Method and device for evaluating fault ride-through capability of network-forming inverter

Abstract

The invention relates to a method and device for evaluating the fault ride-through capability of a network-building type inverter, and belongs to the technical field of photovoltaic power generation, and the method comprises the steps: adjusting the power input parameters of the DC input side of the network-building type inverter according to a preset rule; acquiring real-time response data of the network-forming inverter in response to the change of the power input parameters; and comparing and analyzing the real-time response data and standard response data in a test database, and determining the fault ride-through capability of the network-building inverter. According to the invention, the fault ride-through capability of the to-be-tested network-building type inverter can be determined, the stability of the network-building type inverter in actual use is improved, and potential safety hazards are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic power generation, and in particular to a method and device for evaluating the fault ride-through capability of a grid-connected inverter. Background Art

[0002] An inverter is an electronic device used to convert direct current (DC) power into alternating current (AC) power. It is mainly used in power generation systems, energy storage systems, and variable frequency drives. In the power system, the inverter connects renewable energy and energy storage systems to the AC power grid, provides stable power output, and maintains stable system operation, which promotes the use of clean energy and the development and promotion of renewable energy. Due to the criticality of its application in the power system, the reliability and safety requirements of the inverter are getting higher and higher. Therefore, it is necessary to continuously promote the test level of inverter automation testing.

[0003] In the existing inverter tests, only the conversion efficiency, electrical performance and other parameters of the inverter are tested, and the inverter's ability to respond to external faults is ignored. In particular, the grid-type inverter of the photovoltaic power generation network is affected by various external factors. The working environment of the inverter is relatively complex, and the inverter is required to be able to adapt to various faults. However, the existing inverter testing methods cannot determine the inverter's ability to respond to faults, which poses a safety hazard. Summary of the invention

[0004] In view of this, it is necessary to provide a method and device for evaluating the fault ride-through capability of a grid-connected inverter to solve the problem that the existing inverter testing method cannot determine the inverter's ability to cope with faults and there are safety hazards.

[0005] In order to solve the above problems, the present invention provides a method for evaluating the fault ride-through capability of a grid-connected inverter, comprising:

[0006] Adjust the power input parameters of the DC input side of the grid-forming inverter according to preset rules;

[0007] Collecting real-time response data of the grid-connected inverter in response to changes in the power input parameters;

[0008] The real-time response data is compared and analyzed with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

[0009] In a possible implementation manner, adjusting the power input parameters of the DC input side of the grid-connected inverter according to a preset rule includes:

[0010] According to the preset voltage interval, gradually reduce or increase the input voltage on the DC input side of the grid-type inverter; or

[0011] According to the preset current interval, the input current of the DC input side of the grid-type inverter is gradually reduced or increased;

[0012] Then the real-time response data includes output voltage or output current.

[0013] In a possible implementation manner, comparing and analyzing the real-time response data with standard response data in a test database to determine the fault ride-through capability of the grid-connected inverter includes:

[0014] constructing an output voltage curve based on the output voltage corresponding to each input voltage; constructing an output current curve based on the output current corresponding to each input current;

[0015] constructing an output power curve of the grid-connected inverter based on the output voltage curve and the output current curve;

[0016] Based on the relationship between the output power curve and a standard output power curve in a test database, a fault ride-through capability of the grid-connected inverter is determined.

[0017] In a possible implementation, the method further includes:

[0018] The voltage calculation formula and the current calculation formula are used to calculate the average value of the output voltage corresponding to the input voltage and the average value of the output current corresponding to the input current. The voltage calculation formula is:

[0019]

[0020] Among them, U a is the average value of the output voltage corresponding to the input voltage, n represents the number of collected output voltages corresponding to each input voltage, U i represents the voltage value of the i-th output voltage;

[0021] The current calculation formula is:

[0022]

[0023] Among them, I b is the average value of the output current corresponding to the input current, m represents the number of collected output currents corresponding to each input current, I j represents the current value of the j-th output current;

[0024] The voltage stability index of the grid-connected inverter is calculated using a voltage stability index calculation formula, which is:

[0025]

[0026] Wherein, μ is the voltage stability index of the grid-type inverter, which is used to indicate the voltage fault ride-through capability of the grid-type inverter. r is the standard output voltage in the test database, lg is the logarithmic function with base 10;

[0027] The current stability index calculation formula is used to calculate the current stability index of the grid-connected inverter. The current stability index calculation formula is:

[0028]

[0029] Where η is the current stability index of the grid-type inverter, which is used to indicate the current fault ride-through capability of the grid-type inverter. o This is the standard output current in the test database.

[0030] In a possible implementation, the method further includes:

[0031] constructing an input power curve based on the input voltage and the input current;

[0032] The output stability capability of the grid-connected inverter is determined based on the input power curve and the output power curve.

[0033] In a possible implementation, the method further includes:

[0034] The output side of the grid-type inverter is short-circuited, the short-circuit protection action of the grid-type inverter is collected, the short-circuit protection action is compared and analyzed with the standard protection short-circuit action in the test database, and the short-circuit fault ride-through capability of the grid-type inverter is determined.

[0035] In a possible implementation manner, comparing and analyzing the real-time response data with standard response data in a test database includes:

[0036] Collecting environmental parameters of the grid-connected inverter;

[0037] The influence of the environmental parameters on the fault ride-through capability of the grid-connected inverter is determined in combination with the environmental parameters, the real-time response data, and the standard response data.

[0038] The present invention also provides a device for evaluating the fault ride-through capability of a grid-connected inverter, comprising:

[0039] An input regulation module, used to adjust the power input parameters of the DC input side of the grid-forming inverter according to preset rules;

[0040] A response collection module, used to collect real-time response data of the grid-connected inverter in response to changes in the power input parameters;

[0041] The comparison and analysis module is used to compare and analyze the real-time response data with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

[0042] The present invention also provides an electronic device, comprising a memory and a processor, wherein:

[0043] The memory is used to store programs;

[0044] The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the method for evaluating the fault ride-through capability of a grid-connected inverter described in any of the above embodiments.

[0045] The present invention also provides a computer-readable storage medium for storing computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the method for evaluating the fault ride-through capability of a grid-connected inverter described in any of the above embodiments.

[0046] The beneficial effects of the present invention are as follows: the method for evaluating the fault ride-through capability of a grid-type inverter provided by the present invention can simulate the situation where the input voltage or input current on the input side of the grid-type inverter in a photovoltaic power generation network is unstable by adjusting the input parameters on the input side of the grid-type inverter, and collect the response data of the grid-type inverter when the input voltage and input current change, and compare the response data with the standard response data in the test database, so as to determine the fault ride-through capability of the grid-type inverter to be tested, improve the stability of the grid-type inverter in actual use, and reduce safety hazards. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0048] Figure 1 A schematic flow chart of a method for evaluating the fault ride-through capability of a grid-connected inverter provided in an embodiment of the present invention.

[0049] Figure 2 A flowchart of an implementation method of S103 provided in an embodiment of the present invention.

[0050] Figure 3 A schematic flow chart of an output stability capability testing method provided by an embodiment of the present invention.

[0051] Figure 4A flowchart of a method for testing environmental impact provided by an embodiment of the present invention.

[0052] Figure 5 A schematic diagram of the structure of a device for evaluating the fault ride-through capability of a grid-connected inverter provided in an embodiment of the present invention.

[0053] Figure 6 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0055] Reference to an "embodiment" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] A specific embodiment of the present invention, as Figure 1 As shown, a method for evaluating the fault ride-through capability of a grid-connected inverter is disclosed, comprising:

[0057] S101, adjusting the power input parameters of the DC input side of the grid-connected inverter according to a preset rule;

[0058] S102, collecting real-time response data of the grid-connected inverter in response to changes in power input parameters;

[0059] S103, comparing and analyzing the real-time response data with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

[0060] In an embodiment of the present invention, a grid-type inverter is used to convert the voltage direct current of a solar photovoltaic power generation network into high-voltage alternating current available in a municipal power grid. The DC input side of the grid-type inverter is connected to the DC output end of the solar photovoltaic power generation network, and the AC output end of the grid-type inverter is connected to the municipal power grid or directly connected to a load.

[0061] The method for evaluating the fault ride-through capability of a grid-type inverter provided by the present invention is used to evaluate the fault ride-through capability of a grid-type inverter in a photovoltaic power generation network. The fault ride-through capability refers to the ability of an electrical appliance to withstand abnormal conditions such as transient voltage and transient current without being damaged. Combined with the actual application scenarios of the grid-type inverter, by adjusting the power input parameters on the DC input side of the grid-type inverter according to preset rules, the voltage or current fluctuations of the solar photovoltaic power generation network under different power generation capacities in different weather and environments can be simulated, thereby providing a more reasonable input for the evaluation of the fault ride-through capability of the grid-type inverter.

[0062] In the embodiment of the present invention, the grid-type inverter will respond to the change of the power input parameter, including but not limited to the change of the output voltage or current, necessary protection operation, fault recovery operation, etc. Specifically, the real-time response data of the grid-type inverter corresponding to the change of the power input parameter can be collected, and the real-time response data can be compared and analyzed with the standard response data in the test database to determine the fault ride-through capability of the grid-type inverter.

[0063] The method for evaluating the fault ride-through capability of a grid-type inverter provided by the present invention can simulate the situation where the input voltage or input current on the input side of the grid-type inverter in a photovoltaic power generation network is unstable by adjusting the input parameters on the input side of the grid-type inverter, and collects the response data of the grid-type inverter when the input voltage and input current change, and compares the response data with the standard response data in the test database, so as to determine the fault ride-through capability of the grid-type inverter to be tested, improve the stability of the grid-type inverter in actual use, and reduce safety hazards.

[0064] Optionally, adjusting the power input parameters of the DC input side of the grid-connecting inverter according to a preset rule includes:

[0065] According to the preset voltage interval, gradually reduce or increase the input voltage on the DC input side of the grid-type inverter; or

[0066] According to the preset current interval, the input current of the DC input side of the grid-type inverter is gradually reduced or increased;

[0067] Then the real-time response data includes output voltage or output current.

[0068] In an embodiment of the present invention, when adjusting the power input parameter of the DC input side of the mesh inverter, the input voltage of the DC input side of the mesh inverter can be gradually reduced or increased according to a preset voltage interval. For example, the rated input voltage of the mesh inverter is 24V, and the input voltage of the mesh inverter can be gradually reduced from 24V, such as reducing 0.5V each time until the input voltage reaches the minimum input voltage of the mesh inverter, such as 12V; or starting from 24V, the input voltage of the mesh inverter can be gradually increased, such as increasing 0.5V each time until the input voltage reaches the maximum input voltage of the mesh inverter, such as 36V. Optionally, the power input parameter can also be the input current. Similarly to the adjustment of the input voltage, the input current of the mesh inverter can be gradually reduced or increased according to the adjustment method of the input voltage.

[0069] Furthermore, when adjusting the input voltage or input current, the adjustment interval can be set, that is, after each adjustment of the input voltage or input current, ensure that the input voltage or input current is stable for a period of time before increasing or decreasing the input voltage or input current, so as to give the grid-type inverter sufficient response time and improve the accuracy of the test results.

[0070] When the input voltage of the grid-forming inverter changes, the real-time output voltage of the grid-forming inverter can be collected; when the input current of the grid-forming inverter changes, the real-time output current of the grid-forming inverter can be collected.

[0071] Specifically, each time the power input parameters on the input side of the meshed inverter are adjusted, the response data of the meshed inverter is synchronously collected and recorded. For example, the power input parameters on the input side of the meshed inverter are adjusted at preset time intervals, and correspondingly, the response data of the meshed inverter, such as output voltage, output current, protection operation, fault recovery operation, etc., are collected at the preset time intervals.

[0072] The embodiment of the present invention simulates the instability of the solar photovoltaic power generation network by increasing or decreasing the input voltage or input current of the grid-type inverter, thereby improving the accuracy of the grid-type inverter test.

[0073] Further, such as Figure 2 As shown, the real-time response data is compared and analyzed with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter, including:

[0074] S201, constructing an output voltage curve based on the output voltages corresponding to the input voltages; constructing an output current curve based on the output currents corresponding to the input currents;

[0075] S202, constructing an output power curve of the grid-connected inverter based on the output voltage curve and the output current curve;

[0076] S203, determining the fault ride-through capability of the grid-connected inverter based on the relationship between the output power curve and the standard output power curve in the test database.

[0077] In the embodiment of the present invention, when collecting the output voltage of the grid-type inverter, there are multiple output voltages corresponding to each input voltage, that is, when the input voltage changes, the output voltage gradually changes, so it is necessary to average the multiple output voltages corresponding to each input voltage, which can be calculated using formula (1):

[0078]

[0079] Among them, U a is the average value of the output voltage corresponding to the input voltage, n represents the number of collected output voltages corresponding to each input voltage, U i Represents the voltage value of the i-th output voltage. Similarly, the output current can be calculated using formula (2):

[0080]

[0081] Among them, I b is the average value of the output current corresponding to the input current, m represents the number of collected output currents corresponding to each input current, I j Represents the current value of the j-th output current.

[0082] Based on this, a curve of output voltage and output current is constructed.

[0083] Furthermore, the voltage stability index of the grid-connected inverter can be calculated using formula (3):

[0084]

[0085] Wherein, μ is the voltage stability index of the grid-type inverter, which is used to indicate the voltage fault ride-through capability of the grid-type inverter. r is the standard output voltage in the test database, and lg is a logarithmic function with base 10.

[0086] Similarly, the current stability index of the grid-connected inverter can be calculated using formula (4):

[0087]

[0088] Where η is the current stability index of the grid-type inverter, which is used to indicate the current fault ride-through capability of the grid-type inverter. o This is the standard output current in the test database.

[0089] In this embodiment, the output power curve can be constructed by constructing the output voltage and output current curves, and then the relationship between the curve and the standard output power curve in the test database can be determined to determine the fault ride-through capability of the meshed inverter. For example, if the output power curve is the same as the standard output power curve in the test database, it indicates that the fault ride-through capability of the meshed inverter is good. In addition, in this embodiment, the voltage fault ride-through capability and the current fault ride-through capability of the meshed inverter can also be determined by the voltage stability index and the current stability index. Therefore, the embodiment of the present invention can determine the ability of the meshed inverter to ride through voltage faults and current faults by changing the power input parameters on the input side of the meshed inverter, collecting the response data corresponding to the output side of the meshed inverter, and analyzing the response data.

[0090] As a possible implementation mode of the present invention, in this implementation mode, Figure 3 As shown, the method also includes:

[0091] S301, constructing an input power curve based on the input voltage and the input current;

[0092] S302: Determine the output stability capability of the grid-connected inverter based on the input power curve and the output power curve.

[0093] In an embodiment of the present invention, in the fault ride-through capability test of the grid-type inverter, its output power stability capability also needs to be tested. Specifically, when adjusting the power input parameters on the input side of the grid-type inverter, the input voltage and input current on the input side of the grid-type inverter can be recorded, and the input power is calculated based on the input voltage and input current, and an input power curve is constructed. Correspondingly, each time the power input parameters are adjusted, the output voltage or output current corresponding to the grid-type inverter is collected, and the output power is calculated based on the output voltage and output current to construct an output power curve. By comparing the input power curve and the output power curve, the output stability capability of the grid-type inverter can be determined. Ideally, the output power curve should be a curve after the input power curve is amplified and translated, but due to the existence of various interference and error factors, the derivative function of the input power curve and the derivative function of the output power curve can be calculated to represent the rate of change of the input power and the output power. The output stability capability of the grid-type inverter can be determined by the similarity between the derivative function of the input power curve and the derivative function of the output power curve.

[0094] The embodiment of the present invention can determine the output stability capability of the grid-connected inverter through the input power curve and the output power curve.

[0095] As a possible implementation manner of the present invention, in this implementation manner, the method further includes:

[0096] The output side of the grid-type inverter is short-circuited, the short-circuit protection action of the grid-type inverter is collected, and the short-circuit protection action is compared and analyzed with the standard protection short-circuit action in the test database to determine the short-circuit fault ride-through capability of the grid-type inverter.

[0097] In the implementation of the present invention, the test of the fault ride-through capability of the grid-type inverter also includes the test of the short-circuit fault ride-through capability. Specifically, the output side of the grid-type inverter can be short-circuited, and the short-circuit protection action information of the grid-type inverter can be collected, including but not limited to disconnecting the output, starting the protection function, and recovering the operation. Specifically, the time from the start of the short circuit to disconnecting the output, the time for starting the protection function, and the time for executing the recovery operation can be collected, so as to determine the short-circuit fault ride-through capability of the grid-type inverter.

[0098] Further, such as Figure 4 As shown, the real-time response data is compared and analyzed with the standard response data in the test database, including:

[0099] S401, collecting environmental parameters of the grid-connected inverter;

[0100] S402, determining the influence of the environmental parameters on the fault ride-through capability of the grid-connected inverter by combining the environmental parameters, the real-time response data, and the standard response data.

[0101] In an embodiment of the present invention, in order to ensure the accuracy of the evaluation of the fault ride-through capability of the grid-type inverter, the influence of environmental factors on the fault ride-through capability of the grid-type inverter can also be considered. Specifically, in an actual test environment, the environmental parameters of the grid-type inverter are collected, where the environmental parameters include but are not limited to the ambient temperature, humidity, light intensity of the grid-type inverter, and load changes of the grid-type inverter, etc. The fault ride-through capability of the grid-type inverter is tested multiple times under different environmental parameters to determine the influence of environmental parameters on the fault ride-through capability of the grid-type inverter.

[0102] The embodiment of the present invention adds the influence of environmental factors when testing the grid-connected inverter, thereby improving the accuracy of the test result.

[0103] In order to better implement the method for evaluating the fault ride-through capability of a grid-type inverter in the embodiment of the present invention, based on the method for evaluating the fault ride-through capability of a grid-type inverter, correspondingly, Figure 5 As shown, the embodiment of the present invention further provides a device for evaluating the fault ride-through capability of a grid-type inverter, and the device 500 for evaluating the fault ride-through capability of a grid-type inverter includes:

[0104] An input adjustment module 501, used to adjust the power input parameters of the DC input side of the grid-connected inverter according to a preset rule;

[0105] A response collection module 502 is used to collect real-time response data of the grid-connected inverter in response to changes in power input parameters;

[0106] The comparison and analysis module 503 is used to compare and analyze the real-time response data with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

[0107] The grid-type inverter fault ride-through capability assessment device 500 provided in the above embodiment can implement the technical solution described in the above embodiment of the grid-type inverter fault ride-through capability assessment method. The specific implementation principles of the above modules or units can refer to the corresponding contents in the above embodiment of the grid-type inverter fault ride-through capability assessment method, which will not be repeated here.

[0108] like Figure 6 As shown, the present invention also provides an electronic device 600. The electronic device 600 includes a processor 601, a memory 602 and a display 603. Figure 6 Only some components of the electronic device 600 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0109] In some embodiments, the processor 601 may be a central processing unit (CPU), a microprocessor or other data processing chip, used to run program codes or process data stored in the memory 602, such as the fault ride-through capability evaluation method of the grid-connected inverter in the present invention.

[0110] In some embodiments, the processor 601 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 601 may be local or remote. In some embodiments, the processor 601 may be implemented in a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0111] In some embodiments, the memory 602 may be an internal storage unit of the electronic device 600, such as a hard disk or memory of the electronic device 600. In other embodiments, the memory 602 may also be an external storage device of the electronic device 600, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 600.

[0112] Furthermore, the memory 602 may include both an internal storage unit of the electronic device 600 and an external storage device. The memory 602 is used to store application software installed in the electronic device 600 and various data.

[0113] In some embodiments, the display 603 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an OLED (Organic Light-Emitting Diode) touch device, etc. The display 603 is used to display information of the electronic device 600 and to display a visual user interface. The components 601-603 of the electronic device 600 communicate with each other through a system bus.

[0114] In some embodiments, when the processor 601 executes the grid-connected inverter fault ride-through capability evaluation program in the memory 602, the following steps may be implemented:

[0115] Adjust the power input parameters of the DC input side of the grid-forming inverter according to preset rules;

[0116] Collecting real-time response data of the grid-connected inverter in response to changes in power input parameters;

[0117] The real-time response data is compared and analyzed with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

[0118] It should be understood that: when the processor 601 executes the grid-type inverter fault ride-through capability evaluation program in the memory 602, in addition to the above functions, other functions can also be implemented. For details, please refer to the description of the corresponding method embodiment above.

[0119] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 600 mentioned, and the electronic device 600 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 600 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0120] Correspondingly, an embodiment of the present invention also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions in the method for evaluating the fault ride-through capability of a grid-connected inverter provided in the above-mentioned method embodiments.

[0121] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware through a computer program, and the program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0122] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for evaluating the fault ride-through capability of a grid-connected inverter, characterized in that: include: Adjust the power input parameters of the DC input side of the grid-forming inverter according to preset rules; Collecting real-time response data of the grid-connected inverter in response to changes in the power input parameters; The real-time response data is compared and analyzed with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

2. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 1, characterized in that: The step of adjusting the power input parameters of the DC input side of the grid-connected inverter according to a preset rule includes: According to the preset voltage interval, gradually reduce or increase the input voltage on the DC input side of the grid-type inverter; or According to the preset current interval, the input current of the DC input side of the grid-type inverter is gradually reduced or increased; Then the real-time response data includes output voltage or output current.

3. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 2, characterized in that: The comparing and analyzing the real-time response data with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter includes: constructing an output voltage curve based on the output voltage corresponding to each input voltage; constructing an output current curve based on the output current corresponding to each input current; constructing an output power curve of the grid-connected inverter based on the output voltage curve and the output current curve; Based on the relationship between the output power curve and a standard output power curve in a test database, a fault ride-through capability of the grid-connected inverter is determined.

4. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 3, characterized in that: The method further comprises: The voltage calculation formula and the current calculation formula are used to calculate the average value of the output voltage corresponding to the input voltage and the average value of the output current corresponding to the input current. The voltage calculation formula is: Among them, U a is the average value of the output voltage corresponding to the input voltage, n represents the number of collected output voltages corresponding to each input voltage, U i represents the voltage value of the i-th output voltage; The current calculation formula is: Among them, I b is the average value of the output current corresponding to the input current, m represents the number of collected output currents corresponding to each input current, I j represents the current value of the j-th output current; The voltage stability index of the grid-connected inverter is calculated using a voltage stability index calculation formula, which is: Wherein, μ is the voltage stability index of the grid-type inverter, which is used to indicate the voltage fault ride-through capability of the grid-type inverter. r is the standard output voltage in the test database, lg is the logarithmic function with base 10; The current stability index calculation formula is used to calculate the current stability index of the grid-connected inverter. The current stability index calculation formula is: Where η is the current stability index of the grid-type inverter, which is used to indicate the current fault ride-through capability of the grid-type inverter. o This is the standard output current in the test database.

5. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 3, characterized in that: The method further comprises: constructing an input power curve based on the input voltage and the input current; The output stability capability of the grid-connected inverter is determined based on the input power curve and the output power curve.

6. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 1, characterized in that: The method further comprises: The output side of the grid-type inverter is short-circuited, the short-circuit protection action of the grid-type inverter is collected, the short-circuit protection action is compared and analyzed with the standard protection short-circuit action in the test database, and the short-circuit fault ride-through capability of the grid-type inverter is determined.

7. The method for evaluating the fault ride-through capability of a grid-connected inverter according to claim 1, characterized in that: The comparing and analyzing the real-time response data with the standard response data in the test database includes: Collecting environmental parameters of the grid-connected inverter; The influence of the environmental parameters on the fault ride-through capability of the grid-connected inverter is determined in combination with the environmental parameters, the real-time response data, and the standard response data.

8. A device for evaluating the fault ride-through capability of a grid-connected inverter, characterized in that: include: An input regulation module, used to adjust the power input parameters of the DC input side of the grid-forming inverter according to preset rules; A response collection module, used to collect real-time response data of the grid-connected inverter in response to changes in the power input parameters; The comparison and analysis module is used to compare and analyze the real-time response data with the standard response data in the test database to determine the fault ride-through capability of the grid-connected inverter.

9. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the steps in the method for evaluating the fault ride-through capability of a grid-connected inverter as described in any one of claims 1 to 7 above.

10. A computer-readable storage medium, characterized in that: Used to store computer-readable programs or instructions, which, when executed by a processor, can implement the steps in the method for evaluating the fault ride-through capability of a grid-connected inverter as described in any one of claims 1 to 7 above.

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