A preprocessing method for low-voltage path planning

Abstract

This invention discloses a preprocessing method for low-voltage path planning, comprising: acquiring a dataset of a target array of a photovoltaic power station; determining a preprocessing method based on the routing pattern of the dataset to obtain a distance matrix; and calculating the shortest path based on the distance matrix to complete the low-voltage path planning. This invention achieves the pre-extraction of key information required for the shortest path algorithm in low-voltage path planning, ensuring the solution quality and timeliness of low-voltage path planning, and improving the efficiency and cost-effectiveness of photovoltaic power station construction.

Description

Technical Field

[0001] The invention belongs to the technical field of photovoltaic power station construction, and in particular relates to a preprocessing method for low-voltage path planning. Background Art

[0002] With the large-scale development of photovoltaic power stations, the planning of photovoltaic power stations has become increasingly refined and automated. After the photovoltaic arrays in the photovoltaic power station are automatically divided by the computer, a low-voltage path planning algorithm needs to be designed to plan the connection path and connection method between the junction box and the box transformer in each array to achieve the optimal total cost. A photovoltaic power station planning project often involves the planning of dozens of arrays, and there are certain requirements for the time efficiency and optimization effect of low-voltage path planning. The general routing method is divided into pile foundation routing or gap routing. In order to reduce costs, for pile foundation routing, the connection path should try to use the existing pile foundation. When the path between any two points is long and there is no preset pile foundation, additional piles are used. There are more than 1,000 preset pile foundations in an array; for gap routing, preset gap points should be used as much as possible. There are tens of thousands of gap points in an array. Whether it is pile foundation routing or gap routing, the restrictions of roads and avoidance areas need to be considered in the low-voltage path planning process. If the planned path passes through the road, the cost will increase and it cannot pass through the avoidance area. The general implementation method of the low-voltage path planning algorithm is to establish a scene map for the actual scenes of pile foundation points or gap points, roads, and avoidance areas in the actual square array, and then use the shortest path algorithm to solve the shortest path from each junction box to the box transformer to obtain the initial planning path, and finally use the operations optimization algorithm to minimize the total cost required for the low-voltage path connection in the square array. The speed and initial total cost of solving the initial planning path with the shortest path algorithm are the key to the entire path planning process, and high requirements are placed on the solution speed and solution quality. The time complexity of the shortest path algorithm is highly positively correlated with the number of points and edges in the scene map. Since the two wiring methods involve a large number of points, in the process of solving the shortest path, the physical information and scene information between the point sets are considered when solving the connection weights of any two points in the map, which will inevitably lead to a relatively long and inefficient solution process. Summary of the invention

[0003] In order to solve the above technical problems, the present invention proposes a preprocessing method for low-voltage path planning, which realizes the pre-extraction of key information required for the shortest path algorithm in low-voltage path planning, so as to ensure the solution quality and timeliness of low-voltage path planning, and improve the efficiency and cost-effectiveness of photovoltaic power station construction.

[0004] To achieve the above object, the present invention provides a preprocessing method for low-voltage path planning, comprising:

[0005] Obtain the data set of the target array of the photovoltaic power station;

[0006] Determine a preprocessing method according to the routing mode of the data set to obtain a distance matrix;

[0007] The shortest path is obtained by calculation according to the distance matrix to complete the low-voltage path planning.

[0008] Optionally, the data set of the target array of the photovoltaic power station includes:

[0009] The target array of the photovoltaic power station includes a transformer, several combiner box coordinates, a wiring method, several pile foundation coordinates or several gap point coordinates, an array envelope coordinate set, several bracket area coordinates and parameters related to path planning.

[0010] Optionally, the routing method includes pile foundation routing and gap routing.

[0011] Optionally, determining a preprocessing method according to the routing mode of the data set to obtain a distance matrix includes:

[0012] If the routing method is pile foundation routing, a box-type transformer, several combiner boxes and several pile foundation points are numbered consecutively in the order of box-type transformer, combiner box and pile foundation point, and a distance matrix between a box-type transformer, several combiner boxes and several pile foundation points is calculated;

[0013] If the routing method is gap routing, remove the gap points in the bracket area, map the coordinates of the junction box in the bracket to the nearby gap points, filter the gap points, and number a box-type transformer, several junction boxes and several reserved gap points consecutively in the order of box-type transformer, junction box and reserved gap points, and calculate the distance matrix between a box-type transformer, several junction boxes and several reserved gap points.

[0014] Optionally, the distance matrix in the pile foundation alignment is a Euclidean distance matrix between a box transformer, several junction boxes and several pile foundation points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix.

[0015] Optionally, the distance matrix of the gap routing is a Euclidean distance matrix between a box transformer, several junction boxes and several reserved gap points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix.

[0016] Optionally, a supplementary pile number matrix is ​​determined according to a matrix distance in a Euclidean distance matrix of the pile foundation alignment, and the number of supplementary piles in the supplementary pile number matrix is ​​a ratio of the Euclidean distance to a supplementary pile spacing parameter.

[0017] Optionally, mapping the coordinates of the combiner box in the bracket to nearby gap points is performed according to the orientation of the combiner box and the box-type transformer.

[0018] Optionally, mapping based on the orientation of the combiner box and the box-type transformer includes:

[0019] For the combiner box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding combiner box is greater than the difference between the vertical coordinates, left and right mapping is performed; if the horizontal coordinate of the combiner box is smaller than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate larger than the combiner box is selected for mapping; if the horizontal coordinate of the combiner box is larger than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate smaller than the combiner box is selected for mapping;

[0020] For the junction box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding junction box is less than the difference in the vertical coordinates, they are mapped up and down; if the vertical coordinate of the junction box is less than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate greater than the junction box is selected for mapping; if the vertical coordinate of the junction box is greater than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate less than the junction box is selected for mapping.

[0021] Optionally, filtering of gap points includes:

[0022] Preset distance range to retain clearance points near the bracket area;

[0023] Find the convex hull based on a set of coordinate points composed of a box-type transformer and several junction boxes;

[0024] Remove the gap points outside the convex hull, and retain the bracket area within the convex hull or intersecting with the convex hull as the retained bracket area;

[0025] For the gap points in the reserved bracket area, the gap points in the bracket area within the preset distance from the box-type transformer and the combiner box are reserved as the first gap point set;

[0026] The convex hull area composed of a box-type transformer and several junction boxes is equidistantly selected in the horizontal and vertical coordinates to form an equidistant network, and the vertices of the equidistant network are mapped to the nearest gap points nearby, and the nearest gap points are retained as the second gap point set;

[0027] Map the horizontal and vertical coordinates of a box-type transformer and several combiner boxes, and the intersection points of the equally spaced network, to the nearest gap points nearby, and retain the nearest gap points as the third gap point set;

[0028] The first gap point set, the second gap point set and the third gap point set are aggregated, and physical deduplication is performed to obtain the gap points that are finally retained.

[0029] Technical effect of the invention: The invention discloses a preprocessing method for low-voltage path planning, which obtains a box transformer of a certain array of a photovoltaic power station, coordinates of several junction boxes, routing methods, coordinates of several pile foundations or coordinates of several gap points, a square array envelope coordinate set, several road coordinates, several avoidance zone coordinates, and other parameters related to path planning; the preprocessing method is determined according to the routing method, and if the routing method is pile foundation routing, the box transformer, several junction boxes and several pile foundation points are firstly continuously processed in the order of box transformer, junction box and pile foundation point. Numbering, and then calculating the distance matrix between the one box transformer, several junction boxes and several pile foundation points; if the routing method is gap routing, first remove the gap points in the bracket area, map the coordinates of the junction box in the bracket to the nearby gap points, and then continue to filter the gap points, and number the one box transformer, several junction boxes and several reserved gap points in the order of box transformer, junction box and gap points, and then calculate the distance matrix between the one box transformer, several junction boxes and several reserved gap points; input the obtained distance matrix into the shortest path algorithm and other operations to complete the low-voltage path planning. In this way, the present invention realizes the pre-extraction of key information required for the shortest path algorithm in low-voltage path planning, so as to ensure the solution quality and timeliness of low-voltage path planning, and improve the efficiency and cost-effectiveness of photovoltaic power station construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The drawings constituting a part of the present application are used to provide a further understanding of the present application. The illustrative embodiments and descriptions of the present application are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0031] Figure 1 A schematic diagram of a flow chart of a preprocessing method for low-voltage path planning according to an embodiment of the present invention;

[0032] Figure 2 A schematic diagram of calculating a road matrix in a low-pressure path planning preprocessing method according to an embodiment of the present invention;

[0033] Figure 3 A schematic diagram of a combiner box mapping process in a low-voltage path planning preprocessing method according to an embodiment of the present invention;

[0034] Figure 4 A schematic diagram of a gap point filtering process in a low-voltage path planning preprocessing method according to an embodiment of the present invention;

[0035] Figure 5 This is an implementation diagram of low-voltage path planning for array pile foundation wiring according to an embodiment of the present invention;

[0036] Figure 6 This is the original project information diagram of the square array along the gap alignment according to the embodiment of the present invention;

[0037] Figure 7This is an implementation diagram of an embodiment of the present invention in which the array is routed along the gap and the combiner box is mapped outside the bracket;

[0038] Figure 8 This is an implementation diagram of finding the convex hull of the box-type transformer and the combiner box and the intersecting gap points and the bracket area along the gap routing of the square array in the embodiment of the present invention;

[0039] Fig. 9 An implementation diagram for retaining gap points near the support area along the gap routing of the square array of the embodiment of the present invention and establishing the gap point retention of an equidistant network;

[0040] Fig.10 This is an implementation diagram of low-voltage path planning along the gaps of an array according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0042] It should be noted that the steps shown in the flowcharts of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and that, although a logical order is shown in the flowcharts, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0043] like Figure 1 As shown, this embodiment provides a preprocessing method for low-voltage path planning, including:

[0044] Obtain the data set of the target array of the photovoltaic power station;

[0045] Determine a preprocessing method according to the routing mode of the data set to obtain a distance matrix;

[0046] The shortest path is obtained by calculation according to the distance matrix to complete the low-voltage path planning.

[0047] Furthermore, the data set of the target array of the photovoltaic power station includes:

[0048] The target array of the photovoltaic power station includes a transformer, several combiner box coordinates, a wiring method, several pile foundation coordinates or several gap point coordinates, an array envelope coordinate set, several bracket area coordinates and parameters related to path planning.

[0049] Furthermore, the routing methods include pile foundation routing and gap routing.

[0050] Specifically, if the routing method is pile foundation routing, it is necessary to obtain at least one box transformer of a certain array, several junction boxes, several pile foundation point coordinates, an array envelope line coordinate set, several road coordinates, several avoidance zone coordinates, and pile spacing parameters; if the routing method is gap routing, it is necessary to obtain one box transformer of a certain array, several junction box coordinates, several gap point coordinates, an array envelope line coordinate set, several bracket area coordinates, several road coordinates, and several avoidance zone coordinates.

[0051] Further, determining a preprocessing method according to the routing mode of the data set to obtain a distance matrix includes:

[0052] If the routing method is pile foundation routing, a box-type transformer, several combiner boxes and several pile foundation points are numbered consecutively in the order of box-type transformer, combiner box and pile foundation point, and a distance matrix between a box-type transformer, several combiner boxes and several pile foundation points is calculated;

[0053] If the routing method is gap routing, remove the gap points in the bracket area, map the coordinates of the junction box in the bracket to the nearby gap points, filter the gap points, and number a box-type transformer, several junction boxes and several reserved gap points consecutively in the order of box-type transformer, junction box and reserved gap points, and calculate the distance matrix between a box-type transformer, several junction boxes and several reserved gap points.

[0054] Specifically, a box transformer, the several junction boxes, the several pile foundation points or the several reserved gap points are encoded in the order of 0, 1, ..., and the category attribute of each point is recorded. The point set of the same type is encoded in the order in which the data is acquired. If the origin type is a box transformer, the point category is still a box transformer after encoding. This category assignment method is also applicable to junction boxes, pile foundation points or reserved gap points. If the Euclidean distance between some pile foundation points or gap points and the junction box is close, they will not be encoded.

[0055] Furthermore, the distance matrix in the pile foundation alignment is a Euclidean distance matrix between a box transformer, several junction boxes and several pile foundation points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix. The distance matrix of the gap alignment is a Euclidean distance matrix between a box transformer, several junction boxes and several reserved gap points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix. Regarding the Euclidean distance, if the coordinates of all points in the square matrix are two-dimensional coordinates, the Euclidean matrix is ​​the Euclidean distance between the horizontal and vertical coordinates; if the coordinates of all points in the square matrix are three-dimensional coordinates, the Euclidean matrix is ​​the Euclidean distance between the horizontal, vertical and elevation coordinates. The matrix of the number of supplementary piles is determined according to the matrix distance in the Euclidean distance matrix of the pile foundation alignment, and the number of supplementary piles in the matrix of the number of supplementary piles is the ratio of the Euclidean distance to the parameter of the supplementary pile spacing.

[0056] Specifically, taking the pile foundation alignment as an example, assuming that the point set coordinates of a certain matrix are three-dimensional, assuming that after the encoding step, the coordinates of the box transformer are (x0, y0, z0), and the coordinates of the junction box point set are (x i ,y i ,z i ),i=1,...,m, the coordinates of the pile foundation point set are (x j ,y j ,z j ),j=m+1,...,m+n. The spacing between the piles is n_L, and the road point set is (R k ),k=1,...,n1, where the coordinates of each road point set are The avoidance zone point set is (A l ),l=1,...,n l , where the coordinates of each avoidance zone point set are Then the Euclidean distance matrix D Euclidean The elements of (d i,j ),i=0,...,m+n;j=0,...,m+n,where

[0057] The distance matrix D pile The elements of (p i,j ), i = 0, ..., m + n; j = 0, ..., m + n, each element of which is the Euclidean distance matrix element divided by the spacing between the piles n_L, that is: p i,j =d i,j / n_L;

[0058] Whether to cross the road matrix D road The elements of (d i,j ), i = 0, ..., m + n; j = 0, ..., m + n, each element of which indicates whether the line between any two point sets passes through a certain road. For specific judgment methods, refer to Figure 2 , the specific steps are:

[0059] S1. Calculate the maximum and minimum horizontal and vertical coordinates of the box transformer and combiner box coordinate set, and set the coordinate range in the valid area [x min :x max ,y min :y max ];

[0060] S2. Determine whether each road is in the valid area. If a point cluster in the coordinate point cluster of the road is within the valid area, the road is retained.

[0061] S3, for each reserved road, calculate the convex hull using the computer vision library Opencv;

[0062] S4. Determine successively whether the line connecting a pair of point sets intersects with the convex hull of a reserved road: if so, determine whether the line connecting the pair of point sets passes through the road, and assign a value of 1 to the corresponding element in the road matrix if it does; otherwise, determine whether the line connecting the pair of point sets does not pass through the road, and assign a value of 0 to the corresponding element in the road matrix if it does.

[0063] Whether to cross the road matrix D avoid The elements of (d i,j ), i = 0, ..., m + n; j = 0, ..., m + n, each element of which is whether the line between any two point sets passes through a certain avoidance zone. The method for judging whether the line between point sets passes through the avoidance zone is the same as the above-mentioned method of judging whether the line passes through the road.

[0064] For gap routing, before encoding and obtaining the matrix, the junction box in the bracket must be mapped to the nearby gap point to ensure that the path from the transformer to the junction box obtained by subsequent operations such as the shortest path algorithm does not pass through the bracket area.

[0065] Further, such as Figure 3 The coordinates of the combiner box in the bracket are mapped to the nearby gap points according to the orientation of the combiner box and the transformer, including:

[0066] Removing gap points within the bracket area;

[0067] Determine whether each combiner box is in a certain bracket;

[0068] For the combiner box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding combiner box is greater than the difference between the vertical coordinates, left and right mapping is performed; if the horizontal coordinate of the combiner box is smaller than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate larger than the combiner box is selected for mapping; if the horizontal coordinate of the combiner box is larger than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate smaller than the combiner box is selected for mapping;

[0069] For the combiner box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding combiner box is less than the difference between the vertical coordinates, they are mapped up and down; if the vertical coordinate of the combiner box is less than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate greater than the combiner box is selected for mapping; if the vertical coordinate of the combiner box is greater than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate less than the combiner box is selected for mapping;

[0070] The coordinates of the combiner box to be mapped are updated to the coordinates of the mapping gap point, and the coordinates of the combiner box are updated.

[0071] For gap routing, before encoding and obtaining the distance matrix, in order to calculate the processing time, the initial large number of gap points input into the matrix are filtered first, and only the gap points that may be connected are retained. The distance matrix between the box-type transformer and the retained gap points is solved, and then the subsequent path planning processing operation is performed.

[0072] Further, such as Figure 4 The filtering of gap points shown includes:

[0073] Preset distance range to retain clearance points near the bracket area;

[0074] Find the convex hull based on a set of coordinate points composed of a box-type transformer and several junction boxes;

[0075] Remove the gap points outside the convex hull, and retain the bracket area within the convex hull or intersecting with the convex hull as the retained bracket area;

[0076] For the gap points in the reserved bracket area, the gap points in the bracket area within the preset distance from the box-type transformer and the combiner box are reserved as the first gap point set;

[0077] The convex hull area composed of a box-type transformer and several junction boxes is equidistantly selected in the horizontal and vertical coordinates to form an equidistant network, and the vertices of the equidistant network are mapped to the nearest gap points nearby, and the nearest gap points are retained as the second gap point set;

[0078] Map the horizontal and vertical coordinates of a box transformer and several combiner boxes and the intersection points of the equally spaced network to the nearest gap points nearby, and retain the nearest gap points as the third gap point set;

[0079] The first gap point set, the second gap point set and the third gap point set are aggregated, and physical deduplication is performed to obtain the gap points that are finally retained.

[0080] For the pile foundation alignment, the scene map is constructed by the box transformer, junction box and pile foundation. The impact of the road and avoidance area information on the scene has been taken into account in the distance matrix, so the weighted distance between any two points in the scene is the distance matrix D Euclidean , the distance matrix D of the distance between the piles pile , whether it passes through the road matrix D road and whether to cross the road matrix D avoid Weighted.

[0081] For gap routing, the scenario map is constructed by the box transformer, combiner box and reserved gap points. The weighted distance between any two points in the scenario is the distance matrix D Euclidean , whether it passes through the road matrix D road and whether to cross the road matrix D avoid Weighted.

[0082] Furthermore, the shortest path algorithm can use Dijkstra algorithm, A* algorithm and Floyd algorithm, etc. The Euclidean distance matrix, the number of piles to be added matrix, the matrix of whether to cross the road, and the matrix of whether to cross the avoidance zone can be weighted according to the routing method and the effect of finding the shortest path to obtain the connection weight of any two points in the map.

[0083] like Figure 5 As shown in the figure, for a certain array, pile foundation routing is implemented. The array has box-type transformers, 13 junction boxes, and 1020 pile foundation points. After preprocessing operations, the duration of low-voltage path planning is 15.35s.

[0084] like Figure 6-Figure 10 As shown, gap routing is implemented for a certain array. The array has 1 box-type transformer, 14 junction boxes, 48,976 gap points, and 280 bracket indentation contour lines. After preprocessing operations, there are 85 bracket areas and 1,876 reserved gap points. The duration of low-voltage path planning is 12.49s.

[0085] Examples show that the low-pressure path planning preprocessing method proposed in this application can significantly save the processing time of low-pressure path planning while retaining the optimal low-pressure path planning effect.

[0086] The above are only preferred specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A preprocessing method for low-voltage path planning, characterized in that: include: Obtain the data set of the target array of the photovoltaic power station; Determine a preprocessing method according to the routing mode of the data set to obtain a distance matrix; The shortest path is obtained by calculation according to the distance matrix to complete the low-voltage path planning.

2. The preprocessing method for low-voltage path planning according to claim 1, characterized in that: The data set of the photovoltaic power station target array includes: The target array of the photovoltaic power station includes a transformer, several combiner box coordinates, a wiring method, several pile foundation coordinates or several gap point coordinates, an array envelope coordinate set, several bracket area coordinates and parameters related to path planning.

3. The preprocessing method for low-voltage path planning according to claim 2, characterized in that: The routing methods include pile-based routing and gap routing.

4. The preprocessing method for low-voltage path planning according to claim 3, characterized in that: Determining a preprocessing method according to the routing mode of the data set to obtain a distance matrix includes: If the routing method is pile foundation routing, a box-type transformer, several combiner boxes and several pile foundation points are numbered consecutively in the order of box-type transformer, combiner box and pile foundation point, and a distance matrix between a box-type transformer, several combiner boxes and several pile foundation points is calculated; If the routing method is gap routing, remove the gap points in the bracket area, map the coordinates of the junction box in the bracket to the nearby gap points, filter the gap points, and number a box-type transformer, several junction boxes and several reserved gap points consecutively in the order of box-type transformer, junction box and reserved gap points, and calculate the distance matrix between a box-type transformer, several junction boxes and several reserved gap points.

5. The preprocessing method for low-voltage path planning according to claim 4, characterized in that: The distance matrix in the pile foundation alignment is a Euclidean distance matrix between a box transformer, several junction boxes and several pile foundation points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix.

6. The preprocessing method for low-voltage path planning according to claim 4, characterized in that: The distance matrix of the gap routing is a Euclidean distance matrix between a box transformer, several junction boxes and several reserved gap points, whether it passes through a road matrix and whether it passes through an avoidance zone matrix.

7. The preprocessing method for low-voltage path planning according to claim 4, characterized in that: The number matrix of supplementary piles is determined according to the matrix distance in the Euclidean distance matrix of the pile foundation alignment, and the number of supplementary piles in the number matrix of supplementary piles is the ratio of the Euclidean distance to the parameter of the supplementary pile spacing.

8. The preprocessing method for low-voltage path planning according to claim 4, characterized in that: Mapping the coordinates of the combiner box in the bracket to the nearby gap points is done based on the orientation of the combiner box and the transformer.

9. The preprocessing method for low-voltage path planning according to claim 8, characterized in that: Mapping based on the location of the combiner box and the box-type transformer includes: For the combiner box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding combiner box is greater than the difference between the vertical coordinates, left and right mapping is performed; if the horizontal coordinate of the combiner box is smaller than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate larger than the combiner box is selected for mapping; if the horizontal coordinate of the combiner box is larger than the horizontal coordinate of a box transformer, the nearest gap point with a horizontal coordinate smaller than the combiner box is selected for mapping; For the junction box in the bracket, if the difference between the horizontal coordinates of a box transformer and the corresponding junction box is less than the difference in the vertical coordinates, they are mapped up and down; if the vertical coordinate of the junction box is less than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate greater than the junction box is selected for mapping; if the vertical coordinate of the junction box is greater than the vertical coordinate of a box transformer, the nearest gap point with a vertical coordinate less than the junction box is selected for mapping.

10. The preprocessing method for low-voltage path planning according to claim 1, characterized in that: Filtering of gap points includes: Preset distance range to retain clearance points near the bracket area; Find the convex hull based on a set of coordinate points composed of a box-type transformer and several junction boxes; Remove the gap points outside the convex hull, and retain the bracket area within the convex hull or intersecting with the convex hull as the retained bracket area; For the gap points in the reserved bracket area, the gap points in the bracket area within the preset distance from the box-type transformer and the combiner box are reserved as the first gap point set; The convex hull area composed of a box-type transformer and several junction boxes is equidistantly selected in the horizontal and vertical coordinates to form an equidistant network, and the vertices of the equidistant network are mapped to the nearest gap points nearby, and the nearest gap points are retained as the second gap point set; Map the horizontal and vertical coordinates of a box transformer and several combiner boxes and the intersection points of the equally spaced network to the nearest gap points nearby, and retain the nearest gap points as the third gap point set; The first gap point set, the second gap point set and the third gap point set are aggregated, and physical deduplication is performed to obtain the gap points that are finally retained.

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