Photovoltaic panel grouping and series connection method

Abstract

The present invention discloses a photovoltaic panel grouping and series connection method, which belongs to the field of photovoltaic power generation technology, including: calculating the traveling salesman problem solution between photovoltaic panels according to the wiring cost between photovoltaic panels; decomposing the traveling salesman problem solution into multiple small circles according to design parameters; performing a large neighborhood search on a search neighborhood formed by selecting several small circles; and realizing a variable depth large neighborhood search by expanding the search neighborhood. The present invention can generate a photovoltaic panel grouping and series connection scheme with a shorter line length, lower wire cost and meeting the design parameters by decomposing the traveling salesman problem solution between photovoltaic panels into multiple small circles that meet the design parameters and performing a large neighborhood search on the neighborhood formed by several small circles, effectively optimizing and improving the scheme to achieve the optimal cost, greatly improving the scheme quality and stability compared to the manual design method, and can be applied to various complex environments and irregular photovoltaic panel layouts.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic power generation, and in particular relates to a method for grouping and connecting photovoltaic panels in series. Background Art

[0002] Photovoltaic power generation is a renewable energy technology with broad application prospects. It is of great significance to promote the transformation of energy structure, reduce greenhouse gas emissions and achieve sustainable development goals. The grouping and series connection of photovoltaic panels is an important part of the design of photovoltaic power generation systems. It is necessary to divide the photovoltaic panels in the system into several groups containing a given number of photovoltaic panels, and design a series line connecting the photovoltaic panels in each group. At present, the grouping and series connection of photovoltaic panels mostly relies on manual design. The starting point is selected according to experience in the drawings or software, and the photovoltaic panels are connected in series in rows or columns. The quality of the solution cannot be guaranteed, and it is difficult to adjust and optimize the grouping and series connection solution. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a photovoltaic panel grouping and series connection method, which can efficiently and quickly provide a photovoltaic panel grouping and series connection solution that meets the specifications and saves materials and engineering workload.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A method for connecting photovoltaic panels in series in groups, comprising:

[0006] Calculate the solution of the traveling salesman problem between photovoltaic panels according to the wiring cost between photovoltaic panels; the solution of the traveling salesman problem is represented as a sequence set, the elements in the sequence set are represented as each photovoltaic panel, and there is a cable connection between two adjacent photovoltaic panels;

[0007] The traveling salesman problem solution is decomposed into multiple small circles containing a given number of photovoltaic panels according to the design parameters;

[0008] Perform a large neighborhood search on the search neighborhood formed by selecting several small circles;

[0009] If the large neighborhood search yields no result, then several additional small circles are added to the search neighborhood formed by the selected small circles to form a new search neighborhood, and the large neighborhood search is performed again in the new search neighborhood.

[0010] The beneficial effects of the present invention are:

[0011] The present invention can generate a photovoltaic panel grouping and series connection scheme with a shorter line length, lower wire cost and meeting the design parameters by decomposing the traveling salesman problem between photovoltaic panels into multiple small circles that meet the design parameters and performing a large neighborhood search on the neighborhood formed by several small circles. The present invention can also effectively optimize and improve the scheme to achieve the optimal cost. Compared with the manual design method, the quality and stability of the scheme are greatly improved, and the scheme can be applied to various complex environments and irregular photovoltaic panel layouts. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A flow chart of a method for grouping and connecting photovoltaic panels in series according to the present invention;

[0013] Figure 2 A schematic diagram of the principle of using the traveling salesman problem approximate solution algorithm to find a sample solution of the traveling salesman problem between photovoltaic panels in the present invention;

[0014] Figure 3 A schematic diagram of the principle of decomposing a sequence into small cycles of a given length and calculating the cost increment according to the present invention;

[0015] Figure 4 A schematic diagram of the principle of constructing a search neighborhood for the present invention;

[0016] Figure 5 Schematic diagram of the principle of large neighborhood search of the present invention. DETAILED DESCRIPTION

[0017] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0018] The embodiment of the present invention provides a method for connecting photovoltaic panels in series in groups, such as Figure 1 As shown, it mainly includes:

[0019] Step 1: Calculate the solution of the traveling salesman problem between photovoltaic panels based on the wiring cost between photovoltaic panels.

[0020] In the embodiment of the present invention, the wiring cost between photovoltaic panels includes the cable connection cost between each photovoltaic panel; wherein any two photovoltaic panels and The cable cost between .

[0021] In the embodiment of the present invention, a traveling salesman problem solving algorithm is used to find a solution to the traveling salesman problem between photovoltaic panels.

[0022] For example, the solution to the traveling salesman problem can be represented as a sequence ;in is the total number of photovoltaic panels; , , …, All of them are photovoltaic panels, which are the 1st, 2nd, ..., PV panels; two adjacent PV panels in the sequence are connected by a cable.

[0023] Exemplarily, the traveling salesman problem solving algorithm may be an exact algorithm or an approximate algorithm. Figure 2 An example of using an approximate solution algorithm to find a solution to the traveling salesman problem between photovoltaic panels is provided. The approximate algorithm includes two steps: constructing an initial solution using a greedy strategy and searching locally using the Lin-Kernighan algorithm. The greedy strategy starts with a random starting point. sequence At the beginning, gradually select a photovoltaic panel with the lowest cable connection cost to the photovoltaic panel at the end of the sequence from the photovoltaic panels that have not been added to the sequence and add it to the end of the sequence until all photovoltaic panels are added to the sequence. The specific formula is:

[0024]

[0025] in, is the photovoltaic panel at the end of the sequence at the kth step; the Lin-Kernighan algorithm will try to delete the corresponding two connection relationships in the sequence and replace them with another set of connection relationships that can still maintain connectivity to reduce the wiring cost corresponding to the entire sequence, and update the sequence accordingly. Repeat this operation until the wiring cost cannot be further reduced. The specific formula is:

[0026] ,

[0027] ,

[0028] in, and The two connections are deleted and replaced by and , and accordingly invert from Start to Subsequence up to .

[0029] Step 2: Decompose the traveling salesman problem solution into multiple small circles containing a given number of photovoltaic panels according to the design parameters. The number of photovoltaic panels contained in the small circles is given by the design parameters and may be the same or different.

[0030] In the embodiment of the present invention, the design parameters include the number of groups, which is expressed as , and the number of photovoltaic panels in each group are respectively , , …, .

[0031] For example, the number of groups can be set to ,in is the voltage generated by a single photovoltaic panel, is the maximum input voltage of the inverter used in the PV system; the number of PV panels in each group can be set to or .

[0032] In the embodiment of the present invention, the solution of the traveling salesman problem is gradually decomposed into components of length , , …, Multiple small circles form a photovoltaic panel grouping series scheme, which are recorded as , , …, ; Starting from the solution of the traveling salesman problem as the current sequence, in each step the current sequence is decomposed into small circles of a given length with the minimum cost increment, and another small circle composed of the remaining photovoltaic panels in the original order is used as the current sequence for the next step. Figure 3 Provides a schematic diagram of the principle of decomposing a sequence into small cycles of a given length and calculating the cost increment. In each step, it is necessary to calculate the cost increment from the current sequence. The The length of the decomposition is The incremental cost generated by the small circle is recorded as , and then take the position with the lowest cost increment as the starting point, and transform the sequence The decomposition length is The small circle is denoted as ; The remaining photovoltaic panels form another small circle in the original order as the current sequence in the next step ; The specific formula is:

[0033]

[0034]

[0035]

[0036]

[0037] Among them, the current sequence Expressed as , For sequence The number of photovoltaic panels contained, subscript Greater than Photovoltaic panels Defined as , subscript Photovoltaic panels smaller than 1 Defined as .

[0038] Step 3: Perform a large neighborhood search on the search neighborhood formed by selecting several small circles.

[0039] In the embodiment of the present invention, the search neighborhood is all photovoltaic panels contained in the selected small circles; the search neighborhood is recorded as , the sequence number set of the selected small circles is recorded as , the specific formula is:

[0040]

[0041] For example, Figure 4 A schematic diagram of the principle of constructing the search neighborhood is provided. The selected small circle can be obtained by first randomly selecting a circle, denoted as , calculate the union of the nearest neighbor photovoltaic panels of each photovoltaic panel that are not in the same group, recorded as , then select The other small circles whose intersections are not empty are composed together. The specific formula is:

[0042]

[0043]

[0044]

[0045] in, For photovoltaic panels The nearest neighbor set of non-same group of photovoltaic panels.

[0046] In the embodiment of the present invention, Figure 5 As shown in the schematic diagram of the principle of large neighborhood search provided, large neighborhood search first calculates the neighborhood Traveling Salesman Problem Solution , and then Decomposed into sizes ( )of circle, replace the original serial number in The small circle in the middle forms a new photovoltaic panel grouping and series connection scheme; For collection The size of is the number of small circles selected.

[0047] For example, the neighborhood can be calculated by the method described in step 1 Traveling Salesman Problem Solution , through the method described in step 2 Decomposed into sizes ( )of A circle.

[0048] In the embodiment of the present invention, after a new solution is obtained through a large neighborhood search, a numerical relationship between the total costs of the new solution and the original solution determines whether to update the original solution to the new solution.

[0049] For example, when the total cost of the new solution is lower than the total cost of the original solution, the original solution is updated to the new solution; when the total cost of the new solution is higher than the total cost of the original solution, the original solution is updated to the new solution with a certain probability. The specific formula is:

[0050]

[0051] in, For the original plan, For the new solution, positive number T is the temperature parameter, and are the total costs of the original and new plans respectively, and the specific formula is:

[0052]

[0053]

[0054] Among them, the plan No. A small circle is a sequence , For the The total cost of a small circle, The calculation of is similar.

[0055] Step 4: Implement variable depth large neighborhood search by expanding the search neighborhood.

[0056] In an embodiment of the present invention, if the original solution is not updated to a new solution in the large neighborhood search, several additional small circles are found, and all photovoltaic panels contained in these small circles are added to the original search neighborhood to form a larger search neighborhood, and a large neighborhood search is performed on the search neighborhood; this process is repeated until the original solution is successfully updated or the upper limit of the number of repetitions is reached.

[0057] For example, additional small circles can be calculated by calculating the current search neighborhood The photovoltaic panels do not belong to The union of the nearest neighbor photovoltaic panel sets is denoted as , then select The specific formula is:

[0058]

[0059]

[0060]

[0061] in, For photovoltaic panels Does not belong to The set of nearest neighbor photovoltaic panels, is the set of serial numbers of additional small circles; expand the search neighborhood The specific formula is:

[0062]

[0063] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above embodiments can be implemented by software, or by means of software plus necessary general hardware platforms. Based on such understanding, the technical solutions of the above embodiments can be embodied in the form of software products, which can be stored in a non-volatile storage medium (which can be a CD-ROM, a USB flash drive, a mobile hard disk, etc.), including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0064] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for connecting photovoltaic panels in series by groups, characterized in that: include: Calculate the solution of the traveling salesman problem between photovoltaic panels according to the wiring cost between photovoltaic panels; the solution of the traveling salesman problem is represented as a sequence set, the elements in the sequence set are represented as each photovoltaic panel, and there is a cable connection between two adjacent photovoltaic panels; The traveling salesman problem solution is decomposed into multiple small circles containing a given number of photovoltaic panels according to the design parameters; Perform a large neighborhood search on the search neighborhood formed by a number of selected small circles; If the large neighborhood search yields no result, then several additional small circles are added to the search neighborhood formed by the selected small circles to form a new search neighborhood, and the large neighborhood search is performed again in the new search neighborhood.

2. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: The inter-photovoltaic panel wiring cost includes the cable connection cost between each photovoltaic panel.

3. A method for grouping and connecting photovoltaic panels in series according to claim 1 or 2, characterized in that: Use the traveling salesman problem solving algorithm to find the solution to the traveling salesman problem between photovoltaic panels.

4. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: The design parameters include the number of groups and the number of photovoltaic panels in each group.

5. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: The method of decomposing the solution of the traveling salesman problem into a plurality of small circles containing a given number of photovoltaic panels according to the design parameters includes: taking the solution of the traveling salesman problem as the beginning of the current sequence, calculating in each step the cost increment that will be generated by decomposing a small circle of a given length from each position in the current sequence, and taking the position with the lowest cost increment as the starting point, decomposing the current sequence into a small circle of a given length and another small circle composed of the remaining photovoltaic panels in the original order, and taking the latter as the current sequence in the next step, and forming a photovoltaic panel grouping and series connection scheme after the solution of the traveling salesman problem is decomposed.

6. A method for grouping and connecting photovoltaic panels in series according to claim 1 or 5, characterized in that: The search neighborhood is all photovoltaic panels contained in the selected small circles.

7. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: The large neighborhood search includes first calculating the solution of the traveling salesman problem on the search neighborhood, and then decomposing the solution of the traveling salesman problem into a number of small circles, whose lengths are respectively the lengths of the number of small circles selected corresponding to the search neighborhood, so as to replace the small circles selected in the original search neighborhood, and form a new photovoltaic panel grouping and series connection scheme.

8. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: After obtaining a new solution through large neighborhood search, it is determined whether to update the original photovoltaic panel grouping and series connection scheme to the new photovoltaic panel grouping and series connection scheme based on the numerical relationship between the total costs of the new photovoltaic panel grouping and series connection scheme and the original photovoltaic panel grouping and series connection scheme.

9. A method for grouping and connecting photovoltaic panels in series according to claim 8, characterized in that: If the original photovoltaic panel grouping and series connection scheme is not updated to a new photovoltaic panel grouping and series connection scheme in the large neighborhood search, then find several additional small circles, and add all the photovoltaic panels contained in these additional small circles to the original search neighborhood to form a larger search neighborhood. Perform a large neighborhood search on the larger search neighborhood, and repeat the operation until the original photovoltaic panel grouping and series connection scheme is successfully updated or the upper limit of the number of repetitions is reached.

10. A method for grouping and connecting photovoltaic panels in series according to claim 1, characterized in that: The number of photovoltaic panels contained in each of the plurality of small circles containing a given number of photovoltaic panels is given by a design parameter, and the number of photovoltaic panels contained in each of the small circles is the same or different.

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