Grid-connected inverter control method and device, computer equipment and storage medium

Abstract

The invention discloses a grid-connected inverter control method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining a positive sequence component and a negative sequence component of a power grid when the power grid is in an asymmetric fault; determining a control given parameter of the grid-connected inverter based on the positive sequence component and an active current given value before a power grid fault; the control given parameters comprise a reactive current given value and an active current given value; generating a reactive current compensation value and an active current compensation value based on the positive sequence component, the negative sequence component, the reactive current given value and the active current given value; and issuing the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value to the grid-connected inverter. And enabling the grid-connected inverter to respond to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value for execution.

Description

Technical Field

[0001] The present invention relates to the field of renewable energy power generation technology, and in particular to a grid-connected inverter control method, device, computer equipment and storage medium. Background Art

[0002] In recent years, renewable energy power generation technology has rapidly emerged worldwide, and a large number of new energy power electronic equipment have been connected to the large power grid. Since new energy power stations are currently concentrated in remote areas, they require long-distance transmission lines to connect to the power grid, which makes the grid-connected voltage susceptible to asymmetric grid faults caused by load imbalance or transmission line short circuits. Asymmetric grid faults have a serious impact on the transient stability of grid-connected equipment. For grid-connected inverters, asymmetric grid faults will increase the DC bus voltage fluctuations, increase semiconductor voltage stress, intensify AC side voltage and current harmonics, and reduce the life of bus capacitors. In extreme cases, the inverter may even go off-grid, which has a great impact on the stability of the voltage and frequency of the grid.

[0003] In the prior art, when an asymmetric fault occurs in the power grid, reactive current is usually provided at the grid connection point to inject reactive power into the grid to raise the system voltage, thereby achieving the purpose of supporting the grid voltage. However, supporting reactive current alone cannot suppress DC bus fluctuations, thereby failing to effectively improve the grid-connected inverter's ability to ride through asymmetric faults in the grid, and failing to ensure the safe and stable operation of the grid. On this basis, people usually suppress DC bus fluctuations by adding control links, but this increases the difficulty of system design and makes implementation complex. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a grid-connected inverter control method, device, computer equipment and storage medium that are simple to implement and can effectively improve the fault ride-through capability of the grid-connected inverter.

[0005] In order to solve the above technical problems, in a first aspect, a grid-connected inverter control method is provided, comprising:

[0006] When the power grid has an asymmetric fault, the positive sequence component and negative sequence component of the power grid are obtained;

[0007] Determining control given parameters of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault; the control given parameters include a reactive current given value and an active current given value;

[0008] Generate a reactive current compensation value and an active current compensation value based on a positive sequence component, a negative sequence component, a reactive current given value, and an active current given value;

[0009] The active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value are sent to the grid-connected inverter, so that the grid-connected inverter executes in response to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value.

[0010] In a second aspect, a grid-connected inverter control device is provided, comprising:

[0011] An acquisition module, used for acquiring positive sequence components and negative sequence components of the power grid when an asymmetric fault occurs in the power grid;

[0012] A given parameter determination module is used to determine the control given parameters of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault; the control given parameters include the reactive current given value and the active current given value;

[0013] A compensation generation module, used for generating a reactive current compensation value and an active current compensation value based on a positive sequence component, a negative sequence component, a reactive current given value and an active current given value;

[0014] The control module is used to send the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value to the grid-connected inverter, so that the grid-connected inverter responds to the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value for execution.

[0015] In a third aspect, a computer device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned grid-connected inverter control method when executing the computer program.

[0016] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the above-mentioned grid-connected inverter control method are implemented.

[0017] In the scheme implemented by the above-mentioned grid-connected inverter control method, device, computer equipment and storage medium, when an asymmetric fault occurs in the power grid, the positive sequence component and negative sequence component of the power grid are obtained, and the reactive current given value and the active current given value that the grid-connected inverter needs to send are determined based on the positive sequence component and the active current given value before the power grid fault. The reactive current compensation value and the active current compensation value are generated based on the positive sequence component, the negative sequence component, the reactive current given value and the active current given value. The grid-connected inverter responds to the active current given value, the active current compensation value, the reactive current given value, and the active current given value. The control is executed by using a given value and a reactive current compensation value. It can be seen that the present invention performs transient stability control of the DC bus of the grid-connected inverter by compensating for the active current given and the reactive current given of the grid-connected inverter, that is, by increasing the reactive current compensation value and the active current compensation value to suppress the fluctuation of the output power during an asymmetric fault in the power grid, and realizes transient stability control of the bus of the grid-connected inverter, thereby increasing the service life of the DC bus capacitor, improving the quality of the grid-connected electricity, and being simple to implement. At the same time, it can effectively improve the ability of the grid-connected inverter to ride through asymmetric faults in the power grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is an application schematic diagram of a grid-connected inverter control method in one embodiment of the present invention;

[0019] Figure 2 is a flow chart of a grid-connected inverter control method provided by an embodiment of the present invention;

[0020] Figure 3 It is a schematic diagram of a structural block diagram of a grid-connected inverter control device provided by an embodiment of the present invention;

[0021] Figure 4 It is a structural diagram of a computer device in one embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to more fully understand the technical content of the present invention, the technical solution of the present invention is further introduced and illustrated below in conjunction with schematic diagrams, but is not limited thereto.

[0023] The grid-connected inverter control method provided in the embodiment of the present invention can be applied in the software system of the inverter, for controlling the grid-connected inverter, such as Figure 1 As shown, the AC end of the inverter is connected to the grid, and the DC end is connected to the DC bus. When an asymmetric fault occurs in the grid, the grid-connected inverter control method of the present invention increases the reactive current compensation value and the active current compensation value to compensate for the reactive current given value and the active current given value respectively, so as to suppress the fluctuation of the output power during the asymmetric fault of the grid, realize the transient stability control of the grid-connected inverter bus, thereby prolonging the service life of the DC bus capacitor, improving the grid-connected power quality, and being simple to implement, while effectively improving the ability of the grid-connected inverter to ride through the asymmetric fault of the grid. Figure 2 The specific working process of the grid-connected inverter control method provided by the present invention is described in detail.

[0024] See also Figure 2 As shown, Figure 2 A flow chart of a grid-connected inverter control method provided by an embodiment of the present invention. In the embodiment shown in the accompanying drawings, the grid-connected inverter control method includes the following steps:

[0025] S110. When an asymmetric fault occurs in the power grid, a positive sequence component and a negative sequence component of the power grid are obtained.

[0026] Specifically, this step includes: collecting the grid connection point voltage, and when an asymmetric fault occurs at the grid connection point, obtaining the positive sequence component and the negative sequence component according to the grid connection point voltage; wherein the positive sequence component includes the positive sequence d-axis component u d_pos and the positive sequence q-axis component u q_pos , the negative sequence component includes the negative sequence d-axis component u d_neg and the negative sequence q-axis component u q_neg In this embodiment, when an asymmetric fault occurs at the grid connection point, the coordinate system of the collected grid connection point voltage is transformed to obtain the positive sequence component and the negative sequence component of the grid connection point voltage.

[0027] S120. Determine control given parameters of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault; the control given parameters include a reactive current given value and an active current given value.

[0028] In this step, the positive sequence voltage modulus of the positive sequence component is calculated by formula i q =K×(0.9-U m_pos )×I n Calculate the reactive current given value that the grid-connected inverter needs to emit; according to the positive sequence voltage modulus of the positive sequence component and the active current given value before the grid fault, the formula i d =K1×i d_old +K2×U m_pos ×I n Calculate the active current given value of the grid-connected inverter; in the above formula, i q is the reactive current given value, i d is the active current given value, K is the reactive dynamic adjustment coefficient, K1 and K2 are the dynamic active adjustment coefficients, U m_pos is the positive sequence voltage modulus, I n is the rated output current of the grid-connected inverter, i d_old is the given value of the active current before the power grid fails; in this embodiment, the value of K is preferably 1.5, the value of K1 is preferably 0.1, and the value of K2 is preferably 0.5.

[0029] In the present invention, the positive sequence voltage modulus is the vector length of the positive sequence component projected on the dq axis in the coordinate system, which can be calculated based on the positive sequence component, and the active current given value before the power grid fault can be calculated based on the grid connection point voltage collected before the fault.

[0030] Furthermore, in some other embodiments, after determining the reactive current set value and the active current set value of the grid-connected inverter, the method may further include: detecting the active current set value i d ,like Limit the active current set value i of the grid-connected inverter d , so that the active current given value That is, the active current set value can also be limited according to the active current set value, the reactive current set value and the grid-connected inverter output rated current to increase the corresponding limiting logic, thereby further suppressing the bus voltage fluctuation caused by power fluctuation.

[0031] S130. Generate a reactive current compensation value and an active current compensation value based on the positive sequence component, the negative sequence component, the reactive current set value, and the active current set value.

[0032] In this step, the reactive current compensation value and the active current compensation value are calculated according to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value, with the negative sequence component in the compensated output power being zero as a limiting condition.

[0033] Specifically, according to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value, the reactive current compensation value and the active current compensation value are calculated using the following formula:

[0034]

[0035] Among them, i d_comp is the active current compensation value, i q_comp is the reactive current compensation value, i q is the reactive current given value, i d is the given value of active current, u d_pos is the positive sequence d-axis component, u m_neg is the negative-sequence voltage modulus of the negative-sequence component, that is, the vector length of the negative-sequence component projected on the dq axis in the coordinate system, which can be calculated based on the negative-sequence component, and Where ω is the grid angular frequency, α pos is the positive sequence angle, α neg is the negative sequence angle.

[0036] When an asymmetric fault occurs, the current grid-connected power P = u d_pos i d +u d_neg i d +u q_neg iq , then after compensation, the output power is:

[0037] P new =u d_pos i d +u d_neg i d +u q_neg i q +u d_pos i d_comp +u d_neg i d_comp +u q_neg i q_comp (1)

[0038] According to the projection vector length i of the reactive current compensation value and the active current compensation value in the coordinate system m_comp and compensation angle θ comp It can be concluded that:

[0039]

[0040] In the above formula (2), θ comp for i d_comp and i q_comp The compensation angle of Where ω is the grid angular frequency, α pos is the positive sequence angle, α neg is the negative sequence angle.

[0041] In this embodiment, the reactive current compensation value and the active current compensation value are calculated based on the limiting condition that the negative sequence component in the compensated output power is zero, so the part containing the negative sequence component is 0, that is:

[0042] u d_neg i d +u q_neg i q +u d_pos i d_comp +u d_neg i d_comp +u q_neg i q_comp =0(3)

[0043] From the above formulas (1), (2) and (3), we can get Therefore, the reactive current compensation value and the active current compensation value can be calculated according to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value according to the above formula.

[0044] S140, sending the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value to the grid-connected inverter, so that the grid-connected inverter executes in response to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value.

[0045] In this step, the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value are sent to the current inner loop of the grid-connected inverter for control execution, and the transient stability control of the DC bus of the grid-connected inverter is performed by compensating the active current given value and the reactive current given value of the grid-connected inverter.

[0046] It can be seen that in the above scheme, when an asymmetric fault occurs in the power grid, the positive-sequence component and the negative-sequence component of the power grid are first obtained, and then the reactive current given value and the active current given value that the grid-connected inverter needs to issue are determined based on the positive-sequence component and the active current given value before the power grid fault. Subsequently, the reactive current compensation value and the active current compensation value are generated based on the positive-sequence component, the negative-sequence component, the reactive current given value and the active current given value, and the grid-connected inverter is controlled to respond to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value to execute, thereby suppressing the fluctuation of the output power during the asymmetric fault of the power grid, realizing the transient stability control of the bus of the grid-connected inverter, increasing the service life of the DC bus capacitor, improving the quality of the grid-connected power, and effectively improving the ability of the grid-connected inverter to ride through asymmetric faults in the power grid, and the implementation is simple.

[0047] It should be understood that the above method embodiments are expressed as a series of action combinations for the sake of simplicity of description. However, those skilled in the art should be aware that the present invention is not limited to the described order of actions, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0048] Reference Figure 3 , Figure 3 FIG. 2 is a block diagram of a grid-connected inverter control device 200 provided in an embodiment of the present invention. Figure 3 As shown, the grid-connected inverter control device 200 includes an acquisition module 201, a given parameter determination module 202, a compensation generation module 203 and a control module 204. The functional modules are described in detail as follows:

[0049] An acquisition module 201 is used to acquire positive sequence components and negative sequence components of the power grid when an asymmetric fault occurs in the power grid;

[0050] A given parameter determination module 202 is used to determine the control given parameters of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault; the control given parameters include the reactive current given value and the active current given value;

[0051] A compensation generating module 203, for generating a reactive current compensation value and an active current compensation value based on a positive sequence component, a negative sequence component, a reactive current given value and an active current given value;

[0052] The control module 204 is used to send the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value to the grid-connected inverter, so that the grid-connected inverter executes in response to the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value.

[0053] In one embodiment, the acquisition module 201 is specifically used to: collect the grid connection point voltage, and when an asymmetric fault occurs at the grid connection point, obtain the positive sequence component and the negative sequence component according to the grid connection point voltage; wherein the positive sequence component includes the positive sequence d-axis component u d_pos and the positive sequence q-axis component u q_pos , the negative sequence component includes the negative sequence d-axis component u d_neg and the negative sequence q-axis component u q_neg .

[0054] In one embodiment, a given parameter determination module 202 is specifically configured to:

[0055] According to the positive sequence voltage modulus of the positive sequence component, the formula i q =K×(0.9-U m_pos )×I n Calculate the reactive current given value that the grid-connected inverter needs to generate; where i q is the reactive current given value, U m_pos is the positive sequence voltage modulus, K is the reactive dynamic adjustment coefficient, I n Output rated current for grid-connected inverter;

[0056] According to the positive sequence voltage modulus of the positive sequence component and the given value of the active current before the power grid fault, the formula i d =K1×i d_old +K2×U m_pos ×I n Calculate the active current given value of the grid-connected inverter; where i d is the given value of active current, U m_pos is the positive sequence voltage modulus, i d_old is the given value of active current before the grid fault, K1 and K2 are dynamic active current adjustment coefficients, I n Output rated current for grid-connected inverter.

[0057] In one embodiment, the grid-connected inverter control device 200 further includes a detection and limitation module 205, which is specifically used to: limit the active current given value i of the grid-connected inverter. d , so that the active current given value

[0058] In one embodiment, the detection and limiting module 205 is further used to: detect the active current given value i d ,exist When the active current setting value i of the grid-connected inverter is limited d , so that the active current given value

[0059] In one embodiment, the compensation generation module 203 is specifically configured to:

[0060] According to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value, the reactive current compensation value and the active current compensation value are calculated with the negative sequence component in the compensated output power being zero as a limiting condition.

[0061] In one embodiment, the compensation generation module 203 is specifically configured to:

[0062] According to the positive sequence component, negative sequence component, reactive current given value and active current given value, the reactive current compensation value and active current compensation value are calculated using the following formula:

[0063]

[0064] Among them, i d_comp is the active current compensation value, i q_comp is the reactive current compensation value, i q is the reactive current given value, i d is the given value of active current, u d_pos is the positive sequence d-axis component, u m_neg is the negative sequence voltage modulus, and Where ω is the grid angular frequency, α pos is the positive sequence angle, α neg is the negative sequence angle.

[0065] The present invention provides a grid-connected inverter control device 200, which collects the grid connection point voltage. When an asymmetric fault occurs in the power grid, the positive-sequence component and the negative-sequence component of the power grid are first obtained, and then the reactive current given value and the active current given value that the grid-connected inverter needs to send are determined based on the positive-sequence component and the active current given value before the power grid fault. Subsequently, the reactive current compensation value and the active current compensation value are generated based on the positive-sequence component, the negative-sequence component, the reactive current given value and the active current given value, and the grid-connected inverter is controlled to respond to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value to execute, thereby suppressing the fluctuation of the output power during the asymmetric fault of the power grid, realizing the transient stability control of the bus of the grid-connected inverter, increasing the service life of the DC bus capacitor, improving the quality of the grid-connected electricity, and effectively improving the ability of the grid-connected inverter to ride through the asymmetric fault of the power grid, and the implementation is simple.

[0066] For the specific definition of the grid-connected inverter control device 200, please refer to the definition of the grid-connected inverter control method above, which will not be repeated here. Each module in the above-mentioned grid-connected inverter control device 200 can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0067] In one embodiment, a computer device is provided, whose internal structure diagram can be as follows: Figure 4 As shown. The computer device includes a processor, a memory, a network interface and a database connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile and / or volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external device via a network connection. Further, the computer device may also include a display screen and an input device (such as a mouse, a keyboard, etc.) for interaction.

[0068] Specifically, the processor in the computer device implements each step of the grid-connected inverter control method provided in the above embodiment when executing the computer program.

[0069] In one embodiment, the present invention may further provide a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, each step of the grid-connected inverter control method provided in the above embodiment is implemented.

[0070] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many 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).

[0071] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0072] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some of the technical features can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A grid-connected inverter control method, characterized in that: The grid-connected inverter control method comprises: When the power grid has an asymmetric fault, the positive sequence component and negative sequence component of the power grid are obtained; Determining control given parameters of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault; the control given parameters include a reactive current given value and an active current given value; generating a reactive current compensation value and an active current compensation value based on the positive sequence component, the negative sequence component, the reactive current given value and the active current given value; The active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value are sent to the grid-connected inverter, so that the grid-connected inverter executes in response to the active current given value, the active current compensation value, the reactive current given value and the reactive current compensation value.

2. The grid-connected inverter control method according to claim 1, characterized in that: When the power grid has an asymmetric fault, the positive sequence component and the negative sequence component of the power grid are obtained, specifically including: Collect the grid connection point voltage, and when an asymmetric fault occurs at the grid connection point, obtain the positive sequence component and the negative sequence component according to the grid connection point voltage; wherein the positive sequence component includes the positive sequence d-axis component u d_pos and the positive sequence q-axis component u q_pos , the negative sequence component includes the negative sequence d-axis component u d_neg and the negative sequence q-axis component u q_neg .

3. The grid-connected inverter control method according to claim 1 or 2, characterized in that: The determining of the control given parameters of the grid-connected inverter based on the positive sequence component and the given value of the active current before the grid fault specifically includes: According to the positive sequence voltage modulus of the positive sequence component, the formula i q =K×(0.9-U m_pos )×I n Calculate the reactive current given value that the grid-connected inverter needs to generate; where i q is the reactive current given value, U m_pos is the positive sequence voltage modulus, K is the reactive dynamic adjustment coefficient, I n Output rated current for grid-connected inverter; According to the positive sequence voltage modulus of the positive sequence component and the given value of the active current before the power grid fault, the formula i d =K1×i d_old +K2×U m_pos ×I n Calculate the active current given value of the grid-connected inverter; where i d is the given value of active current, U m_pos is the positive sequence voltage modulus, i d_old is the given value of active current before the grid fault, K1 and K2 are dynamic active current adjustment coefficients, I n Output rated current for grid-connected inverter.

4. The grid-connected inverter control method according to claim 3, characterized in that: The grid-connected inverter control method further includes: limiting the active current set value i of the grid-connected inverter d , so that the active current given value 5. The grid-connected inverter control method according to claim 4, characterized in that: After determining the control given parameter of the grid-connected inverter based on the positive sequence component and the active current given value before the grid fault, the method further includes: detecting the active current given value i d ,like Execute the limiting of the active current given value i of the grid-connected inverter d steps.

6. The grid-connected inverter control method according to claim 1 or 2, characterized in that: The generating of reactive current compensation value and active current compensation value based on the positive-sequence component, the negative-sequence component, the reactive current given value and the active current given value specifically includes: calculating reactive current compensation value and active current compensation value according to the positive-sequence component, the negative-sequence component, the reactive current given value and the active current given value, with the negative-sequence component in the compensated output power being zero as a limiting condition.

7. The grid-connected inverter control method according to claim 6, characterized in that: The calculating of the reactive current compensation value and the active current compensation value according to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value, with the negative sequence component in the compensated output power being zero as a limiting condition, specifically includes: According to the positive sequence component, the negative sequence component, the reactive current given value and the active current given value, the reactive current compensation value and the active current compensation value are calculated using the following formula: Among them, i d_comp is the active current compensation value, i q_comp is the reactive current compensation value, i q is the reactive current given value, i d is the given value of active current, u d_pos is the positive sequence d-axis component, u m_neg is the negative sequence voltage modulus, and Where ω is the grid angular frequency, α pos is the positive sequence angle, α neg is the negative sequence angle.

8. A grid-connected inverter control device, characterized in that: The grid-connected inverter control device comprises: An acquisition module, used for acquiring positive sequence components and negative sequence components of the power grid when an asymmetric fault occurs in the power grid; A given parameter determination module, used to determine the given control parameters of the grid-connected inverter based on the positive sequence component and the given active current value before the grid fault; the given control parameters include a reactive current given value and an active current given value; A compensation generating module, configured to generate a reactive current compensation value and an active current compensation value based on the positive sequence component, the negative sequence component, the reactive current given value and the active current given value; A control module is used to send the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value to the grid-connected inverter, so that the grid-connected inverter responds to the active current set value, the active current compensation value, the reactive current set value and the reactive current compensation value for execution.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the grid-connected inverter control method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the grid-connected inverter control method according to any one of claims 1 to 7 are implemented.

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