Multi-band PLC communication method and device of photovoltaic optimizer

Abstract

The invention relates to the technical field of data processing, and discloses a multi-band PLC communication method and device for a photovoltaic optimizer. The method comprises the following steps: performing communication path calculation on communication quality data to obtain an optimal path considering signal strength and frequency band switching, and performing node address updating according to the optimal path to obtain an optimized network structure; grouping and packaging the communication data to obtain a data packet containing a node address and data content, and transmitting the data packet through a handshake mechanism to obtain a data transmission link; monitoring the communication quality of each frequency band, and switching the frequency band when the communication quality is lower than a threshold value to obtain an updated frequency band scheme; and when communication abnormity occurs, repositioning the abnormal area to obtain a new communication path until normal communication is recovered. According to the invention, the efficiency and accuracy of multi-band PLC communication of the photovoltaic optimizer are improved.

Description

Technical Field

[0001] This application relates to the field of data processing, and particularly to a multi-band PLC communication method and device for a photovoltaic optimizer. Background Art

[0002] Currently, with the large-scale development of photovoltaic power stations, the requirements for their operation and maintenance and communication are getting higher and higher. As a core device for optimizing the efficiency of photovoltaic modules, a photovoltaic optimizer (MPPT) transmits data through power line carrier communication (PLC) method, which can utilize the existing power lines for signal transmission and reduce the additional wiring cost. In common PLC communication methods, data information is transmitted through a single frequency band. However, due to the complex and changeable electromagnetic environment, especially in photovoltaic power stations, it is significantly affected by inverters, components, and the external environment. Single-band communication is prone to problems such as signal attenuation and severe interference, which in turn leads to unstable communication quality. Multi-band PLC communication has been gradually proposed. By selecting appropriate communication frequency bands, frequency band switching and optimization of signals are realized, and the stability and anti-interference ability of data transmission are improved.

[0003] However, the existing multi-band PLC communication technology has certain limitations. First, the electromagnetic environment in a photovoltaic power station is relatively complex. How to select the best communication frequency band among multiple frequency bands depends on the real-time monitoring of the electromagnetic environment and spectrum division. Traditional PLC communication methods mostly adopt single-band or static frequency band allocation, and it is difficult to adapt to the signal attenuation and interference problems caused by environmental changes. Second, the frequency band switching, reconstruction of the topological structure, and stability of signal transmission in multi-band communication often lack intelligent path selection algorithms, resulting in a slow recovery speed of the communication link when interference occurs. In addition, in the case of communication anomalies, traditional methods are difficult to effectively reconstruct the communication path, unable to ensure the real-time data transmission and control of the photovoltaic optimizer, and reducing the reliability of the system. Summary of the Invention

[0004] This application provides a multi-band PLC communication method and device for a photovoltaic optimizer, which is used to improve the efficiency and accuracy of multi-band PLC communication of the photovoltaic optimizer.

[0005] In a first aspect, this application provides a multi-band PLC communication method for a photovoltaic optimizer, and the multi-band PLC communication method for the photovoltaic optimizer includes:

[0006] Perform signal sampling on the electromagnetic environment of a photovoltaic power station to obtain signal intensity data at each position, and perform sub-band division on the frequency range from 0.5 MHz to 10 MHz to obtain a default communication frequency band and a backup frequency band;

[0007] Send detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and allocate logical addresses to each optimizer based on the communication quality data between the optimizers to obtain a communication network topology;

[0008] Calculate the communication path for the communication quality data to obtain the optimal path considering signal strength and frequency band switching, and update the node addresses according to the optimal path to obtain an optimized network structure;

[0009] Group and package the communication data to obtain data packets containing node addresses and data content, and transmit them through a handshake mechanism to obtain a data transmission link;

[0010] Monitor the communication quality of each frequency band, and perform frequency band switching when the communication quality is lower than the threshold to obtain an updated frequency band scheme;

[0011] When communication anomalies occur, relocate the anomaly area to obtain a new communication path until normal communication is restored.

[0012] In a second aspect, the present application provides a multi-band PLC communication device for a photovoltaic optimizer. The multi-band PLC communication device for the photovoltaic optimizer includes:

[0013] An acquisition module for performing signal sampling on the electromagnetic environment of a photovoltaic power station to obtain signal strength data at each location, and dividing the frequency range from 0.5 MHz to 10 MHz into sub-frequency bands to obtain a default communication frequency band and a backup frequency band;

[0014] A sending module for sending detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and allocating logical addresses to each optimizer based on the communication quality data between the optimizers to obtain a communication network topology;

[0015] A calculation module for calculating the communication path for the communication quality data to obtain the optimal path considering signal strength and frequency band switching, and updating the node addresses according to the optimal path to obtain an optimized network structure;

[0016] A packaging module for grouping and packaging the communication data to obtain data packets containing node addresses and data content, and transmitting them through a handshake mechanism to obtain a data transmission link;

[0017] A monitoring module for monitoring the communication quality of each frequency band, and performing frequency band switching when the communication quality is lower than the threshold to obtain an updated frequency band scheme;

[0018] A positioning module for relocating the anomaly area when communication anomalies occur to obtain a new communication path until normal communication is restored.

[0019] In the technical solution provided by this application, through the cooperation of multiple key technical features, stable communication and adaptive frequency band switching in a complex electromagnetic environment are achieved, thereby greatly improving the communication quality and anti-interference ability of the optimizer in the photovoltaic power station. First, by performing signal sampling and sub-band division on the electromagnetic environment of the photovoltaic power station, the system can comprehensively understand the signal intensity and distribution characteristics in different frequency bands, select a suitable data transmission frequency band in the range of 0.5 MHz to 10 MHz, and set the default communication frequency band and the backup frequency band. In this way, when signal attenuation or interference occurs in the default communication frequency band, the system can quickly switch to the backup frequency band to ensure the continuity and stability of data transmission. In addition, the real-time monitoring and frequency band division of the electromagnetic environment also enable the system to flexibly adjust the frequency band configuration according to the signal characteristics in different regions, enhance the adaptive ability of the system, and reduce communication interruptions caused by electromagnetic interference. Detect the communication quality between each MPPT optimizer, and generate the communication topology structure between each optimizer through probe signals and communication quality data. During this process, each optimizer obtains a logical address, forming a clear network connection relationship. This design not only ensures that each optimizer can maintain a stable communication link with adjacent devices, but also makes the network structure have higher management efficiency and scalability in a large-scale photovoltaic power station. When the communication environment changes, the system can dynamically optimize the communication path by adjusting the logical address and topology structure, improving the flexibility of data transmission.

[0020] Meanwhile, the system realizes optimal path selection through path calculation of communication quality data and node address update. By comprehensively considering the signal strength and the cost of frequency band switching, the system achieves a balance between transmission efficiency and communication stability, and selects a communication path with the minimum delay based on the Dijkstra algorithm. Such a path selection mechanism enables the system to still complete data transmission efficiently and stably in a complex electromagnetic environment. Even when switching frequently between different frequency bands, it can still maintain the optimal transmission link. In addition, the node address reallocation and network structure update during the path calculation process endow the system with strong self-healing ability. When encountering interference or faults, it can quickly reconstruct the communication link to ensure the unobstructed flow of data. To further improve communication stability, the communication data is grouped and packed, and a data transmission link is established through a handshaking mechanism. The system checks and confirms the data packets before data transmission to ensure the integrity and reliability of the data. The handshaking mechanism ensures the accurate reception and processing of each data packet during transmission, preventing communication errors caused by data loss or repeated transmission. The packet transmission strategy of data packets not only improves the transmission efficiency but also enables the system to maintain high transmission performance even when the data volume is large. By real-time monitoring the communication quality of each frequency band, the system can quickly switch the frequency band when the communication quality is lower than the threshold to adapt to environmental changes. In addition, when the system detects communication anomalies, it can automatically relocate the abnormal area and find a new communication path through path recalculation and node verification until normal communication is restored. Such a frequency band switching and path reconstruction mechanism greatly improves the fault tolerance and anti-interference ability of the system, ensuring the continuous and stable operation of the PV optimizer in a complex environment. In summary, through the synergistic effect of technical features such as frequency band division, topology optimization, path selection, handshaking mechanism, and frequency band monitoring, the multi-band PLC communication method enables the communication system of the optimizer in the PV power station to have superior performance of high efficiency, stability, flexibility, and anti-interference. Description of the Drawings

[0021] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 It is a schematic diagram of an embodiment of the multi-band PLC communication method of the PV optimizer in the embodiments of the present application;

[0023] Figure 2 It is a schematic diagram of an embodiment of the multi-band PLC communication device of the PV optimizer in the embodiments of the present application. Detailed Embodiments

[0024] The embodiments of the present application provide a multi - band PLC communication method and device for a photovoltaic optimizer. Terms such as "first", "second", "third", "fourth", etc. (if any) in the specification, claims and the above - mentioned drawings of the present application are used to distinguish similar objects, and do not necessarily describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments described here can be implemented in an order other than that illustrated or described here. In addition, the term "including" or "having" and any of its variations are intended to cover non - exclusive inclusion. For example, a process, method, system, product or device that includes a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0025] For ease of understanding, the specific process of the embodiments of the present application is described below. Please refer to Figure 1 , an embodiment of the multi - band PLC communication method for a photovoltaic optimizer in the embodiments of the present application includes:

[0026] Step S101: Sample the electromagnetic environment of the photovoltaic power station to obtain signal strength data at each location, and divide the frequency range from 0.5 MHz to 10 MHz into sub - frequency bands to obtain a default communication band and a backup band;

[0027] Step S102: Send detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and allocate logical addresses to each optimizer based on the communication quality data between the optimizers to obtain a communication network topology structure;

[0028] Step S103: Calculate the communication path for the communication quality data to obtain an optimal path considering signal strength and frequency band switching, and update the node addresses according to the optimal path to obtain an optimized network structure;

[0029] Step S104: Packetize and pack the communication data to obtain data packets containing node addresses and data content, and transmit them through a handshake mechanism to obtain a data transmission link;

[0030] Step S105: Monitor the communication quality of each frequency band, and perform frequency band switching when the communication quality is lower than the threshold to obtain an updated frequency band scheme;

[0031] Step S106: When a communication anomaly occurs, relocate the anomaly area to obtain a new communication path until normal communication is restored.

[0032] It can be understood that the execution entity of this application can be a multi-band PLC communication device of a photovoltaic optimizer, or it can also be a terminal or a server. Specifically, it is not limited here. In this embodiment of the application, the server is used as the execution entity for illustration.

[0033] Specifically, the construction and maintenance of the communication network rely on effectively evaluating the communication quality between each MPPT optimizer to determine the optimal communication path and topology structure, thereby ensuring the stability of data transmission. By sending detection signals to each optimizer and measuring the returned signal strength, the communication quality data between each optimizer can be obtained. The process of each optimizer sending and receiving detection signals ensures that each device node in the communication network can accurately evaluate the signal strength and data transmission stability with surrounding nodes. The collection of communication quality data reflects the connection status between different optimizer nodes and helps to establish the basic structure of the entire communication network. Then, according to the collected communication quality data, logical addresses are assigned to each optimizer node to generate the topology structure of the communication network. The process of logical address assignment ensures the connection of communication nodes and the smooth data transmission, reduces the possibility of data loss under the dynamic network structure, and ensures the orderly transmission of data streams in the network. The communication quality data will be further used for path optimization calculation. This calculation not only considers the signal strength but also pays attention to the impact of different frequency band switches. To find the optimal communication path, the system comprehensively evaluates the communication quality data, establishes a cost model of signal strength and frequency band switch, and selects the communication path with the lowest cost through the path weight algorithm. In this process, the path optimization algorithm will gradually exclude nodes with weak signals or high frequency band switch costs to ensure that the selected path has good signal strength and can also avoid communication interruptions caused by frequent frequency band switches. Finally, according to the calculated optimal path, the address information of each node is updated to achieve the optimized reconstruction of the communication network. This adjustment of the network structure improves the efficiency and stability of data transmission and ensures the data transmission quality in a complex electromagnetic environment.

[0034] During the transmission of communication data, reliable data transmission is achieved through packet packaging. Each group of communication data is divided into packets according to a certain length, and node addresses and data content are added to the data packets to ensure that the receiving party can correctly interpret the data source and data content. After data packaging is completed, the system uses a handshake mechanism to establish and confirm the data transmission link. The handshake mechanism is a data reception confirmation method that ensures the successful transmission of data packets by sending requests and receiving confirmations. The handshake mechanism not only ensures that data packets are intact during transmission but also prevents duplicate transmission or omission of data packets, providing stable guarantees for the real-time communication of optimizers in large-scale photovoltaic power plants. To maintain the stability of communication quality, the system continuously monitors the communication quality of each frequency band. By continuously sampling and analyzing the signal quality of different frequency bands, the system can automatically switch to a backup frequency band when the communication quality drops below the set threshold. The pre-configuration of the backup frequency band is determined through frequency band division and signal strength measurement, and it has communication stability close to the default frequency band. Once the system detects that the quality of the current frequency band drops below the threshold, the backup frequency band will replace the default frequency band for data transmission, ensuring the continuous stability of data communication in a harsh electromagnetic environment.

[0035] In the case of communication anomalies, the system will automatically re-locate the anomaly area to find a new communication path. First, the system detects the status of the communication anomaly area, including the signal strength and response of the abnormal nodes. Subsequently, the system broadcasts anomaly information to adjacent nodes near the anomaly area and obtains a set of available nodes nearby by analyzing the response data of the adjacent nodes. At this time, these available nodes are re-probed, and a new path is recalculated based on the new communication quality data to ensure that data can bypass the anomaly area and be successfully transmitted to the target node. After finding a new communication path through path recalculation and verification, the system uses it for subsequent communication links to ensure the resilience of the network and the continuity of data transmission.

[0036] For example, in a certain photovoltaic power plant, the system sends detection signals to multiple MPPT optimizer nodes and records the signal strength. Under the default frequency band, the signal strength between adjacent optimizers is within a stable range, and the communication quality data clearly shows the optimal communication path between each node. Suppose during communication, the system discovers that the signal strength between nodes B and C decreases due to interference, resulting in a decline in communication quality. By analyzing the signal strength of other adjacent nodes, the system determines that nodes A, B, D, and E form a new path, updating the topology of the communication network to bypass the interfered node C to ensure smooth data flow. In terms of frequency band switching, if it is detected that the quality of the default frequency band drops below the set threshold due to environmental interference, the system will automatically switch to the backup frequency band of 3 - 4 MHz for data transmission, maintaining the stability of the network.

[0037] In the embodiments of the present application, through the cooperation of multiple key technical features, stable communication and adaptive frequency band switching in a complex electromagnetic environment are achieved, thereby greatly improving the communication quality and anti-interference ability of the optimizer in the photovoltaic power station. First, by performing signal sampling and sub-band division on the electromagnetic environment of the photovoltaic power station, the system can comprehensively understand the signal strength and distribution characteristics of different frequency bands, select a suitable data transmission frequency band within the range of 0.5 MHz to 10 MHz, and set the default communication frequency band and the backup frequency band. In this way, when signal attenuation or interference occurs in the default communication frequency band, the system can quickly switch to the backup frequency band to ensure the continuity and stability of data transmission. In addition, the real-time monitoring and frequency band division of the electromagnetic environment also enable the system to flexibly adjust the frequency band configuration according to the signal characteristics of different regions, enhance the adaptive ability of the system, and reduce communication interruptions caused by electromagnetic interference. Detect the communication quality between each MPPT optimizer, and generate the communication topology structure between each optimizer through the detection signal and communication quality data. During this process, each optimizer obtains a logical address, forming a clear network connection relationship. This design not only ensures that each optimizer can maintain a stable communication link with adjacent devices, but also makes the network structure have higher management efficiency and scalability in large-scale photovoltaic power stations. When the communication environment changes, the system can dynamically optimize the communication path by adjusting the logical address and topology structure, improving the flexibility of data transmission.

[0038] Meanwhile, the system achieves optimal path selection through path calculation of communication quality data and node address update. By comprehensively considering the signal strength and the cost of frequency band switching, the system strikes a balance between transmission efficiency and communication stability, and selects a communication path with the minimum delay based on the Dijkstra algorithm. Such a path selection mechanism enables the system to still efficiently and stably complete data transmission in a complex electromagnetic environment. Even when frequently switching between different frequency bands, it can still maintain the optimal transmission link. In addition, the node address reallocation and network structure update during the path calculation process endow the system with strong self-healing capabilities. When encountering interference or faults, it can quickly reconstruct the communication link to ensure the unobstructed flow of data streams. To further improve communication stability, the communication data is grouped and packed, and a data transmission link is established through a handshaking mechanism. The system checks and confirms the data packets before data transmission to ensure the integrity and reliability of the data. The handshaking mechanism ensures the accurate reception and processing of each data packet during transmission, preventing communication errors caused by data loss or repeated transmission. The packet transmission strategy of data packets not only improves the transmission efficiency but also enables the system to maintain high transmission performance even when the data volume is large. By real-time monitoring the communication quality of each frequency band, the system can quickly switch the frequency band when the communication quality is lower than the threshold to adapt to environmental changes. In addition, when the system detects communication anomalies, it can automatically relocate the abnormal area and, through path recalculation and node verification, find a new communication path until normal communication is restored. Such a frequency band switching and path reconstruction mechanism greatly improves the fault tolerance and anti-interference capabilities of the system, ensuring the continuous and stable operation of the PV optimizer in a complex environment. In summary, through the synergistic effect of technical features such as frequency band division, topology optimization, path selection, handshaking mechanism, and frequency band monitoring, this multi-band PLC communication method endows the communication system of the optimizer in the PV power station with excellent performance of high efficiency, stability, flexibility, and anti-interference.

[0039] In a specific embodiment, the process of executing step S101 may specifically include the following steps:

[0040] (1) Sample and detect the electromagnetic environment to obtain signal amplitude data, and perform denoising processing on the signal amplitude data to obtain signal strength data;

[0041] (2) Perform spectral analysis on the signal strength data to obtain frequency distribution data, and perform regional division on the frequency distribution data to obtain regional frequency data;

[0042] (3) Calculate the bandwidth of the regional frequency data to obtain the available frequency band range, and perform division on the available frequency band range to obtain a frequency band set;

[0043] (4) measuring signal attenuation on the frequency band set to obtain attenuation characteristic data, and classifying the attenuation characteristic data to obtain frequency band grade data;

[0044] (5) Perform strength detection on the 3-4 MHz frequency band in the frequency band level data to obtain a default communication frequency band, and sort the remaining frequency bands in the frequency band set to obtain a backup frequency band;

[0045] (6) Perform a delay test on the default communication frequency band and the backup frequency band to obtain delay parameters, and record the delay parameters to obtain frequency band configuration data.

[0046] Specifically, the electromagnetic environment is sampled and detected and the frequency band is divided to ensure that the communication signal can select the best frequency band in a complex electromagnetic environment to ensure the communication quality. The whole process is completed through six steps, from signal sampling to frequency band selection, and then to delay testing. A set of adaptive frequency band configuration mechanisms is gradually built, so that the system can flexibly switch between different frequency bands to adapt to changes in the electromagnetic environment. The electromagnetic environment is sampled and detected to obtain the signal amplitude data at each location. The signal amplitude reflects the signal strength of each frequency band. By collecting these data, the basic situation of the electromagnetic environment can be understood. However, the original signal amplitude data usually contains more noise, so these data are denoised to eliminate the fluctuations caused by environmental interference and obtain more accurate signal strength data. Denoising can be achieved through filtering and other technologies to ensure that the final signal strength data can truly reflect the state of the current electromagnetic environment and lay the foundation for subsequent spectrum analysis.

[0047] The obtained signal strength data is subjected to spectrum analysis to obtain frequency distribution data. Spectral analysis is the process of interpreting the distribution of signals in the frequency dimension. Through spectrum analysis of signal strength data, the signal strength at different frequencies can be observed and which frequency bands have higher signal stability can be identified. The system divides the regions according to these frequency distribution data, divides the electromagnetic environment into multiple frequency regions, and obtains frequency data for each region. This step provides a reference for the division of frequency bands, enabling the system to select the most suitable communication frequency band region. Bandwidth calculation is performed on the regional frequency data to determine the available frequency band range in each region. Bandwidth calculation determines the frequency band that can effectively transmit signals by evaluating the data distribution density and signal interference of the frequencies in each region. The system divides these frequency bands into multiple small frequency band sets to form available frequency band sets with certain signal quality and bandwidth. These frequency band sets represent communication resources in different frequency bands, providing multiple possibilities for the subsequent selection of default and backup communication frequency bands.

[0048] Perform signal attenuation measurements on each frequency band in the frequency band set to obtain attenuation characteristic data. Signal attenuation measurement reflects the loss situation of the signal during transmission. Usually, the signal will have a large attenuation when the frequency is high or the distance is long. Through the analysis of the attenuation characteristic data, the system classifies different frequency bands according to signal stability and anti-attenuation ability to generate frequency band level data. In this way, the system can preferentially select the frequency band with better signal stability according to the attenuation characteristics to ensure that the communication quality is not affected by attenuation. Detect the signal strength of the 3-4 MHz frequency band in the frequency band level data and set it as the default communication frequency band. The default communication frequency band refers to the frequency band that the system preferentially uses under normal circumstances, usually the frequency band with the best signal strength and anti-interference ability. In addition, sort the remaining frequency bands according to their levels to obtain standby frequency bands in turn. The selection order of the standby frequency bands determines the frequency band that the system will first switch to when the default frequency band is interfered. This setting enhances the frequency band switching ability of the system, enabling it to maintain communication stability under different environmental conditions.

[0049] Perform a time delay test on the default communication frequency band and the standby frequency bands to obtain the time delay parameters of each frequency band. The time delay test is to measure the propagation delay of the signal on different frequency bands to ensure that the selected frequency band has low delay characteristics. The system records these time delay parameters as frequency band configuration data to provide a reference basis for the switching of different frequency bands during actual communication. The establishment of the frequency band configuration data not only provides accurate time delay information for communication, but also ensures the efficiency and stability of data transmission when there is a frequency band switch.

[0050] For example, in practical applications, the system first collects the signal amplitude data of each frequency. After denoising processing, it determines the frequency region with the most stable signal in the current environment. In spectrum analysis, the system finds that the signal in the 3-4 MHz band has the smallest attenuation, and the average time delay obtained in the time delay test within this frequency band is only 5 milliseconds. Therefore, the 3-4 MHz frequency band is set as the default communication frequency band. In addition, based on the analysis of the attenuation characteristics and signal strength, the system uses the 4-5 MHz frequency band and the 5-6 MHz frequency band as standby frequency bands to provide switching options when necessary. This frequency band configuration method preferentially uses the 3-4 MHz frequency band in daily communication, ensuring signal stability and low latency. When the electromagnetic environment changes and the quality of the 3-4 MHz frequency band deteriorates, the system will automatically switch to the 4-5 MHz frequency band to maintain the continuity and reliability of communication.

[0051] In a specific embodiment, the process of executing step S102 may specifically include the following steps:

[0052] (1) Assign numbers to the physical positions of each MPPT optimizer to obtain a physical address sequence, and send a detection signal to adjacent optimizers under the default communication frequency band to obtain initial detection data;

[0053] (2) Measure the signal strength of the initial detection data to obtain the signal strength values between nodes, and compare and analyze the signal strength values to obtain the communication quality data between optimizers;

[0054] (3) Judge the threshold of the communication quality data to obtain valid communication node pairs, and generate connection relationships according to the valid communication node pairs to obtain the initial network structure;

[0055] (4) Calculate the connection degree of each node in the initial network structure to obtain node weight data, and allocate logical addresses according to the node weight data to obtain a logical address sequence;

[0056] (5) Establish a mapping relationship between the physical address sequence and the logical address sequence to obtain an address mapping table, and construct a network connection relationship according to the address mapping table to obtain the communication network topology structure.

[0057] Specifically, it is necessary to effectively manage and configure the physical locations and communication qualities of each optimizer to form a clear communication network topology. First, assign numbers to the physical locations of each MPPT optimizer to determine its physical address sequence. The physical address of each optimizer is numbered based on the actual location. This physical address allocation method facilitates the location identification and signal management of each optimizer in a large-scale photovoltaic array. After determining the physical address, the system sends detection signals to adjacent optimizer nodes at the default communication frequency band to obtain the initial detection data. Through this detection process, the system can identify the preliminary communication status between each node, providing basic data for subsequent communication quality evaluation. Next, measure the signal strength of the obtained initial detection data to obtain the signal strength values between each node. The signal strength value reflects the signal transmission quality between different optimizers, providing an important reference for identifying the communication status. The system generates the communication quality data between every two adjacent optimizer nodes by comparing and analyzing the signal strength values between each node. The communication quality data includes the connection status and signal strength between each pair of optimizers, which can further help the system determine whether the optimizer nodes meet the requirements of stable communication.

[0058] After obtaining the communication quality data, these data are subjected to threshold judgment to determine which optimizers have effective communication connections. Through threshold judgment, the system screens out the node pairs that meet the communication quality requirements, that is, the effective communication node pairs. These node pairs will serve as the infrastructure of the communication network, and an initial connection relationship is established based on the effective communication node pairs to form an initial network structure. The initial network structure is generated according to the signal transmission quality between every two optimizers, thus ensuring the connection stability of each node in the initial structure. After constructing the initial network structure, the connection degree of each node in this structure is calculated. The connection degree represents the number of connections of each node. Through the calculation of the connection degree, the relative importance of each node in the network structure, that is, the weight of the node, can be obtained. Nodes with a higher connection degree are usually located in the center of the network and have a higher communication frequency and influence. The system assigns logical addresses to them based on the weight data of the nodes to form a logical address sequence. The logical address sequence is numbered according to the connection degree and communication stability of each node, ensuring that nodes with frequent and stable communication are preferentially assigned lower logical addresses, thereby improving the data circulation efficiency of the network.

[0059] Finally, the system establishes a mapping relationship between the physical address sequence and the logical address sequence to form an address mapping table. The address mapping table is used to correspond the physical address with the logical address to ensure that the position and function of each node can be effectively managed and identified in actual communication. Based on the address mapping table, the system further constructs the network connection relationship to generate a complete communication network topology structure. This topology structure has good node recognition and data transmission capabilities, providing guarantee for the stable communication between photovoltaic optimizers.

[0060] For example, in a photovoltaic power station composed of multiple MPPT optimizers, each optimizer is numbered by position to generate a physical address sequence "P1, P2, P3...". The system sends detection signals to adjacent optimizers at the default frequency band and measures the signal strength values between adjacent nodes. Suppose in the signal strength comparison, the signal quality between nodes P1 and P2, and P2 and P3 reaches the communication threshold, and the system determines these two node pairs as effective communication node pairs and constructs an initial network structure. Further calculation shows that P2 has the highest connection degree, so the system assigns it the logical address "L1", and the other nodes are "L2, L3", etc. through the address mapping table. The system maps "P1, L2" and "P2, L1" together to form a complete communication network topology structure. This topology structure ensures the stable communication connection between nodes and the smooth data transmission between optimizers.

[0061] In a specific embodiment, the process of executing step S103 may specifically include the following steps:

[0062] (1) Perform matrix transformation on the communication quality data to obtain a communication quality matrix, and calculate the frequency band switching cost for the communication quality matrix to obtain switching cost data;

[0063] (2) Conduct a comprehensive evaluation of the switching cost data and the communication quality matrix to obtain path weight data, and perform path search on the path weight data through the Dijkstra algorithm to obtain candidate communication paths;

[0064] (3) Estimate the transmission delay of the candidate communication paths to obtain path delay data, and select the path with the minimum delay based on the path delay data to obtain the optimal path;

[0065] (4) Reallocate the addresses of the nodes on the optimal path to obtain updated node addresses, and reconstruct the network connection based on the updated node addresses to obtain an optimized network structure.

[0066] Specifically, through the optimization process of the communication path, the system can select the optimal communication path in a complex electromagnetic environment to achieve stable and efficient data transmission. The realization of path optimization includes the processing of communication quality data, the calculation of path weights, delay estimation, and the selection of the optimal path and the update of the network structure, ensuring that the system can quickly adjust the communication path when the frequency band is switched or the signal quality deteriorates. Perform matrix transformation on the collected communication quality data to generate a communication quality matrix. The communication quality matrix reflects the signal strength and connection quality between each optimizer node and is the basic data for evaluating path selection. Based on the matrix transformation, the system further calculates the frequency band switching cost to obtain switching cost data. The frequency band switching cost refers to the communication loss caused by factors such as signal attenuation and interference when switching between different frequency bands. The magnitude of the switching cost will directly affect the reliability and efficiency of data transmission. Therefore, the system combines the communication quality matrix and the switching cost data to ensure the comprehensive consideration of signal strength and switching cost during the path optimization process.

[0067] Comprehensively evaluate the handover cost data and the communication quality matrix to obtain path weight data. The path weight data includes the comprehensive quality scores of each path, taking into account factors such as signal strength and handover cost, which can help the system determine the optimal communication path. Based on the path weights, the system uses the Dijkstra algorithm for path search. The Dijkstra algorithm is a shortest path algorithm commonly used for graph data. By gradually selecting the path with the smallest weight, the system can find the candidate communication path with the lowest communication cost among multiple candidate paths. The determination of the candidate path ensures the efficiency of path optimization, enabling the system to quickly select the path with the lowest communication cost in the communication network. After obtaining the candidate communication path, the system further estimates the transmission delay of the candidate path to generate path delay data. The transmission delay refers to the time consumed by the signal on the path, which directly affects the data transmission efficiency. The node transmission delays of each candidate path are cumulatively calculated to obtain the overall delay data of each path. Based on the path delay data, the system selects the path with the minimum delay as the optimal path to ensure the efficiency and real-time performance of data transmission. The selection of the optimal path guarantees the data transmission speed in a complex electromagnetic environment, enabling the photovoltaic optimizers to achieve data communication in the shortest time, thereby enhancing the system's response speed and working efficiency.

[0068] To adapt to the dynamically changing network structure, the node addresses on the optimal path are reallocated, and the communication addresses of each node are updated. The address reallocation is based on the node connection status in the current network, and the nodes on the path are renumbered to match the structural changes of the optimal path. Through the updated node addresses, the system reconstructs the network connection to form an optimized network structure. The new network structure adapts to the current signal state and path requirements, ensuring the stability and flexibility of the communication network. For example, in actual operation, assume that the communication quality matrix collected by the system shows that the signal strength from node A to node B is good, but under the default frequency band, the communication quality between node C and node D is greatly affected by interference. The system incorporates the impact of frequency band switching into the evaluation through matrix transformation and handover cost calculation, and obtains the weight data of the path A - B - C. Based on the search results of the Dijkstra algorithm, the system takes the path A - B - C - D as the candidate path. Subsequently, the transmission delay of each path is estimated, and it is found that the delay of the path A - B - C is the lowest. Therefore, the system takes the A - B - C path as the optimal path, reallocates the node addresses on the path, and updates the network connection. The finally obtained optimized network structure enables more efficient communication between the photovoltaic optimizers, ensuring stable data transmission even in an environment with poor signal conditions.

[0069] In a specific embodiment, the process of executing step S104 may specifically include the following steps:

[0070] (1) Detect the length of the communication data to obtain the data length information, and perform grouping based on the data length information to obtain data groups;

[0071] (2) Add address information to the data groups to obtain data groups with addresses, and generate check codes for the data groups with addresses to obtain complete data packets;

[0072] (3) Broadcast a send request for the complete data packet to obtain receive confirmation information, and establish a handshake connection based on the receive confirmation information to obtain a data transmission link.

[0073] Specifically, detect the length of the communication data to determine the overall size of the data and generate data length information. The data length information is used to determine whether the transmitted data needs to be grouped and the specific size of each group. Especially in long data transmissions, to ensure the transmission stability and efficiency of data in the network, dividing long data into multiple smaller groups helps avoid data loss or transmission congestion. Based on the data length information, perform grouping on the data, dividing the original data into multiple data groups. The grouped data can be sent step by step, improving the transmission stability and reducing the risks associated with transmitting long data at once. Next, add address information to the data groups to form data groups with addresses. The address information is used to identify the source and target nodes of the data, ensuring that each data group can be correctly identified and processed when it reaches the receiving end. Each data group with an address will also be further processed to generate a check code in order to generate a complete data packet. The check code is a string of data generated by a specific algorithm and is used to detect whether the data packet has been damaged or tampered with during transmission. By generating the check code, the system can verify the integrity of the data packet at the receiving end, ensuring that the transmitted data content has not changed during transmission and enhancing the reliability of the data.

[0074] After generating the data packet, a broadcast request for sending the complete data packet is made. Sending a request broadcast is an initial notification of data transmission, which informs the target node that a data packet is about to be sent through broadcasting. After receiving the broadcast, the target node returns a reception confirmation message to confirm its readiness to receive the data packet. Based on the reception confirmation message, the system establishes a handshake connection with the target node. The handshake mechanism ensures that both nodes are ready for data transmission through this two-way confirmation process and establishes a stable transmission link before the start of data transmission. The handshake connection not only guarantees the reliability of data transmission but also prevents the loss or duplicate sending of data packets during transmission, providing a guarantee for the smooth progress of data transmission. For example, in practical applications, the length of the communication data for a one-time transmission is detected, and it is found that the data length is 2000 bytes. Due to the large amount of data, the system divides it into 4 data packets, each with 500 bytes. Then, the target node address is added to each packet, and a checksum is generated to form a complete data packet. The system sends a broadcast request to the target node, and the target node returns a reception confirmation message, and the handshake connection is successfully established, and the data transmission link is then formed. After that, the system transmits the data packets one by one, and at the receiving end, the integrity of each data packet is verified through the checksum to ensure that the 2000-byte data is successfully transmitted to the target node. The establishment of the transmission link and packet processing enable the data to remain stable and accurate in a complex electromagnetic environment.

[0075] In a specific embodiment, the process of executing step S105 may specifically include the following steps:

[0076] (1) Real-time sampling of the communication quality of each frequency band is performed to obtain quality sampling data, and the quality sampling data is processed by a sliding window to obtain quality trend data;

[0077] (2) The quality trend data is compared with a threshold to obtain frequency band status information, and a backup frequency band is selected according to the frequency band status information to obtain a switching target frequency band;

[0078] (3) A switching notification broadcast is made for the switching target frequency band to obtain a switching response message, and the frequency band switching is performed according to the switching response message to obtain an updated frequency band scheme.

[0079] Specifically, the communication quality of each frequency band is sampled in real time to generate quality sampling data. The quality sampling data includes information such as the signal strength, transmission success rate, and delay of each frequency band at the current moment, reflecting the immediate communication status of different frequency bands. To more accurately analyze the communication stability of the frequency band, the quality sampling data is processed with a sliding window to generate quality trend data. The sliding window processing is a signal smoothing technique that observes the changing trend of communication quality through continuous sampling over a period of time, enabling the system to identify short-term fluctuations and long-term stability of the frequency band. The quality trend data can help the system capture the gradual changes in the frequency band quality, avoid unnecessary frequency band switching caused by momentary fluctuations, and thus improve the accuracy of switching. The quality trend data is compared with a threshold to obtain the frequency band status information. The threshold comparison is to compare the quality trend data with the set communication quality threshold to determine whether the current frequency band meets the requirements for stable communication. When the quality trend data of a certain frequency band is lower than the set threshold, it indicates that the communication status of this frequency band is poor and it is no longer suitable to continue as the main communication frequency band. According to the frequency band status information, the system selects a backup frequency band as the new communication frequency band to obtain the switching target frequency band. The backup frequency band is an alternative frequency band pre-configured by the system during electromagnetic environment sampling. It usually undergoes preliminary signal quality testing and time delay evaluation and can quickly switch when the signal of the default frequency band attenuates or is severely interfered, ensuring the continuity of data transmission.

[0080] After determining the switching target frequency band, a switching notification broadcast is sent for the switching target frequency band, sending switching information to all nodes in the network. The switching notification broadcast ensures that all optimizer nodes can receive the switching signal at the same time point, avoiding communication interruption caused by asynchronous switching. After each node receives the switching notification, it will return a switching response message to confirm the switching request. The system checks the response status of all nodes according to the switching response information. After ensuring that the switching process has been confirmed by all nodes, the frequency band switching is executed. At this time, the data transmission link will switch from the default frequency band to the new target frequency band, forming an updated frequency band scheme. For example, in a certain photovoltaic power station, the system monitors in real time that the signal strength of the default frequency band continues to decline, and the quality sampling data shows that the signal stability is lower than the threshold in multiple sliding window periods. After analyzing this quality trend data, it is determined that the current frequency band status does not meet the communication requirements, and then the pre-configured backup frequency band of 4 - 5 MHz is selected as the switching target. The system broadcasts the switching notification to all optimizer nodes, and the nodes return confirmation response messages after receiving it. The system immediately executes the frequency band switching after receiving the responses of all nodes. The implementation of this switching scheme ensures that the photovoltaic optimizer can quickly resume communication when the signal deteriorates, guaranteeing the persistence and reliability of data transmission.

[0081] In a specific embodiment, the process of executing step S106 may specifically include the following steps:

[0082] (1) Detect the communication status of the abnormal area to obtain abnormal node information, and send an abnormal broadcast to adjacent nodes to obtain response status data;

[0083] (2) Analyze and process the response status data to obtain a set of available nodes, and re-probe the set of available nodes to obtain updated communication quality data;

[0084] (3) Recalculate the path for the updated communication quality data to obtain alternative communication paths, and verify and test the alternative communication paths to obtain new communication paths.

[0085] Specifically, detect the communication status of the abnormal area to identify the nodes with problems and obtain abnormal node information. The abnormal node information includes the location of the node with communication failure, the type of failure (such as signal loss or abnormal weakening of signal strength), etc. Through this detection, the system can accurately locate the position of the communication anomaly so as to take targeted recovery measures. Subsequently, the system sends an abnormal broadcast to the adjacent nodes of the abnormal node, notifies the neighboring nodes of the current abnormal situation, and collects the response status data of these adjacent nodes. After receiving the abnormal broadcast, the adjacent nodes will self-check their communication status and feedback response data such as the current signal quality and connection status to the system. These response status data provide necessary references for subsequent path recalculation and communication recovery. Next, analyze the received response status data, screen out the nodes that can maintain normal communication, and generate a set of available nodes. The set of available nodes includes those nodes with good signal strength and stable communication near the abnormal area. To further verify the communication quality of these nodes, re-probe the set of available nodes. The re-probing process obtains updated communication quality data by sending probe signals and measuring the strength and stability of the response signals. This data can clearly show which nodes near the abnormal area have high communication quality and provide data support for subsequent path recalculation.

[0086] After obtaining the updated communication quality data, these data are recalculated for paths to generate alternative communication paths. Path recalculation selects the optimal communication path by analyzing the signal strength and connection status of available nodes to ensure data transmission can still be achieved without using the original abnormal node. Through the calculation of this alternative path, the system can bypass the abnormal area and re-establish the communication link. Subsequently, verification tests are conducted on the alternative communication paths to ensure the reliability of the new paths. The verification tests ensure the communication quality of the new paths meets the system requirements by transmitting test signals on the alternative paths and measuring parameters such as transmission delay and packet loss rate. Once the alternative path passes the verification, the system sets this path as the new communication path, thus realizing the reconstruction of the communication network. The new communication path will bypass the original abnormal area, ensure the communication of the PV optimizer returns to normal, and maintain the stability and reliability of data transmission in a complex electromagnetic environment.

[0087] For example, in a certain PV system, the system detects a signal interruption at node B, identifies node B as an abnormal node, and sends an abnormal broadcast to adjacent nodes A, C, and D. Nodes A, C, and D return response status data after receiving the abnormal broadcast, showing that the communication quality of nodes A and C is good. The system adds A and C to the set of available nodes and re-probes them to obtain updated communication quality data with higher signal strength. Subsequently, the system calculates an alternative path A-C-D that bypasses node B based on the new quality data, and finds that the signal delay and stability of this path meet the communication requirements in the verification test. Finally, the system sets the A-C-D path as the new communication path, restores the connectivity of data transmission, and effectively bypasses the abnormal area and quickly restores communication.

[0088] The multi-band PLC communication method of the PV optimizer in the embodiment of the present application has been described above. Next, the multi-band PLC communication device of the PV optimizer in the embodiment of the present application will be described. Please refer to Figure 2 , an embodiment of the multi-band PLC communication device of the PV optimizer in the embodiment of the present application includes:

[0089] An acquisition module 201, configured to perform signal sampling on the electromagnetic environment of the PV power station to obtain signal strength data at each position, and perform sub-band division on the frequency range from 0.5 MHz to 10 MHz to obtain a default communication band and a standby band;

[0090] A sending module 202, configured to send detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and perform logical address allocation on each optimizer based on the communication quality data between the optimizers to obtain a communication network topology structure;

[0091] The calculation module 203 is configured to calculate the communication path for the communication quality data, obtain the optimal path considering the signal strength and frequency band switching, and update the node addresses according to the optimal path to obtain an optimized network structure;

[0092] The packaging module 204 is configured to group and package the communication data to obtain data packets containing node addresses and data content, and transmit them through a handshaking mechanism to obtain a data transmission link;

[0093] The monitoring module 205 is configured to monitor the communication quality of each frequency band, and perform frequency band switching when the communication quality is lower than the threshold to obtain an updated frequency band scheme;

[0094] The positioning module 206 is configured to reposition the abnormal area when communication anomalies occur, obtain a new communication path until normal communication is restored.

[0095] Through the collaborative cooperation of the above-mentioned components and the coordination of multiple key technical features, stable communication and adaptive frequency band switching in a complex electromagnetic environment are achieved, thereby greatly improving the communication quality and anti-interference ability of the optimizer in the photovoltaic power station. First, by performing signal sampling and sub-frequency band division on the electromagnetic environment of the photovoltaic power station, the system can comprehensively understand the signal strength and distribution characteristics of different frequency bands, select a suitable data transmission frequency band in the range of 0.5 MHz to 10 MHz, and set the default communication frequency band and the backup frequency band. In this way, when signal attenuation or interference occurs in the default communication frequency band, the system can quickly switch to the backup frequency band to ensure the continuity and stability of data transmission. In addition, the real-time monitoring and frequency band division of the electromagnetic environment also enable the system to flexibly adjust the frequency band configuration according to the signal characteristics of different regions, enhancing the adaptive ability of the system and reducing communication interruptions caused by electromagnetic interference. Detect the communication quality between each MPPT optimizer, and generate the communication topology structure between each optimizer through probing signals and communication quality data. During this process, each optimizer obtains a logical address, forming a clear network connection relationship. This design not only ensures that each optimizer can maintain a stable communication link with adjacent devices, but also makes the network structure have higher management efficiency and scalability in a large-scale photovoltaic power station. When the communication environment changes, the system can dynamically optimize the communication path by adjusting the logical address and topology structure, improving the flexibility of data transmission.

[0096] Meanwhile, the system achieves optimal path selection through path calculation of communication quality data and node address update. By integrating signal strength and the cost of frequency band switching, the system strikes a balance between transmission efficiency and communication stability, and selects a communication path with the minimum delay based on the Dijkstra algorithm. Such a path selection mechanism enables the system to efficiently and stably complete data transmission in a complex electromagnetic environment. Even when frequently switching between different frequency bands, it can still maintain the optimal transmission link. In addition, the node address reallocation and network structure update during the path calculation process endow the system with strong self-healing capabilities. When encountering interference or faults, it can quickly reconstruct the communication link to ensure the smooth flow of data streams. To further enhance communication stability, the communication data is grouped and packed, and a data transmission link is established through a handshaking mechanism. The system checks and confirms the data packets before data transmission, ensuring the integrity and reliability of the data. The handshaking mechanism ensures the accurate reception and processing of each data packet during transmission, preventing communication errors caused by data loss or repeated transmission. The packet transmission strategy of data packets not only improves the transmission efficiency but also enables the system to maintain high transmission performance even when the data volume is large. By real-time monitoring the communication quality of each frequency band, the system can quickly switch the frequency band when the communication quality is below the threshold to adapt to environmental changes. In addition, when the system detects communication anomalies, it can automatically relocate the abnormal area and, through path recalculation and node verification, find a new communication path until normal communication is restored. Such a frequency band switching and path reconstruction mechanism greatly improves the fault tolerance and anti-interference capabilities of the system, ensuring the continuous and stable operation of the PV optimizer in a complex environment. In summary, through the synergistic effect of technical features such as frequency band division, topology optimization, path selection, handshaking mechanism, and frequency band monitoring, the multi-band PLC communication method endows the communication system of the optimizer in the PV power station with excellent performance of high efficiency, stability, flexibility, and anti-interference.

[0097] As described above, the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application.

Claims

1. A multi-band PLC communication method for a photovoltaic optimizer, characterized in that, The multi-band PLC communication method of the photovoltaic optimizer includes: Sampling signals from the electromagnetic environment of the photovoltaic power station to obtain signal strength data at each location, and dividing the frequency range from 0.5 MHz to 10 MHz into sub-bands to obtain the default communication band and the backup band; Sending detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and allocating logical addresses to each optimizer based on the communication quality data between the optimizers to obtain the communication network topology; Calculating the communication path for the communication quality data to obtain the optimal path considering signal strength and frequency band switching, and updating the node addresses according to the optimal path to obtain the optimized network structure; Grouping and packing the communication data to obtain data packets containing node addresses and data content, and transmitting them through a handshake mechanism to obtain the data transmission link; Monitoring the communication quality of each frequency band, and performing frequency band switching when the communication quality is lower than the threshold to obtain an updated frequency band scheme; When a communication anomaly occurs, repositioning the anomaly area to obtain a new communication path until normal communication is restored.

2. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, wherein, The step of sampling signals from the electromagnetic environment of the photovoltaic power station to obtain signal strength data at each location, and dividing the frequency range from 0.5 MHz to 10 MHz into sub-bands to obtain the default communication band and the backup band includes: Sampling and detecting the electromagnetic environment to obtain signal amplitude data, and denoising the signal amplitude data to obtain signal strength data; Performing spectrum analysis on the signal strength data to obtain frequency distribution data, and dividing the frequency distribution data into regions to obtain regional frequency data; Calculating the bandwidth of the regional frequency data to obtain the available frequency band range, and dividing the available frequency band range to obtain a frequency band set; Measuring the signal attenuation of the frequency band set to obtain attenuation characteristic data, and classifying the attenuation characteristic data to obtain frequency band level data; Detecting the intensity of the 3 - 4 MHz frequency band in the frequency band level data to obtain the default communication band, and sorting the remaining frequency bands in the frequency band set to obtain the backup band; Testing the time delay of the default communication band and the backup band to obtain time delay parameters, and recording the time delay parameters to obtain frequency band configuration data.

3. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, wherein The step of sending detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and allocating logical addresses to each optimizer based on the communication quality data between the optimizers to obtain the communication network topology includes: Assigning numbers to the physical locations of each MPPT optimizer to obtain a physical address sequence, and sending detection signals to adjacent optimizers in the default communication band to obtain initial detection data; Measuring the signal strength of the initial detection data to obtain the signal strength value between nodes, and comparing and analyzing the signal strength value to obtain the communication quality data between the optimizers; Judging the threshold of the communication quality data to obtain valid communication node pairs, and generating connection relationships according to the valid communication node pairs to obtain the initial network structure; Calculate the connection degree of each node in the initial network structure to obtain node weight data, and allocate logical addresses according to the node weight data to obtain a logical address sequence; Establish a mapping relationship between the physical address sequence and the logical address sequence to obtain an address mapping table, and construct a network connection relationship according to the address mapping table to obtain a communication network topology structure.

4. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, wherein The calculation of the communication path for the communication quality data to obtain the optimal path considering signal strength and frequency band switching, and updating the node addresses according to the optimal path to obtain an optimized network structure, includes: Perform matrix transformation on the communication quality data to obtain a communication quality matrix, and calculate the frequency band switching cost for the communication quality matrix to obtain switching cost data; Comprehensively evaluate the switching cost data and the communication quality matrix to obtain path weight data, and perform path search on the path weight data through the Dijkstra algorithm to obtain candidate communication paths; Estimate the transmission delay of the candidate communication paths to obtain path delay data, and select the path with the minimum delay according to the path delay data to obtain the optimal path; Reallocate the addresses of the nodes on the optimal path to obtain updated node addresses, and reconstruct the network connection according to the updated node addresses to obtain an optimized network structure.

5. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, characterized in that The packetization of the communication data to obtain data packets containing node addresses and data content, and the transmission through a handshaking mechanism to obtain a data transmission link, includes: Detect the length of the communication data to obtain data length information, and perform packet division according to the data length information to obtain data packets; Add address information to the data packets to obtain data groups with addresses, and generate check codes for the data groups with addresses to obtain complete data packets; Broadcast a send request for the complete data packets to obtain receive confirmation information, and establish a handshake connection according to the receive confirmation information to obtain a data transmission link.

6. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, characterized in that, The monitoring of the communication quality of each frequency band, and when the communication quality is lower than the threshold, perform frequency band switching to obtain an updated frequency band scheme, includes: Perform real-time sampling on the communication quality of each frequency band to obtain quality sampling data, and perform sliding window processing on the quality sampling data to obtain quality trend data; Compare the quality trend data with the threshold to obtain frequency band status information, and select a standby frequency band according to the frequency band status information to obtain a switching target frequency band; Broadcast a switching notice for the switching target frequency band to obtain switching response information, and perform frequency band switching according to the switching response information to obtain an updated frequency band scheme.

7. The multi-band PLC communication method of the photovoltaic optimizer according to claim 1, wherein, When a communication anomaly occurs, relocate the anomaly area to obtain a new communication path until normal communication is restored, includes: Detect the communication status of the anomaly area to obtain anomaly node information, and send an anomaly broadcast to adjacent nodes to obtain response status data; Analyze and process the response status data to obtain a set of available nodes, and re-probe the set of available nodes to obtain updated communication quality data; Recalculate the path for the updated communication quality data to obtain alternative communication paths, and perform verification tests on the alternative communication paths to obtain new communication paths.

8. A multi-band PLC communication device for a photovoltaic optimizer, which is used to implement the multi-band PLC communication method of the photovoltaic optimizer according to any one of claims 1-7, characterized in that, The multi-band PLC communication device of the photovoltaic optimizer includes: A collection module, configured to perform signal sampling on the electromagnetic environment of the photovoltaic power station to obtain signal strength data at each position, and perform sub-band division on the frequency range from 0.5 MHz to 10 MHz to obtain a default communication band and a standby band; A sending module, configured to send detection signals to each MPPT optimizer to obtain communication quality data between the optimizers, and perform logical address allocation for each optimizer based on the communication quality data between the optimizers to obtain a communication network topology; A calculation module, configured to calculate a communication path for the communication quality data to obtain an optimal path considering signal strength and frequency band switching, and update the node address according to the optimal path to obtain an optimized network structure; A packaging module, configured to group and package communication data to obtain data packets containing node addresses and data contents, and transmit them through a handshake mechanism to obtain a data transmission link; A monitoring module, configured to monitor the communication quality of each frequency band, and perform frequency band switching when the communication quality is lower than a threshold to obtain an updated frequency band scheme; A positioning module, configured to reposition an abnormal area to obtain a new communication path when a communication anomaly occurs until normal communication is restored.

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