Method for remotely maintaining photovoltaic inverter through distributed power supply access unit

Abstract

The invention discloses a method for remotely maintaining a photovoltaic inverter through a distributed power supply access unit, and particularly relates to the field of photovoltaic inverter maintenance, and the method comprises the steps: sending a maintenance request frame to the distributed power supply access unit, and confirming the reception; the method comprises the following steps: splitting a plurality of data frames, and performing verification operation on the data frames to obtain a maintenance task execution activation instruction so as to execute a maintenance task. According to the method for remotely maintaining the photovoltaic inverter through the distributed power supply access unit, remote maintenance of the photovoltaic inverter is implemented through the distributed power supply access unit, high stability of the maintenance process is ensured, the manpower demand of field maintenance is avoided, and manpower resources are effectively saved; by adopting a wired transmission mode between the distributed power supply access unit and the photovoltaic inverter, resources of a concentrator are released, the transmission stability and safety are further enhanced, and a more reliable and efficient solution is provided for maintenance and management of a photovoltaic system.

Description

Technical Field

[0001] The present invention relates to the technical field of photovoltaic inverter maintenance. More specifically, the present invention relates to a method for remotely maintaining a photovoltaic inverter through a distributed power access unit. Background Art

[0002] With the wide installation and application of photovoltaic inverters, ensuring efficient and stable maintenance of photovoltaic inverters has become the core challenge for improving the reliability and economy of photovoltaic power generation systems; in distributed photovoltaic scenarios, a large number of inverter devices are usually scattered in different geographical locations, and the complexity and frequency of maintenance operations such as firmware upgrade, parameter optimization, and fault diagnosis of photovoltaic inverters have increased exponentially; the traditional maintenance mode is barely feasible when the number of devices is limited, but under the current operation and maintenance requirements of megawatt-level or even gigawatt-level photovoltaic power stations, the maintenance system relying on manual on-site operations and inefficient communication means can no longer meet the stringent requirements for timeliness, resource utilization rate, and cost control in large-scale operation and maintenance.

[0003] The existing maintenance of photovoltaic inverters mainly relies on two types of technical solutions: one is the local maintenance mode based on serial communication interfaces such as RS485 and RS232, and parameters are configured by connecting devices on-site; the other is an independent remote maintenance solution using a GPRS module, and device status monitoring is achieved by transmitting simple instructions through a cellular network; with the emergence of distributed power access units, by integrating multi-protocol conversion and wide-area communication capabilities, scattered local interfaces and remote modules can be integrated into the grid-side communication network, enabling basic operation and maintenance functions to be remotely executed.

[0004] However, in actual use, there are still some drawbacks. For example, the current operation and maintenance of photovoltaic inverters and system maintenance mainly rely on local communication interfaces such as RS485 and RS232 for maintenance, or achieve separate remote maintenance through a GPRS module. This mode is not only time-consuming but also inefficient, and urgently needs to be optimized to improve the timeliness and overall efficiency of maintenance work.

[0005] These problems are particularly prominent in the context of large-scale deployment of photovoltaic inverters. There is an urgent need for a method for remotely maintaining a photovoltaic inverter through a distributed power access unit to systematically solve the core pain points such as manpower requirements, instability, and insufficient security in the existing technology maintenance process, and to meet the advanced requirements of intelligent operation and maintenance of photovoltaic power stations. Summary of the Invention

[0006] In order to overcome the above-mentioned defects of the prior art, the present invention provides a method for remotely maintaining a photovoltaic inverter through a distributed power access unit, through the following solutions, to solve the problems raised in the above-mentioned background art.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A method for remotely maintaining a photovoltaic inverter through a distributed power access unit, comprising:

[0009] S1: Obtain a maintenance request frame transmitted by a concentrator to the distributed power access unit;

[0010] S2: Based on the maintenance request frame, the distributed power access unit receives and confirms the reception status;

[0011] S3: Split the successfully received maintenance request frame into multiple data frames and send them to the distributed power access unit;

[0012] S4: Perform a verification operation on the received multiple data frames, and the verification operation is used to obtain an activation instruction for executing a maintenance task corresponding to a maintenance file;

[0013] S5: Execute a maintenance task based on the activation instruction for executing the maintenance task.

[0014] Preferably, in S1, the maintenance request frame includes a target photovoltaic inverter ID, a maintenance file size, a maintenance file check code, a total number of frames, a maintenance request type, and an allowable load.

[0015] Preferably, in S1, the maintenance task message includes a maintenance file transmission time, a target photovoltaic inverter ID, a maintenance task ID, a maintenance task priority, an expected completion time, and a communication protocol type.

[0016] Preferably, in S2, the distributed power access unit receives and confirms the reception status, specifically including:

[0017] Based on the target photovoltaic inverter ID in the maintenance request frame, accurately match the basic information and configuration parameters of the target photovoltaic inverter from the local device list;

[0018] Check the current operating status of the target photovoltaic inverter in real time and confirm the maintainable conditions;

[0019] Use a standard communication protocol to verify the connectivity of the communication link and confirm that the communication link between the distributed power access unit and the target photovoltaic inverter meets the requirements of maintenance operations;

[0020] Check the firmware version information of the target photovoltaic inverter and confirm its compatibility with the maintenance file through hash value comparison;

[0021] Generate a remote maintenance instruction including an operation sequence and send it to the distributed power access unit.

[0022] Preferably, in S2, the distributed power access unit receives and confirms the reception status, and specifically further includes:

[0023] Obtain the local system time and calculate the time difference with the maintenance file transfer time in the maintenance task message;

[0024] Send a synchronization instruction carrying the calibrated time information to the target photovoltaic inverter to complete device-level time alignment;

[0025] Use the hash algorithm to perform consistency verification on the target photovoltaic inverter ID in the maintenance task message and the target photovoltaic inverter ID stored in the local registry;

[0026] Establish an index through the maintenance task ID and query the local task execution queue;

[0027] Evaluate the CPU load rate, available storage space, and network bandwidth of the distributed power access unit based on the maintenance task priority and expected completion time;

[0028] Generate a remote maintenance execution instruction and send the response confirmation information to the concentrator.

[0029] Preferably, in step S3, the received maintenance request frame is split into multiple data frames, specifically including:

[0030] According to the remote maintenance instruction corresponding to the target photovoltaic inverter, the maintenance request frame is divided into multiple maintenance request data frames. The maintenance request data frame includes a first target maintenance request frame, and the first target maintenance request frame is any one of the multiple maintenance request data frames;

[0031] Send the first target maintenance request frame frame by frame to the distributed power access unit.

[0032] Preferably, in step S3, the maintenance request frame is divided into multiple maintenance request data frames, specifically including:

[0033] Based on the maintenance file size MS in the maintenance request frame and the allowed load amount AL of each frame, determine the total number of frames Sn, which is specifically expressed as:

[0034]

[0035] Among them, Indicates the result of rounding up Of.

[0036] Preferably, in step S4, perform a verification operation on the received multiple data frames, specifically including:

[0037] Based on the first target maintenance request frame D, calculate the frame check value CRC(D) of the first target maintenance request frame, which is specifically expressed as:

[0038] CRC(D) = D × x k modG(x),

[0039] Among them, x is expressed as a polynomial form of preset binary data, k is expressed as the number of bits of the CRC check algorithm, G(x) is expressed as a preset polynomial, and mod represents modulo calculation.

[0040] Technical effects and advantages of the present invention:

[0041] 1. The present invention implements remote maintenance of the photovoltaic inverter through the distributed power access unit, ensuring a high degree of stability in the maintenance process, avoiding the manpower requirements for on-site maintenance, and effectively saving human resources.

[0042] 2. By adopting the wired transmission method between the distributed power access unit and the photovoltaic inverter, the present invention releases the resources of the concentrator, further enhances the stability and security of the transmission, and provides a more reliable and efficient solution for the maintenance and management of the photovoltaic system.

[0043] 3. By performing frame-by-frame transmission, verification, and optimizing the communication protocol, the present invention solves the problems of difficult support for large file transmission and low resource utilization rate, and improves the resource utilization rate. Description of the Drawings

[0044] Figure 1 It is a flowchart of the implementation steps of a method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to an embodiment of the present application.

[0045] Figure 2 It is a flowchart of a system for remotely maintaining a photovoltaic inverter through a distributed power access unit according to an embodiment of the present application.

[0046] Figure 3 It is an architecture diagram of a system for remotely maintaining a photovoltaic inverter through a distributed power access unit according to an embodiment of the present application.

[0047] Figure 4 It is a flowchart of the implementation steps for remotely maintaining a photovoltaic inverter through a distributed power access unit according to an embodiment of the present application.

[0048] Description of the reference numerals: 300, an architecture of a system for remotely maintaining a photovoltaic inverter through a distributed power access unit; 301, concentrator; 302, system communication bus; 303, distributed power access unit; 304, photovoltaic inverter cluster. Detailed Embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. As used in the specification of the present application, the singular forms "a", "an", "the", "above", "said", "this" are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more of the listed items; in the description of the embodiments of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0051] As shown in the attached Figure 1 A method for remotely maintaining a photovoltaic inverter through a distributed power access unit includes sending a maintenance request frame to the distributed power access unit and confirming receipt; splitting multiple data frames and performing a check operation on the data frames to obtain a maintenance task execution activation instruction to execute the maintenance task. The specific steps are as follows:

[0052] S1: Obtain a maintenance request frame transmitted by the concentrator to the distributed power access unit.

[0053] Specifically, in the initialization stage of the remote maintenance process, the steps for the concentrator, as the initiating entity of the maintenance task, to send data to the distributed power access unit through the communication link are as follows:

[0054] S1-1: The concentrator transmits a maintenance request frame in a preset format to the distributed power access unit. The maintenance request frame includes the target photovoltaic inverter ID, the size of the maintenance file, the check code of the maintenance file, the total number of frames, the maintenance request type, and the allowable load.

[0055] It should be noted that the maintenance request frame is the start signal for the entire remote maintenance process. The target PV inverter ID in the maintenance request frame is the unique identification code of the target PV inverter, which is used to accurately locate the device to be maintained; the maintenance file size in the maintenance request frame is the number of bytes of the maintenance file to be transmitted, which is used to estimate the transmission time and resource allocation; the maintenance file checksum in the maintenance request frame is the checksum of the maintenance file calculated through the CRC algorithm, which is used to verify the integrity and accuracy of the file; the total number of frames in the maintenance request frame is the total number of data frames into which the maintenance file is split, which is used by the distributed power access unit for data recombination and integrity verification; the maintenance request type in the maintenance request frame is the specific category that defines the maintenance operation, and the specific categories include but are not limited to software update, parameter configuration, fault troubleshooting, etc., so that the distributed power access unit can make preparations in advance; the allowable load in the maintenance request frame is the maximum load size of the current maintenance request frame.

[0056] S1-2: After the concentrator successfully sends the maintenance request frame and receives the confirmation response from the distributed power access unit, the concentrator continues to transmit the maintenance task message to the distributed power access unit. The maintenance task message includes the maintenance file transmission time, the target PV inverter ID, the maintenance task ID, the maintenance task priority, the expected completion time, and the communication protocol type.

[0057] It should be noted that the maintenance file transmission time in the maintenance task message is the specific timestamp when the maintenance file starts to be transmitted, which is used for time synchronization between the distributed power access unit and the target PV inverter; the maintenance task ID in the maintenance task message is a string generated by combining the timestamp, random number, and device code, which is used to accurately identify this maintenance task; the maintenance task priority in the maintenance task message is represented in the form of a digital level, and the priority is set according to the urgency of the maintenance task; the expected completion time in the maintenance task message is the estimated duration required to complete this maintenance task; the communication protocol type in the maintenance task message is the communication protocol used for data transmission between the distributed power access unit and the target PV inverter.

[0058] S2: Based on the maintenance request frame, the distributed power access unit receives and confirms the reception status.

[0059] Specifically, the distributed power access unit receives the data transmitted in S1 and confirms the reception status of the data transmitted in S1. The steps to confirm the reception status are as follows:

[0060] S2-1: Based on the maintenance request frame transmitted in S1, perform a remote maintenance judgment operation on the target PV inverter. The remote maintenance judgment operation is used to obtain the remote maintenance instruction corresponding to the target PV inverter.

[0061] Furthermore, after receiving the maintenance request frame, the distributed power access unit will immediately initiate a remote maintenance judgment operation. The distributed power access unit makes a preliminary judgment on the operating conditions of the target PV inverter through the maintenance request frame. The judgment content includes but is not limited to the current operating state of the target inverter, the availability of the communication link, the maintenance authority of the PV inverter, the firmware version of the PV inverter, etc. After passing the evaluation, it sends a confirmation reply to the concentrator; otherwise, it terminates the current maintenance process and does not send subsequent maintenance data;

[0062] In a possible implementation manner, obtaining the remote maintenance instruction corresponding to the target PV inverter includes: based on the target PV inverter ID in the maintenance request frame, accurately matching the basic information and configuration parameters of the target PV inverter from the local device list; real-time checking the current operating state of the target PV inverter to confirm the maintainable conditions. The maintainable state includes but is not limited to non-fault, non-full load operation, no fault code, load rate lower than the threshold, having the ability to safely shut down, etc.; verifying the connectivity of the communication link using the standard communication protocol to confirm that the communication link between the distributed power access unit and the target PV inverter meets the requirements of the maintenance operation; checking the firmware version information of the target PV inverter and confirming the compatibility with the maintenance file through hash value comparison; generating a remote maintenance instruction containing an operation sequence. The remote maintenance instruction includes the maintenance task type, the target PV inverter ID, the maintenance file path, the operation step sequence, the expected execution time, the data format for feedback, and the error handling mechanism, and sending it to the distributed power access unit;

[0063] It should be noted that the remote maintenance type in the remote maintenance instruction is to clarify the specific category of this maintenance operation. The specific categories include but are not limited to software update, parameter optimization, fault troubleshooting, etc.; the maintenance file path in the remote maintenance instruction is the storage path of the specified maintenance file in the distributed power access unit; the operation step sequence in the remote maintenance instruction details the execution steps of the maintenance task; the expected execution time in the remote maintenance instruction is the estimated execution time of each operation step, which is convenient for the distributed power access unit to manage time and monitor the progress; the data format for feedback in the remote maintenance instruction defines the data format that the target PV inverter needs to feedback during the maintenance process; the error handling mechanism in the remote maintenance instruction clarifies the errors that occur during the maintenance process and the corresponding handling strategies;

[0064] S2-2: Based on the maintenance task message, perform a response confirmation operation on the target PV inverter. The response confirmation operation is used to obtain the remote maintenance execution instruction corresponding to the maintenance task message;

[0065] Furthermore, after receiving the maintenance task message, the distributed power access unit will immediately initiate a response confirmation operation; through the response confirmation operation, the distributed power access unit records and stores the received maintenance task message information;

[0066] In a possible implementation manner, the operation of performing response confirmation on the target photovoltaic inverter includes: obtaining the local system time, and calculating the time difference with the maintenance file transmission time in the maintenance task message; when the time difference exceeds the preset tolerance threshold, sending a time synchronization request frame containing the local timestamp to the concentrator, and receiving the standard time reference returned by the concentrator and completing the local clock calibration; sending a synchronization instruction carrying the calibrated time information to the target photovoltaic inverter to complete the device-level time alignment; performing consistency verification on the target photovoltaic inverter ID in the maintenance task message and the target photovoltaic inverter ID stored in the local registry by using a hash algorithm; if the verification fails, generating an exception response frame containing an error code and terminating the process; establishing an index through the maintenance task ID to query the local task execution queue; if a duplicate maintenance task ID is found, sending an inquiry request for the conflicting maintenance task ID to the concentrator; evaluating the CPU load rate, available storage space, and network bandwidth of the distributed power access unit based on the maintenance task priority and expected completion time; generating a remote maintenance execution instruction, where the remote maintenance execution instruction includes the maintenance task ID, execution action, timeout threshold, ARQ protocol retransmission policy, and SHA-256 verification information, and sending the response confirmation information to the concentrator;

[0067] In this embodiment, the preset tolerance threshold is set to ±500 ms. When the time difference exceeds the ±500 ms tolerance threshold, a synchronization request containing the local timestamp is sent to the concentrator; when the consistency verification fails, an exception frame containing the error code EC-001 is generated and the process is terminated; while the task uniqueness verification decides whether to continue or terminate the task according to the ACK / NACK instruction; for the distributed power access unit, the CPU load rate ≤ 75%, the available storage space ≥ 120% of the file size, and the network bandwidth ≥ 150% of the transmission rate are evaluated; for the maintenance tasks with high priority and short expected completion time, non-critical background processes are suspended to release at least 30% of the computing resources, and at the same time, a dedicated network channel of no less than 20 Mbps is reserved.

[0068] S3: Split the successfully received maintenance request frame into multiple data frames and send them to the distributed power access unit.

[0069] Specifically, the step of splitting the maintenance request frame into multiple data frames in S3 includes:

[0070] S3-1: Based on the remote maintenance instruction, perform a framed transmission operation on the maintenance request frame, and the framed transmission operation is used to obtain the first target maintenance request frame corresponding to the maintenance request frame;

[0071] Further, the concentrator divides the maintenance request frame into multiple maintenance request data frames according to the remote maintenance instruction corresponding to the target PV inverter. The maintenance request data frame includes a first target maintenance request frame, and the first target maintenance request frame is any one of the multiple maintenance request data frames. The first target maintenance request frame is sent frame by frame to the distributed power access unit.

[0072] It should be noted that the maintenance request data frame is a data unit formed after the concentrator performs a frame splitting transmission operation on the maintenance request frame, and includes frame header information, target PV inverter ID, maintenance file split frame data, frame number identifier, frame check code, and frame tail information. The frame header information is used to identify the purpose and context of the data frame, and includes the target PV inverter ID, maintenance request type, and maintenance file check code. The maintenance file split frame data is the data information of the maintenance file in the maintenance request frame. The frame number identifier is used to identify the position of the current frame in the entire maintenance file. The frame check code is used to verify the integrity and accuracy of the current frame data. The frame tail includes an end flag.

[0073] In a possible implementation manner, the operation of performing frame splitting transmission on the maintenance request frame includes: based on the maintenance file size MS in the maintenance request frame and the allowable load AL of each frame, determining the total number of split frames Sn, which is specifically expressed as:

[0074]

[0075] where represents rounding up the result of , that is, when the maintenance file size in the maintenance request frame cannot be evenly divided by the load size of each frame, the remaining data needs to be transmitted as a separate frame. After determining the total number of split frames, auxiliary information is added to each maintenance request data frame. The auxiliary information includes, but is not limited to, a frame header, a frame sequence number, a frame tail, etc. Among them, the frame sequence number increases sequentially according to the frame splitting order, starting from 0, and the frame check code is added to the maintenance request data frame using the CRC-16 algorithm to detect whether data errors occur during the transmission process.

[0076] In a possible implementation manner, obtaining the first target maintenance request frame corresponding to the maintenance request frame includes: extracting key information in the maintenance request frame, dividing the data in the maintenance request frame into multiple data blocks according to the total number of sub-frames, and each data block corresponds to a maintenance request data frame; sequentially performing an exclusive OR operation on each data bit in the maintenance request data frame and the highest bit of the CRC register; when the exclusive OR result is 1, shifting the CRC register one bit to the left and performing an exclusive OR operation with a preset 16-bit polynomial; if the exclusive OR result is 0, shifting the CRC register one bit to the left; performing an exclusive OR operation on the maintenance request data frame after the exclusive OR processing and 0x0000 to obtain a 16-bit frame check code; encapsulating each maintenance request data frame into a first target maintenance request frame, adding a frame number identifier and a frame check code, and transmitting it to the distributed power access unit through the network;

[0077] In this embodiment, the preset 16-bit polynomial is set to 0xA001;

[0078] S3-2: Based on the remote maintenance execution instruction, perform a secondary sub-framing operation on the maintenance file, and the secondary sub-framing operation is used to obtain the second target maintenance request frame corresponding to the maintenance file;

[0079] It should be noted that according to the same sub-framing transmission operation as in S3-1, the maintenance file corresponding to the target photovoltaic inverter is secondarily sub-framed according to the exclusive 485 communication protocol of the target photovoltaic inverter, and the second target maintenance request frame corresponding to the maintenance file is obtained; the second target maintenance request frame is a data unit formed after the concentrator performs a secondary sub-framing operation on the maintenance file corresponding to the target photovoltaic inverter, and is a specific data carrier for finally transmitting maintenance data to the target photovoltaic inverter, including frame header information composed of the target photovoltaic inverter ID, secondary sub-framing maintenance request type, and secondary sub-framing maintenance file check code, maintenance file secondary sub-framing data, secondary frame number identifier, secondary frame check code, and frame tail information.

[0080] S4: Perform a check operation on the received multiple data frames, and the check operation is used to obtain the maintenance task execution activation instruction corresponding to the maintenance file.

[0081] Specifically, the steps of performing a check operation on the received multiple data frames are as follows:

[0082] S4-1: Perform a check operation on the first target maintenance request frame, and the check operation is used to obtain the check value of the first target maintenance request frame and reorganize the first target maintenance request frame to obtain the maintenance file corresponding to the reorganized target photovoltaic inverter;

[0083] Furthermore, the maintenance file corresponding to the reorganized target photovoltaic inverter includes the maintenance file data reorganized in the order of frame numbers, the file hash value, and the target photovoltaic inverter ID; the distributed power access unit calculates the frame check value of the first target maintenance request frame using the CRC check algorithm and compares it with the check value stored in the frame header information of the first target maintenance request frame; if the checks are consistent, the distributed power access unit stores the valid data in the double-buffer storage area according to the frame number and requests the next frame of data through an ACK confirmation frame; if the checks are inconsistent, the distributed power access unit triggers the NACK retransmission mechanism. If the single-frame retransmission fails the check more than 5 times, the EC-003 error code is recorded and the maintenance process is terminated; for file reorganization, the streaming write technology is used to reorganize the data in the order of frame numbers and then perform the SHA-256 hash check again to ensure that the final file is exactly the same as the original file;

[0084] In a possible implementation manner, the operation of checking the target maintenance request frame includes: calculating the frame check value CRC(D) of the first target maintenance request frame based on the first target maintenance request frame D, specifically expressed as:

[0085] CRC(D) = d × x k mod G(x),

[0086] where x represents the polynomial form of the preset binary data, k represents the number of bits of the CRC check algorithm, G(x) represents the preset polynomial, and mod represents the modulo calculation;

[0087] In this embodiment, the CRC check algorithm used in the check operation in S4 is the same as the CRC check algorithm for generating the frame check value in the first target maintenance request frame in S3; the polynomial form of the preset binary data and the polynomial are determined according to the actual situation;

[0088] It should be noted that the selection of the polynomial of the CRC check algorithm needs to comprehensively balance the error detection ability, calculation efficiency, and compatibility requirements; higher-order polynomials can detect complex error types, and the generation form is determined by the polynomial order k and the coefficient a i determined, and the formula is expressed as G(x) = x k + a k-1 x k-1 + … + a1x + a0; for hardware implementation, polynomials that support fast shift register operations are preferably selected, and for software implementation, the complexity of the lookup table method needs to be considered; when using CRC-16(0xA001), the polynomial form is expressed as G(x) = x 16 + x 15 + x 2 + 1, which can ensure single-bit error detection; when using CRC-8(0x07), the polynomial form is expressed as G(x) = x 8 + x2 +x + 1

[0089] S4 - 2: Perform a secondary verification operation on the second target maintenance request frame. The secondary verification operation is used to obtain the maintenance task execution activation instruction corresponding to the maintenance file.

[0090] It should be noted that the maintenance task execution activation instruction is the final control signal for triggering the target photovoltaic inverter to perform maintenance operations; according to the same verification operation as in S4 - 1, the target photovoltaic inverter uses the CRC verification algorithm to calculate the verification value corresponding to the second target maintenance request frame for the second target maintenance request frame; if the calculated verification value corresponding to the second target maintenance request frame is consistent with the secondary sub - frame maintenance file verification code pre - stored in the frame header, it is sent to the distributed power access unit; and the maintenance task execution activation instruction corresponding to the maintenance file is obtained.

[0091] S5: Execute the maintenance task based on the maintenance task execution activation instruction.

[0092] Specifically, after receiving the maintenance task execution activation instruction, the distributed power access unit broadcasts it to all connected photovoltaic inverters at a rate of 1 Mbps through the industrial - grade communication bus; after each inverter receives the activation instruction, it activates and executes the maintenance file stored locally.

[0093] As shown in the Figure 2 system for remotely maintaining a photovoltaic inverter through a distributed power access unit, including: a remote maintenance judgment module, a response confirmation module, a frame - splitting transmission module, a maintenance request verification module, a secondary frame - splitting module, a secondary verification module, and a maintenance task execution module.

[0094] Remote maintenance judgment module: Used to obtain the maintenance request frame, and based on the maintenance request frame, perform a remote maintenance judgment operation on the target photovoltaic inverter. The remote maintenance judgment operation is used to obtain the remote maintenance instruction corresponding to the target photovoltaic inverter.

[0095] Response confirmation module: Used to obtain the maintenance task message, and based on the maintenance task message, perform a response confirmation operation on the target photovoltaic inverter. The response confirmation operation is used to obtain the remote maintenance execution instruction corresponding to the maintenance task message.

[0096] Frame - splitting transmission module: Based on the remote maintenance instruction transmitted by the remote maintenance judgment module, perform a frame - splitting transmission operation on the maintenance request frame. The frame - splitting transmission operation is used to obtain the target maintenance request frame corresponding to the maintenance request frame.

[0097] Maintenance request verification module: Used to perform a verification operation on the target maintenance request frame transmitted by the frame - splitting transmission module. The verification operation is used to obtain the verification value of the target maintenance request frame, and reorganize the target maintenance request frame to obtain the maintenance file corresponding to the target photovoltaic inverter.

[0098] Secondary framing module: Based on the remote maintenance execution instruction transmitted by the response confirmation module, it performs secondary framing operations on the maintenance file transmitted by the maintenance request verification module. The secondary framing operation is used to obtain the maintenance task data packet corresponding to the maintenance file.

[0099] Secondary verification module: It is used to perform secondary verification operations on the maintenance task data packet transmitted by the secondary framing module. The secondary verification operation is used to obtain the maintenance task execution activation instruction.

[0100] Maintenance task execution module: It executes the maintenance task based on the maintenance task execution activation instruction transmitted by the secondary verification module.

[0101] In this embodiment, a system architecture for remotely maintaining a photovoltaic inverter through a distributed power access unit is also disclosed. Refer to Figure 3 , including: at least one concentrator 301, at least one system communication bus 302, at least one distributed power access unit 303, and a photovoltaic inverter cluster 304.

[0102] Among them, the concentrator 301 is deployed in the area control center for remotely maintaining the photovoltaic inverter through the distributed power access unit, integrating a maintenance strategy generation algorithm and a digital certificate management system; it sends a digitally signed maintenance instruction set to the distributed power access unit 303 through an encrypted communication protocol, supporting two working modes: single-device fixed-point maintenance instruction and global broadcast maintenance instruction, and the instruction transmission success rate is not less than 99.99%.

[0103] Among them, the system communication bus 302 constructs a deterministic transmission channel using the time-sensitive network protocol, deploys a redundant ring network architecture at the physical layer to ensure that the end-to-end delay of the maintenance instruction transmission is less than 50 ms, and is specially configured with a broadcast storm suppression mechanism and a QoS priority marking function to ensure the transmission reliability of critical maintenance instructions.

[0104] Among them, the distributed power access unit 303 is the system core control unit for remotely maintaining the photovoltaic inverter through the distributed power access unit, including an embedded processor and an instruction parsing engine; it is configured with a dual-channel communication interface to establish a bidirectional data transmission link with the concentrator 301 through the system communication bus 302; it has an instruction priority discrimination mechanism and a file storage buffer, can receive and persistently store the maintenance instruction file package sent by the concentrator in real time, and at the same time supports the dynamic configuration of maintenance strategies and the selection of execution paths.

[0105] Among them, the photovoltaic inverter cluster 304 is composed of multiple photovoltaic inverters with software-defined interfaces. A security verification module and a firmware update interface are preset for each node of the photovoltaic inverter. When receiving a maintenance instruction from the distributed power access unit 303, it first performs instruction signature verification and version compatibility detection. After passing the verification, it automatically enters the maintenance process, and the maintenance process data is transmitted back to the core component log system in real time.

[0106] Secondly, in the drawings of the disclosed embodiments of the present invention, only the structures related to the disclosed embodiments are involved. Other structures can refer to the general design. Without conflict, the same embodiment and different embodiments of the present invention can be combined with each other.

[0107] Finally, the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit, characterized in that: include: S1: Obtain the maintenance request frame transmitted by the concentrator to the distributed power access unit; S2: Based on the maintenance request frame, the distributed power access unit receives and confirms the receiving status; S3: Split the successfully received maintenance request frame into multiple data frames and send them to the distributed power access unit; S4: performing a verification operation on the received multiple data frames, where the verification operation is used to obtain a maintenance task execution activation instruction corresponding to the maintenance file; S5: Execute the maintenance task based on the maintenance task execution activation instruction.

2. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: The maintenance request frame in S1 includes the target photovoltaic inverter ID, the maintenance file size, the maintenance file check code, the total number of frames, the maintenance request type and the allowed load.

3. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: The S1, maintenance task message includes the maintenance file transmission time, target photovoltaic inverter ID, maintenance task ID, maintenance task priority, expected completion time and communication protocol type.

4. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: The S2, the distributed power access unit receives and confirms the receiving status, specifically includes: Based on the target PV inverter ID in the maintenance request frame, the basic information and configuration parameters of the target PV inverter are accurately matched from the local device list; Check the current operating status of the target PV inverter in real time and confirm the maintainable conditions; Use standard communication protocols to verify the connectivity of the communication link and confirm that the communication link between the distributed generation access unit and the target PV inverter meets the maintenance work requirements; Check the firmware version information of the target PV inverter and confirm compatibility with the maintenance file through hash value comparison; Generate a remote maintenance instruction containing an operation sequence and send it to the distributed power access unit.

5. The method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: The S2, the distributed power access unit receives and confirms the receiving status, specifically also includes: Get the local system time and calculate the time difference with the maintenance file transmission time in the maintenance task message; Send synchronization instructions with calibrated time information to the target PV inverter to complete device-level time alignment; A hash algorithm is used to perform consistency check between the target PV inverter ID in the maintenance task message and the target PV inverter ID stored in the local registry; Create an index by maintaining the task ID and query the local task execution queue; Based on the maintenance task priority and expected completion time, the CPU load rate, available storage space and network bandwidth of the distributed power access unit are evaluated; Generate a remote maintenance execution instruction and send the response confirmation information to the concentrator.

6. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: S3, splitting the successfully received maintenance request frame into multiple data frames, specifically includes: According to the remote maintenance instruction corresponding to the target photovoltaic inverter, the maintenance request frame is divided into a plurality of maintenance request data frames, the maintenance request data frame includes a first target maintenance request frame, and the first target maintenance request frame is any one data frame among the plurality of maintenance request data frames; The first target maintenance request frame is sent frame by frame to the distributed power supply access unit.

7. A method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 6, characterized in that: S3, dividing the maintenance request frame into a plurality of maintenance request data frames, specifically includes: Based on the maintenance file size MS in the maintenance request frame and the allowed load AL of each frame, the total number of sub-frames Sn is determined, which is specifically expressed as: in, Expressed as a pair The result is rounded up.

8. The method for remotely maintaining a photovoltaic inverter through a distributed power access unit according to claim 1, characterized in that: The step S4, performing a verification operation on the received multiple data frames, specifically includes: Based on the first target maintenance request frame D, the frame check value CRC(D) of the first target maintenance request frame is calculated, which is specifically expressed as: CRC(D)=D×x k modG(x), Among them, x represents the polynomial form of preset binary data, k represents the number of bits of the CRC check algorithm, G(x) represents the preset polynomial, and mod represents the modulus calculation.

Images