Anti-backflow system, power generation system, anti-backflow method, device and storage medium

Abstract

The present application relates to an anti-backflow system, a power generation system, an anti-backflow method, an apparatus and a storage medium. The anti-backflow system of the present application includes: at least one switch; each switch is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the switch, forming a photovoltaic string and connected to an inverter; the switch is configured to detect the current flow direction of a single photovoltaic module; and in the case of reverse current flow, enter the shutdown state to cut off the connection between the single photovoltaic module and the photovoltaic string, and make the single photovoltaic module be bypassed from the power transmission path from the photovoltaic string to the inverter; in the case of normal current flow, enter the connected state to connect the single photovoltaic module in series to the photovoltaic string. The current detection, reverse flow blocking and automatic recovery of the embodiments of the present application can all be automatically controlled by the system without manual intervention, which greatly reduces the maintenance cost of the power station.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic power generation technology, and in particular to a backflow prevention system, a power generation system, a backflow prevention method, a device and a storage medium. Background Art

[0002] During the installation and use of solar photovoltaic modules, on the one hand, due to improper installation, the number of photovoltaic modules installed between photovoltaic strings is different under the same MPPT (Max-Power-Point-Tracking) path or different MPPT paths, resulting in voltage differences, which in turn causes current backflow between different photovoltaic strings / modules, causing serious accidents such as abnormal power generation and fire before the photovoltaic modules are put into use.

[0003] On the other hand, even if different PV strings are installed with the same number of PV modules in strict accordance with the specifications, in reality, due to shading, optimizer control and other factors, there will still be a high voltage difference between different PV strings / modules, causing current backflow, resulting in severe heating of the modules, damage to the modules, and even fire accidents.

[0004] Therefore, it is crucial to prevent possible current backflow, avoid abnormal accidents, and ensure the safety of solar photovoltaic module power generation systems. Summary of the invention

[0005] In view of this, the embodiments of the present application provide a backflow prevention system, a backflow prevention photovoltaic power generation system, a backflow prevention method, a control device, a system platform end and a storage medium to solve at least one problem existing in the background technology.

[0006] In a first aspect, an embodiment of the present application provides a backflow prevention system, the backflow prevention system comprising:

[0007] At least one switch; each switch is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the switch to form a photovoltaic string and connected to an inverter;

[0008] The circuit breaker is configured to detect the current flow direction of a single photovoltaic component; and when the current flow direction is reversed, it enters a shutdown state to cut off the connection between the single photovoltaic component and the photovoltaic string, and bypasses the single photovoltaic component from the power transmission path from the photovoltaic string to the inverter; when the current flow direction is normal, it enters a connected state to connect the single photovoltaic component in series to the photovoltaic string.

[0009] In combination with the first aspect, in an optional implementation,

[0010] The circuit breaker comprises:

[0011] An electronic switch circuit is configured to switch the switch to an off state or a connected state; a first signal terminal of the electronic switch circuit is connected to an input terminal of the bypass diode circuit and is configured as a first terminal of the switch; a second signal terminal of the electronic switch circuit is connected to a first power supply terminal of a single photovoltaic module and is configured as a third terminal of the switch;

[0012] A detection circuit configured to detect the current flow direction of a single photovoltaic component; a first detection terminal of the detection circuit is connected to the second power supply terminal of the single photovoltaic component and configured as the fourth terminal of the circuit breaker; a second detection terminal of the detection circuit is connected to the output terminal of the bypass diode circuit and configured as the second terminal of the circuit breaker; wherein the first terminal and the second terminal are used to connect to the power transmission path from the photovoltaic string to the inverter; and

[0013] The bypass diode circuit is configured to unidirectionally conduct the first wiring terminal and the second wiring terminal so that when the circuit breaker is in the off state, the power transmission path between the photovoltaic string and the inverter is connected.

[0014] In combination with the first aspect, in an optional implementation,

[0015] The switch includes at least one of the following:

[0016] The electronic switch circuit comprises a first switch device; a first end of the first switch device is configured as a first signal end of the electronic switch circuit, and a second end of the first switch device is configured as a second signal end of the electronic switch circuit;

[0017] The detection circuit comprises a first current sensor; a first power input terminal of the first current sensor is configured as a first detection terminal of the detection circuit, and a second power input terminal of the first current sensor is configured as a second detection terminal of the detection circuit;

[0018] The bypass diode circuit includes a first diode; a first electrode of the first diode is connected to the first terminal, and a second electrode of the first diode is connected to the second terminal.

[0019] In combination with the first aspect, in an optional implementation,

[0020] The anti-backflow system includes at least one of the following:

[0021] A first breaker; the first breaker includes a first switching device, a first current sensor and a first diode;

[0022] A second breaker; the second breaker includes a second switching device, a second current sensor and a second diode;

[0023] The third breaker includes a third switch device, a third current sensor and a third diode;

[0024] Wherein, when the second switch is adjacent to one side of the first switch, the first end of the first switch device is respectively connected to the first pole of the first diode, the second power input end of the second current sensor and the second pole of the second diode; the second end of the first switch device is connected to the first power end of the first photovoltaic component; the first power input end of the first current sensor is connected to the second power end of the first photovoltaic component; the second power input end of the first current sensor is connected to the second pole of the first diode and is connected to the inverter;

[0025] The first end of the second switch device is connected to the first electrode of the second diode, and the second end of the second switch device is connected to the first power supply end of the second photovoltaic component; the first power supply input end of the second current sensor is connected to the second power supply end of the second photovoltaic component;

[0026] In a case where the third switch is adjacent to the other side of the first switch, the first end of the third switch device is respectively connected to the first pole of the third diode, the second power input end of the first current sensor and the second pole of the first diode; the second end of the third switch device is connected to the first power end of the third photovoltaic component; the first power input end of the third current sensor is connected to the second power end of the third photovoltaic component; the second power input end of the third current sensor is connected to the second pole of the third diode and is connected to the inverter;

[0027] The first end of the first switch device is connected to the first electrode of the first diode, the second end of the first switch device is connected to the first power supply end of the first photovoltaic component; the first power supply input end of the first current sensor is connected to the second power supply end of the first photovoltaic component.

[0028] In combination with the first aspect, in an optional implementation,

[0029] The switch is configured to obtain power supply from a photovoltaic component.

[0030] In combination with the first aspect, in an optional implementation,

[0031] The anti-backflow system also includes a system platform end, which is respectively connected to each of the circuit breakers for communicating with each other, and is used to monitor the current flow direction of each photovoltaic component and control the shutdown state and connection state of each of the circuit breakers.

[0032] In combination with the first aspect, in an optional implementation,

[0033] The backflow prevention system also includes a communication base station, which is respectively connected to the system platform end and each of the circuit breakers for transmitting communication data and instructions between the system platform end and the circuit breakers.

[0034] In combination with the first aspect, in an optional implementation,

[0035] The switch includes a control device, which is communicatively connected to the system platform end and is respectively connected to a control end of an electronic switch circuit in the switch and a signal output end of a detection circuit in the switch, and is used to control the switch to enter an off state or a connected state according to output data of the detection circuit; and / or, transmit the output data to the system platform end so that the system platform end generates a control instruction according to the output data, and controls the switch to enter an off state or a connected state according to the control instruction.

[0036] In a second aspect, an embodiment of the present application provides a backflow prevention photovoltaic power generation system, the backflow prevention photovoltaic power generation system comprising:

[0037] At least one photovoltaic string circuit; each photovoltaic string circuit is connected in parallel and is respectively connected to an inverter through a power transmission path;

[0038] Wherein, the photovoltaic string circuit comprises at least one photovoltaic module and the anti-backflow system as described in the first aspect;

[0039] The output electric energy of each photovoltaic module is integrated into the power transmission path through a single circuit breaker in the anti-backflow system to form a photovoltaic string in which adjacent photovoltaic modules are connected end to end through circuit breakers.

[0040] In a third aspect, an embodiment of the present application provides a backflow prevention method, which is applied to a backflow prevention system. The backflow prevention method includes:

[0041] During the operation of connecting a single photovoltaic module in series to a photovoltaic string through a disconnector, the current flow direction of the single photovoltaic module is obtained; wherein each of the disconnectors is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the disconnectors to form a photovoltaic string and connected to an inverter;

[0042] When the current flow direction is opposite to the preset safe flow direction, the switch is controlled to enter the shutdown state to cut off the connection between the single photovoltaic component and the photovoltaic string, so that the single photovoltaic component is bypassed from the power transmission path from the photovoltaic string to the inverter;

[0043] Starting timing when the shutoff device enters the shutoff state to obtain a first duration;

[0044] When the first duration reaches a first threshold time, the current direction is reacquired, and when the reacquired current direction is the same as the preset safety direction, the circuit breaker is controlled to maintain the connected state; when the reacquired current direction is opposite to the preset safety direction, the process returns to the step of controlling the circuit breaker to enter the disconnected state.

[0045] In conjunction with the third aspect, in an optional implementation manner, the backflow prevention method further includes:

[0046] After the power plant is built and put into operation, the current flow direction of each photovoltaic module is obtained;

[0047] Reporting the current flow direction to the system platform end;

[0048] Acquire a whole string of shutdown instructions issued by the system platform end when the current flow direction is opposite to the preset safe flow direction;

[0049] Under the control of the whole string shutdown instruction, all the circuit breakers in the photovoltaic string where the photovoltaic component is located are controlled to enter a shutdown state;

[0050] Acquire a whole series of opening instructions issued by the system platform end at a second threshold time after issuing the whole series of closing instructions;

[0051] Under the control of the whole string start instruction, all the circuit breakers in the photovoltaic string are controlled to enter a connected state to reacquire the current flow direction of all photovoltaic modules in the photovoltaic string, and return to the step of reporting the current flow direction to the system platform end, so that when the current flow direction of all photovoltaic modules is the same as the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to maintain a connected state; when there is a current flow direction in all the photovoltaic modules that is opposite to the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to enter a closed state.

[0052] In a fourth aspect, an embodiment of the present application provides a backflow prevention method, which is applied to a system platform end in a backflow prevention system, and the backflow prevention method includes:

[0053] Obtain the current flow direction of each photovoltaic module;

[0054] When the current flow direction of any photovoltaic module is opposite to the preset safe flow direction, a whole string shutdown instruction is generated and sent to all the circuit breakers in the photovoltaic string where the photovoltaic module is located, so as to control all the circuit breakers in the photovoltaic string to enter the shutdown state;

[0055] After the entire string of shutdown instructions is issued, start timing to obtain a second duration;

[0056] When the second duration reaches the second threshold time, a whole string opening instruction is issued to all the switches in the photovoltaic string to control all the switches in the photovoltaic string to enter a connected state, and return to the step of obtaining the current flow direction of each photovoltaic component.

[0057] In a fifth aspect, an embodiment of the present application provides a control device, the control device comprising:

[0058] A first processing module is used to obtain the current flow direction of a single photovoltaic component during the operation process of connecting a single photovoltaic component in series with a photovoltaic string through a circuit breaker;

[0059] The second processing module is used to control the switch to enter a shutdown state when the current flow direction is opposite to the preset safe flow direction, so as to cut off the connection between the single photovoltaic component and the photovoltaic string, so that the single photovoltaic component is bypassed from the power transmission path from the photovoltaic string to the inverter;

[0060] A third processing module, configured to start timing when the switch enters the shutdown state to obtain a first duration;

[0061] The fourth processing module is used to reacquire the current flow direction when the first duration reaches a first threshold time, and when the reacquired current flow direction is the same as the preset safety direction, control the circuit breaker to maintain the connection state; when the reacquired current flow direction is opposite to the preset safety direction, return to the first processing module.

[0062] In a sixth aspect, an embodiment of the present application provides a system platform end, wherein the system platform end includes:

[0063] A fifth processing module, used to obtain the current flow direction of each photovoltaic module;

[0064] The sixth processing module is used to generate and send a whole string shutdown instruction to all the switches in the photovoltaic string where the photovoltaic component is located when the current flow direction of any photovoltaic component is opposite to the preset safe flow direction, so as to control all the switches in the photovoltaic string to enter the shutdown state;

[0065] A seventh processing module, configured to start timing after the entire string of shutdown instructions is issued to obtain a second duration;

[0066] The eighth processing module is used to send a whole string opening instruction to all the switches in the photovoltaic string when the second duration reaches the second threshold time, so as to control all the switches in the photovoltaic string to enter a connected state, and return to the fifth processing module.

[0067] In a seventh aspect, an embodiment of the present application provides a control device, the control device comprising:

[0068] a memory storing instructions; and

[0069] A processor is configured to execute the instructions to implement the backflow prevention method as described in the third aspect.

[0070] In an eighth aspect, an embodiment of the present application provides a system platform end, wherein the system platform end includes:

[0071] a memory storing instructions; and

[0072] A processor is configured to execute the instructions to implement the anti-backflow method as described in the fourth aspect.

[0073] In a ninth aspect, an embodiment of the present application provides a storage medium, in which a computer program is stored. When the computer program is executed, it can implement the anti-backflow method as described in the third aspect or the anti-backflow method as described in the fourth aspect.

[0074] The beneficial effects of the technical solution provided by the embodiment of the present application include: the embodiment of the present application configures a connection disconnector for each photovoltaic module, and the adjacent photovoltaic modules are connected end to end through the disconnector to form a photovoltaic string, so as to realize real-time monitoring of the current flow direction of a single photovoltaic module and adjacent photovoltaic modules, and detect the current backflow. Therefore, once the current flow direction of a single photovoltaic module is reversed, the disconnector enters the shutdown state, and the circuit breaker can cut off the passage between the single photovoltaic module and the adjacent photovoltaic module, cut off the connection between the single photovoltaic module and the photovoltaic string, cut off the current backflow passage, and prevent the reverse flow from occurring, thereby preventing the reverse flow between the photovoltaic modules and the photovoltaic strings, avoiding abnormal accidents, and ensuring the safety of the solar photovoltaic module power generation system. Therefore, it can be compatible with the backflow prevention between the photovoltaic module and the photovoltaic string at the same time, and can realize the backflow prevention during the series connection of the photovoltaic modules in the early stage of the power station construction; and the quick installation, access and disassembly operation of a single photovoltaic module can be realized through the disconnector, which facilitates the maintenance of the photovoltaic power generation system, and has high reliability, simple structural design and high cost performance. After the current flow returns to normal, the circuit breaker enters the connected state and automatically resumes power generation; and current detection, reverse current blocking and automatic recovery can all be automatically controlled by the system without human intervention, greatly reducing the maintenance cost of the power station.

[0075] Additional aspects and advantages of the embodiments of the present application will be given in part in the description below and in part will become apparent from the description below or will be learned through the practice of the embodiments of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0076] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0077] Figure 1 This is a schematic diagram of a principle block diagram of Example 1 of the anti-backflow system in the embodiment of the present application;

[0078] Figure 2 This is a schematic diagram of a principle block diagram of Example 2 of the anti-backflow system in the embodiment of the present application;

[0079] Figure 3 A schematic diagram of a specific example of current flow in an embodiment of the present application;

[0080] Figure 4 This is a schematic diagram of a principle block diagram of Example 3 of the anti-backflow system in the embodiments of the present application;

[0081] Figure 5 A schematic diagram of a principle block diagram of a specific example of a circuit breaker in an embodiment of the present application;

[0082] Figure 6 A schematic diagram of a principle block diagram of a specific example of an anti-backflow photovoltaic power generation system in an embodiment of the present application;

[0083] Figure 7 This is a schematic flow chart of Example 1 of the backflow prevention method in the embodiments of the present application;

[0084] Figure 8 This is a schematic flow chart of Example 2 of the backflow prevention method in the embodiment of the present application;

[0085] Fig. 9 This is a schematic flow chart of Example 3 of the backflow prevention method in the embodiments of the present application;

[0086] Fig.10 A schematic diagram of a principle block diagram of a specific example of a control device in an embodiment of the present application;

[0087] Fig.11 A schematic diagram of a specific example of a system platform end in an embodiment of the present application;

[0088] Fig.12 It is a structural diagram of a specific example of a control device or system platform in an embodiment of the present application. DETAILED DESCRIPTION

[0089] In order to make the technical solutions and beneficial effects of the present application more obvious and easy to understand, the following is a detailed description by listing specific embodiments. The drawings are not necessarily drawn to scale, and local features may be enlarged or reduced to more clearly show the details of the local features; unless otherwise defined, the technical and scientific terms used herein have the same meanings as those in the technical field to which the present application belongs.

[0090] The embodiments of the present application are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present application. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, in a certain embodiment, the solution after removing some steps can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementations in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementations of other embodiments.

[0091] In each embodiment of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

[0092] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0093] In the embodiments of the present application, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "said", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.

[0094] In the embodiments of the present application, "plurality" refers to two or more.

[0095] In some embodiments, the terms "at least one", "one or more", "a plurality of", "multiple", etc. can be used interchangeably.

[0096] The prefixes such as "first" and "second" in the embodiments of the present application are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, value or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute unnecessary restrictions due to the use of prefixes. For example, the numerical value of the description object is not limited by the ordinal number, and can be one or more. Take "first device" as an example, where the numerical value of "device" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different.

[0097] In some embodiments, the term "connection" may indicate that an electrical signal or data is transmitted between a connected end and a connected end, and may be understood as "electrical connection", "communication connection", etc. "Connection" may be a direct connection between two components, an indirect connection established through other components, internal communication between two components, or any other possible connection form.

[0098] This specification provides method operation steps such as embodiments or flow charts, but may include more or fewer operation steps based on conventional or non-creative labor. The order of steps listed in the embodiments is only one way of executing the order of many steps and does not represent the only execution order. When the actual device, system or server product is executed, it can be executed in the order of the method shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment).

[0099] In the process of implementing this application, the inventor found that the related technology has the following problems:

[0100] At present, in order to ensure the safety of solar photovoltaic module power generation systems and prevent possible current backflow, there are mainly the following anti-backflow solutions for photovoltaic modules / photovoltaic strings:

[0101] (1) For a single PV module / PV string, the voltage on the MOS diode connected in series with the output end of the PV module / PV string is monitored to determine whether current backflow occurs, and then other electronic switches are used to cut off the current backflow path to protect the PV module / PV string. However, the voltage monitoring and cut-off control process of this solution is complicated and costly.

[0102] (2) For the entire PV module / PV string, a traditional high-voltage axial diode is used to cut off the current backflow between different PV modules / PV strings; however, this solution has a problem of excessive forward voltage drop under normal circumstances, consuming tens of watts of power and causing severe heat generation, high power consumption, and low reliability.

[0103] To this end, an embodiment of the present application provides an anti-backflow system that can be applied to solar photovoltaic power generation, etc. Figure 1 The schematic diagram of the principle block diagram of Example 1 of the anti-backflow system in the embodiment of the present application is shown. As shown in the figure, the anti-backflow system includes:

[0104] At least one switch 101; each switch 101 is connected to a single photovoltaic (PV) module 102, so that adjacent PV modules 102 are connected end to end through the switch 101 to form a PV string and connected to an inverter;

[0105] The circuit breaker 101 is configured to detect the current flow direction of a single photovoltaic component 102; and when the current flow direction is reversed, it enters a shutdown state to cut off the connection between the single photovoltaic component 102 and the photovoltaic string, so that the single photovoltaic component 102 is bypassed from the power transmission path from the photovoltaic string to the inverter; when the current flow direction is normal, it enters a connected state to connect the single photovoltaic component 102 in series with the photovoltaic string.

[0106] In this way, the embodiment of the present application configures a connection switch for each photovoltaic module, and the adjacent photovoltaic modules are connected end to end through the switch to form a photovoltaic string, which realizes real-time monitoring of the current flow direction of a single photovoltaic module and adjacent photovoltaic modules, and detects the current backflow. Therefore, once the current flow direction of a single photovoltaic module is reversed, the switch enters the shutdown state, and the switch can cut off the passage between the single photovoltaic module and the adjacent photovoltaic module, cut off the connection between the single photovoltaic module and the photovoltaic string, cut off the current backflow passage, and prevent the reverse flow from occurring, thereby preventing the reverse flow between the photovoltaic modules and the photovoltaic strings, avoiding abnormal accidents, and ensuring the safety of the solar photovoltaic module power generation system. Therefore, it can be compatible with the backflow prevention between the photovoltaic module and the photovoltaic string at the same time, and can realize the backflow prevention during the initial stage of the power station construction and the series connection of the photovoltaic modules; and the switch can realize the rapid installation, access and disassembly operation of a single photovoltaic module, which facilitates the maintenance of the photovoltaic power generation system, and has high reliability, simple structural design and high cost performance. After the current flow returns to normal, the circuit breaker enters the connected state and automatically resumes power generation; and current detection, reverse current blocking and automatic recovery can all be automatically controlled by the system without human intervention, greatly reducing the maintenance cost of the power station.

[0107] In the embodiment of the present application, the specific structure of the circuit breaker 101 can be set according to actual needs, and can have the performance of fast switching. The series connection of photovoltaic modules can form a photovoltaic string. The number of photovoltaic modules can be N, the number of photovoltaic strings can be M, and N and M can be natural numbers greater than or equal to 1.

[0108] In some examples, the circuit breaker 101 may detect the current flow direction of a single photovoltaic component 102 through a current sensor, or may detect the current flow direction through other detection methods, such as using a magnetic induction sensor, a Hall effect device, etc.

[0109] In other examples, the circuit breaker 101 can switch between the off state and the on state through a controllable switch, such as an electronic switch.

[0110] In an optional implementation, the switch 101 includes:

[0111] The electronic switch circuit 11 is configured to switch the circuit breaker 101 to an off state or a connected state; the first signal terminal of the electronic switch circuit 11 is connected to the input terminal of the bypass diode circuit 13 and is configured as the first terminal A1 of the circuit breaker 101; the second signal terminal of the electronic switch circuit 11 is connected to the first power supply terminal of a single photovoltaic module 102 and is configured as the third terminal A3 of the circuit breaker 101;

[0112] A detection circuit 12 is configured to detect the current flow direction of a single photovoltaic component 102; a first detection terminal of the detection circuit 12 is connected to the second power supply terminal of the single photovoltaic component 102, and is configured as the fourth terminal A4 of the circuit breaker 101; a second detection terminal of the detection circuit 12 is connected to the output terminal of the bypass diode circuit 13, and is configured as the second terminal A2 of the circuit breaker 101; wherein the first terminal A1 and the second terminal A2 are used to connect to the power transmission path from the photovoltaic string to the inverter; and

[0113] The bypass diode circuit 13 is configured to unidirectionally conduct the first wiring terminal A1 and the second wiring terminal A2, so that when the circuit breaker 101 is in the off state, the power transmission path between the photovoltaic string and the inverter is connected.

[0114] In the embodiment of the present application, the first power supply terminal of a single photovoltaic module 102 may be a negative power supply terminal, and the second power supply terminal of a single photovoltaic module 102 may be a positive power supply terminal. In addition, the transmission path of the photovoltaic string and the inverter is connected through the bypass diode circuit 13, that is, by connecting multiple bypass diode circuits in series in the transmission path (such as multiple bypass diodes in series), a high reverse withstand voltage is achieved to avoid breakdown.

[0115] The first terminal A1, the second terminal A2, the third terminal A3 and the fourth terminal A4 of the switch 101 can be set as a quick connection interface, or other forms of connection ports. The first terminal A1 and the second terminal A2 are connected to the power transmission path, and the third terminal A3 and the fourth terminal A4 are respectively connected to the two ends of the power supply of the photovoltaic module, so that the photovoltaic module can be connected to the existing photovoltaic string, so that the photovoltaic module can be quickly installed, connected and disassembled through the switch, which facilitates the maintenance of the photovoltaic power generation system.

[0116] The detection circuit 12 may use a current sensor, or other sensors (such as a voltage sensor) to detect the current flow direction of a single photovoltaic component 102, and may be set according to actual needs.

[0117] refer to Figure 1 In an optional implementation manner, the switch 101 includes at least one of the following:

[0118] The electronic switch circuit 11 includes a first switch device S1; a first end of the first switch device S1 is configured as a first signal end of the electronic switch circuit 11, and a second end of the first switch device S1 is configured as a second signal end of the electronic switch circuit 11;

[0119] The detection circuit 12 includes a first current sensor U1; a first power input terminal of the first current sensor U1 is configured as a first detection terminal of the detection circuit 12, and a second power input terminal of the first current sensor U1 is configured as a second detection terminal of the detection circuit 12;

[0120] The bypass diode circuit 13 includes a first diode D1 ; a first electrode of the first diode D1 is connected to the first wiring terminal A1 , and a second electrode of the first diode D1 is connected to the second wiring terminal A2 .

[0121] In the embodiment of the present application, the first pole of the first diode D1 may be a positive pole, and the second pole of the first diode D1 may be a negative pole, but it is not limited thereto. The positive and negative pole connection method of the first diode D1 may be determined according to the positive and negative poles of the PV component.

[0122] It is understandable that the specific circuit structures of the electronic switch circuit 11, the detection circuit 12 and the bypass diode circuit 13 are not limited thereto (see Figure 1 ), can be set according to actual needs. For example, the electronic switch circuit 11 may include a plurality of switch devices connected in series and / or in parallel, or may also include other devices such as resistors. The detection circuit 12 may also include other devices such as resistors. The bypass diode circuit 13 may include a plurality of diodes connected in series and / or in parallel, or may also include other devices such as resistors.

[0123] In the embodiment of the present application, the first power input terminal of the first current sensor U1 can be a positive power input terminal or a negative power input terminal; accordingly, the second power input terminal of the first current sensor U1 can be a negative power input terminal or a positive power input terminal.

[0124] Figure 2 The schematic diagram of the principle block diagram of Example 2 of the anti-backflow system in the embodiment of the present application is shown. As shown in the figure, in the exemplary embodiment, the anti-backflow system includes at least one of the following:

[0125] The first breaker 1011 includes a first switch device S1, a first current sensor U1 and a first diode D1;

[0126] The second breaker 1012 includes a second switch device S2, a second current sensor U2 and a second diode D2;

[0127] The third breaker 1013 includes a third switch device S3, a third current sensor U3 and a third diode D3;

[0128] Wherein, when the second switch 1012 is adjacent to one side of the first switch 1011, the first end of the first switch device S1 is respectively connected to the first pole of the first diode D1, the second power input end of the second current sensor U2 and the second pole of the second diode D2; the second end of the first switch device S1 is connected to the first power end of the first photovoltaic component P1; the first power input end of the first current sensor U1 is connected to the second power end of the first photovoltaic component P1; the second power input end of the first current sensor U1 is connected to the second pole of the first diode D1, and is connected to the inverter;

[0129] The first end of the second switch device S2 is connected to the first electrode of the second diode D2, and the second end of the second switch device S2 is connected to the first power supply end of the second photovoltaic component P2; the first power supply input end of the second current sensor U2 is connected to the second power supply end of the second photovoltaic component P2;

[0130] In the case where the third switch 1013 is adjacent to the other side of the first switch 1011, the first end of the third switch device S3 is respectively connected to the first pole of the third diode D3, the second power input end of the first current sensor U1 and the second pole of the first diode D1; the second end of the third switch device S3 is connected to the first power end of the third photovoltaic component P3; the first power input end of the third current sensor U3 is connected to the second power end of the third photovoltaic component P3; the second power input end of the third current sensor U3 is connected to the second pole of the third diode D3, and is connected to the inverter;

[0131] The first end of the first switch device S1 is connected to the first electrode of the first diode D1, and the second end of the first switch device S1 is connected to the first power supply end of the first photovoltaic component P1; the first power supply input end of the first current sensor U1 is connected to the second power supply end of the first photovoltaic component P1.

[0132] Then, in a photovoltaic string formed by connecting adjacent photovoltaic modules 102 end to end through the circuit breakers 101, the first circuit breaker 1011 can be connected to the second circuit breaker 1012 upstream thereof, or can be connected to the third circuit breaker 1013 downstream thereof, or can be connected to the second circuit breaker 1012 upstream thereof and the third circuit breaker 1013 downstream thereof respectively.

[0133] Figure 3 A schematic diagram showing a specific example of current flow in an embodiment of the present application is shown. As shown in the figure, under normal circumstances, photovoltaic modules are connected end to end through a circuit breaker to form a photovoltaic string, and finally output voltage to the inverter input terminal.

[0134] When current backflow occurs and a photovoltaic module in the photovoltaic string is shut down individually, the current will follow Figure 3 When the photovoltaic string is shut down, the current flows in the direction through the bypass diode (such as the first diode D1), and then connects other non-shutdown photovoltaic components in the photovoltaic string, so that the photovoltaic component is bypassed from the power transmission path between the photovoltaic string and the inverter, and finally the output voltage is sent to the input terminal of the inverter. Figure 3 The backflow current flow direction is the current flow direction when the current backflow occurs. At this time, the photovoltaic component cuts off the connection path between the photovoltaic string through the electronic switch (such as the first switch device S1) to prevent backflow.

[0135] In the embodiment of the present application, each switching device may include but is not limited to: a MOS tube (metal oxide semiconductor field effect transistor), a normally open relay, other thyristor switches, etc.

[0136] In an optional implementation, the switch 101 is configured to obtain power supply from the photovoltaic assembly 102 .

[0137] In the embodiment of the present application, the circuit breaker 101 can be powered by a single photovoltaic module 102 connected thereto, thereby simplifying the circuit structure design. Each circuit breaker is connected to a single photovoltaic module and powered by the photovoltaic module, and controls the physical connection between the module and the adjacent module through a built-in electronic switch. The built-in current sensor is used to monitor the current flow in real time, and the bypass diode is used to maintain the current path of other adjacent modules when the circuit breaker is turned off.

[0138] In this way, when the power station is under construction and the photovoltaic modules are connected in series, the photovoltaic modules are not connected to the system. Each photovoltaic module is equipped with a circuit breaker. The built-in current sensor of the circuit breaker can monitor the current flow direction of itself and adjacent photovoltaic modules in real time. The switch device built into the circuit breaker is in the on state by default; when the current sensor detects that the current is flowing in the reverse direction, the local control device can immediately control the switch device to disconnect, cut off the reverse flow path, and take necessary local protection actions to prevent reverse flow between modules. Then, according to the detection cycle set by the local control device, the switch device can be closed to monitor the current flow again; if the current flow is normal, the switch device switches to the on state, otherwise it continues to remain in the off state until the current flow is normal, and then the switch device is closed.

[0139] Figure 4 The schematic diagram of the principle block diagram of Example 3 of the anti-backflow system in the embodiment of the present application is shown. As shown in the figure, the anti-backflow system also includes a system platform end 103, which is respectively connected to each of the circuit breakers 101 for communicating with each other, and is used to monitor the current flow direction of each photovoltaic module 102, and control the shutdown state and connection state of each of the circuit breakers 101.

[0140] In the embodiment of the present application, the system platform end 103 is mainly used for real-time monitoring of the current flow direction of each photovoltaic module in each photovoltaic string after the photovoltaic string is installed and put into operation, and sending a shutdown or closing instruction to the circuit breaker 101. For example, the system platform end 103 can be a cloud management platform.

[0141] In an exemplary embodiment, when the system platform end 103 detects that the current flow of a certain photovoltaic component 102 is reversed, a shutdown command can be issued to control the circuit breakers of all photovoltaic components in the photovoltaic string where the photovoltaic component 102 is located to be turned off, so that the entire photovoltaic string is disconnected from the inverter and other photovoltaic strings, thereby improving reliability.

[0142] Then, the system platform end 103 can issue an opening instruction according to the set cycle, and at the same time detect whether the current flow direction returns to normal. If it returns to normal, these circuit breakers are controlled to switch to the connected state to ensure normal power generation of the photovoltaic strings; otherwise, the photovoltaic strings continue to be shut down to prevent current backflow from causing abnormalities.

[0143] In an optional embodiment, the backflow prevention system further includes a communication base station 104 , which is respectively communicatively connected to the system platform end 103 and each of the circuit breakers 101 to transmit communication data and instructions between the system platform end 103 and the circuit breakers 101 .

[0144] In the embodiment of the present application, the communication base station 104 serves as a communication hub between the system platform end 103 and the circuit breaker 101, and each circuit breaker 101 can serve as an RSD node. RSD (Rack Scale Design) nodes may refer to the basic hardware components that constitute the rack computing unit, and each node may include a processor (such as a CPU), memory, local storage, and a network interface, etc. The communication base station 104 may receive the current sensor output data from the circuit breaker 101, and transmit it uplink to the system platform end 103; and may receive real-time control instructions from the system platform end 103 downlink, and send them to the designated circuit breaker, ultimately achieving rapid shutdown or closure of a single photovoltaic module and / or photovoltaic string.

[0145] The communication method between the system platform 103 and the switch 101 is not limited to the communication base station 104, and may also be a direct communication interaction.

[0146] Figure 5 A schematic block diagram of a specific example of a circuit breaker in an embodiment of the present application is shown. As shown in the figure, in an optional embodiment, the circuit breaker 101 includes a control device 14, which is communicatively connected to the system platform end 103, and is respectively connected to the control end of the electronic switch circuit 11 in the circuit breaker 101 and the signal output end of the detection circuit 12 in the circuit breaker 101, and is used to control the circuit breaker 101 to enter the off state or the connected state according to the output data of the detection circuit 12; and / or, transmit the output data to the system platform end 103 so that the system platform end 103 generates a control instruction according to the output data, and controls the circuit breaker 101 to enter the off state or the connected state according to the control instruction.

[0147] In this way, the embodiment of the present application detects the current backflow by means of the linkage control of the switch installed on the photovoltaic module and the system platform end, cuts off the current backflow path, avoids abnormal accidents, and ensures the safety of the solar photovoltaic module power generation system. And by combining the switch installed on a single photovoltaic module with the system platform end, it can cover the anti-backflow in all stages of the power station construction stage and the operation stage, and can target the current backflow phenomenon caused by the voltage difference between photovoltaic modules and strings due to the number of deployments, optimizers, shading, etc., and achieve the anti-backflow effect in the two situations of the photovoltaic module series connection process in the early stage of power station construction and the operation process after the power station construction is completed.

[0148] In the early stage of power station construction, during the process of connecting components in series, a connection circuit breaker is configured for each photovoltaic component. The detection circuit 12 (such as a current sensor) inside the circuit breaker detects the current flow direction of adjacent components. Once a reverse flow occurs, the circuit breaker cuts off the passage between it and the adjacent components through an electronic switch circuit 11 (such as a switch device) to prevent the reverse flow from occurring.

[0149] When the power station is completed and put into operation, if current backflow occurs between different PV strings due to shading of some PV modules and mismatch of optimizer control voltage regulation, the system platform (such as the cloud management platform) monitors the current flow direction of each PV module in each PV string in real time. When reverse flow occurs, the platform sends a shutdown command to the string, disconnecting all modules in the string and preventing reverse flow from occurring.

[0150] Then, the embodiment of the present application can effectively avoid the voltage mismatch between different photovoltaic strings during the construction phase of the photovoltaic power station, as well as the current backflow between different photovoltaic modules and different photovoltaic strings, abnormal heating of modules, fire and other serious accidents caused by optimizer control, shadow shielding and other reasons during operation. In addition, the installation is simple and convenient. During the operation of the power station, it can automatically detect and cut off the reverse flow. After the reverse flow fault disappears, the system can automatically resume normal operation. No manual participation is required throughout the process, which greatly reduces the operation and maintenance costs of the power station and ensures that the power station operates stably and reliably throughout its life cycle during the construction and deployment phase and the normal operation phase.

[0151] In the embodiment of the present application, the control device 14 may include a processor, the processor is connected to a memory, instructions are stored in the memory, and the processor calls the instructions stored in the memory to implement the functions of the control device 14.

[0152] The embodiment of the present application also provides a backflow prevention photovoltaic power generation system, Figure 6 The schematic diagram of the principle block diagram of a specific example of the anti-backflow photovoltaic power generation system in the embodiment of the present application is shown. As shown in the figure, the anti-backflow photovoltaic power generation system includes:

[0153] At least one photovoltaic string circuit 100; each photovoltaic string circuit 100 is connected in parallel and is connected to an inverter through a power transmission path;

[0154] Wherein, the photovoltaic string circuit 100 includes at least one photovoltaic component 102 and the anti-backflow system as described in the above embodiment;

[0155] The output electric energy of each photovoltaic module 102 is integrated into the power transmission path through a single circuit breaker 101 in the anti-backflow system to form a photovoltaic string in which adjacent photovoltaic modules 102 are connected end to end through the circuit breakers 101 .

[0156] The embodiment of the present application also provides a backflow prevention method, which can be applied to the backflow prevention system, for example, can be applied to the control device of the circuit breaker in the backflow prevention system to prevent backflow between photovoltaic modules and photovoltaic strings during the construction stage and the operation stage of the power station. Figure 7 The flowchart of Example 1 of the anti-backflow method in the embodiment of the present application is shown. As shown in the figure, the anti-backflow method includes:

[0157] S101: during the operation of connecting a single photovoltaic module in series to a photovoltaic string through a circuit breaker, obtaining the current flow direction of the single photovoltaic module; wherein each circuit breaker is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the circuit breakers to form a photovoltaic string and connected to an inverter;

[0158] S102: When the current flow direction is opposite to the preset safe flow direction, the circuit breaker is controlled to enter a shutdown state to cut off the connection between the single photovoltaic module and the photovoltaic string, so that the single photovoltaic module is bypassed from the power transmission path from the photovoltaic string to the inverter;

[0159] S103: starting timing when the switch enters the shutdown state to obtain a first duration;

[0160] S104: When the first duration reaches a first threshold time, the current direction is reacquired, and when the reacquired current direction is the same as the preset safety direction, the circuit breaker is controlled to maintain the connected state; when the reacquired current direction is opposite to the preset safety direction, the circuit breaker is returned to the step of controlling the circuit breaker to enter the disconnected state.

[0161] In an exemplary embodiment, controlling the switch to enter the connected state may be to turn on the electronic switch circuit of the switch to turn on the photovoltaic assembly to output power to the inverter. Controlling the switch to enter the disconnected state may be to turn off the electronic switch circuit of the switch to turn off the photovoltaic assembly to output power to the inverter.

[0162] The current direction of a single photovoltaic module in step S101 can be obtained by determining the current direction of the photovoltaic module based on the output data of the detection circuit of the received circuit breaker; or, the current direction inside the photovoltaic module can be determined by detecting the voltage conditions at both ends of the photovoltaic module, thereby knowing the external current direction, etc. The specific detection method of the current direction can be set according to actual needs.

[0163] When the current flow direction of the photovoltaic module is the same as the preset safe flow direction in step S102, the process may return to step S101 to continue acquiring the current flow direction of the single photovoltaic module.

[0164] The preset safe flow direction and the first threshold time can be set according to actual needs. The control device can be configured with a detection cycle through the first threshold time, and when the first duration reaches the first threshold time, it can be indicated that a detection cycle is completed.

[0165] In this way, when the power station is in the construction stage and the photovoltaic modules are not connected to the system, the embodiments of the present application monitor the current flow direction of the photovoltaic modules themselves and the adjacent photovoltaic modules in real time during the access operation of the photovoltaic modules. For example, the electronic switch circuit is initially in a connected state by default. When the detection circuit detects that the current is flowing in reverse, the control device (local controller) immediately controls the electronic switch circuit to shut down and cut off the reverse flow path. Then, according to the detection cycle set by the local controller, the electronic switch circuit is closed and the current flow direction is monitored again; if the current flow direction is normal, the electronic switch circuit is maintained in a connected state, otherwise it continues to be controlled in a disconnected state until the current flow direction is normal, and then the electronic switch circuit is closed. In this way, during the access operation of a single photovoltaic module, current backflow can be detected to prevent reverse flow, avoid abnormal accidents, and improve safety.

[0166] Figure 8 The flowchart of Example 2 of the anti-backflow method in the embodiment of the present application is shown. As shown in the figure, in an optional embodiment, the anti-backflow method further includes:

[0167] S201: After the power station is completed and put into operation, the current flow direction of each photovoltaic module is obtained; for example, the current flow direction of a single photovoltaic module is obtained by controlling the circuit breaker to enter a connected state;

[0168] S202: reporting the current flow direction to the system platform end;

[0169] S203: Acquire a whole string of shutdown instructions issued by the system platform when the current flow direction is opposite to the preset safe flow direction;

[0170] S204: Under the control of the whole string shutdown instruction, all the circuit breakers in the photovoltaic string where the photovoltaic component is located are controlled to enter a shutdown state;

[0171] S205: Acquire a whole string of start instructions issued by the system platform end within a second threshold time after issuing the whole string of shut-down instructions;

[0172] S206: Under the control of the whole string start instruction, all the circuit breakers in the photovoltaic string are controlled to enter a connected state to reacquire the current flow direction of all photovoltaic modules in the photovoltaic string, and return to the step of reporting the current flow direction to the system platform end, so that when the current flow direction of all photovoltaic modules is the same as the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to maintain a connected state; when there is a current flow direction in all the photovoltaic modules that is opposite to the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to enter a shut-off state.

[0173] In an exemplary embodiment, the reporting of the current flow direction to the system platform end in step S202 may be sending a signal containing the current flow direction information to the system platform end; or, may be reporting through a communication base station.

[0174] The sending of the whole string of shutdown instructions in step S203 and the sending of the whole string of start instructions in step S205 may also be sent through a communication base station.

[0175] In step S205, the system platform end sends a whole string of start instructions at the second threshold time after sending the whole string of shutdown instructions. The system platform end may start timing after sending the whole string of shutdown instructions to obtain a second duration, and when the second duration reaches the second threshold time, send the whole string of start instructions.

[0176] The second threshold time can be set according to actual needs. The second threshold time can be used to configure a detection cycle for the system platform. When the second duration reaches the second threshold time, it can indicate that a detection cycle is completed.

[0177] In this way, when the power station is put into operation, the switch configured on the photovoltaic module side monitors the current flow of each photovoltaic module in the photovoltaic string in real time and uploads it to the system platform (such as the cloud management platform). When the system platform finds that the current of any photovoltaic module is reversed, it can immediately send the whole string shutdown command to all the switch-off devices in the photovoltaic string corresponding to the photovoltaic module through the communication base station, so that they are all shut down and the current backflow path is blocked; next, the whole string opening command is sent according to the set detection cycle, and the current flow of all photovoltaic modules in the photovoltaic string is detected at the same time. If it is restored to normal, it is switched to the fully connected state to ensure the normal power generation of the photovoltaic string; otherwise, it continues to control all shutdowns, the photovoltaic string is shut down, and the abnormality caused by the current backflow is prevented. In this way, the reverse flow between photovoltaic modules and photovoltaic strings can be prevented, and the safety of the solar photovoltaic module power generation system can be guaranteed.

[0178] The embodiment of the present application also provides a backflow prevention method, which can be applied to the backflow prevention system, for example, can be applied to the system platform end of the backflow prevention system to prevent backflow between photovoltaic modules and photovoltaic strings during the operation phase of the power station. Fig. 9 The flowchart of Example 3 of the anti-backflow method in the embodiment of the present application is shown. As shown in the figure, the anti-backflow method includes:

[0179] S301: Obtain the current flow direction of each photovoltaic module;

[0180] S302: When the current flow direction of any photovoltaic component is opposite to the preset safe flow direction, a whole string shutdown instruction is generated and sent to all the circuit breakers in the photovoltaic string where the photovoltaic component is located, so as to control all the circuit breakers in the photovoltaic string to enter the shutdown state;

[0181] S303: starting timing after the entire string of shutdown instructions is issued to obtain a second duration;

[0182] S304: When the second duration reaches the second threshold time, a whole string start instruction is issued to all the switches in the photovoltaic string to control all the switches in the photovoltaic string to enter a connected state, and return to the step of obtaining the current flow direction of each photovoltaic component.

[0183] In this way, the system platform can monitor the current flow of each photovoltaic module in each photovoltaic string in real time during the operation phase, and can send shutdown or closing instructions to each circuit breaker through the communication base station, ultimately achieving rapid shutdown or closing of the photovoltaic strings, and realizing full automatic control of current detection, reverse current blocking and automatic recovery without human intervention, greatly reducing the maintenance cost of the power station.

[0184] The following describes the device, electronic device, storage medium, etc. used to execute the anti-backflow method provided in this application. The specific implementation process and technical effects are described above and will not be repeated below.

[0185] The present application also provides a control device, Fig.10 The following is a schematic diagram of a principle block diagram of a specific example of a control device in an embodiment of the present application. As shown in the figure, the control device includes:

[0186] The first processing module 141 is used to obtain the current flow direction of a single photovoltaic component during the operation process of connecting a single photovoltaic component in series to a photovoltaic string through a disconnector; wherein each of the disconnectors is connected to a single photovoltaic component, so that adjacent photovoltaic components are connected end to end through the disconnectors to form a photovoltaic string and connected to an inverter;

[0187] The second processing module 142 is used to control the switch to enter the shutdown state when the current flow direction is opposite to the preset safe flow direction, so as to cut off the connection between the single photovoltaic component and the photovoltaic string, so that the single photovoltaic component is bypassed from the power transmission path from the photovoltaic string to the inverter;

[0188] A third processing module 143, configured to start timing when the switch enters the shutdown state to obtain a first duration;

[0189] The fourth processing module 144 is used to reacquire the current flow direction when the first duration reaches a first threshold time, and when the reacquired current flow direction is the same as the preset safety direction, control the circuit breaker to maintain the connection state; when the reacquired current flow direction is opposite to the preset safety direction, return to the second processing module 142.

[0190] The embodiment of the present application also provides a system platform end, Fig.11 A schematic diagram of a principle block diagram of a specific example of a system platform end in an embodiment of the present application is shown. As shown in the figure, the system platform end includes:

[0191] A fifth processing module 131 is used to obtain the current flow direction of each photovoltaic module;

[0192] The sixth processing module 132 is used to generate and send a whole string shutdown instruction to all the switches in the photovoltaic string where the photovoltaic component is located when the current flow direction of any photovoltaic component is opposite to the preset safe flow direction, so as to control all the switches in the photovoltaic string to enter the shutdown state;

[0193] A seventh processing module 133, configured to start timing after the entire string of shutdown instructions is issued to obtain a second duration;

[0194] The eighth processing module 134 is used to send a whole string opening instruction to all the circuit breakers in the photovoltaic string when the second duration reaches the second threshold time, so as to control all the circuit breakers in the photovoltaic string to enter a connected state, and return to the fifth processing module 131.

[0195] It should be understood that the division of the units or modules in the above devices is only a division of logical functions, and in actual implementation, they can be fully or partially integrated into one physical entity, or they can be physically separated. In addition, the units or modules in the device can be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, the memory stores instructions, and the processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the units or modules of the above devices.

[0196] The present application also provides a control device, the control device comprising:

[0197] a memory storing instructions; and

[0198] A processor is configured to execute the instructions to implement the above-mentioned backflow prevention method.

[0199] The embodiment of the present application further provides a system platform end, wherein the system platform end includes:

[0200] a memory storing instructions; and

[0201] A processor is configured to execute the instructions to implement the above-mentioned backflow prevention method.

[0202] Fig.12 A structural schematic diagram of a specific example of a control device or system platform end in an embodiment of the present application is shown. As shown in the figure, the control device or system platform end may include a processor, a memory, a network interface, a display, and an input device connected via a system bus. Among them, the processor can be used to provide computing and control capabilities. The memory may include a non-volatile storage medium and an internal memory. The non-volatile storage medium may store an operating system and a computer program. The internal memory may provide an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface may be used to communicate with an external terminal via a network connection. The display may be a liquid crystal display or an electronic ink display. The input device may be a touch layer covered on the display, or a button, a trackball or a touchpad provided on the housing of the control device or the system platform end, or an external keyboard, touchpad or mouse, etc.

[0203] Those skilled in the art will understand that Fig.12 The structure shown in the figure is merely a block diagram of a partial structure related to the scheme of the present application, and does not constitute a limitation on the control device or system platform to which the scheme of the present application is applied. The specific control device or system platform may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0204] An embodiment of the present application also provides a storage medium, in which a computer program is stored. When the computer program is executed, it can implement the above-mentioned anti-backflow method applied to the control device or the above-mentioned anti-backflow method applied to the system platform.

[0205] The computer program may also be used in Fig.12 The memory of the control device or system platform contains the above-mentioned program modules, and the computer program composed of the program modules can realize the functions corresponding to the steps in the anti-backflow method described in the above-mentioned embodiment when executed.

[0206] The embodiment of the present application also provides a computer program product or a computer program, which includes a computer instruction stored in a computer-readable storage medium. The processor of the control device or system platform reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the control device or system platform performs the anti-backflow method provided in the above various implementations.

[0207] Those skilled in the art will appreciate that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. Among them, any reference to memory, storage, database or other medium used in the embodiments provided in the present application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in a variety of forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0208] It should be understood that the above embodiments are exemplary and are not intended to include all possible implementations included in the claims. Various modifications and changes may be made on the basis of the above embodiments without departing from the scope of the present disclosure. Similarly, the various technical features of the above embodiments may be arbitrarily combined to form other embodiments of the present application that may not be explicitly described. Therefore, the above embodiments only express several implementations of the present application and do not limit the scope of protection of the patent of this application.

Claims

1. A backflow prevention system, characterized in that: The anti-backflow system comprises: At least one switch; each switch is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the switch to form a photovoltaic string and connected to an inverter; The circuit breaker is configured to detect the current flow direction of a single photovoltaic component; and when the current flow direction is reversed, it enters a shutdown state to cut off the connection between the single photovoltaic component and the photovoltaic string, and bypasses the single photovoltaic component from the power transmission path from the photovoltaic string to the inverter; when the current flow direction is normal, it enters a connected state to connect the single photovoltaic component in series to the photovoltaic string.

2. The backflow prevention system according to claim 1, characterized in that: The circuit breaker comprises: An electronic switch circuit is configured to switch the switch to an off state or a connected state; a first signal terminal of the electronic switch circuit is connected to an input terminal of the bypass diode circuit and is configured as a first terminal of the switch; a second signal terminal of the electronic switch circuit is connected to a first power supply terminal of a single photovoltaic module and is configured as a third terminal of the switch; A detection circuit configured to detect the current flow direction of a single photovoltaic component; a first detection terminal of the detection circuit is connected to the second power supply terminal of the single photovoltaic component and configured as the fourth terminal of the circuit breaker; a second detection terminal of the detection circuit is connected to the output terminal of the bypass diode circuit and configured as the second terminal of the circuit breaker; wherein the first terminal and the second terminal are used to connect to the power transmission path from the photovoltaic string to the inverter; and The bypass diode circuit is configured to unidirectionally conduct the first wiring terminal and the second wiring terminal so that when the circuit breaker is in the off state, the power transmission path between the photovoltaic string and the inverter is connected.

3. The backflow prevention system according to claim 2, characterized in that: The switch includes at least one of the following: The electronic switch circuit comprises a first switch device; a first end of the first switch device is configured as a first signal end of the electronic switch circuit, and a second end of the first switch device is configured as a second signal end of the electronic switch circuit; The detection circuit comprises a first current sensor; a first power input terminal of the first current sensor is configured as a first detection terminal of the detection circuit, and a second power input terminal of the first current sensor is configured as a second detection terminal of the detection circuit; The bypass diode circuit includes a first diode; a first electrode of the first diode is connected to the first terminal, and a second electrode of the first diode is connected to the second terminal.

4. The backflow prevention system according to claim 1, characterized in that: The anti-backflow system includes at least one of the following: A first breaker; the first breaker includes a first switching device, a first current sensor and a first diode; A second breaker; the second breaker includes a second switching device, a second current sensor and a second diode; The third breaker includes a third switch device, a third current sensor and a third diode; Wherein, when the second switch is adjacent to one side of the first switch, the first end of the first switch device is respectively connected to the first pole of the first diode, the second power input end of the second current sensor and the second pole of the second diode; the second end of the first switch device is connected to the first power end of the first photovoltaic component; the first power input end of the first current sensor is connected to the second power end of the first photovoltaic component; the second power input end of the first current sensor is connected to the second pole of the first diode and is connected to the inverter; The first end of the second switch device is connected to the first electrode of the second diode, and the second end of the second switch device is connected to the first power supply end of the second photovoltaic component; the first power supply input end of the second current sensor is connected to the second power supply end of the second photovoltaic component; In a case where the third switch is adjacent to the other side of the first switch, the first end of the third switch device is respectively connected to the first pole of the third diode, the second power input end of the first current sensor and the second pole of the first diode; the second end of the third switch device is connected to the first power end of the third photovoltaic component; the first power input end of the third current sensor is connected to the second power end of the third photovoltaic component; the second power input end of the third current sensor is connected to the second pole of the third diode and is connected to the inverter; The first end of the first switch device is connected to the first electrode of the first diode, the second end of the first switch device is connected to the first power supply end of the first photovoltaic component; the first power supply input end of the first current sensor is connected to the second power supply end of the first photovoltaic component.

5. The backflow prevention system according to claim 1, characterized in that: The switch is configured to obtain power supply from a photovoltaic component.

6. The backflow prevention system according to any one of claims 1 to 5, characterized in that: The anti-backflow system also includes a system platform end, which is respectively connected to each of the circuit breakers for communicating with each other, and is used to monitor the current flow direction of each photovoltaic component and control the shutdown state and connection state of each of the circuit breakers.

7. The backflow prevention system according to claim 6, characterized in that: The backflow prevention system also includes a communication base station, which is respectively connected to the system platform end and each of the circuit breakers for transmitting communication data and instructions between the system platform end and the circuit breakers.

8. The backflow prevention system according to claim 7, characterized in that: The switch includes a control device, which is communicatively connected to the system platform end and is respectively connected to a control end of an electronic switch circuit in the switch and a signal output end of a detection circuit in the switch, and is used to control the switch to enter an off state or a connected state according to output data of the detection circuit; and / or, transmit the output data to the system platform end so that the system platform end generates a control instruction according to the output data, and controls the switch to enter an off state or a connected state according to the control instruction.

9. A backflow prevention photovoltaic power generation system, characterized in that: The anti-backflow photovoltaic power generation system comprises: At least one photovoltaic string circuit; each photovoltaic string circuit is connected in parallel and is respectively connected to an inverter through a power transmission path; Wherein, the photovoltaic string circuit comprises at least one photovoltaic module and the anti-backflow system according to any one of claims 1 to 8; The output electric energy of each photovoltaic module is integrated into the power transmission path through a single circuit breaker in the anti-backflow system to form a photovoltaic string in which adjacent photovoltaic modules are connected end to end through circuit breakers.

10. A backflow prevention method, applied to a backflow prevention system, characterized in that: The anti-backflow method comprises: During the operation of connecting a single photovoltaic module in series to a photovoltaic string through a disconnector, the current flow direction of the single photovoltaic module is obtained; wherein each of the disconnectors is connected to a single photovoltaic module, so that adjacent photovoltaic modules are connected end to end through the disconnectors to form a photovoltaic string and connected to an inverter; When the current flow direction is opposite to the preset safe flow direction, the switch is controlled to enter the shutdown state to cut off the connection between the single photovoltaic component and the photovoltaic string, so that the single photovoltaic component is bypassed from the power transmission path from the photovoltaic string to the inverter; Starting timing when the shutoff device enters the shutoff state to obtain a first duration; When the first duration reaches a first threshold time, the current direction is reacquired, and when the reacquired current direction is the same as the preset safety direction, the circuit breaker is controlled to maintain the connected state; when the reacquired current direction is opposite to the preset safety direction, the process returns to the step of controlling the circuit breaker to enter the disconnected state.

11. The backflow prevention method according to claim 10, characterized in that: The anti-backflow method also includes: After the power plant is built and put into operation, the current flow direction of each photovoltaic module is obtained; Reporting the current flow direction to the system platform end; Acquire a whole string of shutdown instructions issued by the system platform end when the current flow direction is opposite to the preset safe flow direction; Under the control of the whole string shutdown instruction, all the circuit breakers in the photovoltaic string where the photovoltaic component is located are controlled to enter a shutdown state; Acquire a whole series of opening instructions issued by the system platform end at a second threshold time after issuing the whole series of closing instructions; Under the control of the whole string start instruction, all the circuit breakers in the photovoltaic string are controlled to enter a connected state to reacquire the current flow direction of all photovoltaic modules in the photovoltaic string, and return to the step of reporting the current flow direction to the system platform end, so that when the current flow direction of all photovoltaic modules is the same as the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to maintain a connected state; when there is a current flow direction in all the photovoltaic modules that is opposite to the preset safety flow direction, all the circuit breakers in the photovoltaic string are controlled to enter a closed state.

12. A backflow prevention method, applied to a backflow prevention system, characterized in that: The anti-backflow method comprises: Obtain the current flow direction of each photovoltaic module; When the current flow direction of any photovoltaic module is opposite to the preset safe flow direction, a whole string shutdown instruction is generated and sent to all the circuit breakers in the photovoltaic string where the photovoltaic module is located, so as to control all the circuit breakers in the photovoltaic string to enter the shutdown state; After the entire string of shutdown instructions is issued, start timing to obtain a second duration; When the second duration reaches the second threshold time, a whole string opening instruction is issued to all the switches in the photovoltaic string to control all the switches in the photovoltaic string to enter a connected state, and return to the step of obtaining the current flow direction of each photovoltaic component.

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