dynamic stringing device for photovoltaic cells and modules. The device includes a main controller 1 and several sub-controllers 2. The main controller 1, serving as the core control hub of the entire dynamic stringing device, is electrically connected to the combiner box 200. The main controller 1 receives information from each sub-controller 2 and controls the operation of the entire device according to preset thresholds, ensuring that each photovoltaic string 300 can be combined in an optimal manner to achieve electrical balance within the photovoltaic system. The several sub-controllers 2 are electrically connected to the main controller 1, and each sub-controller 2 is electrically connected to at least two photovoltaic modules 301 on each of the photovoltaic strings 300. Furthermore, the sub-controllers 2 are arranged in series.

[0024] The sub-controller 2 is a key component for realizing the dynamic stringing of photovoltaic modules 301, and it includes at least a voltage detection component 21, a switching circuit 22, and a microcontroller 23. The voltage detection component 21 is electrically connected to the photovoltaic modules 301 and is used to detect the output voltage of the photovoltaic modules 301 in real time. The voltage detection component 21 acquires the voltage value of each photovoltaic module 301 and transmits the detected voltage signal to the microcontroller 23. By monitoring the voltage in real time, voltage deviations caused by shading problems or module aging can be detected promptly.

[0025] The switching circuit 22 is electrically connected to the microcontroller 23. The switching circuit 22 can be an electronic component such as a relay or transistor. Under the control of the main controller 1, the microcontroller 23 can start the switching circuit 22, thereby switching the connection relationship between the photovoltaic module 301 and other photovoltaic modules 301 or photovoltaic strings 300. For example, when an abnormal voltage is detected in a photovoltaic module 301, the microcontroller 23 can control the switching circuit 22 to disconnect the abnormal photovoltaic module 301 from the current string, or the main controller 1 can control different sub-controllers 2 to start and stop the switching circuit 22, so that the disconnected photovoltaic module 301 can be recombined into other suitable strings to ensure the stability of the string voltage.

[0026] The microcontroller 23, acting as the control unit of the sub-controller 2, is electrically connected to both the voltage detection component 21 and the switching circuit 22. The microcontroller 23 receives voltage signals from the voltage detection component 21 and analyzes and processes the voltage data according to preset thresholds. Once a voltage deviation exceeds the set threshold, the microcontroller 23 immediately issues a control command to control the switching circuit 22 to perform corresponding actions, thereby achieving dynamic string adjustment of the photovoltaic modules 301. Furthermore, the microcontroller 23 also uploads the voltage detection data and string adjustment information to the main controller 1 for global monitoring and scheduling management.

[0027] In some alternative embodiments, the voltage detection component described above may be a digital voltmeter PD284U-9D4-3A, or a low-power voltage detector FS61C series from Pansea Microelectronics.

[0028] In some alternative embodiments, the switching circuit 22 described above may employ common power transistors, such as 9012, 9013, 9014, 9022, 8050, 8550 transistors, 2SA, 2SB, 2SC, 2SD series transistors (e.g., 2SA1787, 2SB1202, 2SC2458, 2SD200 transistors), 2N series transistors (e.g., 2N2222, 2N3906, 2N4400), BC series transistors (e.g., BC807, BC574, BC550 transistors), KTA series transistors, KSA series transistors, 3AD, 3AG, 3AK, 3AX, 3CA, 3CK, 3DK series transistors, MMBT, FMMT series transistors, 3DD series transistors, etc.

[0029] In some alternative embodiments, the microcontrollers described above may be PIC series (Microchip Technology) such as PIC16F84, ATmega series (Microchip Technology) such as ATmega328, 8051 series (Intel) such as P89V51RD2, MSP430 series (Texas Instruments) such as MSP430G2553, AVR series (Microchip Technology) such as ATtiny85, STM32 series, etc., and the overall control may be a programmable computer, etc.

[0030] In actual operation, in some embodiments, the dynamic stringing device for photovoltaic cells and modules operates according to the following workflow:

[0031] Voltage detection stage: The voltage detection component 21 in each sub-controller 2 detects the output voltage of the photovoltaic module 301 connected to it in real time, and transmits the detected voltage signal to the microcontroller 23. The microcontroller 23 transmits the voltage signal to the main controller 1 through the communication module.

[0032] Data analysis and judgment phase: The main controller 1 analyzes the received voltage data to determine whether the voltage of each photovoltaic module 301 is within the normal range. If the voltage deviation of a photovoltaic module 301 exceeds the set threshold, it is considered that the photovoltaic module 301 has an abnormality, and the main controller 1 needs to adjust the string. For example, for a photovoltaic module 301 with 15 cells connected in series, its open circuit voltage threshold is set to 22V.

[0033] String adjustment phase: Based on the analysis results, the main controller 1 sends instructions to the sub-controller 2. The microcontroller 23 of the sub-controller 2 sends control instructions to the switching circuit 22, controlling the corresponding switching action in the switching circuit 22 to separate the abnormal photovoltaic module 301 from the current string or reassemble it into other suitable strings. Simultaneously, the microcontroller 23 uploads the string adjustment information to the main controller 1. For example, ... Figure 4 The open-circuit voltage range of a normal single battery string is 360V~540V. Each battery string has 15 photovoltaic modules. When it is detected that the voltage of one photovoltaic module in a battery string is less than or equal to 22V, and the voltage of the other photovoltaic modules is 30V, the microcontroller 23 controls the switching circuit 22 to disconnect the photovoltaic module 301 with a voltage of less than or equal to 22V from the battery string. At this time, the voltage of the battery string formed by the other 14 battery modules 301 connected in series is 420V, which meets the power generation requirements.

[0034] Global Monitoring and Management Phase: The main controller 1 receives string adjustment information from each sub-controller 2, and performs global monitoring and management of the string status of the entire photovoltaic system. Based on the feedback information from each sub-controller 2, the main controller 1 can further optimize the string scheme, ensure the electrical balance within the entire photovoltaic system, and improve the efficiency and stability of photovoltaic power generation.

[0035] For example: in another embodiment, such as Figure 5 The normal open-circuit voltage range of a single battery string is 360~540V. Each battery string contains 15 photovoltaic modules. When a certain period of time is detected:

[0036] The voltage of the five photovoltaic modules in the first battery string is 20V~22V, and the voltage of the other ten photovoltaic modules is 25V~35V.

[0037] The voltage of the 7 photovoltaic modules in the second battery string is 18V~22V, while the voltage of the other 8 photovoltaic modules is 25V~35V.

[0038] The voltage of the six photovoltaic modules in the third battery string is 18V~22V, while the voltage of the other nine photovoltaic modules is 30V~32V.

[0039] To achieve a voltage of 360~540V for the battery strings, the main controller 2 sorts the voltages of the photovoltaic modules in the first, second, and third battery strings. Photovoltaic modules with a voltage less than or equal to 22V are detected and switched on / off by the microcontroller-controlled switching circuit 22. Then, the photovoltaic modules with a voltage less than or equal to 22V in the first, second, and third battery strings are re-connected into a single battery string with a voltage of 365V.

[0040] The photovoltaic modules with voltage values ​​of 25V~35V in the first, second, and third battery strings are re-stringed into two battery strings. For example, the remaining 10 photovoltaic modules 301 in the first string and the 4 photovoltaic modules 301 in the second string are re-stringed to form a battery string of 14 photovoltaic modules with a voltage of 420V. The remaining 4 photovoltaic modules in the second string and the 9 photovoltaic modules in the third string are re-stringed to form a battery string of 13 photovoltaic modules with a voltage of 390V.

[0041] Reference Figure 6 In another embodiment, the open-circuit voltage range of a normal single-string battery is 360~540V, and each string contains 15 photovoltaic modules.

[0042] The voltage of the five photovoltaic modules in the first battery string is 20V~22V, and the voltage of the other ten photovoltaic modules is 25V~35V.

[0043] The voltage of the 7 photovoltaic modules in the second battery string is 18V~22V, while the voltage of the other 8 photovoltaic modules is 25V~35V.

[0044] The voltage of the six photovoltaic modules in the third battery string is 18V~22V, while the voltage of the other nine photovoltaic modules is 30V~32V.

[0045] The main controller 1 sorts the photovoltaic modules based on the voltage detected by the sub-controller 2. After sorting the photovoltaic module voltages in the three battery strings, it reassembles them, sorting them from high to low voltage. Then, the first, second, and third battery strings are reordered into three strings in descending order of voltage value. Figure 6 After reordering, the 13 photovoltaic modules with voltage values ​​of 30V~35V from the original first, second, and third strings are re-stringed into one string, and the voltage of the re-stringed battery is 403V; the 14 photovoltaic modules with voltage values ​​of 25V~30V from the original first, second, and third strings are re-stringed into one string, and the voltage of the re-stringed battery is 407V; the 18 photovoltaic modules with voltage values ​​of 18V~22V from the original first, second, and third strings are re-stringed into one string, and the voltage of the re-stringed battery is 365V.

[0046] Reference Figures 5-6 In some embodiments, photovoltaic module strings can be allocated according to voltage requirements, and stringing can be stopped when the voltage after stringing reaches 360~540V. Through the above specific implementation methods, the photovoltaic cell and photovoltaic module dynamic stringing device of this utility model can effectively solve the string voltage deviation caused by shading problems and module aging problems resulting from the fixed stringing method of existing photovoltaic power plants, realize dynamic stringing of photovoltaic modules, and improve the power generation efficiency and reliability of photovoltaic systems.

[0047] Continue to refer to Figure 1 In some embodiments, the sub-controller 2 includes at least two voltage detection components 21, and each voltage detection component 21 is connected to a single photovoltaic module 301, so that each photovoltaic module 301 can be independently and accurately monitored for its output voltage, which further improves the detection accuracy of the photovoltaic module status, helps to detect voltage abnormalities caused by shading, module aging and other problems more timely and accurately, and allows for stringing as appropriate.

[0048] Taking a single sub-controller 2 connected to three photovoltaic modules 301 as an example, the sub-controller 2 is equipped with three voltage detection components 21, each of which is electrically connected to a corresponding photovoltaic module 301. Based on the analysis results, the microcontroller 23 sends control commands to the switching circuit 22, controlling the corresponding switch action in the switching circuit 22 to separate the abnormal photovoltaic module 301 from the current string or reassemble it into another suitable string. Simultaneously, the microcontroller 23 records detailed information about the string adjustment, including the adjustment time, the photovoltaic module number being adjusted, and the adjusted string connection method, and uploads this information to the main controller 1.

[0049] Continue to refer to Figures 1-3 In a preferred embodiment, the sub-controller 2 includes at least two switching circuits 22. Each switching circuit 22 includes a first switching circuit 221 and a second switching circuit 222. The first switching circuit 221 is connected in series between two photovoltaic modules 301. The second switching circuit 222 is connected to the main line and is connected in parallel with the first switching circuit 221. The switching circuit 22 also includes a third switching circuit 223, which is connected to the photovoltaic modules 301 on the two photovoltaic strings 300. It should be noted that although... Figure 3 In the photovoltaic module 301, a first switching circuit 221 is connected to both the positive and negative terminals. Those skilled in the art may also connect the first switching circuit 221 to either the positive or negative terminal of the photovoltaic module 301.

[0050] This design approach provides greater flexibility and reliability for the connection control of photovoltaic module 301, enabling more precise dynamic string adjustment of photovoltaic modules to address voltage anomalies caused by various conditions such as shading and module aging.

[0051] Continue to refer to Figure 1 In addition to the original voltage detection component 21, switching circuit 22, and microcontroller 23, sub-controller 2 also includes a communication module 24, which is electrically connected to the microcontroller 23. The addition of the communication module 24 enables sub-controller 2 to perform efficient and stable data interaction with the main controller 1, realizing real-time transmission and coordinated control of information within the photovoltaic system.

[0052] Taking a photovoltaic power generation system containing multiple sub-controllers 2 as an example, each sub-controller 2 is responsible for managing a certain number of photovoltaic modules 301. Through the communication module 24, each sub-controller 2 can promptly upload the detected photovoltaic module voltage data, switching circuit status information, and string adjustment records to the main controller 1, and simultaneously receive control commands and global optimization strategies issued by the main controller 1, thereby improving the operating efficiency and reliability of the entire photovoltaic system.

[0053] Wireless communication modules can employ ZigBee or LoRa modules. ZigBee modules can meet the data transmission requirements between sub-controller 2 and main controller 1. Through ZigBee modules, sub-controller 2 can wirelessly transmit real-time data to main controller 1, reducing wiring complexity and cost. When the photovoltaic power station is distributed over a wide area, LoRa modules can ensure stable communication between sub-controller 2 and main controller 1. The LoRa modem chip can communicate with microcontroller 23 via an SPI interface, enabling long-distance data transmission. The low power consumption of LoRa modules also allows sub-controller 2 to save energy during long-term operation.

[0054] Wired communication modules can include RS485 modules and Ethernet modules. In photovoltaic power generation systems, RS485 modules can be used for wired connections between sub-controllers 2 and the main controller 1. For example, using a MAX485 chip as an RS485 transceiver can convert the TTL level signals of microcontroller 23 into RS485 differential signals for transmission. Multiple sub-controllers 2 can be connected to the RS485 bus for data interaction with the main controller 1, providing stable and reliable communication suitable for scenarios with high real-time communication requirements. Ethernet modules can connect sub-controllers 2 to a local area network (LAN) for high-speed communication with the main controller 1. Through Ethernet, sub-controllers 2 can upload large amounts of detection data and status information in real time, while simultaneously receiving complex control commands from the main controller 1.

[0055] Regardless of whether a wireless or wired communication module is selected, the communication module 24 is electrically connected to the microcontroller 23 through a specific interface. For wireless communication modules, data exchange with the microcontroller 23 is typically achieved through interfaces such as UART, SPI, or I2C; for wired communication modules, such as RS485 modules, the connection is via a UART interface, and Ethernet modules are connected via SPI or a parallel interface. During the connection process, attention must be paid to interface level matching and signal isolation to ensure communication stability and reliability.

[0056] Finally, it should be noted that each of the above modules is connected to a power supply module, which can provide continuous power; further details will not be provided here. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion.

[0057] In the description of the embodiments of this utility model, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this utility model, "multiple" means two or more, unless otherwise explicitly defined.

[0058] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the present invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0059] In the description of the embodiments of this utility model, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0060] In the description of the embodiments of this utility model, the technical terms "upper", "lower", "front", "rear", "left", "right", "clockwise", "counterclockwise", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model.

[0061] In the description of the embodiments of this utility model, unless otherwise explicitly specified and limited, the technical terms such as "set," "equipped with," "installed," "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, an integral part, or a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this utility model can be understood according to the specific circumstances.

[0062] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dynamic stringing device for photovoltaic cells and photovoltaic modules, characterized in that, include: The main controller (1) is electrically connected to the combiner box (200); A plurality of sub-controllers (2) are electrically connected to the main controller (1), each of the sub-controllers (2) being electrically connected to at least two photovoltaic modules (301) on two photovoltaic strings (300), and the plurality of sub-controllers (2) are arranged in series; The sub-controller (2) includes at least a voltage detection component (21), a switching circuit (22), and a microcontroller (23). The voltage detection component (21) is electrically connected to the photovoltaic module (301), the switching circuit (22) is electrically connected to the microcontroller (23), and the voltage detection component (21) is electrically connected to the microcontroller (23).

2. The dynamic stringing device for photovoltaic cells and modules according to claim 1, characterized in that, The sub-controller (2) includes at least two voltage detection components (21), and each voltage detection component (21) is connected to a single photovoltaic module (301).

3. The dynamic stringing device for photovoltaic cells and modules according to claim 1 or 2, characterized in that, The sub-controller (2) includes at least two switching circuits (22), each of which includes a first switching circuit (221) and a second switching circuit (222). The first switching circuit (221) is connected in series between two photovoltaic modules (301), and the second switching circuit (222) is connected to the main line. The second switching circuit (222) is connected in parallel with the first switching circuit (221).

4. The dynamic stringing device for photovoltaic cells and modules according to claim 3, characterized in that, The switching circuit (22) also includes a third switching circuit (223), which is connected to the photovoltaic modules (301) on the two photovoltaic strings (300).

5. The dynamic stringing device for photovoltaic cells and modules according to claim 1 or 2, characterized in that, The sub-controller (2) also includes a communication module (24), which is electrically connected to the microcontroller (23).

6. The dynamic stringing device for photovoltaic cells and modules according to claim 5, characterized in that, The communication module (24) is at least one of a wireless communication module or a wired communication module.

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