Inverter grid-connected mutual inductor reverse connection detection method, device, medium and equipment

Abstract

The application relates to the current detection technical field and discloses a mutual inductor reverse connection detection method, device, medium and equipment for inverter grid connection. The mutual inductor is detachably installed on a target line between an inverter and a power grid. The reverse connection detection method comprises the following steps: controlling the inverter to output a self-checking current through the target line; collecting a first current detection signal flowing through the inverter and collecting a second current detection signal of the mutual inductor; comparing the first current detection signal with the second current detection signal to determine whether the first current detection signal and the second current detection signal satisfy a reverse characteristic condition; when the reverse characteristic condition is satisfied, it is determined that the mutual inductor is reversely connected; and when the mutual inductor is reversely connected, the polarity of the mutual inductor is corrected. The application can automatically detect and judge whether the current mutual inductor is reversely connected, and if the current mutual inductor is reversely connected, the polarity of the current mutual inductor is automatically corrected to prevent the reverse connection of the current mutual inductor.

Description

Technical Field

[0001] This application relates to the field of current detection technology, and in particular to a method, apparatus, medium and equipment for detecting reverse connection of current transformers used in inverter grid connection. Background Technology

[0002] In energy storage and photovoltaic inverter systems, grid-side current transformers (CTs) are key sensors for achieving reverse current control, zero-power grid connection, and grid dispatch. The installation direction (polarity) and phase sequence of the current transformers (CTs) must be absolutely correct; otherwise, the reverse current control loop will diverge, leading to excessive reverse current or even equipment damage.

[0003] Existing technologies have some drawbacks: 1. Most detection schemes use a pulse method to increase the self-test current by instantaneous voltage boost. The step-type pulse self-test current will cause active power impact on the power grid, affecting power quality, and is prone to voltage flicker at the grid connection point under weak power grid conditions.

[0004] 2. After detecting an incorrect direction of the current transformer (CT), most technologies rely solely on manual on-site rewiring, lacking an arbitration mechanism for conflicts between "automatic correction" and "user manual correction," which can easily lead to misoperation.

[0005] 3. If the software correction logic fails or the power grid topology changes unexpectedly, directly unlocking full-power operation after correction will face a huge risk of system crash or illegal internet access. Summary of the Invention

[0006] The purpose of this application is to provide a method, device, medium and equipment for detecting reverse connection of current transformers used for inverter grid connection, which automatically detects and determines whether the current transformer is reverse connected. If the current transformer is detected to be reverse connected, the polarity of the current transformer is automatically corrected to prevent the current transformer from being reverse connected.

[0007] Other features and advantages of this application will become apparent from the following detailed description, or may be learned in part from practice of this application.

[0008] According to one aspect of the embodiments of this application, a method for detecting reverse connection of a current transformer used for inverter grid connection is provided. The current transformer is detachably installed on the target line under test between the inverter and the power grid. The reverse connection detection method includes: controlling the inverter to output a self-test current through the target line under test; acquiring a first current detection signal flowing through the inverter and acquiring a second current detection signal of the current transformer; comparing the first current detection signal and the second current detection signal to determine whether the first current detection signal and the second current detection signal satisfy a reverse characteristic condition; when the reverse characteristic condition is satisfied, determining that the current transformer is reverse connected; when the current transformer is reverse connected, correcting the polarity of the current transformer.

[0009] In some embodiments, when the current transformer is reverse-connected, the method for correcting the polarity of the current transformer includes: detecting and acquiring a preset automatic correction permission; when the automatic correction permission exists, automatically correcting the polarity of the current transformer; when the automatic correction permission does not exist, issuing a polarity correction prompt.

[0010] In some embodiments, before controlling the inverter to output a self-test current through the target line under test, the method further includes: obtaining a first current direction of the set self-test current; obtaining a preset current value of the set self-test current; and preparing a self-test current according to the first current direction and the preset current value.

[0011] In some embodiments, in controlling the inverter to output a self-test current through the target line under test, the method includes: controlling the inverter to output a self-test current with a gradually increasing current value; obtaining a first average current value of the self-test current in a first time period, and obtaining a second average current value in a second time period connected to the first time period; calculating a first absolute value of the difference between the first average current value and the second average current value; and proceeding to the next step when the first absolute value of the difference is less than a first preset threshold.

[0012] In some embodiments, before controlling the self-test current that gradually increases the output current value of the inverter, the method further includes: when the inverter is a three-phase inverter, selecting the target line under test corresponding to any phase uncorrected current transformer as the self-test line; outputting the self-test current to the self-test line, and shutting off the current signal of the target line under test other than the self-test line.

[0013] In some embodiments, in determining whether the first current detection signal and the second current detection signal satisfy the reverse characteristic condition, the method includes: obtaining a second current direction of the first current detection signal and a third current direction of the second current detection signal; obtaining a first phase of the first current detection signal and a second phase of the second current detection signal, and calculating the phase difference between the first phase and the second phase; calculating the absolute value of the second difference between the first current detection signal and the second current detection signal; when the second current direction and the third current direction are opposite, or when the phase difference is greater than a set angle, or when the absolute value of the second difference is greater than a second preset threshold, then the reverse characteristic condition is satisfied.

[0014] In some embodiments, when the current transformer is reverse-connected, after correcting the polarity of the current transformer, the method further includes: controlling the inverter to output a verification current through the target line under test; acquiring a third current detection signal flowing through the inverter and a fourth current detection signal of the current transformer; outputting a verification result based on the third current detection signal and the fourth current detection signal; when the verification result indicates that the polarity correction of the current transformer is successful, locking the corrected configuration of the current transformer; when the verification result indicates that the polarity correction of the current transformer fails, blocking the inverter and issuing a fault warning.

[0015] According to one aspect of the embodiments of this application, a reverse connection detection device for an inverter grid connection is provided. The transformer is detachably installed on the target line under test between the inverter and the power grid. The reverse connection detection device includes: a self-test current output module for controlling the inverter to output a self-test current through the target line under test; a current acquisition module for acquiring a first current detection signal flowing through the inverter and a second current detection signal of the transformer; a determination module for comparing the first current detection signal and the second current detection signal to determine whether the first current detection signal and the second current detection signal satisfy a reverse characteristic condition, and determining that the transformer is reverse connected when the reverse characteristic condition is satisfied; and a correction module for correcting the polarity of the transformer when the transformer is reverse connected.

[0016] According to one aspect of the embodiments of this application, a computer-readable medium is provided having a computer program stored thereon, which, when executed by a processor, implements the reverse connection detection method as described in the above embodiments.

[0017] According to one aspect of the embodiments of this application, an electronic device is provided, including: one or more processors; and a memory for storing executable instructions of the processors, wherein when the executable instructions are executed by the one or more processors, the one or more processors implement the reverse connection detection method as described in the above embodiments.

[0018] Compared with the prior art, the significant advantages of the technical solution of this application are as follows: This application can automatically detect and determine whether the current transformer is reverse-connected. If reverse connection is detected, the polarity of the current transformer can be automatically corrected according to the user's permissions, or the user can be prompted to manually correct the polarity of the current transformer to prevent reverse connection. When inputting the self-test current, this application gradually and smoothly increases the self-test current to prevent instantaneous pulses from impacting the power grid. When the self-test current rises to a stable level, the testing process can begin. After the current transformer is corrected, a verification current is input again to verify the correction. If the verification result shows that the polarity correction of the current transformer is successful, the corrected configuration of the current transformer is locked. If the verification result shows that the polarity correction of the current transformer fails, the inverter is blocked and a fault warning is issued to prevent the inverter from being directly unlocked for full-power operation when the software correction logic malfunctions, which would face a huge risk of overheating or illegal grid connection.

[0019] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0020] The above and other features and advantages of this application will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.

[0021] Figure 1 A flowchart of a current transformer reverse connection detection method according to an embodiment of this application is shown; Figure 2 A simplified diagram of a current transformer reverse connection detection device according to an embodiment of this application is shown; Figure 3 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown. Detailed Implementation

[0022] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided to make this application more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art.

[0023] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0024] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0025] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily need to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0026] The technical solutions of the embodiments of this application are briefly described below: According to some embodiments, such as Figure 1 As shown, this application provides a method for detecting reverse connection of an instrument transformer used for inverter grid connection. The instrument transformer is detachably installed on the target line under test between the inverter and the power grid. The reverse connection detection method includes: Step 101: Control the inverter to output a self-test current through the target line under test; Step 102: Acquire the first current detection signal flowing through the inverter and the second current detection signal of the current transformer; Step 103: Compare the first current detection signal and the second current detection signal to determine whether the first current detection signal and the second current detection signal meet the reverse characteristic condition. If the reverse characteristic condition is met, it is determined that the current transformer is reverse connected. Step 104: When the current transformer is reversed, correct the polarity of the current transformer.

[0027] Based on the above embodiments, a current transformer is installed on the grid-connected line of the photovoltaic energy storage inverter to detect the current. The current transformer is a manually detachable current transformer. Manual installation may result in the current transformer being installed in reverse. Therefore, the reverse connection detection method described in this application automatically detects and determines whether the current transformer is reverse connected through steps 101 to 104. If the current transformer is detected to be reverse connected, the polarity of the transformer is automatically corrected to prevent the current transformer from being reverse connected, thereby improving the safety of current detection.

[0028] To enable those skilled in the art to better understand this application, the following will be combined with Figure 1 The details of this application are described in detail.

[0029] According to some embodiments, in step 104, when the current transformer is reverse-connected, the method for correcting the polarity of the current transformer includes: Step 1041: Detect and obtain preset automatic correction permissions; Step 1042: When automatic calibration permission exists, the polarity of the current transformer is automatically calibrated; Step 1043: If there is no automatic correction permission, a polarity correction prompt will be issued.

[0030] The automatic calibration permission can be manually set to be enabled or disabled in advance. When the automatic calibration permission is disabled, the user will be clearly prompted with a local screen pop-up or cloud push to indicate which current transformer has the wrong polarity, guiding the user to make on-site physical wiring adjustments, or to manually issue a correction command through the host computer.

[0031] This application can automatically detect and determine whether a current transformer is reverse-connected. If a reverse connection is detected, the polarity of the transformer can be automatically corrected according to the user's permissions, or the user can be prompted to manually correct the polarity of the transformer. This provides greater flexibility and helps prevent the current transformer from being reverse-connected.

[0032] According to some embodiments, before step 101, whereby the inverter is controlled to output a self-test current through the target line under test, the method further includes: Step 91: Obtain the first current direction of the set self-test current; Step 92: Obtain the preset current value of the self-test current; Step 93: Prepare the self-test current according to the first current direction and the preset current value.

[0033] Based on the above embodiments, when the inverter is running in grid-connected mode, and the user initiates a self-test operation of the current transformer through a local human-machine interface or a remote monitoring platform, the system first obtains the first current direction and the preset current value of the self-test current set by the user. The first current direction of the self-test current includes the current direction when the grid charges the photovoltaic energy storage inverter and the current direction when the photovoltaic energy storage inverter discharges to the grid. The preset current value can be set according to actual needs; in some specific embodiments, the preset current value is set to within 20% of the rated current.

[0034] According to some embodiments, in step 101, when controlling the inverter to output a self-test current through the target line under test, the method includes: Step 10111: Control the inverter output current value to gradually increase the self-test current; Step 10112: Obtain the first average current value of the self-test current in the first time period, and obtain the second average current value of the second time period connected to the first time period; Step 10113: Calculate the absolute value of the first difference between the first average current value and the second average current value; Step 10114: When the absolute value of the first difference is less than the first preset threshold, proceed to the next step.

[0035] Based on the above embodiments, traditional methods often use a pulsed, instantaneous voltage boost to raise the self-test current. This step-like pulsed self-test current can cause active power surges on the grid, affecting power quality, and is prone to voltage flicker at the grid connection point in weak grid conditions. Therefore, in step 1011 of this application, when inputting the self-test current, the self-test current is gradually and smoothly increased to prevent instantaneous pulses from impacting the grid. In steps 1012 to 1014, it is detected whether the self-test current tends to stabilize. When the self-test current rises to a stable level (i.e., close to 20% of the rated current), it is possible to start detecting whether the current transformer is reverse-connected.

[0036] According to some embodiments, before step 10111, where the self-test current gradually increases the inverter output current value, the method further includes: Step 1011: When the inverter is a three-phase inverter, select the target line under test corresponding to any uncorrected current transformer as the self-test line. Step 1012: Output self-test current to the self-test circuit and shut off the current signal of the target circuit outside the self-test circuit.

[0037] Following step 1012, the method further includes step 1013, which includes: When the inverter is a three-phase inverter, repeat steps 1011 to 1012 to complete the detection of the remaining phase lines of the inverter in sequence.

[0038] Based on the above embodiments, the system automatically controls the inverter to enter a single-phase sequential test sequence. For a three-phase inverter, phases A, B, and C are tested independently in sequence. During the testing cycle of any phase of the target line under test, the system outputs a self-test current to that target line while simultaneously forcibly setting the current in the other two phases of the target line under test to zero, ensuring that only one phase has current during the test. For a single-phase inverter, only one target line needs to be tested.

[0039] According to some embodiments, in step 103, determining whether the first current detection signal and the second current detection signal satisfy the reverse characteristic condition includes: Obtain the second current direction of the first current detection signal and the third current direction of the second current detection signal; Obtain the first phase of the first current detection signal and the second phase of the second current detection signal, and calculate the phase difference between the first phase and the second phase; Calculate the absolute value of the second difference between the first current detection signal and the second current detection signal; When the direction of the second current is opposite to that of the direction of the third current, or when the phase difference is greater than the set angle, or when the absolute value of the second difference is greater than the second preset threshold, the reverse characteristic condition is met.

[0040] According to some embodiments, in step 104, when the current transformer is reverse-connected, after correcting the polarity of the current transformer, the method further includes: Step 1051: Control the inverter to output verification current through the target line under test; Step 1052: Collect the third current detection signal flowing through the inverter and the fourth current detection signal of the current transformer; Step 1053: Output the verification result based on the third current detection signal and the fourth current detection signal; Step 1054: If the verification result shows that the polarity correction of the current transformer is successful, then the corrected configuration of the current transformer is locked. If the verification result shows that the polarity correction of the current transformer fails, then the inverter is blocked and a fault warning is issued.

[0041] Following step 1054, the method further includes step 1055, which includes: If the inverter is a three-phase inverter, repeat steps 1051 to 1054 to complete the verification of the remaining phase lines of the inverter in sequence.

[0042] The verification current is 1% to 5% of the rated current.

[0043] Based on the above embodiments, the ratio of the third current detection signal and the fourth current detection signal is calculated in real time to evaluate the feedback characteristics of the verification current. If the verification current is determined to exhibit negative feedback convergence characteristics, that is, when the inverter increases its output, the same-direction power detected by the current transformer increases synchronously, and the error converges towards the anti-reverse current target value, then the current correction configuration is confirmed to be absolutely correct, the system locks the configuration and smoothly restores to the normal operating power.

[0044] If the control loop exhibits positive feedback divergence characteristics—meaning that when the inverter increases its output, the current transformer detects an increase in reverse power and the error continues to widen—it indicates that the direction is still incorrect or that other fatal faults exist. The system will immediately trigger hardware-level fast protection, blocking the inverter's PWM pulses and outputting a fault alarm. This completely eliminates the risk of reverse current leakage, excessive reverse current, or equipment damage caused by incorrect current transformer direction. This also prevents the significant risk of system failure or unauthorized internet access during full-power operation.

[0045] The following describes an embodiment of the apparatus of this application, which can be used to perform the reverse connection detection method in the above embodiments of this application.

[0046] Figure 2A simplified diagram of a reverse connection detection device for a current transformer is shown in one embodiment of this application. The current transformer is detachably installed on the target line under test between the inverter and the power grid. The reverse connection detection device includes: The self-test current output module is used to control the inverter to output a self-test current through the target line under test. The current acquisition module is used to acquire the first current detection signal flowing through the inverter and the second current detection signal from the current transformer. The determination module is used to compare the first current detection signal and the second current detection signal to determine whether the first current detection signal and the second current detection signal meet the reverse characteristic condition. When the reverse characteristic condition is met, the transformer is determined to be reverse connected. The correction module is used to correct the polarity of the current transformer when it is reverse-connected.

[0047] Based on the above embodiments, a current transformer is installed on the grid-connected line of the photovoltaic energy storage inverter to detect the current. The current transformer is a manually detachable current transformer. Manual installation may result in the current transformer being installed in reverse. Therefore, the self-testing current output module, current acquisition module, judgment module and correction module of the reverse connection detection device described in this application automatically detect and judge whether the current transformer is reverse connected. If the current transformer is detected to be reverse connected, the polarity of the transformer is automatically corrected to prevent the current transformer from being reverse connected, thereby improving the safety of current detection.

[0048] Figure 3 A schematic diagram of the structure of a computer system suitable for implementing the electronic device of the present application is shown.

[0049] It should be noted that, Figure 3 The computer system 300 of the electronic device shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of this application.

[0050] like Figure 3 As shown, the computer system 300 includes a Central Processing Unit (CPU) 301, which can perform various appropriate actions and processes based on programs stored in Read-Only Memory (ROM) 302 or programs loaded from storage portion 308 into Random Access Memory (RAM) 303, such as executing the reverse connection detection method described in the above embodiments. The RAM 303 also stores various programs and data required for system operation. The CPU 301, ROM 302, and RAM 303 are interconnected via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0051] The following components are connected to I / O interface 305: an input section 306 including a keyboard, mouse, etc.; an output section 307 including a cathode ray tube (CRT), liquid crystal display (LCD), etc., and speakers, etc.; a storage section 308 including a hard disk, etc.; and a communication section 309 including a network interface card such as a LAN (Local Area Network) card, modem, etc. The communication section 309 performs communication processing via a network such as the Internet. A drive 310 is also connected to I / O interface 305 as needed. Removable media 311, such as a disk, optical disk, magneto-optical disk, semiconductor memory, etc., are installed on drive 310 as needed so that computer programs read from them can be installed into storage section 308 as needed.

[0052] Specifically, according to embodiments of this application, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of this application include a computer program product comprising a computer program carried on a computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via communication section 309, and / or installed from removable medium 311. When the computer program is executed by central processing unit (CPU) 301, it performs various functions defined in the system of this application.

[0053] It should be noted that the computer-readable medium shown in the embodiments of this application can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of a computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, optical fiber, portable compact disc read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this application, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In this application, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such transmitted data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. The computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, etc., or any suitable combination thereof.

[0054] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. Each block in a flowchart or block diagram may represent a module, segment, or portion of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram or flowchart, and combinations of blocks in a block diagram or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.

[0055] The modules described in the embodiments of this application can be implemented in software or hardware, and can also be located in a processor. The names of these modules do not necessarily limit the module itself.

[0056] In another aspect, this application also provides a computer program product or computer program including computer instructions stored in a computer-readable storage medium. A processor of an electronic device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the electronic device to perform the reverse connection detection method described in the above embodiments.

[0057] In another aspect, this application also provides a computer-readable medium, which may be included in the electronic device described in the above embodiments; or it may exist independently and not assembled into the electronic device. The computer-readable medium carries one or more programs, which, when executed by the electronic device, cause the electronic device to implement the reverse connection detection method described in the above embodiments.

[0058] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to the embodiments of this application, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0059] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this application can be embodied in the form of a software product. This software product can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, and includes several instructions to cause a computing device (such as a personal computer, server, touch terminal, or network device, etc.) to execute the reverse connection detection method described in the above embodiments.

[0060] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the embodiments disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0061] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for detecting reverse connection of an instrument transformer used in inverter grid connection, wherein the instrument transformer is detachably installed on the target line under test between the inverter and the power grid, characterized in that, The reverse connection detection method includes: The inverter is controlled to output a self-test current through the target circuit under test; The first current detection signal flowing through the inverter and the second current detection signal of the current transformer are collected. By comparing the first current detection signal and the second current detection signal, it is determined whether the first current detection signal and the second current detection signal meet the reverse characteristic condition. When the reverse characteristic condition is met, it is determined that the current transformer is reverse connected. When the current transformer is reversed, the polarity of the current transformer is corrected.

2. The reverse connection detection method according to claim 1, characterized in that, When the current transformer is reverse-connected, the method for correcting the polarity of the current transformer includes: Detect and obtain preset automatic correction permissions; When automatic calibration permission is available, the polarity of the current transformer is automatically calibrated; If automatic correction permission is not available, a polarity correction prompt will be issued.

3. The reverse connection detection method according to claim 1, characterized in that, Before controlling the inverter to output a self-test current through the target line under test, the method further includes: Obtain the first current direction of the set self-test current; Obtain the preset current value of the self-test current; Prepare a self-test current based on the first current direction and the preset current value.

4. The reverse connection detection method according to claim 1, characterized in that, In controlling the inverter to output a self-test current through the target line under test, the method includes: A self-test current that controls the inverter's output current value to gradually increase; The self-test current is obtained as a first average current value in a first time period, and a second average current value in a second time period connected to the first time period is obtained. Calculate the absolute value of the first difference between the first average current value and the second average current value; When the absolute value of the first difference is less than the first preset threshold, proceed to the next step.

5. The reverse connection detection method according to claim 4, characterized in that, Before controlling the self-test current, which gradually increases the output current of the inverter, the method further includes: When the inverter is a three-phase inverter, select the target line under test corresponding to any uncorrected current transformer as the self-test line. Output a self-test current to the self-test circuit and shut off the current signal of the target circuit under test outside the self-test circuit.

6. The reverse connection detection method according to claim 1, characterized in that, In determining whether the first current detection signal and the second current detection signal satisfy the reverse characteristic condition, the method includes: Obtain the second current direction of the first current detection signal and the third current direction of the second current detection signal; Obtain the first phase of the first current detection signal and the second phase of the second current detection signal, and calculate the phase difference between the first phase and the second phase; Calculate the absolute value of the second difference between the first current detection signal and the second current detection signal; When the direction of the second current is opposite to the direction of the third current, or when the phase difference is greater than a set angle, or when the absolute value of the second difference is greater than a second preset threshold, the reverse characteristic condition is satisfied.

7. The reverse connection detection method according to claim 1, characterized in that, When the current transformer is reversed, after correcting the polarity of the current transformer, the method further includes: The inverter is controlled to output a verification current through the target circuit under test; The third current detection signal flowing through the inverter and the fourth current detection signal of the current transformer are collected. The verification result is output based on the third current detection signal and the fourth current detection signal; When the verification result indicates that the polarity correction of the current transformer is successful, the corrected configuration of the current transformer is locked. When the verification result indicates that the polarity correction of the current transformer fails, the inverter is blocked and a fault warning is issued.

8. A reverse connection detection device for an inverter used in grid connection, wherein the transformer is detachably installed on the target line to be tested between the inverter and the power grid, characterized in that, The reverse connection detection device includes: The self-test current output module is used to control the inverter to output a self-test current through the target line under test. The current acquisition module is used to acquire the first current detection signal flowing through the inverter and the second current detection signal of the current transformer. The determination module is used to compare the first current detection signal and the second current detection signal to determine whether the first current detection signal and the second current detection signal meet the reverse characteristic condition. When the reverse characteristic condition is met, the current transformer is determined to be reverse connected. A correction module is used to correct the polarity of the current transformer when the current transformer is reversed.

9. A computer-readable medium, characterized in that, It stores a computer program that, when executed by a processor, implements the reverse connection detection method as described in any one of claims 1 to 7.

10. An electronic device, characterized in that, include: One or more processors; A memory for storing executable instructions of the processor, which, when executed by the one or more processors, cause the one or more processors to implement the reverse connection detection method as described in any one of claims 1 to 7.

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