On-load current limiting control method of off-grid inverter, electronic equipment and storage medium

Abstract

The invention discloses an on-load current-limiting control method of an off-grid inverter, electronic equipment and a storage medium, and the method comprises the steps: continuously obtaining the real-time inversion current of the off-grid inverter under the condition that the off-grid inverter is in an on-load operation state, and monitoring the on-load real-time operation state of the off-grid inverter; according to the size relation between the real-time inversion current and the first preset current-limiting threshold value and the size relation between the real-time inversion current and the second preset current-limiting threshold value, in combination with the on-load real-time operation condition of the off-grid inverter, current-limiting control is executed on the off-grid inverter. According to the invention, not only can the special working condition requirements of sudden inductive load adding, sudden capacitive load adding and rated double load non-limiting of the off-grid inverter be met, but also the current-limiting control of the off-grid inverter can be realized especially when protection is carried out under the limiting working condition, and the magnitude of the peak current of the inverter circuit is effectively limited; therefore, the device protection type selection requirement is greatly reduced, and the purpose of reducing the device protection cost of the off-grid inverter is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronic control, and in particular to an on-load current limiting control method of an off-grid inverter, an electronic device and a computer-readable storage medium. Background Art

[0002] At present, the current limiting point of the off-grid inverters on the market is set at a single point. In order to meet the requirement of no current limiting for twice the rated load, the value of the current limiting point is usually set relatively large. This causes the inverter system to have excessive instantaneous impact current when facing sudden capacitive loads or sudden inductive loads. Therefore, in the overall design, devices with higher peak current resistance capabilities need to be selected, which increases the protection cost. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. To this end, the present invention proposes a load-limiting current control method, an electronic device and a storage medium for an off-grid inverter, which can reduce the device protection cost of the off-grid inverter.

[0004] In a first aspect, an embodiment of the present invention provides a load-limiting current control method for an off-grid inverter, comprising the following steps: Step S1: When the off-grid inverter is in a loaded operation state, continuously obtain the real-time inverter current of the off-grid inverter, and monitor the real-time loaded operation status of the off-grid inverter; Step S2: according to the magnitude relationship between the real-time inverter current and the first preset current limiting threshold and the second preset current limiting threshold, and in combination with the real-time load operation status of the off-grid inverter, current limiting control is performed on the off-grid inverter, wherein the first preset current limiting threshold is less than the second preset current limiting threshold.

[0005] Optionally, in one embodiment of the present invention, step S2 includes the following steps: Step S21: when the real-time inverter current is greater than or equal to the first preset current limiting threshold and less than the second preset current limiting threshold, determine the current loaded power frequency period of the off-grid inverter according to the loaded real-time operation status of the off-grid inverter; Step S22: performing current limiting control on the off-grid inverter according to the current load frequency cycle of the off-grid inverter.

[0006] Optionally, in one embodiment of the present invention, step S22 includes the following steps: Step S221: When the current loaded power frequency cycle of the off-grid inverter is less than or equal to the maximum short-time current limiting power frequency cycle, the first preset current limiting threshold is used as the first current limiting point to perform cycle-by-cycle protection on the off-grid inverter; or, Step S222: When the current loaded power frequency period of the off-grid inverter is greater than the maximum short-time current limiting power frequency period, the current operating state of the off-grid inverter is maintained.

[0007] Optionally, in one embodiment of the present invention, step S2 includes the following steps: Step S23: when the real-time inverter current is greater than or equal to the second preset current limiting threshold, the second preset current limiting threshold is used as the second current limiting point, and single trigger protection is performed on the off-grid inverter until the next on-load power frequency cycle of the off-grid inverter is reached, wherein the next on-load power frequency cycle of the off-grid inverter is determined according to the on-load real-time operating status of the off-grid inverter; Step S24: soft-start the off-grid inverter in the next loaded power frequency cycle of the off-grid inverter, and continuously obtain the real-time inverter current of the off-grid inverter, and return to execute step S23; Step S25, real-time monitoring of the number of cycles of step S23 and step S24, and performing current limiting control on the off-grid inverter according to the relationship between the number of cycles and a preset cycle protection number threshold.

[0008] Optionally, in one embodiment of the present invention, the step in step S25, performing current limiting control on the off-grid inverter according to the magnitude relationship between the number of cycles and a preset cycle protection number threshold, comprises the following steps: Step S251: When the number of cycles is less than or equal to the preset cycle protection number threshold, continue to execute steps S23 and S24; or, Step S252: When the cycle number is greater than a preset cycle protection number threshold, shut down the off-grid inverter.

[0009] Optionally, in one embodiment of the present invention, step S2 includes the following steps: Step S26: When the real-time inverter current is less than the first preset current limiting threshold, the current operating state of the off-grid inverter is maintained.

[0010] Optionally, in one embodiment of the present invention, the first preset current limiting threshold is the inverter peak current of the off-grid inverter under rated load, and the second preset current limiting threshold is twice the first preset current limiting threshold.

[0011] In a second aspect, an embodiment of the present invention provides an electronic device, including: at least one processor; at least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the load-limiting current control method for the off-grid inverter as described in the first aspect is implemented.

[0012] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium, which stores a program executable by a processor, and when the program executable by the processor is executed by the processor, it is used to implement the load current limiting control method of the off-grid inverter as described in the first aspect.

[0013] The load-limiting current control method, electronic device and computer-readable storage medium of the off-grid inverter proposed in the present invention, when the off-grid inverter is in a load-operating state, obtains the real-time inverter current of the off-grid inverter to compare the real-time inverter current with two preset inverter circuit current limiting points, thereby judging the magnitude relationship between the real-time inverter current and the first preset current limiting threshold value and the second preset current limiting threshold value, and also monitors the load-limiting real-time operating status of the off-grid inverter. Compared with the relevant prior art, it can not only meet the special operating conditions of the off-grid inverter with sudden inductive load, sudden capacitive load and rated double load without current limiting, but also, especially when protecting under extreme working conditions, combined with the above-mentioned relationship parameters and the load-limiting real-time operating status of the off-grid inverter, realize the current limiting control of the off-grid inverter, effectively limit the magnitude of the peak current of the inverter circuit, thereby greatly reducing the device protection selection requirements, and achieving the purpose of reducing the device protection cost of the off-grid inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flow chart of a load-limiting current control method for an off-grid inverter provided by an embodiment of the present invention; Figure 2 is a schematic diagram of a control structure for executing a load current limiting control method for an off-grid inverter provided by an embodiment of the present invention; Figure 3 yes Figure 1 A flow chart of step S2 in FIG. Figure 4 yes Figure 1 Another flow chart of step S2 in ; Figure 5 yes Figure 1 Another flow chart of step S2 in ; Figure 6 It is a schematic diagram of the execution flow of a load current limiting control method for an off-grid inverter provided by an embodiment of the present invention; Figure 7 It is a structural schematic diagram of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0016] It should be noted that although the functional modules are divided in the device schematic and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the device or the order in the flowchart.

[0017] Figure 1 Flow chart of a load-limiting current control method for an off-grid inverter provided by an embodiment of the present invention, such as Figure 1 As shown, the load current limiting control method of the off-grid inverter may include but is not limited to steps S1 to S2.

[0018] Step S1: When the off-grid inverter is in a loaded operation state, continuously obtain the real-time inverter current of the off-grid inverter, and monitor the real-time loaded operation status of the off-grid inverter; Step S2: according to the magnitude relationship between the real-time inverter current and the first preset current limiting threshold and the second preset current limiting threshold, and in combination with the real-time load operation status of the off-grid inverter, current limiting control is performed on the off-grid inverter, wherein the first preset current limiting threshold is less than the second preset current limiting threshold.

[0019] In this step, when the off-grid inverter is in a loaded operation state, the real-time inverter current of the off-grid inverter is obtained to compare the real-time inverter current with two preset inverter circuit current limiting points, so as to judge the magnitude relationship between the real-time inverter current and the first preset current limiting threshold value and the second preset current limiting threshold value, and the loaded real-time operation status of the off-grid inverter is also monitored. Compared with the relevant prior art, it can not only meet the special working conditions of the off-grid inverter with sudden inductive load, sudden capacitive load and rated double load without current limiting, but also, especially when protecting under extreme working conditions, combined with the above-mentioned relationship parameters and the real-time loaded operation status of the off-grid inverter, the current limiting control of the off-grid inverter is realized, and the peak current of the inverter circuit is effectively limited. The size of the current is reduced, thereby greatly reducing the device protection selection requirements and achieving the purpose of reducing the device protection cost of the off-grid inverter. The "extreme operating conditions" shown above may include but are not limited to sudden inductive loads, sudden capacitive loads, sudden impact loads, and short circuits on the inverter output side, etc., and considering that in the relevant prior art, under extreme operating conditions, when the actual current value is reduced to the only current limiting point, the inverter continues to generate waves in the next switching cycle, and a large impact current continues to exist, causing the device junction temperature to rise rapidly, thereby reducing the reliability of the device at high temperatures. In contrast, the present application effectively limits the size of the peak current of the inverter circuit, thereby avoiding the above situation and improving the reliability of the device at high temperatures.

[0020] It should be noted that the types and specifications of off-grid inverters can be of various types, which are not limited here. In order to better illustrate the working principle of the embodiment of the present invention, a control structure associated with an off-grid inverter is given below as an example but not limited. The control structure can be but is not limited to being used to execute the load current limiting control method of the embodiment of the present invention.

[0021] like Figure 2 As shown, the control structure may include but is not limited to an inverter power inductor L_inv, a current sensor I_sam, an inverter filter capacitor C1, a sampling circuit, a drive circuit, and a control chip (which may be but is not limited to an MCU, etc.). The specific connection relationship can be referred to Figure 2 , which will not be described in detail here, wherein the drive circuit is used to provide starting power for the inverter circuit of the off-grid inverter, the output side V_out of the inverter circuit is loaded, and the current sensor I_sam is connected to one side of the inverter circuit, which is used to collect the real-time inverter current of the off-grid inverter, and report the collected real-time inverter current to the sampling circuit, and then the sampling circuit reports the real-time inverter current to the control chip, thereby realizing the current limiting control of the off-grid inverter through the control chip, the drive circuit, etc.; According to the experimental results, the load-limiting current control method of the embodiment of the present invention is executed based on the control structure, and the peak current of the inverter circuit can be reduced to 0.6~0.8 times of the original, that is, the peak current of the inverter circuit is effectively limited.

[0022] In one embodiment, the specific values ​​of the first preset current limiting threshold and the second preset current limiting threshold can be set accordingly according to the actual application scenario, and are not limited here. For example, the first preset current limiting threshold can be, but is not limited to, set to be the peak inverter current of the off-grid inverter under the rated load, and the second preset current limiting threshold is twice the first preset current limiting threshold, that is, ; ; in, is the first preset current limiting threshold, is the second preset current limiting threshold, is the rated output power of the inverter circuit, is the effective value of the AC output voltage of the inverter circuit, is an error coefficient that can be adjusted according to the actual application scenario, and its value is about 1, for example, 1.1.

[0023] like Figure 3 As shown, in one embodiment of the present invention, step S2 may include but is not limited to steps S21 to S22.

[0024] Step S21: when the real-time inverter current is greater than or equal to the first preset current limiting threshold and less than the second preset current limiting threshold, determine the current load power frequency cycle of the off-grid inverter according to the real-time load operation status of the off-grid inverter; Step S22: performing current limiting control on the off-grid inverter according to the current load frequency cycle of the off-grid inverter.

[0025] In this step, when the off-grid inverter is turned on and connected to the load, if it is determined that the real-time inverter current is greater than or equal to the first preset current limiting threshold and less than the second preset current limiting threshold, the current loaded power frequency cycle of the off-grid inverter is further determined in combination with the real-time loaded operation status of the off-grid inverter, thereby achieving effective current limiting control of the off-grid inverter based on the current loaded power frequency cycle of the off-grid inverter, so as to limit the peak current of the off-grid inverter and reduce the device protection cost of the off-grid inverter.

[0026] In one embodiment of the present invention, step S22 may include, but is not limited to, step S221 or S222.

[0027] Step S221: When the current loaded power frequency cycle of the off-grid inverter is less than or equal to the maximum short-time current limiting power frequency cycle, the first preset current limiting threshold is used as the first current limiting point, and the off-grid inverter is subjected to cycle-by-cycle protection, wherein the cycle-by-cycle protection is CBC protection, which is characterized in that once triggered, the PWM output level is set to a preset level (such as high level, low level, high impedance state or unchanged), but whenever the CNT of PWM is 0, it will re-detect whether the input of the TZ pin is still triggered. If it is no longer triggered, the protection state is cleared and the PWM output is restored. If it is triggered again, the protection state is maintained; or, Step S222: When the current loaded power frequency period of the off-grid inverter is greater than the maximum short-time current limiting power frequency period, the current operating state of the off-grid inverter is maintained.

[0028] In this step, the purpose of using the maximum short-time current limiting power frequency cycle as the cycle threshold is to solve the problem of excessive transient current caused by the sudden addition of special loads. Figure 2 When the current load frequency cycle of the off-grid inverter is less than or equal to the maximum short-time current-limiting power frequency cycle, it means that at the peak of the inverter voltage, due to the characteristics of the BUCK circuit, the wave-generating time of the drive circuit calculated by the control chip will reach the maximum value. At this time, the wave-generating time is greater than the sampling delay Tdelay of the sampling circuit, that is, the blocking delay of the inverter circuit is limited by the sampling delay Tdelay. However, at this time, since the first current limiting point (corresponding to the first preset current limiting threshold) is small, the peak current can be effectively limited. On the contrary, if the current load frequency cycle of the off-grid inverter is greater than the maximum short-time current-limiting power frequency cycle, the predetermined time limit of continuous current limiting is exceeded. In order to prevent the load from failing to obtain the power required for starting and causing the load to fail to start, current limiting control is no longer performed in this case, and normal loading is performed.

[0029] It should be noted that the specific value of the maximum short-time current-limiting power frequency cycle can be set accordingly according to the actual application scenario, and there is no restriction here. For example, it can be but is not limited to being set to any value greater than 1 load-bearing power frequency cycle and less than 3 load-bearing power frequency cycles. Preferably, it is set to 3 load-bearing power frequency cycles. This is considered by the applicant based on actual experience, that is, if the number of load-bearing power frequency cycles exceeds 3, the double load situation may be unstable. This is because the off-grid inverter has a limited time to resist double load, generally 200ms, and the power during current limiting is small, so it cannot be current limited for a long time. Taking the air-conditioning load as an example, 3 load-bearing power frequency cycles are the measured values. Short-term current limiting is performed within 3 load-bearing power frequency cycles, and then no current limiting is performed. Then the air-conditioning load can start successfully. If the current limiting continues for a long time, the air-conditioning load will not be able to obtain the power required for startup and cannot be started.

[0030] like Figure 4As shown, in one embodiment of the present invention, step S2 may include but is not limited to steps S23 to S25.

[0031] Step S23, when the real-time inverter current is greater than or equal to the second preset current limiting threshold, the second preset current limiting threshold is used as the second current limiting point, and single-trigger protection is performed on the off-grid inverter until the next on-load power frequency cycle of the off-grid inverter is reached, wherein the next on-load power frequency cycle of the off-grid inverter is determined according to the on-load real-time operating status of the off-grid inverter. The single-trigger protection is one-shot protection, which is characterized in that once triggered, it cannot be automatically restored and will always be in a protection state until the OST bit in TZFLG is manually cleared; Step S24: In the next loaded power frequency cycle of the off-grid inverter, the off-grid inverter is soft-started, and the real-time inverter current of the off-grid inverter is continuously obtained, and the process returns to step S23; Step S25, real-time monitoring of the number of cycles of step S23 and step S24, and performing current limiting control on the off-grid inverter according to the relationship between the number of cycles and a preset cycle protection number threshold.

[0032] In this step, the peak current of the inverter circuit is effectively limited by cyclically executing step S23 and step S24. Figure 2 In the process of repeated single trigger protection, when it is detected for the first time that the real-time inverter current is greater than or equal to the second preset current limiting threshold, the inverter voltage phase has not reached the peak value. Due to the characteristics of the BUCK circuit, the wave generation time of the drive circuit calculated by the control chip has not reached the maximum value, that is, the wave generation time is less than the sampling delay Tdelay of the sampling circuit. At this time, the blocking delay of the inverter circuit is not limited by the sampling delay Tdelay, which effectively limits the peak current of the inverter circuit. At the same time, considering that the single trigger protection shuts down the off-grid inverter at one time, there may be false triggering. Therefore, a certain degree of cyclic execution steps are set to ensure that the off-grid inverter finally reaches a stable and good working state.

[0033] In one embodiment of the present invention, the step in step S25 performs current limiting control on the off-grid inverter according to the relationship between the number of cycles and a preset cycle protection number threshold, which may include but is not limited to step S251 or S252.

[0034] Step S251: When the number of cycles is less than or equal to the preset cycle protection number threshold, continue to execute steps S23 and S24; or, Step S252: When the number of cycles is greater than the preset cycle protection number threshold, the off-grid inverter is turned off.

[0035] In this step, considering that the single-trigger protection shuts down the off-grid inverter at one time, if the number of protection cycles is too small, the false triggering will affect the operating function of the off-grid inverter. However, if the number of cycles is too large, first of all, a large impact current will continue to exist, resulting in a certain amount of heat accumulation, causing the off-grid inverter temperature to rise. Therefore, a preset cycle protection number threshold is set for judgment. When the number of cycles is less than or equal to the preset cycle protection number threshold, the cycle step continues to be executed. Otherwise, it means that the protection of the off-grid inverter has reached the relative expectation, and there is no need to re-soft-start the off-grid inverter. Instead, the off-grid inverter is turned off and shut down for protection.

[0036] It should be noted that the specific value of the preset loop protection number threshold can be set accordingly according to the actual application scenario, and there is no restriction here. For example, it can be but not limited to being set to 3 times. According to actual experience, 3 cycles or so can basically eliminate false positives. Setting it to more may cause a waste of circuit resources and is unnecessary.

[0037] like Figure 5 As shown, in one embodiment of the present invention, step S2 may include but is not limited to step S26.

[0038] Step S26: When the real-time inverter current is less than the first preset current limiting threshold, the current operating state of the off-grid inverter is maintained.

[0039] In this step, if the real-time inverter current is less than the first preset current limiting threshold, it means that the real-time inverter current of the off-grid inverter meets the normal working requirements and does not need to be current limited. Therefore, the current operating state of the off-grid inverter is maintained, and normal load is executed at this time.

[0040] It should be noted that the steps of the above embodiments are not executed in a single manner. In different implementation scenarios, they can be combined and analyzed according to specific circumstances, so as to effectively and reliably control the off-grid inverter with load current limiting. For example, it can be but not limited to continuously monitoring the off-grid inverter for a preset period of time, and performing load current limiting control according to the actual situation during the monitoring process, such as Figure 6 As shown in FIG. 1 , a specific execution flow diagram of the load current limiting control method of an embodiment of the present invention is given. It can be seen that by continuously monitoring the off-grid inverter within the preset period, the load current limiting control can be effectively performed on it. Figure 6 The contents shown have been described in detail through the aforementioned embodiments, so they will not be repeated here.

[0041] Figure 7 FIG. 1 is a schematic diagram of the structure of an electronic device 1000 provided by an embodiment of the present invention. Figure 7As shown, the electronic device 1000 includes a memory 1100 and a processor 1200. The number of the memory 1100 and the processor 1200 may be one or more. Figure 7 In the embodiment, a memory 1100 and a processor 1200 are taken as an example; the memory 1100 and the processor 1200 in the device may be connected via a bus or other means. Figure 7 The example of connecting through bus is taken in the following.

[0042] The memory 1100, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the load current limiting control method of the off-grid inverter provided by any embodiment of the present invention. The processor 1200 implements the load current limiting control method of the off-grid inverter by running the software programs, instructions and modules stored in the memory 1100.

[0043] The memory 1100 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function. In addition, the memory 1100 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 1100 may further include a memory remotely arranged relative to the processor 1200, and these remote memories may be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof. An embodiment of the present invention further provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are used to execute the load current limiting control method for an off-grid inverter provided in any embodiment of the present invention.

[0044] An embodiment of the present invention further provides a computer program product, including a computer program or computer instructions, wherein the computer program or computer instructions are stored in a computer-readable storage medium, a processor of a computer device reads the computer program or computer instructions from the computer-readable storage medium, and the processor executes the computer program or computer instructions, so that the computer device executes the load current limiting control method for an off-grid inverter provided in any embodiment of the present invention.

[0045] The electronic devices and application scenarios described in the embodiments of the present invention are intended to more clearly illustrate the technical solutions of the embodiments of the present invention, and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those skilled in the art will appreciate that with the evolution of electronic devices and the emergence of new application scenarios, the technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems.

[0046] Those skilled in the art will appreciate that all or some of the steps in the methods disclosed above, and the functional modules / units in the systems and devices may be implemented as software, firmware, hardware, or a suitable combination thereof.

[0047] In hardware implementation, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all physical components may be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or transient medium). As is well known to those of ordinary skill in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disk (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

[0048] The terms "component", "module", "system", etc. used in this specification are used to represent computer-related entities, hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component can be, but is not limited to, a process running on a processor, a processor, an object, an executable file, an execution thread, a program, or a computer. By way of illustration, both applications running on a computing device and a computing device can be components. One or more components may reside in a process or an execution thread, and a component may be located on a computer or distributed between two or more computers. In addition, these components may be executed from various computer-readable media having various data structures stored thereon. Components may, for example, communicate through a local or remote process based on a signal having one or more data packets (e.g., data from two components interacting with another component between a local system, a distributed system, or a network, such as the Internet interacting with other systems through signals).

Claims

1. A load-limiting current control method for an off-grid inverter, characterized in that: The steps include: Step S1: When the off-grid inverter is in a loaded operation state, continuously obtain the real-time inverter current of the off-grid inverter, and monitor the real-time loaded operation status of the off-grid inverter; Step S2: according to the magnitude relationship between the real-time inverter current and the first preset current limiting threshold and the second preset current limiting threshold, and in combination with the real-time load operation status of the off-grid inverter, current limiting control is performed on the off-grid inverter, wherein the first preset current limiting threshold is less than the second preset current limiting threshold.

2. The load-limiting current control method for an off-grid inverter according to claim 1, characterized in that: The step S2 comprises the following steps: Step S21: when the real-time inverter current is greater than or equal to the first preset current limiting threshold and less than the second preset current limiting threshold, determine the current loaded power frequency period of the off-grid inverter according to the loaded real-time operation status of the off-grid inverter; Step S22: performing current limiting control on the off-grid inverter according to the current load frequency cycle of the off-grid inverter.

3. The load-limiting current control method for an off-grid inverter according to claim 2, characterized in that: The step S22 comprises the following steps: Step S221: When the current loaded power frequency cycle of the off-grid inverter is less than or equal to the maximum short-time current limiting power frequency cycle, the first preset current limiting threshold is used as the first current limiting point to perform cycle-by-cycle protection on the off-grid inverter; or, Step S222: When the current loaded power frequency period of the off-grid inverter is greater than the maximum short-time current limiting power frequency period, the current operating state of the off-grid inverter is maintained.

4. The load-limiting current control method for an off-grid inverter according to claim 1, characterized in that: The step S2 comprises the following steps: Step S23: when the real-time inverter current is greater than or equal to the second preset current limiting threshold, the second preset current limiting threshold is used as the second current limiting point, and single trigger protection is performed on the off-grid inverter until the next on-load power frequency cycle of the off-grid inverter is reached, wherein the next on-load power frequency cycle of the off-grid inverter is determined according to the on-load real-time operating status of the off-grid inverter; Step S24: soft-start the off-grid inverter in the next loaded power frequency cycle of the off-grid inverter, and continuously obtain the real-time inverter current of the off-grid inverter, and return to execute step S23; Step S25, real-time monitoring of the number of cycles of step S23 and step S24, and performing current limiting control on the off-grid inverter according to the relationship between the number of cycles and a preset cycle protection number threshold.

5. The load-limiting current control method for an off-grid inverter according to claim 4, characterized in that: The step in step S25, performing current limiting control on the off-grid inverter according to the magnitude relationship between the number of cycles and a preset cycle protection number threshold, comprises the following steps: Step S251: When the number of cycles is less than or equal to the preset cycle protection number threshold, continue to execute steps S23 and S24; or, Step S252: When the cycle number is greater than a preset cycle protection number threshold, shut down the off-grid inverter.

6. The load-limiting current control method for an off-grid inverter according to claim 1, characterized in that: The step S2 comprises the following steps: Step S26: When the real-time inverter current is less than the first preset current limiting threshold, the current operating state of the off-grid inverter is maintained.

7. The on-load current limiting control method for an off-grid inverter according to any one of claims 1 to 6, characterized in that: The first preset current limiting threshold is the peak inverter current of the off-grid inverter under rated load, and the second preset current limiting threshold is twice the first preset current limiting threshold.

8. An electronic device, characterized in that: include: at least one processor; at least one memory for storing at least one program; When at least one of the programs is executed by at least one of the processors, the load current limiting control method for the off-grid inverter as described in any one of claims 1 to 7 is implemented.

9. A computer-readable storage medium, characterized in that: A program executable by a processor is stored therein, and when the program executable by the processor is executed by the processor, it is used to implement the load current limiting control method of the off-grid inverter as described in any one of claims 1 to 7.

Images