An overload protection detection method, an overload protection device and an overload protection system of a parallel system

Abstract

This application discloses an overload protection detection method, overload protection device, and system for a parallel power system, applicable to the field of overload protection technology. The method includes: when the parallel power system detects an overload protection fault before multiple power converters, controlling the parallel power system to send the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information; when the parallel power system is powered on again after detecting the overload protection fault, controlling the parallel power system to extract the overload protection fault information from the power converters. This allows the parallel power system to extract the overload protection fault information from the power converters and upload it to the client after power-on, effectively saving the overload protection fault information of the parallel power system and improving user experience.

Description

Technical Field

[0001] This application relates to the field of overload protection technology, and in particular to an overload protection detection method, overload protection device and system for a parallel system. Background Technology

[0002] A power converter is an electronic device that converts one type of current into another, such as an inverter, rectifier, charger, and uninterruptible power supply. Because the power output of a single power converter is relatively small, multiple power converters are often connected in parallel to expand their capacity; the parallel connection device and multiple power converters form a parallel system.

[0003] In existing parallel power systems, overload protection detection is required during operation to determine if an overload protection fault has occurred. During this process, the paralleling devices and multiple power converters in the system all perform overload protection detection. This detection relies on their respective voltage and current sampling. Because the voltage and current sampling methods differ, the order in which the paralleling devices and power converters detect overload protection faults may also differ. When a paralleling device detects an overload protection fault first, it needs to upload the overload protection fault information to the client to save the system's overload protection fault information.

[0004] In a parallel system, the power supply for the parallel devices comes from the grid voltage and the operating drive voltages of multiple power converters (such as the inverter voltage during inverter operation). However, when the parallel system operates in off-grid mode, if the parallel device detects an overload protection fault first, it will control multiple power converters to stop operating. At this time, the parallel device will not receive the operating drive voltages from the multiple power converters, and the parallel device will lose power. The overload protection fault information detected by the power converters also needs to be uploaded to the client through the parallel device. If the parallel device loses power, it will be difficult to upload the overload protection fault information to the client. For the corresponding user, if the client does not receive the overload protection fault information of the parallel system before the power outage, the user will assume that the parallel system itself has malfunctioned, and it will be difficult to determine whether the power outage was caused by an external factor (overload). This will mislead the user and affect the user experience. Summary of the Invention

[0005] This application provides an overload protection detection method, overload protection device, and system for a parallel system, which can effectively save overload protection fault information of the parallel system and improve user experience.

[0006] This application provides an overload protection detection method for a parallel system, wherein the parallel system operates in off-grid mode and includes a parallel device and multiple power converters, the parallel device communicating in parallel with the multiple power converters; including:

[0007] When the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to multiple power converters through parallel communication, so that multiple power converters record the overload protection fault information.

[0008] When the parallel device re-energizes after detecting an overload protection fault, it is controlled to extract the overload protection fault information from the power converter.

[0009] Furthermore, the method also includes:

[0010] The overload protection detection time of the parallel operation device is set to be less than the overload protection detection time of the multiple power converters. The parallel operation device is controlled to perform overload protection detection based on the overload protection detection time of the parallel operation device, so that the parallel operation device detects the overload protection fault before the multiple power converters.

[0011] Specifically, if the duration of the overload detected by the parallel operation device exceeds the overload protection detection time, an overload protection fault is determined to have occurred.

[0012] Furthermore, the control of the parallel operation device to perform overload protection detection based on the overload protection detection time of the parallel operation device includes:

[0013] Control the parallel operation device and detect the overload range of the load power corresponding to the parallel operation device when it is overloaded; determine whether the overload duration reaches the overload protection detection time corresponding to the overload range. If so, it is determined that an overload protection fault has occurred; otherwise, no overload protection fault has occurred.

[0014] Furthermore, the overload protection detection time of the parallel device includes a preset overload protection detection time and a first detection time margin, and the overload protection detection time of the power converter includes the preset overload protection detection time and a second detection time margin.

[0015] Setting the overload protection detection time of the parallel operation device to be less than the overload protection detection time of the multiple power converters includes:

[0016] The first detection time margin corresponding to the parallel operation device is set to be less than the second detection time margin corresponding to the multiple power converters.

[0017] Furthermore, after setting the overload protection detection time of the parallel operation device to be less than the overload protection detection time of the multiple power converters, the method further includes:

[0018] The overload protection detection time of the newly connected power converter in the parallel system is detected;

[0019] If the overload protection detection time of the newly connected power converter in the parallel system is less than or equal to the overload protection detection time of the parallel device, then the overload protection time of the parallel device is adjusted to be less than the overload protection detection time of the newly connected power converter in the parallel system.

[0020] Furthermore, the overload protection fault information includes: a signal containing an overload protection flag bit;

[0021] The control of the parallel operation device to send overload protection fault information to multiple power converters via parallel communication includes:

[0022] The control unit will send a signal containing the overload protection flag to multiple power converters via parallel communication.

[0023] Furthermore, the multiple power converters record the overload protection fault information including:

[0024] Multiple power converters are shut down and the overload protection fault information is recorded in the history module.

[0025] Furthermore, the step of controlling the parallel operation device to extract the overload protection fault information from the power converter includes:

[0026] The parallel operation device is controlled to query the overload protection fault information from the historical record modules of multiple power converters;

[0027] The control unit will report the overload protection fault information it finds to the client.

[0028] This application embodiment also provides an overload protection detection device for a parallel operation system. The parallel operation system operates in off-grid mode and includes a parallel operation device and multiple power converters. The parallel operation device communicates in parallel with the multiple power converters. The device includes:

[0029] The first control unit is configured to control the parallel device to send the overload protection fault information to the multiple power converters via parallel communication when the parallel device detects an overload protection fault before the multiple power converters, so that the multiple power converters record the overload protection fault information.

[0030] The second control unit is used to control the parallel device to extract the overload protection fault information from the power converter when the parallel device is powered on again after detecting an overload protection fault.

[0031] This application embodiment also provides a parallel system, which includes a parallel device and multiple power converters, wherein the parallel device communicates in parallel with the multiple power converters;

[0032] The power supply interface of the parallel device is connected to the power grid and multiple power converters. When the parallel system is operating in off-grid mode, the parallel device is powered only by the operating drive voltage of the multiple power converters. The method described above is used to perform overload protection detection on the parallel system.

[0033] This application embodiment also provides an overload protection detection device for a parallel system, including:

[0034] Central processing unit, memory, input / output interface, wired or wireless network interface, power supply;

[0035] The memory is either a short-term storage memory or a persistent storage memory;

[0036] The central processing unit is configured to communicate with the memory and execute instructions in the memory on a control plane functional entity to perform the methods described above.

[0037] This application also provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the method described above.

[0038] As can be seen from the above technical solutions, the embodiments of this application have the following advantages:

[0039] In this embodiment, when the parallel operation device detects an overload protection fault before multiple power converters, it is controlled to send the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information. When the parallel operation device is powered on again after detecting the overload protection fault, it is controlled to retrieve the overload protection fault information from the power converters. When the parallel operation device detects an overload protection fault, the power failure of the parallel operation device will not affect the recording function of the multiple power converters. At this time, the parallel operation device is controlled to send the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information. After the parallel operation device is powered on again, it can be controlled to retrieve the overload protection fault information from the power converters and upload the overload protection fault information to the client, which can effectively save the overload protection fault information of the parallel system and improve the user experience. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings.

[0041] Figure 1 This is a schematic diagram of the structure of a parallel system disclosed in an embodiment of this application;

[0042] Figure 2 This is a flowchart illustrating the overload protection detection of a parallel system disclosed in an embodiment of this application;

[0043] Figure 3 This is a flowchart illustrating the overload protection detection of another parallel system disclosed in an embodiment of this application;

[0044] Figure 4 This is a schematic diagram of an overload protection device disclosed in an embodiment of this application;

[0045] Figure 5 This is a schematic diagram of another overload protection device disclosed in an embodiment of this application. Detailed Implementation

[0046] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0047] In the description of the embodiments of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0048] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0049] Existing parallel systems such as Figure 1 As shown, the parallel system includes a parallel device and multiple power converters 101. The multiple power converters 101 are connected in parallel through the parallel interface of the parallel device, that is, the output terminals of the multiple power converters can be physically connected through the parallel interface provided by the parallel device. The power converters can be inverters, rectifiers, or power adapters, and are not specifically limited here. The parallel device communicates with the multiple power converters 101 in parallel. This parallel communication can be CAN bus communication or serial communication (such as RS232), and is not specifically limited here.

[0050] During operation, the parallel system requires overload protection detection to determine if an overload protection fault has occurred. When the output of the parallel system is loaded, the parallel devices and multiple power converters 101 can detect the load power through voltage and current sampling, and perform overload protection detection based on the load power. The detection depends on the individual voltage and current sampling methods; due to differences in voltage and current sampling, the order in which the parallel devices and multiple power converters 101 detect the overload protection fault may differ. When the parallel device in the parallel system detects the overload protection fault first, it needs to upload the overload protection fault information to the client 104 to save the overload protection fault information of the parallel system. This client can be a cloud platform or an app; the specific method is not limited here.

[0051] In a parallel system, the power supply for the parallel devices comes from the grid voltage and the operating drive voltages of multiple power converters (such as the inverter voltage during inverter drive). However, when the parallel system operates in off-grid mode, if the parallel device detects an overload protection fault first, it triggers a drive stop signal, which controls multiple power converters to stop operating. At this time, the parallel device will not receive the operating drive voltages from the multiple power converters, and the parallel device will lose power. The parallel operation device includes a parallel control board 102 and a data communication module 103 (KC541). The data acquisition device can be wired or wireless, and this is not specifically limited here. The parallel control board 102 of the parallel operation device does not have a historical record function. The parallel control board 102 is used for overload protection detection and reports overload protection fault information to the client 104 through the data communication module 103. When the parallel operation device loses power, the data communication module 103 in the parallel operation device also loses power. At this time, it will be impossible to report the overload protection fault information to the client 104 through the data communication module 103, which may easily lead to the failure to save the overload protection fault information. Therefore, this application embodiment provides an overload protection detection method for a parallel operation system, which can effectively save the overload protection fault information of the parallel operation system, such as... Figure 2 As shown, the specific steps include the following:

[0052] 201. When the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to multiple power converters through parallel communication, so that multiple power converters record the overload protection fault information.

[0053] In this embodiment, the parallel system includes a parallel device and multiple power converters. The multiple power converters are connected in parallel via a parallel interface on the parallel device, meaning the outputs of the multiple power converters are physically connected to the parallel interface on the parallel device. The parallel control board communicates with the multiple power converters in parallel. The power supply for the parallel device in the parallel system is the grid voltage and the operating drive voltage of the multiple power converters. In this embodiment, the parallel system operates in off-grid mode, meaning the grid voltage is disconnected from the parallel device, and the parallel device is powered only by the operating drive voltage of the multiple power converters.

[0054] Understandably, when a parallel system is operating under overload, the load power may exceed the rated power of the parallel system. In this case, the parallel system needs overload protection. Overload protection detection can be performed on the parallel system to check for overload protection faults. In a parallel system, both the parallel device and multiple power converters can perform overload protection detection. However, due to differences in the sampling accuracy of voltage and current in the parallel device and multiple power converters, the parallel device may detect the load power corresponding to the voltage and current exceeding the rated power first. In this case, the parallel device will detect the overload protection fault before the multiple power converters.

[0055] In this embodiment, when the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information. That is, when the parallel operation device detects an overload protection fault before the multiple power converters, it controls the parallel operation device to no longer trigger a drive stop signal, but instead sends the overload protection fault information to the multiple power converters via parallel communication (such as CAN communication). The overload protection fault information can be a signal containing an overload protection flag bit; that is, the parallel operation device can be controlled to send a signal containing the overload protection flag bit to the multiple power converters via parallel communication. At this time, all the multiple power converters can receive the signal containing the overload protection flag bit via parallel communication.

[0056] Understandably, the power converter includes a historical record module, which contains a storage module within the power converter and has a historical record function to record operating information. When multiple power converters receive overload protection fault information, they can confirm that an overload protection fault exists in the parallel system. Multiple power converters can shut down their operating drives; for example, multiple inverters can shut down their inverter drives through their own logic. The overload protection fault information is recorded in the historical record module. Understandably, when multiple power converters shut down their operating drives, the parallel devices in the grid-connected parallel system will disconnect the operating drive voltage of the multiple power converters. That is, after detecting an overload protection fault, multiple power converters shut down their operating drives, and the parallel devices will lose power; the overload protection fault information is recorded in the historical record module of the multiple power converters.

[0057] 202. When the parallel unit re-energizes after detecting an overload protection fault, it controls the parallel unit to extract the overload protection fault information from the power converter.

[0058] When the parallel-connected device restarts after detecting an overload protection fault, it can be controlled to retrieve the overload protection fault information from the power converter. Specifically, the parallel-connected device can be controlled to query the overload protection fault information from the power converter's historical record module. For example, it can be controlled to send query information with an overload protection identifier to the power converter; and it can be controlled to report the retrieved overload protection fault information to the client.

[0059] As can be seen, in this embodiment, when the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information. When the parallel operation device is powered on again after detecting an overload protection fault, it controls the parallel operation device to retrieve the overload protection fault information from the power converters. When the parallel operation device detects an overload protection fault, the power failure of the parallel operation device will not affect the recording function of the multiple power converters. At this time, the parallel operation device sends the overload protection fault information to the multiple power converters via parallel communication, so that the multiple power converters record the overload protection fault information. After the parallel operation device is powered on again, it can retrieve the overload protection fault information from the power converters and upload the overload protection fault information to the client, which can effectively save the overload protection fault information of the parallel system and improve the user experience.

[0060] Furthermore, during overload protection detection in parallel operation devices and multiple power converters, deviations in voltage and current sampling may cause one power converter to detect an overload protection fault before the others. Since this particular power converter is connected in parallel, its load will be transferred to the others. Overcurrent protection detection is also performed in the power converters, but its detection time is short. Before other power converters detect overload protection faults, their inverter overcurrent protection will be triggered, resulting in inaccurate overcurrent protection information reported by the other power converters, making it difficult to determine the cause of protection in the parallel system. Therefore, in this embodiment, the parallel operation device can be controlled to detect overload protection faults before the other power converters, preventing them from reporting inaccurate inverter overcurrent protection information and improving the accuracy of determining the cause of protection in the parallel system. Figure 3 As shown, the specific steps include the following:

[0061] 301. Set the overload protection detection time of the parallel unit to be less than the overload protection detection time of multiple power converters.

[0062] In this embodiment, the overload protection detection time of the parallel operation device can be set to be less than the overload protection detection time of multiple power converters. The overload protection detection time is a time standard used to determine whether an overload protection fault has occurred. When the duration of the overload detected by the parallel operation device exceeds the overload protection detection time, an overload protection fault is determined to have occurred. It is understood that in this embodiment, the parallel operation device and multiple power converters perform overload protection detection simultaneously. When both the parallel operation device and the multiple power converters detect an overload, if the overload protection detection time of the parallel operation device is less than the overload protection detection time of the multiple power converters, the overload protection detection time of the parallel operation device is satisfied first. In this case, the parallel operation device reports an overload protection fault before the multiple power converters.

[0063] The overload protection detection time of the parallel operation device includes a preset overload protection detection time and a first detection time margin, while the overload protection detection time of the power converter includes the preset overload protection detection time and a second detection time margin. That is, the original overload protection algorithm of the parallel operation device and the power converter is the same, containing the same preset overload protection detection time and corresponding detection time margin. In this case, the first detection time margin corresponding to the parallel operation device can be set to be less than the second detection time margin corresponding to multiple power converters. For example, the original overload protection detection time of the parallel operation device and the power converter can be: preset overload protection detection time + 1s, where 1s is the detection time margin. In this case, the overload protection detection time of the parallel operation device can be set to: preset overload protection detection time + 500ms; while the overload protection detection time of the power converter remains at the preset overload protection detection time + 1s, or is increased to the preset overload protection detection time + 2s, the specific setting is not limited here.

[0064] Furthermore, in a parallel system, there may be newly connected power converters. To ensure that the parallel device detects overload protection faults before multiple power converters, in this embodiment, after setting the overload protection detection time of the parallel device to be less than the overload protection detection time of multiple power converters, the overload protection detection time of the newly connected power converter can also be detected. The overload protection detection time of the newly connected power converter is compared with the overload protection detection time of the parallel device. If the overload protection detection time of the newly connected power converter is less than or equal to the overload protection detection time of the parallel device, then the overload protection time of the parallel device is adjusted to be less than the overload protection detection time of the newly connected power converter.

[0065] 302. Control the parallel operation device to perform overload protection detection based on the overload protection detection time of the parallel operation device, so that the parallel operation device can detect the overload protection fault before multiple power converters.

[0066] By setting the overload protection detection time of the parallel operation device to be less than the overload protection detection time of multiple power converters, the parallel operation device can be controlled to perform overload protection detection based on its own overload protection detection time, so that the parallel operation device can detect overload protection faults before the multiple power converters.

[0067] Understandably, during overload protection detection, when an overload is detected, the corresponding overload range needs to be determined. Different overload ranges have corresponding overload protection detection times; for example, if 100% of rated power < load power ≤ 110% of rated power, the overload protection detection time is 10 minutes; if 110% of rated power < load power ≤ 120% of rated power, the overload protection detection time is 3 minutes; if 120% of rated power < load power ≤ 167% of rated power, the overload protection detection time is 2 minutes; if 167% of rated power < load power ≤ 200% of rated power, the overload protection detection time is 1 minute; and if 200% of rated power > load power, the overload protection detection time is 200 ms.

[0068] In this embodiment, the parallel operation device can be controlled to detect the overload range of the load power corresponding to the parallel operation device during overload; it can be determined whether the overload duration reaches the overload protection detection time corresponding to the overload range. If so, an overload protection fault is determined to have occurred; otherwise, no overload protection fault has occurred. For example, when the overload range is determined to be 110% of rated power < load power ≤ 120% of rated power, it is determined whether the overload duration reaches 3 minutes. If so, an overload protection fault is determined to have occurred; otherwise, no overload protection fault has occurred. In other words, the load power corresponding to the parallel operation device can be detected in real time to determine whether the overload duration within the current overload range reaches the overload protection detection time corresponding to the current overload range, thereby determining whether an overload protection fault has occurred.

[0069] 303. When the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to multiple power converters through parallel communication, so that multiple power converters record the overload protection fault information.

[0070] 304. When the parallel unit is powered on again after detecting an overload protection fault, the control unit extracts the overload protection fault information from the power converter.

[0071] It is understandable that steps 303 and 304 are similar to steps 201 and 202 above, and will not be described in detail here.

[0072] As can be seen, in this embodiment of the application, by setting the overload protection detection time of the parallel device to be less than the overload protection detection time of multiple power converters, the parallel device can detect the overload protection fault before multiple power converters when the parallel system is in an overload protection fault, thereby avoiding other power converters reporting inverter overcurrent protection information that does not match the actual situation and improving the accuracy of determining the protection cause of the parallel system.

[0073] This application embodiment also provides an overload protection detection device for a parallel operation system. The parallel operation system operates in off-grid mode and includes a parallel operation device and multiple power converters. The parallel operation device communicates in parallel with the multiple power converters. The overload protection detection device is as follows: Figure 4 As shown, it includes:

[0074] The first control unit 401 is configured to control the parallel device to send the overload protection fault information to the multiple power converters via parallel communication when the parallel device detects an overload protection fault before the multiple power converters, so that the multiple power converters record the overload protection fault information.

[0075] The second control unit 402 is used to control the parallel device to extract the overload protection fault information from the power converter when the parallel device is powered on again after detecting an overload protection fault.

[0076] This application embodiment also provides a parallel system, which includes a parallel device and multiple power converters, wherein the parallel device communicates in parallel with the multiple power converters;

[0077] The power supply interface of the parallel device is connected to the power grid and multiple power converters. When the parallel system is operating in off-grid mode, the parallel device is powered only by the operating drive voltage of the multiple power converters. The method described above is used to perform overload protection detection on the parallel system.

[0078] This application embodiment also provides an overload protection detection device 500 for a parallel system, such as... Figure 5 As shown, the overload protection detection device 500 of this application embodiment may include one or more central processing units (CPUs) 501 and a memory 502, wherein the memory 502 stores one or more application programs or data.

[0079] The memory 502 can be volatile or persistent storage. The program stored in the memory 502 can include one or more modules, each module including a series of instruction operations on the electronic device. Furthermore, the central processing unit 501 can be configured to communicate with the memory 502 and execute the series of instruction operations in the memory 502 on the overload protection detection device 500.

[0080] The overload protection detection device 500 may also include one or more power supplies 505, one or more wired or wireless network interfaces 504, one or more input / output interfaces 503, and / or one or more operating systems, such as Windows Server™, Mac OS X™, Unix™, Linux™, FreeBSD™, etc.

[0081] The central processing unit 501 can perform the operations performed by the first aspect or any specific method embodiment of the first aspect, which will not be described in detail here.

[0082] This application also provides a computer-readable storage medium including instructions that, when executed on a computer, cause the computer to perform the method described above.

[0083] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0084] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0085] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0086] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0087] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

Claims

1. An overload protection detection method for a parallel system, wherein the parallel system operates in off-grid mode, the parallel system includes a parallel device and multiple power converters, the parallel device communicating in parallel with the multiple power converters; characterized in that, include: When the parallel operation device detects an overload protection fault before multiple power converters, it controls the parallel operation device to send the overload protection fault information to multiple power converters through parallel communication, so that multiple power converters record the overload protection fault information. When the parallel device re-energizes after detecting an overload protection fault, it is controlled to extract the overload protection fault information from the power converter.

2. The overload protection detection method according to claim 1, characterized in that, The method further includes: The overload protection detection time of the parallel operation device is set to be less than the overload protection detection time of the multiple power converters. The parallel operation device is controlled to perform overload protection detection based on the overload protection detection time of the parallel operation device, so that the parallel operation device detects the overload protection fault before the multiple power converters. Specifically, if the duration of the overload detected by the parallel operation device exceeds the overload protection detection time, an overload protection fault is determined to have occurred.

3. The overload protection detection method according to claim 2, characterized in that, The control of the parallel operation device to perform overload protection detection based on the overload protection detection time of the parallel operation device includes: Control the parallel operation device and detect the overload range of the load power corresponding to the parallel operation device when it is overloaded; determine whether the overload duration reaches the overload protection detection time corresponding to the overload range. If so, it is determined that an overload protection fault has occurred; otherwise, no overload protection fault has occurred.

4. The overload protection detection method according to claim 2, characterized in that, The overload protection detection time of the parallel device includes a preset overload protection detection time and a first detection time margin, and the overload protection detection time of the power converter includes the preset overload protection detection time and a second detection time margin. Setting the overload protection detection time of the parallel operation device to be less than the overload protection detection time of the multiple power converters includes: The first detection time margin corresponding to the parallel operation device is set to be less than the second detection time margin corresponding to the multiple power converters.

5. The overload protection detection method according to claim 2, characterized in that, After setting the overload protection detection time of the parallel operation device to be less than the overload protection detection time of multiple power converters, the method further includes: The overload protection detection time of the newly connected power converter in the parallel system is detected; If the overload protection detection time of the newly connected power converter in the parallel system is less than or equal to the overload protection detection time of the parallel device, then the overload protection time of the parallel device is adjusted to be less than the overload protection detection time of the newly connected power converter in the parallel system.

6. The overload protection detection method according to claim 1, characterized in that, The overload protection fault information includes: a signal containing an overload protection flag bit; The control of the parallel operation device to send overload protection fault information to multiple power converters via parallel communication includes: The control unit will send a signal containing the overload protection flag to multiple power converters via parallel communication.

7. The overload protection detection method according to claim 1, characterized in that, The multiple power converters record the overload protection fault information, including: Multiple power converters are shut down and the overload protection fault information is recorded in the history module.

8. The overload protection detection method according to claim 1, characterized in that, The process of controlling the parallel operation device to extract the overload protection fault information from the power converter includes: The parallel operation device is controlled to query the overload protection fault information from the historical record modules of multiple power converters; The control unit will report the overload protection fault information it finds to the client.

9. An overload protection and detection device for a parallel operation system, the parallel operation system operating in off-grid mode, the parallel operation system comprising a parallel operation device and multiple power converters, the parallel operation device communicating in parallel with the multiple power converters; characterized in that, include: The first control unit is configured to control the parallel device to send the overload protection fault information to the multiple power converters via parallel communication when the parallel device detects an overload protection fault before the multiple power converters, so that the multiple power converters record the overload protection fault information. The second control unit is used to control the parallel device to extract the overload protection fault information from the power converter when the parallel device is powered on again after detecting an overload protection fault.

10. A parallel system, characterized in that, The parallel system includes a parallel device and multiple power converters, and the parallel device communicates in parallel with the multiple power converters. The power supply interface of the parallel device is connected to the power grid and multiple power converters. When the parallel system is operating in off-grid mode, the parallel device is powered only by the operating drive voltage of the multiple power converters. The method described in any one of claims 1 to 8 is used to perform overload protection detection on the parallel system.

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