Control method and system of photovoltaic string shunt, product and storage medium

Abstract

The invention discloses a control method and system of a photovoltaic string shunt, a product and a storage medium, and relates to the technical field of the intelligent power grid industry. The central control system obtains fault data and determines a fault type, so that related parts electrically connected with a fault assembly (an inverter or a photovoltaic string) are identified, a key shunt is determined, and a working group is formed to solve the problems of data lakes and data islands. And the working group combines related shunt units together, so that effective integration of data is realized, and information islands are avoided. Meanwhile, due to the fact that only necessary assemblies are included, formation of a data lake is also prevented. And the working group executes specific fault processing operation, such as disconnection of fault connection and adjustment of current distribution proportion. The integrated data is fully utilized, effective cooperation among system components is realized, the overall optimization capability is enhanced, the required data is reduced, and the response speed is improved.

Description

Technical Field

[0001] The present application relates to the technical field of smart grid industry, and in particular to a smart dispatching system. Background Art

[0002] Photovoltaic power generation systems mainly include photovoltaic strings, inverters, and shunts, etc. Photovoltaic strings convert solar energy into DC power, inverters convert DC power into AC power, and shunts are used to control and optimize the flow of current.

[0003] At present, photovoltaic power stations use control systems of photovoltaic string shunts to monitor various operating parameters in real time during operation. These parameters include electrical parameters such as voltage, current, and power, as well as environmental parameters such as temperature and irradiance. The control system collects data through sensors distributed on each photovoltaic string and inverter, and then transmits the data to the central control room for centralized processing and analysis. When the system detects an abnormality, such as a problem with the photovoltaic string or inverter, the control system automatically adjusts the switch settings of the shunt according to preset rules to deal with the fault.

[0004] As the scale of photovoltaic power plants continues to expand and the requirements for system response speed increase, the control systems of related photovoltaic string shunts face new problems. First, when the system tries to collect data from all components, a huge data lake is formed. This data lake contains a large amount of unnecessary data, which increases the complexity of processing and analysis, and may also slow down the response speed of the system because it takes additional time and resources to analyze and store a large amount of irrelevant data. If each component processes its own data, although the creation of a huge data lake is avoided, it leads to the problem of data islands. These data islands mean that key data is isolated in different components, and also hinder the synergy between systems, making it difficult to optimize the entire photovoltaic power plant as a whole. In summary, the control systems of related photovoltaic string shunts face the problems of data lakes and data islands, resulting in slow response speed and poor coordination capabilities. Summary of the invention

[0005] The present application provides a control method, system, product and storage medium for a photovoltaic string shunt, which are used to solve the problems of data lakes and data islands and increase response speed and collaboration capabilities.

[0006] In a first aspect, the present application provides a control method for a photovoltaic string shunt, including: a central control system acquires fault data; the central control system determines the fault type based on the fault data; when the central control system determines that an inverter has failed, the central control system identifies the connected photovoltaic strings electrically connected to the faulty inverter; the central control system determines a first shunt between the faulty inverter and the connected photovoltaic strings, and a second shunt between the connected photovoltaic strings and the normally operating inverter; a first shunt unit corresponding to the first shunt and a second shunt unit corresponding to the second shunt are formed into a first working group; the central control system controls the first working group; disconnects the faulty inverter from the connected photovoltaic strings; and controls the current distribution thereof proportion, redistributing the current originally flowing to the faulty inverter to the normally working inverter; when the central control system diagnoses that the fault occurs in the PV string, the central control system identifies the connected inverter electrically connected to the faulty PV string; the central control system determines the third shunt between the connected inverter and the faulty PV string, and the fourth shunt between the connected inverter and the normally working PV string; the third shunt unit corresponding to the third shunt and the fourth shunt unit corresponding to the fourth shunt form a second working group; the central control system controls the second working group; disconnects the faulty PV string from the connected inverter; and adjusts its current distribution ratio to increase the current input from the normally working PV string to the connected inverter.

[0007] By adopting the above technical solutions, the central control system obtains fault data and determines the fault type, and then identifies the relevant components electrically connected to the faulty component (inverter or photovoltaic string), determines the key shunt, and then forms a working group to solve the problem of data lake and data island. The working group combines the relevant shunt units together to achieve effective data integration and avoid information islands. At the same time, since only necessary components are included, the formation of data lakes is also prevented. The working group performs specific fault handling operations, such as disconnecting fault connections and adjusting current distribution ratios. The integrated data is fully utilized to achieve effective collaboration between system components, enhance overall optimization capabilities, and reduce the required data and improve response speed.

[0008] In combination with some embodiments of the first aspect, in some embodiments, before the step of the central control system obtaining fault data, the method also includes: the shunt unit obtains performance indicators of the photovoltaic strings and inverters connected to the shunt, the performance indicators including current, voltage, temperature and power parameters; the shunt unit marks the parameters in the performance indicators that exceed the corresponding preset parameter thresholds as abnormal data; the shunt unit obtains historical data corresponding to the abnormal data, converts the abnormal data and the corresponding historical data into a time series format, and obtains the converted data; the shunt unit determines the changing trend of the converted data over time; the shunt unit marks the abnormal data as fault data when the difference between the changing trend and the set changing trend is greater than the trend threshold, wherein the set changing trend is the changing trend of the expected or historical mode; the shunt unit reports the fault data to the central control system.

[0009] By adopting the above technical solution, the diverter unit, as an edge computing node, actively obtains performance indicators and performs preliminary processing, realizing front-end screening and abnormal marking of data. The edge node converts the abnormal data into a time series format and analyzes its change trend. The system completes the verification by comparing the actual change trend with the set change trend. This verification mechanism filters out short-term fluctuations and instantaneous interference, improving the accuracy of fault detection. Only data that has been verified as a fault will be reported to the central control system, greatly reducing the false alarm rate and data transmission volume. The entire double verification process is completed at the diverter unit level, reflecting the advantages of edge computing and reducing the burden on the central control system.

[0010] In combination with some embodiments of the first aspect, in some embodiments, the step of redistributing the current originally flowing to the faulty inverter to the normally operating inverter by controlling the current distribution ratio specifically includes: the central control system obtains the current total output current of all photovoltaic strings connected to the faulty inverter; the central control system obtains the rated capacity and current load value of all normally operating inverters; the central control system calculates the current distribution ratio value for each normally operating inverter based on the current total output current of the photovoltaic strings, the rated capacity and current load value of all normally operating inverters; the central control system sends a control signal containing the corresponding current distribution ratio value to each shunt unit in the first working group; each shunt unit in the first working group adjusts the corresponding shunt according to the received control signal, and redistributes the current originally flowing to the faulty inverter to each normally operating inverter according to the calculated ratio.

[0011] By adopting the above technical solution, the central control system first obtains real-time data related to the fault, including the current total output current of the photovoltaic string and the actual operating status of the normal inverter, taking into account not only the rated capacity of the inverter but also its current load value to ensure that the allocation decision can adapt to the real-time operating conditions. Based on the actual data obtained, the system can calculate the optimal current distribution ratio for each normally operating inverter. This dynamic calculation takes into account the actual available capacity of each inverter and ensures the best use of resources. The central control system sends a control signal containing the precise current distribution ratio to the first working group, realizing the combination of centralized control and distributed execution based on actual conditions.

[0012] In combination with some embodiments of the first aspect, in some embodiments, after the central control system obtains the rated capacity and current load value of all normally operating inverters, the method also includes: the central control system calculates the total remaining capacity of all normally operating inverters in the first working group; the central control system calculates the current value originally received by the faulty inverter; the central control system compares the total remaining capacity with the current value originally received by the faulty inverter; when the total remaining capacity is not less than the current value originally received by the faulty inverter, the central control system calculates the current distribution ratio value for each normally operating inverter according to the current total output current of the photovoltaic string, the rated capacity of all normally operating inverters and the current load value; when the total remaining capacity is less than the current value originally received by the faulty inverter, the central control system determines the range that needs to be expanded according to the additional current value that needs to be allocated; the central control system determines the range to be expanded the shunt between other normally operating inverters and the connected PV strings; the central control system adds the shunt unit corresponding to the shunt to the first working group to form an expanded first working group; the central control system reacquires the rated capacity and current load value of all normally operating inverters in the expanded first working group; the central control system recalculates the current distribution ratio value for each normally operating inverter according to the current total output current of the PV strings, the rated capacity and current load value of all normally operating inverters in the expanded first working group; the central control system sends a control signal containing the corresponding current distribution ratio value to each shunt unit in the expanded first working group; each shunt unit in the expanded first working group adjusts the corresponding shunt according to the received control signal, and distributes the current originally flowing to the faulty inverter to each normally operating inverter according to the recalculated ratio.

[0013] By adopting the above technical solution, the system first evaluates whether the capacity of the current working group is sufficient. This step avoids unnecessary scope expansion. When the capacity is insufficient, the system can automatically determine the scope that needs to be expanded, reducing the complexity of control. The system can identify and incorporate adjacent normally operating inverters. This neighbor-first strategy minimizes the complexity of system adjustment. By gradually calculating the accumulated remaining capacity, the system can accurately determine the scope that needs to be expanded, avoiding over-expansion. After expansion, the system will recalculate and distribute the current to ensure the optimal use of resources.

[0014] In combination with some embodiments of the first aspect, in some embodiments, the central control system determines the steps to expand the range according to the additional current value that needs to be allocated, specifically including: the central control system identifies other normally operating inverters adjacent to the normally operating inverters in the first working group; the central control system obtains the rated capacity and current load value of these adjacent normally operating inverters; the central control system calculates the remaining capacity of these inverters one by one in order of distance from the first working group; when the accumulated remaining capacity reaches or exceeds the current value that needs to be additionally allocated for the first time, the central control system determines the range to be expanded.

[0015] By adopting the above technical solution, the system first identifies the normal inverters adjacent to the current working group. This proximity-first strategy minimizes the complexity of system adjustment. The capacity and load information of adjacent inverters are obtained to provide an accurate data basis for subsequent decision-making. The remaining capacity is calculated one by one in order of distance. This progressive calculation method not only ensures calculation efficiency, but also avoids unnecessary over-expansion of the range. The system can accurately determine when the required additional capacity is reached, ensuring the accuracy and necessity of range expansion.

[0016] In combination with some embodiments of the first aspect, in some embodiments, the step of adjusting the current distribution ratio and increasing the current input from the normally operating photovoltaic strings to the connected inverters specifically includes: the central control system obtains the current total output current of all normally operating photovoltaic strings; the central control system obtains the rated capacity and current load value of all connected inverters; the central control system calculates the current distribution ratio value for each connected inverter based on the current total output current value of the normally operating photovoltaic strings, the rated capacity and current load value of all connected inverters; the central control system sends a control signal containing the corresponding current distribution ratio value to each shunt unit in the second working group; each shunt unit in the second working group adjusts the corresponding shunt according to the received control signal, and redistributes the current from the normally operating photovoltaic strings to each connected inverter according to the calculated ratio.

[0017] By adopting the above technical solutions, the system first comprehensively evaluates the current situation, obtains the real-time capacity data of the normally operating photovoltaic string output and the connected inverter, and provides an accurate information basis for decision-making. Based on these real-time data, the system can dynamically calculate the optimal current distribution ratio for each connected inverter. This calculation based on actual conditions ensures the accuracy and adaptability of resource allocation. The central control system sends a control signal containing the current distribution ratio calculated in real time to the second working group, realizing the issuance of instructions based on the current situation. The shunt unit accurately adjusts the shunt according to the received real-time control signal to realize the dynamic redistribution of current.

[0018] In combination with some embodiments of the first aspect, in some embodiments, the central control system controls the second working group; disconnects the connection between the faulty photovoltaic string and the connected inverter; and adjusts the current distribution ratio to increase the current input from the normally operating photovoltaic string to the connected inverter. The method also includes: when the central control system detects that the faulty inverter or the faulty photovoltaic string has returned to normal, it starts a recovery program to gradually restore the original connection and current distribution.

[0019] By adopting the above technical solution, the system can automatically detect the recovery of the faulty component (inverter or PV string) without manual monitoring, which improves the autonomy of the system. After detecting the recovery, the system automatically starts the recovery program. This automated mechanism ensures that the system can be restored to the optimal state in a timely manner.

[0020] In a second aspect, the present application provides a control system for a photovoltaic string shunt, the control system for the photovoltaic string shunt comprising: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code comprises computer instructions, and one or more processors call the computer instructions to enable the control system of the photovoltaic string shunt to execute the method described in the first aspect and any possible implementation method of the first aspect.

[0021] In a third aspect, the present application provides a computer program product comprising instructions, which, when run on a control system of a photovoltaic string shunt, enables the control system of the photovoltaic string shunt to execute the method described in the first aspect and any possible implementation of the first aspect.

[0022] In a fourth aspect, the present application provides a computer-readable storage medium comprising instructions, which, when executed on a control system of a photovoltaic string shunt, causes the control system of the photovoltaic string shunt to execute the method described in the first aspect and any possible implementation of the first aspect.

[0023] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. The central control system obtains fault data and determines the fault type, avoiding the formation of a huge data lake and reducing unnecessary data processing. Identify the relevant components that are electrically connected to the faulty component (inverter or PV string), determine the key shunts, and then form a working group to solve the problems of data lakes and data islands. The working group combines the relevant shunt units together to achieve effective data integration and avoid information islands. At the same time, since only necessary components are included, the formation of data lakes is also prevented. The working group performs specific fault handling operations, such as disconnecting fault connections and adjusting current distribution ratios. This approach makes full use of the integrated data, realizes effective collaboration between system components, enhances overall optimization capabilities, and reduces the required data and improves response speed.

[0024] 2. As an edge computing node, the diverter unit actively obtains performance indicators and performs preliminary processing, realizing front-end screening and abnormal marking of data. The edge node converts abnormal data into a time series format and analyzes its change trend. The system completes the verification by comparing the actual change trend with the set change trend. This verification mechanism filters out short-term fluctuations and instantaneous interference, improves the accuracy of fault detection, and only data that is confirmed as a fault through verification will be reported to the central control system, greatly reducing the false alarm rate and data transmission volume. The entire double verification process is completed at the diverter unit level, reflecting the advantages of edge computing and reducing the burden on the central control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a structural schematic diagram of an applicable system architecture of a control method for a photovoltaic string shunt in an embodiment of the present application; Figure 2 is a flow chart of a control method for a photovoltaic string shunt in an embodiment of the present application; Figure 3 is another flow chart of the control method of the photovoltaic string shunt in the embodiment of the present application; Figure 4 It is a schematic diagram of an exemplary hardware structure of a control system of a photovoltaic string shunt in an embodiment of the present application. DETAILED DESCRIPTION

[0026] 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 be used as limitations to the present application. As used in the specification and appended claims of the present application, the singular expressions "one", "a kind of", "said", "above", "the" and "this" are intended to also include plural expressions, unless there is a clear indication to the contrary in the context. 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 listed items.

[0027] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as suggesting or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features, and in the description of the embodiments of the present application, unless otherwise specified, "plurality" means two or more.

[0028] Figure 1 is a structural schematic diagram of an applicable system architecture of a control method for a photovoltaic string shunt in an embodiment of the present application; See also Figure 1 , the photovoltaic power generation system includes: a number of photovoltaic strings, a number of inverters and a number of shunts; but the system architecture also includes the central control system and a number of shunt units; PV strings consist of multiple PV panels connected in series or in parallel, directly converting solar energy into DC power. They are connected to the shunt unit via dedicated DC cables to form the primary power input.

[0029] The shunt is directly connected between the PV string and the inverter. Its main function is to accurately control and adjust the current flow direction. It can dynamically distribute the current of a PV string to multiple inverters, or intelligently aggregate the current of multiple PV strings to one inverter. It can adjust the shunt ratio in real time according to the instructions of the central control system to adapt to changes in the system operation status.

[0030] It should be noted that the connection relationship between photovoltaic strings, shunts, and inverters is not a simple one-to-one or one-to-many, but presents a complex many-to-many structure. It is precisely because the system needs to flexibly change the current flow direction of the photovoltaic strings or adjust the current reception of the inverter during subsequent operation that this many-to-many connection method is adopted, or in other embodiments, a shunt may be connected to multiple photovoltaic strings and multiple inverters at the same time. It is worth noting that there are some lines in the shunt that are only hardware connections but have not yet been activated. Although these reserved connections have been physically established, they have not actually been put into use. The system can activate these connections at any time according to actual operating requirements, thereby realizing dynamic adjustment of current distribution.

[0031] The inverter is connected to the output end of the shunt unit, and its output end is connected to the grid or load. The main function of the inverter is to convert the direct current generated by the photovoltaic string into alternating current that meets the grid standards.

[0032] The diverter unit can be regarded as an extended component or superstructure of the diverter. It not only contains the core functions of the diverter, but also has additional processing capabilities and communication interfaces. The main responsibility of the diverter unit is to perform preliminary data processing and control logic while maintaining a real-time communication connection with the central control system. Through this design, the diverter unit is able to accurately control the diverters under its jurisdiction according to the instructions received, achieving a higher level of functional coordination.

[0033] It is worth noting that the configuration relationship between the diverter unit and the diverter is flexible. In some embodiments, a diverter unit may be responsible for managing and controlling multiple diverters. This many-to-one configuration method can optimize the system structure, improve control efficiency, and reduce hardware costs. However, the specific configuration method can be adjusted according to the system scale, complexity and specific needs, and this article does not limit this.

[0034] The central control system maintains a real-time two-way communication connection with all shunt units, forming the neural network of the entire photovoltaic power generation system. When any part of the system is abnormal or fails, the central control system can quickly capture these signals. Based on the preset fault handling strategy and real-time data analysis, the central control system will immediately start the corresponding emergency procedure.

[0035] The following describes the control method of the photovoltaic string shunt in the embodiment of the present application in combination with the above exemplary system architecture diagram: See also Figure 2 , which is a flow chart of a control method for a photovoltaic string shunt in an embodiment of the present application.

[0036] S201, the central control system obtains fault data; Fault data is a collection of key information that reflects the abnormal conditions of photovoltaic power generation systems. These data cover various abnormal conditions that may occur during system operation, including but not limited to: voltage deviation from the normal range, abnormal current fluctuations, inverter efficiency decline, communication interruption and other indicators.

[0037] It is worth noting that in some embodiments, the transmitted fault data may already be the judgment result after processing. For example, the judgment result such as "inverter efficiency is low" or "PV string output is abnormal" is directly received. This preprocessing method can reduce the amount of data transmission, improve the system response speed, and provide a more intuitive decision-making basis for the central control system.

[0038] S202, the central control system determines the fault type according to the fault data; The fault type is a classification system for various abnormal situations that may occur in photovoltaic power generation systems. In general, these faults are mainly classified into two categories: inverter faults and photovoltaic string faults. In other embodiments, the shunt itself may also fail, but due to its relatively low failure rate, it is not included in the main consideration for the time being.

[0039] It should be noted that the collection and transmission of fault data follows a specific path: First, the shunt, as the core node of the system, is directly connected to the PV strings and inverters. Therefore, the data passing through the shunt actually contains the output data of the PV strings and the input data of the inverter. These data are then transmitted to the shunt unit, which performs preliminary processing and analysis. Based on this data flow, the system's fault data can be roughly divided into two categories: data related to the PV strings and data related to the inverter.

[0040] S203, when the central control system determines that the inverter fails, the central control system identifies the connected photovoltaic strings electrically connected to the failed inverter; A connected PV string is a group or multiple groups of PV panels that are directly electrically connected to a specific inverter via a shunt.

[0041] In some embodiments, the central control system first accesses a database of the system, which stores the connection relationship of all components in the photovoltaic power generation system. The system searches for the identifier of the faulty inverter and then tracks all electrical connections associated with it, which is not limited here.

[0042] S204, the central control system determines a first shunt between the faulty inverter and the connected photovoltaic string, and a second shunt between the connected photovoltaic string and the normally operating inverter; The first shunt refers to the shunt device located between the faulty inverter and the PV string connected to it. The second shunt refers to the shunt device located between the connected PV string and the normally working inverter. Normally working inverters refer to inverters other than the faulty inverter. It should be noted that the "normally working inverters" mentioned here do not refer to all inverters in the system that have not failed, but specifically refer to those inverters that are connected to the affected PV strings.

[0043] It should be noted that, in some embodiments, normally operating inverters specifically refer to inverters that have a potential connection relationship with the affected photovoltaic strings. Such a potential connection relationship may be a pre-set physical connection, but is not activated during normal operation.

[0044] S205, forming a first working group by combining a first diverter unit corresponding to the first diverter and a second diverter unit corresponding to the second diverter; S206, the central control system controls the first working group; disconnects the faulty inverter from the connected photovoltaic strings; and controls the current distribution ratio to redistribute the current originally flowing to the faulty inverter to the inverter that is operating normally; In some embodiments, the central control system first sends a series of coordination instructions to the first working group. The system instructs the first shunt unit to perform a disconnection operation to cut off the circuit connection between the faulty inverter and the connected photovoltaic string, which can effectively isolate the faulty component and prevent it from affecting other parts of the system. At the same time, the system calculates the optimal current redistribution plan, taking into account factors such as the capacity of the normally operating inverter and the current load. Then, the system sends detailed current distribution instructions to the second shunt unit, instructing it on how to adjust the shunt ratio to redirect the current originally flowing to the faulty inverter to the normally operating inverter. During this process, the system monitors the changes in current in real time to ensure that the redistribution process proceeds smoothly without causing voltage fluctuations or other negative effects. If necessary, the system will also fine-tune other related shunts to optimize the current distribution of the entire system.

[0045] In some specific embodiments, the current originally flowing to the faulty inverter is redistributed to the inverter that is normally operating as follows: S2061. The central control system obtains the total current output current of all photovoltaic strings connected to the faulty inverter; Specifically, the central control system first identifies all PV strings directly connected to the faulty inverter. Then, it obtains the real-time output current data of each relevant string by communicating with the first shunt unit. Finally, the system adds these individual current values ​​to obtain the total output current value.

[0046] S2062. The central control system obtains the rated capacity and current load value of all inverters operating normally; Specifically, the central control system first identifies all inverters that are operating normally in the system. Then, it extracts the rated capacity information of each normal inverter from the system configuration database. At the same time, the system obtains the current load data of each normal inverter through it by communicating with the second shunt unit. This information will be used to calculate how much additional load each normal inverter can bear, thereby providing a decision basis for subsequent current redistribution.

[0047] S2063. The central control system calculates a current distribution ratio value for each normally operating inverter according to the current total output current value of the photovoltaic string, the rated capacity of all normally operating inverters, and the current load value; In some embodiments, the system calculates the remaining capacity percentage of each normal inverter (remaining capacity divided by rated capacity); then adds up the remaining capacities of all normal inverters to obtain the total remaining capacity; then calculates the proportion of the remaining capacity of each inverter to the total remaining capacity; then multiplies this proportion by the total current that needs to be redistributed to obtain the specific current value that each inverter should allocate; finally, divides this current value by the total current to obtain the final current distribution ratio value.

[0048] S2064, the central control system sends a control signal including a corresponding current distribution ratio value to each shunt unit in the first working group; S2065. Each shunt unit in the first working group adjusts the corresponding shunt according to the received control signal, and redistributes the current originally flowing to the faulty inverter to each normally operating inverter according to the calculated ratio.

[0049] The shunt unit adjusts the shunt device it controls based on these parameters. This adjustment may include changing the internal circuit configuration of the shunt, adjusting the opening and closing state of the electronic switch, or modifying the operating parameters of the power electronic device. Through these adjustments, the shunt can accurately control the direction and size of the current, thereby redistributing the current originally flowing to the faulty inverter to each normal working inverter according to the calculated proportion.

[0050] It can be seen that the central control system first obtains real-time data related to the fault, including the current total output current of the photovoltaic string and the actual operating status of the normal inverter, taking into account not only the rated capacity of the inverter, but also its current load value, to ensure that the allocation decision can adapt to the real-time operating conditions. Based on the actual data obtained, the system can calculate the optimal current distribution ratio for each normally operating inverter. This dynamic calculation takes into account the actual available capacity of each inverter and ensures the best use of resources. The central control system sends a control signal containing the precise current distribution ratio to the first working group, realizing the combination of centralized control and distributed execution based on actual conditions.

[0051] S207, when the central control system diagnoses that the fault occurs in the photovoltaic string, the central control system identifies the connected inverter electrically connected to the faulty photovoltaic string; The faulty PV string refers to a PV string that is abnormal and cannot generate electricity normally. The connected inverter refers to an inverter that is directly electrically connected to a specific PV string.

[0052] S208, the central control system determines a third shunt between the connected inverter and the faulty photovoltaic string, and a fourth shunt between the connected inverter and the photovoltaic string that is operating normally; The third shunt refers to the shunt device located between the connected inverter and the faulty PV string. These shunts play a vital role in fault isolation and current redistribution. They can cut off the current path from the faulty PV string to the connected inverter, or redistribute the output of the faulty PV string.

[0053] The fourth shunt refers to the shunt device located between the connected inverter and the normally functioning PV strings. These shunts are also important during the system reconstruction process, as they can be used to adjust the output distribution of the normally functioning PV strings to adapt to the new configuration after the system reconstruction.

[0054] It should be noted that "connected inverters" here refer to those inverters that have a direct or potential connection relationship with the faulty PV string. This connection relationship may be an active connection currently in use, or a potential physical connection that has been pre-set but not yet activated.

[0055] In some embodiments, "normally functioning PV strings" refer to PV strings in the system that have no faults, particularly those that have a direct or potential connection with a connected inverter.

[0056] S209, forming a second working group with the third diverter unit corresponding to the third diverter and the fourth diverter unit corresponding to the fourth diverter; S210, the central control system controls the second working group; disconnects the faulty PV string from the connected inverter; and adjusts the current distribution ratio to increase the current input from the normally functioning PV string to the connected inverter.

[0057] The central control system first sends a control instruction to the second working group, causing the third shunt unit to disconnect the electrical connection between the faulty PV string and the connected inverter to achieve fault isolation. Then, the central control system calculates the new current distribution ratio and sends an adjustment instruction to the fourth shunt unit in the second working group to increase the current input from the normally working PV string to the connected inverter.

[0058] It can be seen that the central control system obtains fault data and determines the fault type, avoiding the formation of a huge data lake and reducing unnecessary data processing. Identify the relevant components that are electrically connected to the faulty component (inverter or PV string), determine the key shunts, and then form a working group to solve the problems of data lakes and data islands. The working group combines the relevant shunt units together to achieve effective data integration and avoid information islands. At the same time, since only necessary components are included, the formation of data lakes is also prevented. The working group performs specific fault handling operations, such as disconnecting the fault connection and adjusting the current distribution ratio. This method makes full use of the integrated data, realizes effective collaboration between system components, enhances the overall optimization capability, and reduces the required data and improves the response speed.

[0059] In some embodiments, the step of adjusting the current distribution ratio and increasing the current input from the normally operating photovoltaic strings to the connected inverter specifically includes: S2101, the central control system obtains the total current output current of all photovoltaic strings operating normally; Specifically, the central control system first identifies all the normally operating PV strings in the system. Then, it communicates with the third and fourth shunt units to obtain the real-time output current data of each normally operating string. Finally, the system adds these individual current values ​​to obtain the total output current value. This total value reflects the current power generation capacity of all normally operating PV strings in the system.

[0060] S2102, the central control system obtains the rated capacity and current load value of all connected inverters; Specifically, the central control system first identifies all inverters that have a direct or potential connection relationship with the normally functioning photovoltaic strings (i.e., "connected inverters"). Then, it extracts the rated capacity information of each connected inverter from the system configuration database. At the same time, the system obtains the current load data of each connected inverter by communicating with the third and fourth shunt units. This information will be used to calculate how much additional load each connected inverter can bear or need to reduce, thereby providing a decision basis for subsequent current redistribution.

[0061] S2103, the central control system calculates a current distribution ratio value for each connected inverter according to the current total output current value of the normally operating photovoltaic strings, the rated capacity of all connected inverters, and the current load value; In some embodiments, the system calculates the current distribution ratio value by the following method: first, the percentage of available capacity of each connected inverter is calculated (rated capacity minus current load, divided by rated capacity); then the available capacities of all connected inverters are added together to obtain the total available capacity; then the ratio of the available capacity of each inverter to the total available capacity is calculated; then this ratio is multiplied by the total output current of the normally operating photovoltaic string to obtain the specific current value that should be allocated to each inverter; finally, this current value is divided by the total current to obtain the final current distribution ratio value.

[0062] S2104, the central control system sends a control signal including a corresponding current distribution ratio value to each shunt unit in the second working group; The central control system converts the calculated current distribution ratio into specific control parameters and packages these parameters into control signals. The system then sends these control signals to each shunt unit in the second working group through the communication network. Each control signal contains precise adjustment instructions for a specific shunt.

[0063] S2105. Each shunt unit in the second working group adjusts the corresponding shunt according to the received control signal, and redistributes the current from the normally operating photovoltaic string to each connected inverter according to the calculated ratio.

[0064] After receiving the control signal, the shunt unit adjusts the shunt device it controls according to these parameters. This adjustment may include changing the internal circuit configuration of the shunt, adjusting the opening and closing state of the electronic switch, or modifying the operating parameters of the power electronic device. Through these precise adjustments, the shunt can control the direction and size of the current from the normally operating photovoltaic string, and redistribute it to each connected inverter according to the calculated proportion. This dynamic adjustment ensures that the system can still maintain optimal power generation efficiency and load balance in the event of a photovoltaic string failure.

[0065] It can be seen that the system first comprehensively evaluates the current situation, obtains the real-time capacity data of the normally operating photovoltaic string output and the connected inverter, and provides an accurate information basis for decision-making. Based on these real-time data, the system can dynamically calculate the optimal current distribution ratio for each connected inverter. This calculation based on actual conditions ensures the accuracy and adaptability of resource allocation. The central control system sends a control signal containing the current distribution ratio calculated in real time to the second working group, realizing the issuance of instructions based on the current situation. The shunt unit accurately adjusts the shunt according to the received real-time control signal to realize the dynamic redistribution of current.

[0066] In some other embodiments, after step S210, the following steps are further included: S211. When the central control system detects that the faulty inverter or faulty PV string has returned to normal, it starts the recovery program and gradually restores the original connection and current distribution.

[0067] The central control system first needs to confirm that the faulty device (inverter or PV string) has returned to normal working condition, which may be achieved through the device's own status report, system diagnostic test or manual confirmation. Once it is confirmed to be back to normal, the system will start the pre-set recovery program. This program will adjust the system configuration back to the state before the fault occurred in a step-by-step and orderly manner. During the process, the system will gradually restore the original electrical connections, including reconnecting the repaired equipment, and gradually adjust the current distribution plan to return it to the original design state.

[0068] It can be seen that the system can automatically detect the recovery of the faulty component (inverter or PV string) without manual monitoring, which improves the autonomy of the system. After detecting the recovery, the system automatically starts the recovery procedure. This automated mechanism ensures that the system can be restored to the optimal state in a timely manner.

[0069] In some embodiments, before step S201, the method further includes: S301, the shunt unit obtains performance indicators of the photovoltaic strings and inverters connected to the shunt, the performance indicators including current, voltage, temperature and power parameters; In some embodiments, the shunt unit can obtain performance indicators in a variety of ways: Optionally, the shunt unit first activates various built-in sensors; then reads sensor data at a preset time interval (such as once per second); then performs preliminary processing on the read data (such as unit conversion, removal of obvious error values, etc.); then temporarily stores the processed data in a local cache; finally, packages the data and prepares it for subsequent analysis. Optionally, the shunt unit first sends a data request instruction to the connected photovoltaic strings and inverters; then waits for these devices to return their respective performance indicator data; then verifies the integrity and validity of the received data; then integrates the valid data into a unified data structure; finally, timestamps the integrated data for subsequent analysis, which is not limited here.

[0070] S302, the diverter unit marks the parameters in the performance indicators that exceed the corresponding preset parameter thresholds as abnormal data; The preset parameter threshold refers to the normal operating range of each performance indicator predefined by the system. Abnormal data refers to data points that exceed the preset threshold range.

[0071] In some embodiments, the splitter unit compares each acquired performance indicator with its corresponding preset parameter threshold. If the value of a certain indicator exceeds the preset normal range, the splitter unit will mark the data point as abnormal data. The purpose of this process is to quickly identify data points that may have problems and prepare for subsequent in-depth analysis.

[0072] S303, the splitter unit obtains historical data corresponding to the abnormal data, converts the abnormal data and the corresponding historical data into a time series format, and obtains converted data; Among them, historical data refers to the same type of performance indicator data collected within a certain period of time in the past. The splitter unit first retrieves the historical data corresponding to the data marked as abnormal from the local storage or central database. Then, it integrates the current abnormal data and the retrieved historical data, and reorganizes the data in chronological order to form a unified time series format.

[0073] S304, the splitter unit determines the changing trend of the converted data over time; In some embodiments, the splitter unit analyzes the converted time series data to identify patterns in the data over time. This may include identifying rising or falling trends, periodic changes, sudden changes, etc. Through this analysis, the generation process and possible causes of abnormal data can be better understood.

[0074] For example: Optionally, first smooth the time series data to reduce the impact of short-term fluctuations; then calculate the moving average of the data to show the overall trend; then use linear regression method to fit the data to obtain a trend line; then calculate the slope of the trend line to determine whether the overall trend is rising or falling.

[0075] S305, the diverter unit marks the abnormal data as fault data when the difference between the change trend and the set change trend is greater than the trend threshold, wherein the set change trend is the change trend of the expected or historical pattern; The set change trend refers to the expected change pattern in normal operation that is predefined by the system or derived based on historical data. The trend threshold represents the acceptable deviation range of the change trend. In some embodiments, the set change trend model and trend threshold are first loaded from the system configuration; then the difference between the actual change trend and the set change trend is calculated, and indicators such as the root mean square error (RMSE) or the mean absolute error (MAE) can be used; then the calculated difference value is compared with the preset trend threshold; if the difference exceeds the threshold, the relevant abnormal data is traversed; finally, the label of these data is updated from "abnormal" to "fault", and the specific degree of deviation is recorded.

[0076] S306. The diverter unit reports the fault data to the central control system.

[0077] It can be seen that the diverter unit, as an edge computing node, actively obtains performance indicators and performs preliminary processing, realizing front-end screening and abnormal marking of data. The edge node converts abnormal data into a time series format and analyzes its change trend. The system completes the verification by comparing the actual change trend with the set change trend. This verification mechanism filters out short-term fluctuations and instantaneous interference, improving the accuracy of fault detection. Only data that has been verified as a fault will be reported to the central control system, greatly reducing the false alarm rate and data transmission volume. The entire double verification process is completed at the diverter unit level, reflecting the advantages of edge computing and reducing the burden on the central control system.

[0078] It should be noted that S2061 to S2065 describe the situation where the first working group initially formulated can meet the system reconstruction requirements under ideal conditions. This situation usually occurs when the system has sufficient redundant capacity and the normally working inverter can easily absorb the current originally responsible for the faulty inverter.

[0079] However, in actual use, most normally operating inverters are already close to their rated capacity and are unable to bear additional loads. In these cases, relying solely on the first working group may not be able to meet the requirements of system reconstruction.

[0080] Therefore, in some embodiments, after step S2061, the process further includes step S2066: the central control system calculates the sum of the remaining capacities of all inverters in the first working group that are operating normally; The central control system calculates the remaining capacity of each inverter by subtracting the current load value from the rated capacity. Then, the system adds up the remaining capacities of all these individual inverters to get the total remaining capacity. This sum represents the maximum additional current capacity that the first working group can currently receive.

[0081] S2067, the central control system calculates the current value originally received by the faulty inverter; The original received current value indicates the input current normally handled by the faulty inverter before the fault occurs, usually in amperes (A).

[0082] In some embodiments, the system identifies all first shunt units directly connected to the faulty inverter, and the central control system obtains from each first shunt unit the current value currently transmitted to the faulty inverter by its corresponding shunt, and this current value represents the current output current of each connected photovoltaic string. The central control system adds up the single current values ​​obtained from all relevant first shunt units, and the result of the addition operation is the total current output current of all photovoltaic strings connected to the faulty inverter.

[0083] S2068, the central control system compares the total remaining capacity with the current value originally received by the faulty inverter; S2069: When the total remaining capacity is not less than the current value originally received by the faulty inverter, execute step S2062; S20610, when the total remaining capacity is less than the current value originally received by the faulty inverter, the central control system determines the range that needs to be expanded according to the additional current value that needs to be allocated; In some embodiments, the central control system first calculates the current value that needs to be additionally distributed, that is, the current value originally received by the faulty inverter minus the sum of the remaining capacities of the existing normal working inverters. The system then evaluates the topology and current operating status of the entire photovoltaic power generation system to determine which additional inverters can be taken into consideration. The system may consider multiple factors, such as the convenience of electrical connection and the current load conditions of other inverters. Based on these factors, the system will gradually expand the scope of consideration until it finds enough additional capacity to handle all the currents that need to be redistributed.

[0084] For example: S1, the central control system identifies other normally operating inverters adjacent to the normally operating inverters in the first working group; The central control system first determines the location and connection relationship of all normally working inverters in the first working group. Then, the system identifies other normally working inverters that are directly connected to these inverters in physical layout or electrical topology. This process may involve querying the system's layout diagram or connection database to accurately locate adjacent inverters. The purpose of identifying adjacent inverters is to expand the scope of current redistribution when necessary.

[0085] S2, the central control system obtains the rated capacity and current load value of these adjacent inverters that are normally working; The central control system needs to collect two key parameters for each identified adjacent normal working inverter: rated capacity and current load value. Rated capacity is usually a fixed device parameter, while the current load value is real-time changing operating data. The system may need to access the device database to obtain the rated capacity, and obtain the current load value through a real-time monitoring system or direct communication with the inverter. These data are crucial for the subsequent calculation of the remaining capacity of each inverter, thereby deciding whether to include it in the expanded current distribution range.

[0086] S3, the central control system calculates the remaining capacity of these inverters one by one in the order of distance from the first working group; The central control system first needs to determine the distance or degree of connection of each adjacent inverter to the first working group and sort the adjacent inverters accordingly. Then, starting from the nearest inverter, the system calculates the remaining capacity of each inverter using the formula "remaining capacity = rated capacity - current load value". This distance-ordered calculation method helps to give priority to inverters that are closer to reduce current transmission losses and system complexity.

[0087] S4. When the accumulated remaining capacity reaches or exceeds the current value requiring additional allocation for the first time, the central control system determines the scope of expansion.

[0088] The central control system starts with the nearest neighboring inverter and gradually accumulates its remaining capacity. After each accumulation, the system compares the accumulated value with the current value that needs to be additionally allocated. Once the accumulated remaining capacity reaches or exceeds the required additional allocated current value for the first time, the system stops the accumulation process. At this point, all neighboring inverters that have been counted in the accumulation constitute the expanded range. This approach ensures that only the necessary number of inverters are selected to participate in current redistribution, which not only meets the current distribution requirements but also avoids unnecessary increase in system complexity.

[0089] It can be seen that the system first identifies the normal inverters adjacent to the current working group. This proximity-first strategy minimizes the complexity of system adjustment. The capacity and load information of adjacent inverters are obtained to provide an accurate data basis for subsequent decision-making. The remaining capacity is calculated one by one in order of distance. This progressive calculation method not only ensures calculation efficiency, but also avoids unnecessary over-expansion of the range. The system can accurately determine when the required additional capacity is reached, ensuring the accuracy and necessity of range expansion.

[0090] S20611. The central control system determines the shunt between other normally operating inverters within the expanded range and the PV strings connected thereto; The expanded range refers to the area that is newly taken into account to handle the additional current. Other normally functioning inverters refer to the newly identified, functioning inverter devices within the expanded range. The central control system first identifies all normally functioning inverters within the expanded range. The system then tracks the input connections of each identified inverter and determines all PV strings connected to it. Next, the system locates the shunts between each inverter and its corresponding PV string. These shunts are the key execution units for current redistribution.

[0091] S20612, the central control system adds the diverter unit corresponding to the diverter to the first working group to form an expanded first working group; The central control system first matches the previously identified diverters with their corresponding diverter units. Then, the system adds these newly identified diverter units to the original first working group one by one.

[0092] S20613, the central control system reacquires the rated capacity and current load value of all normally operating inverters in the expanded first working group; It should be noted that the principle and process of this step have been described in detail in step S2062, and reference may be made to S2062, which will not be repeated here.

[0093] S20614, the central control system recalculates the current distribution ratio value for each normally operating inverter according to the current total output current value of the photovoltaic string, the rated capacity of all normally operating inverters in the expanded first working group, and the current load value; It should be noted that the principle and process of this step have been described in detail in step S2062, and reference may be made to S2063, which will not be repeated here.

[0094] S20615, the central control system sends a control signal containing a corresponding current distribution ratio value to each shunt unit in the expanded first working group; It should be noted that the principle and process of this step have been described in detail in step S2064, and reference may be made to S2064, which will not be repeated here.

[0095] S20616. Each shunt unit in the expanded first working group adjusts the corresponding shunt according to the received control signal, and distributes the current originally flowing to the faulty inverter to each normally operating inverter according to the recalculated ratio.

[0096] It should be noted that the principle and process of this step have been described in detail in step S2065, and reference may be made to S2065, which will not be repeated here.

[0097] It can be seen that the system first evaluates whether the capacity of the current working group is sufficient. This step avoids unnecessary scope expansion. When the capacity is insufficient, the system can automatically determine the scope that needs to be expanded, reducing the complexity of control. The system can identify and incorporate adjacent normally working inverters. This neighbor-first strategy minimizes the complexity of system adjustment. By gradually calculating the accumulated remaining capacity, the system can accurately determine the scope that needs to be expanded, avoiding over-expansion. After expansion, the system will recalculate and distribute the current to ensure the optimal use of resources.

[0098] The following introduces an exemplary photovoltaic string shunt control system 400 provided in an embodiment of the present application. Figure 4 Schematic diagram of an exemplary hardware structure of a control system 400 for a photovoltaic string shunt provided in an embodiment of the present application.

[0099] In some embodiments, the control system 400 of the photovoltaic string shunt is a computer device or the control system 400 of the photovoltaic string shunt includes a computer device. The computer device includes a processor, a memory and a network interface connected via a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with other external terminals or servers through a network connection. In some embodiments, the network interface can be a wired network interface, and in some embodiments, the network interface can also be a wireless network interface. When the computer program is executed by the processor, the method in the embodiment of the present application is implemented.

[0100] Those skilled in the art will understand that Figure 4 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0101] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0102] As used in the above embodiments, the term "when..." may be interpreted to mean "if..." or "after..." or "in response to determining..." or "in response to detecting...", depending on the context. Similarly, the phrases "upon determining..." or "if (the stated condition or event) is detected" may be interpreted to mean "if determining..." or "in response to determining..." or "upon detecting (the stated condition or event)" or "in response to detecting (the stated condition or event)", depending on the context.

[0103] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk), etc.

[0104] Those skilled in the art can understand that to implement all or part of the processes in the above-mentioned embodiments, the processes can be completed by computer programs to instruct related hardware, and the programs can be stored in computer-readable storage media. When the programs are executed, they can include the processes of the above-mentioned method embodiments. The aforementioned storage media include: ROM or random access memory RAM, magnetic disk or optical disk and other media that can store program codes.

Claims

1. A control method for a photovoltaic string shunt, characterized in that: include: The central control system obtains fault data; The central control system determines the fault type according to the fault data; When the central control system determines that the inverter has failed, the central control system identifies connected photovoltaic strings that are electrically connected to the failed inverter; The central control system determines a first shunt between the faulty inverter and the connected photovoltaic string, and a second shunt between the connected photovoltaic string and a normally operating inverter; The first splitter unit corresponding to the first splitter and the second splitter unit corresponding to the second splitter form a first working group; The central control system controls the first working group; Disconnect the connection between the faulty inverter and the connected photovoltaic string; and control the current distribution ratio to redistribute the current originally flowing to the faulty inverter to the normally operating inverter; When the central control system diagnoses that a fault has occurred in a photovoltaic string, the central control system identifies a connected inverter electrically connected to the faulty photovoltaic string; The central control system determines a third shunt between the connected inverter and the faulty photovoltaic string, and a fourth shunt between the connected inverter and the normally operating photovoltaic string; The third diverter unit corresponding to the third diverter and the fourth diverter unit corresponding to the fourth diverter form a second working group; The central control system controls the second working group; disconnects the faulty photovoltaic string from the connected inverter; and adjusts the current distribution ratio to increase the current input from the normally functioning photovoltaic string to the connected inverter.

2. The method according to claim 1, characterized in that: Before the step of the central control system acquiring fault data, the method further includes: The shunt unit obtains performance indicators of the photovoltaic strings and inverters connected to the shunt, wherein the performance indicators include current, voltage, temperature and power parameters; The diverter unit marks the parameters in the performance indicators that exceed the corresponding preset parameter thresholds as abnormal data; The splitter unit obtains historical data corresponding to the abnormal data, converts the abnormal data and the corresponding historical data into a time series format, and obtains converted data; The splitter unit determines a trend of the converted data over time; The diverter unit marks the abnormal data as fault data when the difference between the change trend and a set change trend is greater than a trend threshold, wherein the set change trend is a change trend of an expected or historical pattern; The diverter unit reports the fault data to a central control system.

3. The method according to claim 1, characterized in that The step of controlling the current distribution ratio to redistribute the current originally flowing to the faulty inverter to the normally functioning inverter specifically includes: The central control system obtains the total current output current of all photovoltaic strings connected to the faulty inverter; The central control system obtains the rated capacity and current load value of all inverters operating normally; The central control system calculates a current distribution ratio value for each normally operating inverter according to the current total output current value of the photovoltaic string, the rated capacity of all normally operating inverters and the current load value; The central control system sends a control signal containing a corresponding current distribution ratio value to each shunt unit in the first working group; Each shunt unit in the first working group adjusts the corresponding shunt according to the received control signal, and redistributes the current originally flowing to the faulty inverter to each inverter operating normally according to the calculated ratio.

4. The method according to claim 3, characterized in that After the step of the central control system acquiring the rated capacity and current load value of all normally operating inverters, the method further comprises: The central control system calculates the sum of remaining capacities of all inverters in the first working group that are operating normally; The central control system calculates the current value originally received by the faulty inverter; The central control system compares the sum of the remaining capacities with the current value originally received by the faulty inverter; When the total remaining capacity is not less than the current value originally received by the faulty inverter, the central control system calculates the current distribution ratio value for each normally functioning inverter according to the current total output current value of the photovoltaic string, the rated capacity of all normally functioning inverters and the current load value; When the sum of the remaining capacities is less than the current value originally received by the faulty inverter, the central control system determines the range that needs to be expanded according to the additional current value that needs to be allocated; The central control system determines the shunt between other normally operating inverters within the expanded range and the photovoltaic strings connected thereto; The central control system adds the diverter unit corresponding to the diverter to the first working group to form an expanded first working group; The central control system reacquires the rated capacity and current load value of all normally operating inverters in the expanded first working group; The central control system recalculates the current distribution ratio value for each normally operating inverter according to the current total output current value of the photovoltaic string, the rated capacity of all normally operating inverters in the expanded first working group, and the current load value; The central control system sends a control signal containing a corresponding current distribution ratio value to each shunt unit in the expanded first working group; Each shunt unit in the expanded first working group adjusts the corresponding shunt according to the received control signal, and distributes the current originally flowing to the faulty inverter to each inverter operating normally according to the recalculated ratio.

5. The method according to claim 4, characterized in that The central control system determines the step of expanding the range according to the additional current value to be allocated, specifically including: The central control system identifies other normally operating inverters adjacent to the normally operating inverters in the first working group; The central control system obtains the rated capacity and current load value of these adjacent inverters that are normally working; The central control system calculates the remaining capacity of the inverters one by one in order of distance from the first working group; When the accumulated remaining capacity reaches or exceeds the current value requiring additional allocation for the first time, the central control system determines the scope of expansion.

6. The method according to claim 1, characterized in that The step of adjusting the current distribution ratio to increase the current input from the normally functioning photovoltaic string to the connected inverter specifically includes: The central control system obtains the total current output current of all photovoltaic strings operating normally; The central control system obtains the rated capacity and current load value of all connected inverters; The central control system calculates a current distribution ratio value for each connected inverter according to the current total output current value of the normally operating photovoltaic strings, the rated capacity of all connected inverters and the current load value; The central control system sends a control signal including a corresponding current distribution ratio value to each shunt unit in the second working group; Each shunt unit in the second working group adjusts the corresponding shunt according to the received control signal, and redistributes the current from the normally operating photovoltaic string to each connected inverter according to the calculated ratio.

7. The method according to claim 1, characterized in that After the steps of the central control system controlling the second working group; disconnecting the faulty photovoltaic string from the connected inverter; and adjusting the current distribution ratio thereof to increase the current input from the normally functioning photovoltaic string to the connected inverter, the method further comprises: When the central control system detects that the faulty inverter or the faulty photovoltaic string has returned to normal, it starts a recovery program to gradually restore the original connection and current distribution.

8. A control system for a photovoltaic string shunt, characterized in that: The control system of the photovoltaic string shunt includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the control system of the photovoltaic string shunt to execute the method described in any one of claims 1-7.

9. A computer program product comprising instructions, characterized in that When the computer program product runs on a control system of a photovoltaic string shunt, the control system of the photovoltaic string shunt is enabled to perform the method according to any one of claims 1 to 7.

10. A computer-readable storage medium comprising instructions, characterized in that: When the instruction is executed on the control system of the photovoltaic string shunt, the control system of the photovoltaic string shunt is caused to execute the method according to any one of claims 1 to 7.

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