Method and device for protecting a photovoltaic power generation system

Abstract

The present disclosure provides a protection method and device for a photovoltaic power generation system, relating to the technical field of electric power, the photovoltaic power generation system comprising an inverter, an inverter connection end, a rectification control circuit and a circuit breaker, wherein the rectification control circuit is arranged on any two phases of the inverter AC side and the inverter connection end, and the circuit breaker is arranged on three phases of the inverter connection end, the method comprising: controlling the rectification control circuit to work when the inverter fails; obtaining the current of the rectification control circuit; and controlling the circuit breaker according to the current. Thus, by arranging the rectification circuit, the connection between the inverter and the inverter connection end can be disconnected when the inverter fails, thereby preventing secondary accidents and protecting the inverter and the inverter connection end, improving the safety of the photovoltaic power generation system, and at the same time, manual disconnection operation is not required, reducing the risk of personnel operation and disconnection cost.

Description

Technical Field

[0001] This disclosure relates to the field of power technology, and in particular to a protection method and device for a photovoltaic power generation system. Background Technology

[0002] The DC-side voltage of a photovoltaic (PV) inverter in a photovoltaic (PV) power plant is determined by the PV modules, typically 1000VDC or 1500VDC. The corresponding AC-side voltage is 500VAC or 800VAC, and the neutral point is ungrounded. In current PV inverter technology, inverters operating in ungrounded neutral systems can detect single-phase ground faults and disconnect the inverter from the system upon fault occurrence. However, this protection measure does not disconnect the fault point from the grid; the fault point will persist until a switch is manually disconnected or a phase-to-phase grounding trip occurs. For large-scale, unmanned PV power plants, manually disconnecting switches increases maintenance costs. Summary of the Invention

[0003] This disclosure aims to at least partially address one of the technical problems in the related art.

[0004] Therefore, one objective of this disclosure is to propose a protection method for photovoltaic power generation systems.

[0005] The second objective of this disclosure is to provide a protection device for a photovoltaic power generation system.

[0006] The third objective of this disclosure is to propose an electronic device.

[0007] The fourth objective of this disclosure is to provide a non-transitory computer-readable storage medium.

[0008] The fifth objective of this disclosure is to provide a computer program product.

[0009] To achieve the above objectives, the first aspect of this disclosure proposes a protection method for a photovoltaic power generation system. The photovoltaic power generation system includes an inverter, an inverter connection terminal, a rectifier control circuit, and a circuit breaker. The rectifier control circuit is disposed on any two phases between the AC side of the inverter and the inverter connection terminal, and the circuit breaker is disposed on all three phases of the inverter connection terminal. The method includes: controlling the rectifier control circuit to operate when a fault occurs in the inverter; acquiring the current of the rectifier control circuit; and controlling the circuit breaker based on the current.

[0010] According to one embodiment of this disclosure, the rectifier control circuit includes: a switching element, a control element, and a circuit element. The circuit element includes a first insulated gate bipolar transistor (IGBT), a second IGBT, a third IGBT, and a fourth IGBT. The control element is connected to the circuit element. A first terminal of the switching element is connected to any two phases between the inverter connection terminals. A second terminal of the switching element is connected to the first terminals of the first IGBT and the second IGBT, respectively. The second terminal of the first IGBT is connected to the first terminal of the third IGBT, and the second terminal of the second IGBT is connected to the first terminal of the fourth IGBT. A current transformer and a resistor are connected between the connection points of the second terminals of the first and third IGBTs and the second and fourth IGBTs. The second terminals of the third and fourth IGBTs are each connected to any two phases between the inverter connection terminals. The phase connected to the second terminals of the third and fourth IGBTs is different from the phase connected to the first terminal of the switching element.

[0011] According to one embodiment of this disclosure, controlling the rectifier control circuit to operate when the inverter malfunctions includes: when the inverter malfunctions, the switching element closes, and the control element controls the first insulated-gate bipolar transistor (IGBT) and the third insulated-gate bipolar transistor (IGBT) or the second insulated-gate bipolar transistor (IGBT) and the fourth insulated-gate bipolar transistor (IGBT) to form a loop between any two phases of the inverter connection terminal; in response to the loop satisfying a preset current, the circuit breaker is controlled to disconnect the three phases of the inverter connection terminal.

[0012] According to one embodiment of this disclosure, obtaining the preset current includes: obtaining the operating current of the circuit breaker, wherein the operating current is the minimum current at which the circuit breaker can operate normally; and multiplying the operating current by a preset range as the preset current.

[0013] According to one embodiment of this disclosure, the method further includes: when the current in the circuit reaches a preset current, and the duration of the preset current is greater than a first preset time but less than or equal to a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, an error judgment alarm is triggered.

[0014] According to one embodiment of this disclosure, the method further includes: when the current in the circuit reaches a preset current and the duration of the preset current is greater than the second preset time, when the circuit breaker fails to disconnect the inverter and the inverter connection terminal, a resistance alarm is triggered and the switching element is disconnected.

[0015] According to one embodiment of this disclosure, the control element includes a power supply element for providing power to the rectifier control circuit.

[0016] To achieve the above objectives, a second aspect of this disclosure provides a protection device for a photovoltaic power generation system, comprising: an inverter, an inverter connection terminal, a rectifier control circuit, and a circuit breaker, wherein the rectifier control circuit is disposed on any two phases between the AC side of the inverter and the inverter connection terminal, and the circuit breaker is disposed on three phases of the inverter connection terminal; the device comprises: a generation module for controlling the rectifier control circuit to operate when a fault occurs in the inverter; an acquisition module for acquiring the current of the rectifier control circuit; and a control module for controlling the circuit breaker based on the current.

[0017] To achieve the above objectives, a third aspect of this disclosure provides an electronic device, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to implement the protection method for a photovoltaic power generation system as described in the first aspect of this disclosure.

[0018] To achieve the above objectives, a fourth aspect of this disclosure provides a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to implement the protection method for a photovoltaic power generation system as described in the first aspect of this disclosure.

[0019] To achieve the above objectives, a fifth aspect of this disclosure provides a computer program product, including a computer program that, when executed by a processor, is used to implement the protection method for a photovoltaic power generation system as described in the first aspect of this disclosure.

[0020] Therefore, by setting up a rectifier circuit, the connection between the inverter and the inverter terminal can be disconnected in the event of an inverter failure. This can prevent secondary accidents, protect the inverter and the inverter terminal, improve the safety of the photovoltaic power generation system, and eliminate the need for manual disconnection, thus reducing personnel operation risks and disconnection costs. Attached Figure Description

[0021] Figure 1This is a schematic diagram of a protection method for a photovoltaic power generation system according to one embodiment of the present disclosure;

[0022] Figure 2 This is a schematic diagram of the circuit structure of a photovoltaic power generation system according to one embodiment of the present disclosure;

[0023] Figure 3 This is a schematic diagram of the circuit structure of a rectifier control circuit according to one embodiment of the present disclosure;

[0024] Figure 4 This is a schematic diagram of another protection method for a photovoltaic power generation system according to one embodiment of the present disclosure;

[0025] Figure 5 This is a schematic diagram of a protection device for a photovoltaic power generation system according to one embodiment of the present disclosure;

[0026] Figure 6 This is a schematic diagram of an electronic device according to one embodiment of the present disclosure. Detailed Implementation

[0027] Embodiments of this disclosure are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this disclosure, and should not be construed as limiting this disclosure.

[0028] The acquisition, storage, use, and processing of data in this disclosed technical solution all comply with the relevant provisions of national laws and regulations.

[0029] Figure 1 This is a schematic diagram of a protection method for a photovoltaic power generation system according to one embodiment of this disclosure, as shown below. Figure 1 As shown, the protection method for this photovoltaic power generation system includes the following steps:

[0030] S101 controls the operation of the rectifier control circuit when the inverter malfunctions.

[0031] In the embodiments disclosed herein, such as Figure 2 As shown, Figure 2 This is a schematic diagram of the circuit structure of a photovoltaic power generation system according to one embodiment of the present disclosure. The photovoltaic power generation system includes an inverter, an inverter connection terminal, a rectifier control circuit and a circuit breaker. The rectifier control circuit is installed on any two phases between the AC side of the inverter and the inverter connection terminal, and the circuit breaker is installed on all three phases of the inverter connection terminal.

[0032] It should be noted that the inverter connection can be of various types, and no limitation is made here. For example, the inverter connection can be a generator or the low-voltage side of a transformer, and no limitation is made here.

[0033] It should be noted that the inverter connection terminal is a three-phase circuit. The control rectifier control circuit is a circuit proposed by the inventor of this disclosure for controlling the operation of a circuit breaker. This circuit breaker is installed on the three phases of the inverter connection terminal to disconnect the circuit connection between the inverter and the inverter connection terminal when needed.

[0034] In this embodiment, the control rectifier control circuit can be embedded in the inverter or connected in parallel to the inverter output as an independent device; no limitation is made here.

[0035] The protection method for photovoltaic power generation systems in this application can be applied to inverter circuit protection scenarios. The entity executing the protection of the photovoltaic power generation system in this disclosure can be the protection device of the photovoltaic power generation system in this application, and the protection device of the photovoltaic power generation system can be installed on electronic equipment.

[0036] The rectifier control circuit is a circuit that controls the operation of the circuit breaker, which is installed on the three phases of the inverter connection terminal to disconnect the inverter and the circuit connection terminal when needed.

[0037] In the embodiments of this disclosure, there are various methods for controlling the operation of the rectifier control circuit, and no limitation is made here.

[0038] Optionally, when an inverter malfunctions, the control rectifier control circuit can detect the fault or the inverter stops working and enter the working state.

[0039] Optionally, when the inverter stops working or malfunctions, the inverter can generate a start signal and send it to the rectifier control circuit, so that the rectifier control circuit enters the working state.

[0040] It should be noted that inverter failures can be ground faults. Ground faults can be detected by the hard contacts of the photovoltaic inverter and received by the control chip of the dashed circuit for judgment. Alternatively, a ground fault detection circuit can be built, and there are no restrictions on this.

[0041] S102, obtain the current of the rectifier control circuit.

[0042] In this embodiment of the disclosure, after an inverter malfunctions, the rectifier control circuit is activated and controls the operation of the circuit breaker via current.

[0043] In this embodiment of the disclosure, the current of the rectifier control circuit can be obtained through a sensor.

[0044] S103 controls the circuit breaker based on the current.

[0045] It should be noted that the circuit breaker can be controlled by setting its starting conditions. These starting conditions can be varied and are not limited here.

[0046] Optionally, the starting condition can be that when the current in the rectifier control circuit reaches a preset starting current, the circuit breaker starting condition is considered met. It should be noted that the starting current is preset and can be changed according to actual design needs; no limitations are imposed here.

[0047] Optionally, the starting condition can also be that when the current in the rectifier control circuit reaches a preset starting current and the starting current continues for a preset time, the circuit breaker starting condition is considered met. It should be noted that the preset time is pre-set and can be changed according to actual design needs; no limitations are imposed here.

[0048] Optionally, the activation condition may also be that the circuit breaker receives a preset electrical signal sent by the rectifier control circuit, thereby performing a circuit breaking operation. This preset electrical signal can be generated and transmitted by a specific device, and no limitation is made here.

[0049] In this embodiment, when an inverter malfunctions, the rectifier control circuit is first activated. Then, the current of the rectifier control circuit is acquired, and finally, the circuit breaker is controlled based on the current. Therefore, by setting up the rectifier circuit, the connection between the inverter and its connection point can be disconnected in the event of an inverter malfunction. This prevents secondary accidents, protects the inverter and its connection point, improves the safety of the photovoltaic power generation system, and eliminates the need for manual disconnection, reducing operational risks and costs.

[0050] In the above embodiments, such as Figure 3 As shown, Figure 3 This is a schematic diagram of the circuit structure of a rectifier control circuit according to one embodiment of the present disclosure. The rectifier control circuit includes a switching element, a control element, and a circuit element. The circuit element includes a first insulated gate bipolar transistor (IGBT), a second IGBT, a third IGBT, and a fourth IGBT. The control element is connected to the circuit element.

[0051] In this configuration, the first terminal of the switching element is connected to any two phases between the inverter connection terminals. The second terminal of the switching element is connected to the first terminal of the first IGBT and the first terminal of the second IGBT. The second terminal of the first IGBT is connected to the first terminal of the third IGBT. The second terminal of the second IGBT is connected to the first terminal of the fourth IGBT. A current transformer and a resistor are connected between the connection points of the second terminals of the first and third IGBTs and the connection points of the second and fourth IGBTs. The second terminals of the third and fourth IGBTs are each connected to any two phases between the inverter connection terminals. The phase connected to the second terminals of the third and fourth IGBTs is different from the phase connected to the first terminal of the switching element.

[0052] In this embodiment, the resistance value of the resistor in the rectifier control circuit is preset and can be changed according to actual design needs; no limitation is made here. It should be noted that the resistor can be a fixed resistor or an adjustable resistor. When selecting the resistor, it is necessary to ensure that the allowable power is greater than the circuit power I. set 2 t b This ensures the safe operation of the resistor. Where I set For the rectifier control circuit, t b I is the minimum operating time corresponding to the operating current. set 2 t b The heat generated over time.

[0053] In this embodiment, the operating current of the circuit breaker on the opposite side is I1, and the typical instantaneous tripping range is (4-12)I1. The instantaneous tripping range is defined as K2. For example, it can trip instantaneously when the current exceeds 1.6kA to 4.8kA. This value is close to the short-circuit current of the IGBT, therefore, such current must be avoided in the circuit. I can be... set The short-time operating range is defined as (2-3)I1, and K3 is defined as the short-time operating range to prevent the first IGBT-D1, the second IGBT-D2, the third IGBT-D3, and the fourth IGBT-D4 from malfunctioning due to excessive current. The short-circuit current of the corresponding IGBT can be consulted to ensure circuit safety. That is, multiply by a coefficient less than 1 to obtain I. set The maximum value of I set.max =K1I igbt.sc , among which, I igbt.sc为 The short-circuit current of the IGBT. Therefore, the resistance value in the rectifier control circuit can be selected using the following formula:

[0054] R>(U / I1) / K2, and R<(U / I1) / K3

[0055] The normal operating voltage of the photovoltaic inverter is U.

[0056] It should be noted that, in this embodiment, when the switching element is closed, the rectifier control circuit operates in rectifier mode, switching on and off the first IGBT-D1, the second IGBT-D2, the third IGBT-D3, and the fourth IGBT-D4 respectively. The automatic control logic of the rectifier is not constrained, and the operating current is set to I. set The action time is set to t. set When the circuit is activated, control I2 to I. set Run t set After that, the operating conditions of the circuit breaker on the other side will be met, thus tripping the faulty circuit.

[0057] It should be noted that the power supply for the rectifier control circuit in this embodiment can be an external independent power supply, such as an externally connected motor or battery.

[0058] In one possible implementation, the control element includes a power supply element that provides power to the rectifier control circuit.

[0059] In the above embodiments, when the inverter malfunctions, the rectifier control circuit is activated, and the operation can also be achieved through... Figure 4 To explain further, Figure 4 This is a schematic diagram of another protection method for a photovoltaic power generation system according to one embodiment of the present disclosure, as shown in the figure:

[0060] S401 When an inverter malfunctions, the switching element closes, and the control element controls the first insulated gate bipolar transistor (IGBT) and the third insulated gate bipolar transistor (IGBT) or the second insulated gate bipolar transistor (IGBT) and the fourth insulated gate bipolar transistor (IGBT) to form a circuit between any two phases of the inverter connection terminal.

[0061] S402, in response to the circuit meeting the preset current, controls the circuit breaker to disconnect the three phases of the inverter connection terminal.

[0062] In this embodiment of the disclosure, the preset current can be obtained by first obtaining the operating current of the circuit breaker, which is the minimum current at which the circuit breaker can work normally, and then multiplying the operating current by a preset range as the preset current.

[0063] It should be noted that this preset range is pre-defined and can be changed according to actual design needs; no limitations are imposed here. In one possible implementation, the preset range could be 4-12.

[0064] It should be noted that the operating current is generally less than the rated current of the IGBT, and the current value controlling the rectifier control circuit can be determined based on the rated current and operating current of the IGBT. For example, the IGBT can be... set It is determined to be (2-3)I1, and the short-time action range is defined as K3 to prevent the first IGBT, second IGBT, third IGBT and fourth IGBT from malfunctioning due to excessive current.

[0065] In this embodiment, when an inverter malfunctions, the switching element closes, and the control element controls the first and third IGBTs or the second and fourth IGBTs to form a loop between any two phases of the inverter connection. In response to the loop meeting a preset current, the circuit breaker is controlled to disconnect the three phases of the inverter connection. Thus, by setting a control rectifier control circuit, power can still be supplied to the circuit breaker even when there is a potential open circuit at the inverter connection. Furthermore, by setting the operating current, precise control of the circuit breaker's disconnection timing can be achieved.

[0066] In this embodiment of the disclosure, in order to prevent the inverter and inverter connection terminal from being unable to be disconnected due to circuit breaker failure, the operating status of the circuit breaker is also monitored.

[0067] In one possible implementation, when the circuit current reaches a preset current, and the duration of the preset current is greater than a first preset time but less than or equal to a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, an error alarm is triggered.

[0068] In one possible implementation, when the circuit current reaches a preset current and the duration of the preset current is greater than a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, a resistance alarm is triggered and the switching element is disconnected.

[0069] It should be noted that the second preset time is longer than the first preset time. The first and second preset times are pre-set and can be changed according to actual design needs. They can also be set according to the actual circuit breaker. No restrictions are imposed here.

[0070] Corresponding to the protection methods for photovoltaic power generation systems provided in the above embodiments, one embodiment of this disclosure also provides a protection device for photovoltaic power generation systems. Since the protection device for photovoltaic power generation systems provided in this disclosure corresponds to the protection methods for photovoltaic power generation systems provided in the above embodiments, the implementation methods of the above protection methods for photovoltaic power generation systems are also applicable to the protection device for photovoltaic power generation systems provided in this disclosure, and will not be described in detail in the following embodiments.

[0071] Figure 5 This is a schematic diagram of a protection device for a photovoltaic power generation system according to one embodiment of this disclosure, as shown below. Figure 5 As shown, the protection device 500 of the photovoltaic power generation system includes: a generation module 510, an acquisition module 520, and a control module 530.

[0072] The generation module 510 is used to control the operation of the rectifier control circuit when the inverter fails.

[0073] The acquisition module 520 is used to acquire the current of the rectifier control circuit.

[0074] The control module 530 is used to control the circuit breaker based on the current.

[0075] In one embodiment of this disclosure, the rectifier control circuit includes: a switching element, a control element, and a circuit element. The circuit element includes a first insulated gate bipolar transistor (IGBT), a second IGBT, a third IGBT, and a fourth IGBT. The control element is connected to the circuit element. A first terminal of the switching element is connected to any two phases between the inverter connection terminals. A second terminal of the switching element is connected to the first terminals of the first and second IGBTs, respectively. The second terminal of the first IGBT is connected to the first terminal of the third IGBT, and the second terminal of the second IGBT is connected to the first terminal of the fourth IGBT. A current transformer and a resistor are connected between the connection points of the second terminals of the first and third IGBTs and the second and fourth IGBTs. The second terminals of the third and fourth IGBTs are each connected to any two phases between the inverter connection terminals. The phase connected to the second terminals of the third and fourth IGBTs is different from the phase connected to the first terminal of the switching element.

[0076] In one embodiment of this disclosure, the generation module 510 is further configured to: when a fault occurs in the inverter, close the switching element, and control the first insulated gate bipolar transistor (IGBT) and the third insulated gate bipolar transistor (IGBT) or the second insulated gate bipolar transistor (IGBT) and the fourth insulated gate bipolar transistor (IGBT) to form a loop between any two phases of the inverter connection terminal; in response to the loop satisfying a preset current, control the circuit breaker to disconnect the three phases of the inverter connection terminal.

[0077] In one embodiment of this disclosure, obtaining a preset current includes: obtaining the operating current of the circuit breaker, wherein the operating current is the minimum current at which the circuit breaker can operate normally; and multiplying the operating current by a preset range as the preset current.

[0078] In one embodiment of this disclosure, the control module 530 is further configured to: perform a judgment error alarm when the circuit current reaches a preset current and the duration of the preset current is greater than a first preset time but less than or equal to a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal.

[0079] In one embodiment of this disclosure, the control module 530 is further configured to: when the current in the circuit reaches a preset current and the duration of the preset current is greater than a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, perform a resistance alarm and disconnect the switching element.

[0080] In one embodiment of this disclosure, the control element includes a power supply element for providing power to the rectifier control circuit.

[0081] Therefore, by setting up a rectifier circuit, the connection between the inverter and the inverter terminal can be disconnected in the event of an inverter failure. This can prevent secondary accidents, protect the inverter and the inverter terminal, improve the safety of the photovoltaic power generation system, and eliminate the need for manual disconnection, thus reducing personnel operation risks and disconnection costs.

[0082] To implement the above embodiments, this disclosure also proposes an electronic device 600. Figure 6 This is a schematic diagram of an electronic device according to one embodiment of the present disclosure, such as... Figure 6 As shown, the electronic device 600 includes a processor 601 and a memory 602 communicatively connected to the processor. The memory 602 stores instructions that can be executed by at least one processor. The instructions are executed by at least one processor 601 to implement the protection method of the photovoltaic power generation system as described in the first aspect embodiment of this disclosure.

[0083] To implement the above embodiments, this disclosure also proposes a non-transitory computer-readable storage medium storing computer instructions, wherein the computer instructions are used to enable a computer to implement the protection method for a photovoltaic power generation system as described in the first aspect of this disclosure.

[0084] To implement the above embodiments, this disclosure also proposes a computer program product, including a computer program that, when executed by a processor, implements the protection method for a photovoltaic power generation system as described in the first aspect of this disclosure.

[0085] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this disclosure and simplifying the description, and are not intended to 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 this disclosure.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise expressly specified.

[0087] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0088] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A protection method for a photovoltaic power generation system, characterized in that, A photovoltaic power generation system includes an inverter, an inverter connection terminal, a rectifier control circuit, and a circuit breaker. The inverter connection terminal is a three-phase circuit. The rectifier control circuit is installed on any two phases of the inverter's AC side and the inverter connection terminal. The circuit breaker is installed on all three phases of the inverter connection terminal. The method includes: When the inverter malfunctions, the rectifier control circuit is controlled to operate. Obtain the current of the rectifier control circuit; The circuit breaker can be controlled based on the current. The rectifier control circuit includes: The system includes a switching element, a control element, and a circuit element, wherein the circuit element comprises a first insulated-gate bipolar transistor (IGBT), a second insulated-gate bipolar transistor (IGBT), a third insulated-gate bipolar transistor (IGBT), and a fourth insulated-gate bipolar transistor (IGBT), and the control element is connected to the circuit element. In this configuration, the first terminal of the switching element is connected to any two phases between the inverter connection terminals. The second terminal of the switching element is connected to the first terminals of the first and second insulated-gate bipolar transistors (IGBTs). The second terminal of the first IGBT is connected to the first terminal of the third IGBT. The second terminal of the second IGBT is connected to the first terminal of the fourth IGBT. A current transformer and a resistor are connected between the connection points of the second and third IGBTs and the connection points of the second and fourth IGBTs. The second terminals of the third and fourth IGBTs are each connected to any two phases between the inverter connection terminals. The phase connected to the second terminals of the third and fourth IGBTs is different from the phase connected to the first terminal of the switching element. When the inverter malfunctions, controlling the rectifier control circuit to operate includes: When the inverter malfunctions, the switching element closes, and the control element controls the first insulated gate bipolar transistor (IGBT) and the third insulated gate bipolar transistor (IGBT) or the second insulated gate bipolar transistor (IGBT) and the fourth insulated gate bipolar transistor (IGBT) to form a circuit between any two phases of the inverter connection terminal. In response to the circuit meeting the preset current, the circuit breaker is controlled to disconnect the three phases of the inverter connection terminal.

2. The method according to claim 1, characterized in that, Obtaining the preset current includes: Obtain the operating current of the circuit breaker, which is the minimum current at which the circuit breaker can operate normally; The product of the operating current and the preset range is used as the preset current.

3. The method according to claim 1, characterized in that, The method further includes: When the current in the circuit reaches a preset current, and the duration of the preset current is greater than a first preset time but less than or equal to a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, an error alarm is triggered.

4. The method according to claim 2, characterized in that, The method further includes: If the current in the circuit reaches a preset current and the duration of the preset current is greater than a second preset time, and the circuit breaker fails to disconnect the inverter and the inverter connection terminal, a resistance alarm will be triggered, and the switching element will be disconnected.

5. The method according to claim 1, characterized in that, The control element includes a power supply element, which provides power to the rectifier control circuit.

6. A protection device for a photovoltaic power generation system, characterized in that, The device implements the method as described in claim 1. The photovoltaic power generation system includes an inverter, an inverter connection terminal, a rectifier control circuit, and a circuit breaker. The rectifier control circuit is disposed on any two phases between the AC side of the inverter and the inverter connection terminal. The circuit breaker is disposed on all three phases of the inverter connection terminal. The device includes: The generation module is used to control the operation of the rectifier control circuit when the inverter fails; An acquisition module is used to acquire the current of the rectifier control circuit; The control module is used to control the circuit breaker based on the current.

7. An electronic device, characterized in that, Including memory and processor; The processor runs a program corresponding to the executable program code stored in the memory to implement the method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1-5.

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