Whole village household distributed photovoltaic access grid-connected method and system and photovoltaic system

Abstract

The application discloses a whole-village household distributed photovoltaic access and grid connection method and system and a photovoltaic system. The method and system are combined with local user roof resource endowment, comprehensively consider regional photovoltaic installable capacity, regional distribution transformer openable capacity, single distribution transformer average capacity, photovoltaic investment subject development progress, regional distribution transformer average load rate, regional distribution transformer average power supply radius and the like, and a more suitable photovoltaic access and grid connection scheme can be selected for whole-village distributed photovoltaic large-area access.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of point-of-use, in particular to a whole-village household distributed photovoltaic access and grid connection method and system and a photovoltaic system. BACKGROUND

[0002] Distributed photovoltaics have become an important part of China's renewable energy and have made positive contributions to the green and low-carbon transformation of energy. From the development scale and the mainstream business model, distributed photovoltaics are in a stage of quantitative change leading to qualitative change in development, access, consumption, market operation and management. Power grid companies need to take the lead, take the initiative and adapt actively.

[0003] First, the development of distributed photovoltaics has shifted from slow growth to accelerated growth. In recent stages, rural household photovoltaics in Shandong, Henan, Jiangsu and other places have entered an accelerated development stage. Under the background of a substantial decrease in photovoltaic component costs, rapid improvement in energy density and policy encouragement, rural household photovoltaic installations will continue to maintain high-speed development, and distributed photovoltaics need to be considered as the main power source.

[0004] Second, the planning and construction of distribution networks have shifted from supply preservation to supply preservation and green preservation. For example, Jiangsu has a good foundation for the development of distribution networks, and the overall capacity of regional public distribution transformers can basically meet the future distributed photovoltaic installation needs. However, under the commercial development model, the growth of rural distributed photovoltaics is inversely distributed with the development of load, and the layout of distribution network facilities configured according to load development cannot meet the demand for large-scale access of distributed photovoltaics in some areas, and the local distribution network has increased its carrying capacity, so the planning and construction approach needs to be changed.

[0005] Third, the consumption mode of distributed photovoltaics has shifted from local consumption to system-wide regulation and consumption. It is estimated that by 2030, there will be larger-scale and longer-duration distributed photovoltaic power generation transported by 220-kilovolt and above power grids, and means for balancing sources and loads in a larger range (such as the use of cross-provincial channels for transmission and consumption, the promotion of photovoltaic hydrogen production industries, etc.) or the configuration of large-scale energy storage for consumption need to be considered, but the current cost guidance mode for related consumption regulation has not been clearly defined.

[0006] Fourth, the development model of distributed photovoltaics has shifted from "subsidy-driven" to "mature commercialization". At present, a mature commercial model of distributed photovoltaics has been formed in rural areas, which is initiated by source enterprises, constructed by regional agents, and provided with roof (or homestead) resources by individual owners. The profit chain is of considerable scale. However, the policies related to distributed photovoltaics, such as electricity prices and transactions, still maintain the traditional mode of unified purchase and sale, and cannot quickly adapt to the needs of commercial distributed photovoltaic development.

[0007] In summary, the industrial and commercial nature of photovoltaic power generation by source enterprises is operated as household photovoltaic power generation through the agent mode, and part of the centralized photovoltaic power generation is divided into household ground photovoltaic power generation. Due to the high commission mode between the source enterprises and the agents, and between the agents and the salesmen, the agents and the salesmen are driven by interests, and there is a common mentality of multiple installations and fast installations, which promotes the continuous explosive growth of the household photovoltaic power generation grid connection quantity, and brings many problems of exceeding the carrying capacity of the power grid. SUMMARY

[0008] To solve the problems in the prior art, the present application provides a method and system for accessing and connecting a whole village household distributed photovoltaic power generation to the grid, and provides different grid connection schemes such as accessing the existing distribution transformer, expanding the capacity of the existing distribution transformer, accessing the newly added distribution transformer, concentrating the newly added distribution transformer, and direct current concentration of the newly added distribution transformer, in combination with the construction and reconstruction technology guide of the rural low-voltage distribution network. The problems disclosed in the background art are solved.

[0009] To solve the above technical problems, the technical scheme adopted by the present application is:

[0010] The method for accessing and connecting a whole village household distributed photovoltaic power generation to the grid comprises:

[0011] obtaining the photovoltaic installable capacity of a to-be-added photovoltaic village, the openable capacity of the distribution transformer, the average capacity of a single distribution transformer, the average load rate of the distribution transformer, and the average required distance of the newly added photovoltaic access line;

[0012] If the photovoltaic installable capacity is less than the openable capacity of the distribution transformer, the newly added photovoltaic power generation is accessed to the distribution transformer of the village; otherwise, the photovoltaic development potential of the to-be-added photovoltaic village is evaluated;

[0013] If the photovoltaic installable capacity corresponding to the photovoltaic development potential of the village is greater than the openable capacity of the distribution transformer, it is judged that the average capacity of a single distribution transformer is less than or equal to the capacity setting threshold, and the distribution transformer satisfies the photovoltaic development potential after expansion; when the average load rate of the distribution transformer is greater than the load rate setting threshold, the newly added photovoltaic power generation is accessed to the expanded distribution transformer;

[0014] It is judged that the average load rate of the distribution transformer of the village is less than the load rate setting threshold; the average required distance of the newly added photovoltaic access line is less than the distance setting threshold, and the newly added photovoltaic power generation is accessed to the expanded distribution transformer by the concentration method;

[0015] It is judged that the average required distance of the newly added photovoltaic access line is greater than the distance setting threshold, and the newly added photovoltaic power generation is accessed to the expanded distribution transformer by the direct current concentration method.

[0016] Further, the expansion method is to add a distribution transformer.

[0017] Further, the concentration method is:

[0018] In the power supply range of the newly added distribution transformer, all newly added photovoltaics are connected to the newly added distribution transformer through the AC 380V line.

[0019] Further, the direct current convergence method is:

[0020] The low-voltage side of the newly added photovoltaic is provided with a converter, and in the power supply range of the newly added distribution transformer, all newly added photovoltaics are converged through a direct current line, and then converted and inverted through the converter on the low-voltage side to access the newly added distribution transformer.

[0021] Further, the capacity of the newly added distribution transformer is at least 400 kVA.

[0022] Further, the direct current line voltage is 700V-750V direct current.

[0023] Further, the method for evaluating the photovoltaic development potential of the village to be newly added photovoltaics comprises:

[0024] The area of the roof on which photovoltaics can be installed is identified through satellite pictures and / or unmanned aerial vehicle pictures, and the installed capacity of the roof photovoltaics is converted.

[0025] Further, the capacity threshold is 200 kVA.

[0026] Further, the load rate threshold is 10%.

[0027] Further, the distance threshold is 300m.

[0028] Correspondingly, the application also provides a whole-village household distributed photovoltaic access and grid-connected system, comprising:

[0029] A data acquisition module is configured to acquire the installable capacity of photovoltaics, the openable capacity of distribution transformers, the average capacity of single distribution transformer, the average load rate of distribution transformers, and the average required distance of the line for connecting newly added photovoltaics in the village to be newly added photovoltaics.

[0030] A newly added photovoltaic access module is configured to judge whether the installable capacity of photovoltaics is less than the openable capacity of distribution transformers, and access the newly added photovoltaics to the distribution transformer in the village.

[0031] A photovoltaic development potential evaluation module is configured to evaluate the photovoltaic development potential of the village to be newly added photovoltaics when the installable capacity of photovoltaics is greater than or equal to the openable capacity of distribution transformers.

[0032] A distribution transformer expansion module is configured to expand the distribution transformer in the village when the installable capacity of photovoltaics corresponding to the photovoltaic development potential is greater than the openable capacity of distribution transformers, the average capacity of single distribution transformer is not greater than the set capacity threshold, and the expanded distribution transformer meets the photovoltaic development potential; and connect the newly added photovoltaics to the expanded distribution transformer when the average load rate of distribution transformers is greater than the load rate threshold.

[0033] The centralized access module is used for judging whether the average load rate of the distribution transformer of the village is less than a load rate setting threshold; whether the average required distance of the newly added photovoltaic access line is less than a distance setting threshold; and the newly added photovoltaic is accessed to the expanded distribution transformer by using the centralized access method.

[0034] The direct current access module is used for judging whether the average required distance of the newly added photovoltaic access line is greater than the distance setting threshold; and the newly added photovoltaic is accessed to the expanded distribution transformer by using the direct current access method.

[0035] The photovoltaic system connected to the grid by the method includes a distribution transformer with a capacity of 400 kVA, the distribution transformer with the capacity of 400 kVA is used to replace an original distribution transformer, and the load of the original distribution transformer and the newly added photovoltaic are accessed to the distribution transformer with the capacity of 400 kVA.

[0036] The photovoltaic system connected to the grid by the method includes a distribution transformer with a capacity of 400 kVA, the distribution transformer with the capacity of 400 kVA is used to replace an original distribution transformer, and the load of the original distribution transformer and the newly added photovoltaic are accessed to the distribution transformer with the capacity of 400 kVA.

[0037] The photovoltaic system connected to the grid by the method includes a distribution transformer with a capacity of 400 kVA, the distribution transformer with the capacity of 400 kVA is used to replace an original distribution transformer, and the load of the original distribution transformer and the newly added photovoltaic are accessed to the distribution transformer with the capacity of 400 kVA.

[0038] The application further provides a computer readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0039] The application has the advantages that: the application can select a more suitable photovoltaic access and grid connection scheme for the whole village distributed photovoltaic large-area access by comprehensively considering the local user roof resource endowment, the region photovoltaic installable capacity, the region distribution transformer openable capacity, the single distribution transformer average capacity, the photovoltaic investment subject development progress, the region distribution transformer average load rate, the region distribution transformer average power supply radius and the like. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 It is a whole village household distributed photovoltaic access and grid connection method schematic diagram;

[0041] Figure 2 It is a distribution transformer expansion design scheme schematic diagram;

[0042] Figure 3 The schematic diagram of the design scheme of the newly added distribution transformer nearby access;

[0043] Figure 4 The schematic diagram of the design scheme of the newly added distribution transformer centralized gathering;

[0044] Figure 5 The schematic diagram of the design scheme of the newly added distribution transformer direct current gathering. DETAILED DESCRIPTION

[0045] The application will be further described below with reference to the drawings. The following examples are only used to more clearly illustrate the technical solutions of the application, and cannot be used to limit the protection scope of the application. EMBODIMENT

[0046] As shown in the figure, the whole-village household distributed photovoltaic access and grid connection method of the embodiment comprises the following steps: Figure 1

[0047] Step one, in combination with the local resource endowment and the local user roof resource endowment, the region photovoltaic installable capacity, the region distribution transformer openable capacity, the single distribution transformer average capacity, the region distribution transformer average load rate, and the region distribution transformer average power supply radius are obtained.

[0048] Step two, it is judged that the region photovoltaic developable capacity < the region distribution transformer openable capacity, that is, the existing distribution network in the region is sufficient in photovoltaic carrying capacity, and the newly added photovoltaic nearby access existing distribution transformer scheme is adopted.

[0049] Step three, it is judged that the region photovoltaic development potential > the region distribution transformer openable capacity, the single distribution transformer average capacity ≤ 200 kVA, and the expansion after expansion satisfies the photovoltaic development potential, as shown in the figure, the existing distribution transformer needs to be expanded and reconstructed. Figure 2

[0050] Among them, the photovoltaic development potential is evaluated by the following three methods:

[0051] 1. The region roof installable photovoltaic area is identified through satellite pictures and unmanned aerial vehicle pictures, and is converted into a prospective roof photovoltaic installation capacity.

[0052] 2. According to the investment willingness of the developer, at present, photovoltaic starts to develop a village, for a village (natural village), usually a developer, the willingness of the developer needs to be investigated and communicated.

[0053] 3. According to the actual installation willingness of the local residents.

[0054] ​​In the combination of the three methods, the residents will report the proposed new photovoltaic capacity to the power supply station (marketing team), and if the capacity (development potential) is greater than the open capacity of the regional distribution transformer (how much can the distribution transformer still access), that is, the conclusion of step three is obtained.

[0055] Step four, when the regional photovoltaic development potential is greater than the open capacity of the regional distribution transformer, the average capacity of a single distribution transformer is greater than 200kVA, the photovoltaic investment subject is short-term and one-time concentrated investment, and the average load rate of the regional distribution transformer is greater than 10%, the expansion of the distribution transformer after the expansion of the distribution transformer is recommended to be accessed, such as Figure 3 The expansion and reconstruction scheme is to replace a larger capacity distribution transformer. The original distribution transformer is 200kVA capacity, which is not enough, and a 400kVA distribution transformer is replaced. This scheme can better realize the balance of source and load in place, and the investment economy and operation economy are better than the centralized aggregation scheme, and the equipment utilization rate is high.

[0056] Step five, when the average load rate of the distribution transformer is less than 10%, or the photovoltaic investment subject is short-term and one-time concentrated investment, and the village scale is small, the average required distance of the photovoltaic access line is less than 300m, the centralized aggregation access scheme can be selected, such as Figure 4 The newly added capacity of the distribution transformer is 400kVA. In the power supply range of the distribution transformer, all new photovoltaic is accessed to the distribution transformer through the AC 380V line. The distribution transformer only accesses photovoltaic and does not access other loads, which is convenient for management and control. This scheme is convenient for controlling the scale of the accessed photovoltaic, and the investment economy is better than the DC aggregation.

[0057] Step six, when the photovoltaic investment subject is short-term and one-time concentrated investment, and the village scale is large, the average required distance of the photovoltaic access line is greater than 300m, the AC aggregation power supply distance is insufficient, and the DC aggregation can save a line compared with the AC aggregation. Considering the technology and investment economy, the newly added distribution transformer DC aggregation scheme can be used, such as Figure 5 The newly added capacity of the distribution transformer is 400kVA. In the power supply range of the distribution transformer, all new photovoltaic is accessed to the distribution transformer through the AC 380V line. The distribution transformer only accesses photovoltaic and does not access other loads, which is convenient for management and control. This scheme is convenient for controlling the scale of the accessed photovoltaic, and the investment economy is better than the DC aggregation. Embodiment

[0058] The whole-village household distributed photovoltaic access and grid-connected system of the embodiment comprises:

[0059] The data acquisition module is configured to acquire the photovoltaic installable capacity, the transformer available capacity, the single transformer average capacity, the transformer average load rate, and the average required distance of the photovoltaic access line of the photovoltaic village to be added.

[0060] The newly added photovoltaic nearby access module is configured to judge that the photovoltaic installable capacity is less than the transformer available capacity, and access the newly added photovoltaic to the transformer of the village nearby.

[0061] The photovoltaic development potential evaluation module is configured to evaluate the photovoltaic development potential of the photovoltaic village to be added when the photovoltaic installable capacity is greater than the transformer available capacity.

[0062] The transformer expansion module is configured to expand the transformer of the village when the photovoltaic installable capacity corresponding to the photovoltaic development potential of the village is greater than the transformer available capacity, the single transformer average capacity is not greater than the set capacity threshold, and the transformer after expansion meets the photovoltaic development potential; and access the newly added photovoltaic to the expanded transformer when the transformer average load rate is greater than the load rate set threshold.

[0063] The centralized gathering access module is configured to judge that the transformer average load rate of the village is less than the load rate set threshold, and the average required distance of the photovoltaic access line is less than the distance set threshold, and access the newly added photovoltaic to the expanded transformer by using the centralized gathering method.

[0064] The direct current gathering access module is configured to judge that the average required distance of the photovoltaic access line is greater than the distance set threshold, and access the newly added photovoltaic to the expanded transformer by using the direct current gathering method. Embodiment

[0065] The embodiment replaces the original transformer with a photovoltaic system connected to the grid with a larger capacity, including a transformer with a capacity of 400 kVA, the transformer with a capacity of 400 kVA replaces the original transformer, and the load of the original transformer and the newly added photovoltaic are connected to the transformer with a capacity of 400 kVA. The embodiment is applicable to a village where the average capacity of the original single transformer is greater than 200 kVA, the photovoltaic investment subject invests in a short period of time, and the average load rate of the original transformer is greater than 10%. Embodiment

[0066] The embodiment adds a transformer to a photovoltaic system connected to the grid on the basis of the original transformer, including a transformer with a capacity of 400 kVA, the transformer with a capacity of 400 kVA is a newly added transformer based on the original transformer, and all newly added photovoltaic low-voltage sides are connected to the transformer with a capacity of 400 kVA through an alternating current 380V line within the power supply range of the transformer with a capacity of 400 kVA. The embodiment is applicable to a village where the average load rate of the original transformer is less than 10%; or the photovoltaic investment subject invests in a short period of time, and the village scale is small, and the average required distance of the photovoltaic access line is less than 300 m. Embodiment

[0067] The photovoltaic system of the embodiment is connected to the grid through the DC line convergence method based on the original distribution transformer, comprising a converter and a distribution transformer with a capacity of 400kVA, wherein the distribution transformer with a capacity of 400kVA is a newly added distribution transformer based on the original distribution transformer, the converter is arranged on the low-voltage side of the newly added photovoltaic, all the newly added photovoltaic within the power supply range of the distribution transformer with a capacity of 400kVA is converged through the DC line, and then connected to the distribution transformer with a capacity of 400kVA through the converter on the low-voltage side. The embodiment is suitable for the village with large scale and the average required distance of photovoltaic connection line > 300m. Embodiment

[0068] The embodiment provides a computer readable storage medium storing one or more programs, the one or more programs comprising instructions which, when executed by a computing device, cause the computing device to perform the method for whole-village household distributed photovoltaic access and grid connection.

[0069] Those skilled in the art will appreciate that embodiments of the application can be supplied as methods, systems, or computer program products. Accordingly, the application can be embodied in the form of complete hardware embodiments, complete software embodiments, or embodiments combining software and hardware aspects. Furthermore, the application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) having computer usable program code embodied thereon.

[0070] The present application is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, as well as combinations of flows and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing apparatus to produce a machine, so that the instructions which are executed by the processor of the computer or other programmable data processing apparatus generate an apparatus that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 An apparatus for performing the functions specified in the flowcharts and / or block diagrams. Figure 1 An apparatus for performing the functions specified in the flowcharts and / or block diagrams.

[0071] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to work in a specific manner, so that the instructions stored in the computer readable memory produce a manufactured product including instruction apparatus, which implements the functions specified in the flowcharts and / or block diagrams. Figure 1 An apparatus for performing the functions specified in the flowcharts and / or block diagrams. Figure 1the function specified in the one or more blocks.

[0072] These computer program instructions can also be loaded into computer or other programmable data processing devices, so that a series of operation steps are performed on the computer or other programmable data processing devices to generate computer-implemented processes, so that the instructions executed on the computer or other programmable data processing devices provide processes for implementing the flows Figure 1 the flows or the flows and / or blocks Figure 1 the steps of the function specified in the one or more blocks.

[0073] The above only is the embodiment of the present application, and is not used to limit the present application, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application, are included in the claim range of the application to be approved of the present application.

Claims

1. A method for grid connection of distributed photovoltaic power to households throughout a village, characterized in that, include: Obtain the installable photovoltaic capacity, available transformer capacity, average capacity of a single transformer, average load rate of transformer, and average distance required for new photovoltaic access lines for the villages to be added; If the installable photovoltaic capacity is less than the available transformer capacity, then the newly added photovoltaic system should be connected to the nearest transformer in the village; otherwise, assess the photovoltaic development potential of the village to be added. If the photovoltaic installation capacity corresponding to the photovoltaic development potential of the village is greater than the open capacity of the distribution transformer, the distribution transformer in the village is expanded if the average capacity of a single distribution transformer is less than or equal to the capacity setting threshold and the expansion of the distribution transformer meets the photovoltaic development potential; when the average load rate of the distribution transformer is greater than the load rate setting threshold, the photovoltaic connection of the expanded distribution transformer is added. If the average load rate of the distribution transformer in the village is less than the load rate setting threshold, and the average distance required for the new photovoltaic access line is less than the distance setting threshold, the new photovoltaic power will be connected to the expanded distribution transformer using a centralized aggregation method. If the average distance required for the newly added photovoltaic access line is greater than the distance setting threshold, the newly added photovoltaic power will be connected to the expanded distribution transformer using the DC combiner method.

2. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 1, characterized in that: The expansion method is to add a new distribution transformer.

3. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 2, characterized in that: The centralized aggregation method is as follows: Within the power supply range of the newly added distribution transformer, all newly added photovoltaic systems are connected to the new distribution transformer via AC 380V lines.

4. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 2, characterized in that: The DC bus method is as follows: A converter is installed on the low-voltage side of the newly added photovoltaic system. Within the power supply range of the newly added distribution transformer, all newly added photovoltaic systems are connected to the DC line, and then converted and inverted by the converter on the low-voltage side before being connected to the newly added distribution transformer.

5. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 2, characterized in that: The capacity of the newly added distribution transformer is at least 400 kVA.

6. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 4, characterized in that: The DC line voltage is 700V-750V DC.

7. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 1, characterized in that: Methods for assessing the photovoltaic development potential of new photovoltaic villages include: Identify the area of ​​rooftops suitable for photovoltaic installation in a region using satellite and / or drone images, and convert it into a projected rooftop photovoltaic installation capacity.

8. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 1, characterized in that: The capacity setting threshold is 200 kVA.

9. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 1, characterized in that: The load rate threshold is set to 10%.

10. The method for grid connection of distributed photovoltaic power to households throughout a village according to claim 1, characterized in that: The distance setting threshold is 300m.

11. A village-wide household distributed photovoltaic grid-connected system, characterized in that, include: The data acquisition module is used to obtain the installable photovoltaic capacity, available transformer capacity, average capacity of a single transformer, average load rate of transformers, and average distance required for new photovoltaic access lines for the villages to be added to the photovoltaic system. A new photovoltaic (PV) grid connection module is added to determine if the installed PV capacity is less than the available transformer capacity, and then connect the new PV to the transformer in the village. The photovoltaic development potential assessment module is used to assess the photovoltaic development potential of villages to be newly added when the installable photovoltaic capacity is greater than or equal to the openable capacity of distribution transformers. The transformer expansion module is used to expand the transformer capacity of the village when the photovoltaic installation capacity corresponding to the photovoltaic development potential of the village is greater than the openable capacity of the transformer, and when the average capacity of a single transformer is not greater than a set capacity threshold, and the transformer expansion meets the photovoltaic development potential; when the average load rate of the transformer is greater than the set load rate threshold, the transformer after the photovoltaic expansion is added. The centralized aggregation access module is used to determine if the average load rate of the distribution transformer in the village is less than the load rate setting threshold; if the average distance required for the new photovoltaic access line is less than the distance setting threshold, the new photovoltaic power will be connected to the expanded distribution transformer using the centralized aggregation method; The DC combiner access module is used to determine if the average distance required for the new photovoltaic access line is greater than the distance setting threshold, and the new photovoltaic is connected to the expanded distribution transformer using the DC combiner method.

12. A photovoltaic system, characterized in that: It includes the whole-village household distributed photovoltaic grid connection system as described in claim 11 and a distribution transformer with a capacity of 400kVA, wherein the distribution transformer with a capacity of 400kVA replaces the original distribution transformer, and the load of the original distribution transformer and the newly added photovoltaic are both connected to the distribution transformer with a capacity of 400kVA.

13. A photovoltaic system, characterized in that: It includes the whole-village household distributed photovoltaic grid connection system as described in claim 11 and a distribution transformer with a capacity of 400kVA. The distribution transformer with a capacity of 400kVA is a new distribution transformer on the basis of the original distribution transformer. Within the power supply range of the distribution transformer with a capacity of 400kVA, all the newly added photovoltaic low-voltage sides are connected to the distribution transformer with a capacity of 400kVA through AC 380V lines.

14. A photovoltaic system, characterized in that: The system includes a village-wide household distributed photovoltaic grid-connected system as described in claim 11, as well as a converter and a 400kVA distribution transformer. The 400kVA distribution transformer is an additional distribution transformer added to the existing distribution transformer. The converter is located on the low-voltage side of the newly added photovoltaic system. Within the power supply range of the 400kVA distribution transformer, all newly added photovoltaic systems are connected via DC lines, and then converted and inverted by the converter on the low-voltage side before being connected to the 400kVA distribution transformer.

15. A computer-readable storage medium for storing one or more programs, characterized in that: The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods according to claims 1 to 10.

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