A substation equipment identification method and system based on engineering design drawings

Abstract

The application discloses a kind of based on engineering design drawing substation equipment identification method and system, comprising: equipment set acquisition and graph data structuring;From the existing configuration read all possible substation in-station equipment, denoted as set S, graph data structuring is indicated to each equipment Si in set S, and according to global equipment atomic element distribution situation, select the atomic element in equipment Si and set as index element;Based on graph data structure G-S, construct search comparison tree S-Tree;Using all atomic elements in CAD drawing, construct spatial index tree R-tree;Obtain subgraph G1 to be identified;Equipment identification matching;Matching result output.The present application can efficiently and accurately identify each substation equipment and its coordinate position from CAD drawing, provide solid support for the automatic construction of three-dimensional model and the whole life cycle management of power grid equipment, and further promote the construction of digital power grid and modern equipment management system.

Description

TECHNICAL FIELD

[0001] The application relates to a substation equipment identification method and system, in particular to a substation equipment identification method and system based on engineering design drawings. BACKGROUND

[0002] As an advanced digital technology, the digital twin model of power grid equipment connects physical power grid equipment with virtual digital models, realizes real-time data monitoring and intelligent decision-making, and plays a key role in the whole life cycle of power system planning, design, construction and operation and maintenance, and helps to improve the intelligent level, operation efficiency and reliability of the power system. However, the digital twin technology encounters many challenges in the whole life cycle management of power grid equipment, especially the continuity of digital twin model in the whole process of "design, construction and operation". Although the GIM three-dimensional drawings handed over by the design unit can provide rough information of equipment position and topological relationship, its precision is insufficient, and it is difficult to accurately reflect the spatial characteristics and correlation between devices, which limits the practicality in the subsequent application stage.

[0003] To solve the problem of automatic conversion of engineering design data and digital twin model, the traditional method usually adopts the "laser point cloud + manual processing" method to construct the model, which not only has high cost and long time, but also cannot meet the needs of the rapid development of power grid. If the three-dimensional model can be directly converted from the plane CAD drawing by the method, this problem will be effectively solved. Among them, efficiently and accurately identifying each substation equipment and coordinate position from CAD drawing is the key to realize this scheme. SUMMARY

[0004] The purpose of the application is to provide a substation equipment identification method and system based on engineering design drawings, which aims to efficiently and accurately identify each substation equipment and its coordinate position from CAD drawings.

[0005] Technical scheme: The application includes: device set acquisition and graph data structuring: read all possible substation equipment in the existing configuration, denoted as set S, perform graph data structuring representation on each device Si in set S, and select atomic elements in device Si as index elements according to the distribution of global device atomic elements; based on graph data structure G-S, construct retrieval comparison tree S-Tree; use all atomic elements in CAD drawings to construct spatial index tree R-tree; obtain subgraph G1 to be identified; equipment identification and matching; output the matching result.

[0006] The graph data structuring representation of each device Si in set S is as follows: the index element list is a multi-level index ordered queue, each device has at least one index element, and the index element is an atomic element.

[0007] The index element is obtained from the graph data structure G-S, and a retrieval comparison tree is constructed according to the characteristics of the equipment represented by the index element.

[0008] The spatial index tree R-tree can quickly locate all atomic elements in the CAD drawing that have an overlapping relationship with the given rectangular coordinates.

[0009] The to-be-identified subgraph G1 is a to-be-identified device composed of part of the equipment in the entire CAD drawing.

[0010] The to-be-identified subgraph G1 is obtained by setting a retrieval radius R for each index element a, constructing a retrieval rectangle with the index element as the center, and retrieving the to-be-retrieved graph G-Si in the R-tree, thereby obtaining the to-be-identified subgraph G1.

[0011] The device recognition matching is specifically: for a to-be-identified subgraph G1, starting from the root node Root of the retrieval comparison tree, sequentially performing matching judgment; if the node element can be matched in G1, then enter the left subtree to continue node matching, if it cannot be matched, then enter the right subtree to perform node matching, until the entered subtree is a leaf node, denoted as Node1, then end; according to Node1, obtaining the corresponding device G-S1, judging whether G-S1 is a subgraph of the subgraph G1; if yes, then identifying G1 as the device S1, if not, then it is indicated that there is no corresponding device.

[0012] In the device recognition matching, the method for performing device matching search on any device is as follows:

[0013] All the equipment in the CAD drawing is converted into atomic elements, and a spatial index tree R-tree is constructed;

[0014] According to the index element in the retrieval comparison tree S-tree, the corresponding to-be-identified subgraph G is obtained;

[0015] According to the to-be-identified subgraph G and the retrieval comparison tree S-tree, a possible device is judged by retrieval comparison, and full-quantity atomic element matching judgment is performed on the possible device, so that all atomic elements of the device can be found in the to-be-identified subgraph G;

[0016] Matching verification: for all atomic elements marked as candidate matching, check whether the topological relationship between them conforms to the expected layout of the device; and verify whether the overall layout of the candidate matching atomic element is consistent with the layout of the device atomic element;

[0017] Matching result record: if all device atomic elements can find a suitable match in the drawing, and the overall layout is consistent, record the matching result of the device; and record the device name, type, coordinate information in the drawing and the matching atomic element list.

[0018] Matching failure processing: if the device atomic element fails to find a suitable match in the drawing, or the accuracy of the match is lower than the preset threshold, skip the current device and continue to match the next device;

[0019] Matching cycle end: when all devices are tried to match, or the predetermined matching number limit is reached, end the matching cycle, and output all successfully matched devices and their related information.

[0020] The matching result output is specifically: after completing the matching search of all devices, record all the found devices and coordinate information, and output the recognition result to the specified file or system.

[0021] A substation device identification system based on engineering design drawings, comprising: a device set acquisition and graph data structuring module, a search comparison tree S-Tree module, a spatial index tree R-Tree module, a to-be-identified subgraph G1 acquisition module, a device identification matching module and a matching result output module.

[0022] Beneficial effects: the present application can efficiently and accurately identify each substation device and its coordinate position from CAD drawings, providing solid support for automatic construction of three-dimensional models and life cycle management of power grid devices, and further promoting the construction of digital power grids and modern device management systems. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flowchart of the present application;

[0024] Figure 2 The search comparison tree S-Tree structure diagram of the present application;

[0025] Figure 3 The method flowchart of device matching search of the present application;

[0026] Figure 4 The calculation diagram of search radius R of the present application. DETAILED DESCRIPTION

[0027] The present application will be further described below in conjunction with the drawings.

[0028] As Figure 1As shown, the substation equipment identification method based on engineering design drawings of the application first reads all possible substation equipment from the configuration, and the set formed by the equipment is denoted as set S and a graph data structure is created for each equipment in set S; then multi-level indexes are set for all equipment in set S, and an index comparison binary tree is constructed; then all elements in the drawing are converted into atomic elements, and a spatial index tree R-tree is created; then each equipment in S is searched for matching elements in the drawing by using the index comparison binary tree through its graph data structure, and if each atomic element constituting a device can complete matching, the matching search of the device is completed; the coordinate information of all found devices is recorded and output, and thus the substation equipment identification of a given drawing is completed. Specifically, the following steps are included:

[0029] Step 1: Equipment set acquisition and graph data structuring

[0030] All possible substation equipment in the existing configuration is read, denoted as set S, and the information of the equipment can include the name, type, and constituent atomic elements of the equipment, so as to facilitate subsequent matching and identification. In order to improve the identification efficiency and accuracy, each equipment Si in set S is represented by a graph data structure, and according to the global equipment atomic element distribution, the atomic elements with obvious characteristics and high specificity in the equipment Si are selected as the first-level index elements, and according to the actual needs, multiple levels of index elements can be set. For example, the selected atomic element appears in very few equipment, and preferably only in one equipment, so as to quickly locate the corresponding equipment through this atomic element. The atomic elements include points, line segments, circular arcs, and circles. The main characteristics are geometric characteristics, such as length and width, which affect the shape and size. Therefore, the "point" element is not the first choice because it is difficult to represent a certain equipment, but it can be used as a multi-level index element in combination with other atomic elements to represent a device.

[0031] Each equipment Si in set S is represented by a graph data structure, specifically:

[0032] Equipment set S:

[0033] Equipment S1:

[0034] Equipment ID: D001

[0035] Equipment name: transformer

[0036] Equipment type: power equipment

[0037] Index element list:

[0038] Node 2

[0039] Node 3

[0040] Negative index element list:

[0041] Node A

[0042] Device node list:

[0043] Node 1:

[0044] Node ID: N101

[0045] Element type: line segment

[0046] Geometry attribute: length = 100

[0047] Position information: x1 = 100, y1 = 200, x2 = 200, y2 = 200 / / starting points of line segment

[0048] Node 2:

[0049] Node ID: N102

[0050] Element type: circular arc

[0051] Geometry attribute: radius = 30

[0052] Position information: x1 = 150, y1 = 190, x2 = 150, y2 = 210 / / starting points of circular arc

[0053] Negative device node list:

[0054] Node A: ...

[0056] Device edge list:

[0057] Edge 1:

[0058] Edge ID: E101

[0059] Connection nodes: N101-N102

[0060] Topological relationship: intersection

[0061] Device S2: ...

[0063] Perform graph data structure construction for each device in the device set, where the index element list is a multi-level index ordered queue, and each device has at least one index element, and the index element is an atomic element. In order to distinguish the existence of the index element list in the set, which leads to the existence of the case that only relying on the index element is not enough to quickly match the device, the negative index element list is increased. The negative index element list is the node information of the atomic element that does not appear in the device.

[0064] In the device for organizing the graph data structure, the topological relation description is a very key link, and the topological relation describes the connection mode and relative position between the spatial objects, and does not involve the specific shape or distance of the object. As shown in Table 1, the topological relation of the corresponding device of the present application includes the following:

[0065] Adjacency: refers to two spatial objects sharing a boundary or an end point.

[0066] Containment: a spatial object is completely located inside another spatial object.

[0067] Intersection: two spatial objects overlap in some parts.

[0068] Separation: two spatial objects do not overlap, that is, there is no intersection between them.

[0069] Table 1: Topological relation table between atomic elements of the present application

[0070]

[0071]

[0072] The device of the present application can be divided into four types of atomic elements: point, line segment, circle and circular arc, and the following topological relation combinations can be formed by combination (without considering self-intersection or overlap):

[0073] 1. Point and point:

[0074] Intersection: two points coincide when they are at the same position, which belongs to the intersection relation.

[0075] Separation: two points are separated when they are not at the same position.

[0076] 2. Point and line segment:

[0077] Adjacency: if the point is an end point of the line segment, they are adjacent.

[0078] Intersection: if the point is inside the line segment (not an end point), the point intersects with the line segment.

[0079] Separation: if the point is not on the line segment, the point is separated from the line segment.

[0080] 3. Point and circular arc:

[0081] Adjacency: if the point is an end point of the circular arc, the point is adjacent to the circular arc.

[0082] Intersection: if the point is on the circular arc (not an end point), the point intersects with the circular arc.

[0083] Separate: If the point is not on the arc, the point is separate from the arc.

[0084] 4. Point and circle:

[0085] Intersect: If the point is on the edge of the circle, the point intersects the circle.

[0086] Contain: If the point is inside the circle, the circle contains the point.

[0087] Separate: If the point is outside the circle, the point is separate from the circle.

[0088] 5. Line segment and line segment:

[0089] Adjacent: If the endpoints of the line segments coincide, the line segments are adjacent.

[0090] Intersect: If the line segments intersect at a point other than the endpoints, the line segments intersect.

[0091] Separate: If the line segments have no common point, the line segments are separate.

[0092] 6. Line segment and arc:

[0093] Adjacent: If the endpoint of the line segment coincides with the endpoint of the arc, the line segment and the arc are adjacent.

[0094] Intersect: If the line segment and the arc intersect within a certain region, the line segment and the arc intersect.

[0095] Separate: If the line segment and the arc have no intersection point, the line segment and the arc are separate.

[0096] 7. Line segment and circle:

[0097] Adjacent: If the line segment intersects the circle at exactly one point, and all other points on the line segment are outside the circle, the line segment is tangent to the circle and belongs to the adjacent relationship.

[0098] Intersect: If the line segment passes through the circle and intersects the circle at one or two points, that is, the points on the line segment are partially inside the circle and partially outside the circle, then the line segment intersects the circle.

[0099] Contain: If the line segment is completely inside the circle, the circle contains the line segment.

[0100] Separate: If the line segment is completely outside the circle, the line segment is separate from the circle.

[0101] 8. Arc and arc:

[0102] Adjacent: If the endpoints of the arcs coincide, the arcs are adjacent.

[0103] Intersect: If the arcs intersect within a certain region, the arcs intersect.

[0104] Separate: If the arcs have no common point, the arcs are separate.

[0105] 9. Arc and circle:

[0106] Adjacent: If the arc is tangent to the circle, it is an adjacent relationship.

[0107] Intersect: If the arc intersects the circle in some area, the arc intersects the circle.

[0108] Contain: If the arc is completely located in the circle, the circle contains the arc.

[0109] Separate: If the arc and the circle have no intersection, the arc and the circle are separated.

[0110] 10. Circle and circle:

[0111] Adjacent: Two circles are tangent, including internal tangent and external tangent, all belong to adjacent relationship.

[0112] Contain: If one circle is completely located inside another circle without touching the boundary, the first circle is contained by the second circle.

[0113] Intersect: If two circles partially overlap but do not completely contain each other, the circles intersect.

[0114] Separate: If two circles have no overlapping area, the circles are separated.

[0115] Step 2: Construct search comparison tree S-Tree:

[0116] Get all index elements in G-S, and construct search comparison tree according to the characteristics of the equipment they can represent. Generally, the more equipment a search represents, the shallower its layer depth in the search comparison tree. The search comparison tree is a binary tree, and its leaf nodes are substation devices, and other nodes are index elements. The search comparison tree is created to optimize the goal of filtering possible substation devices with the least number of comparisons, as shown in Figure 2 .

[0117] When creating the graph data structure of the device in step 1, multiple index elements have been set for each device. The set of all index elements corresponding to each device can specifically identify the corresponding device, just like the primary key in the database, that is, different devices can be distinguished and represented by the index element group of the device. There may be an intersection between the index element groups of different devices, so all the index elements of the devices are taken out to create a search comparison binary tree to reduce the comparison times and improve the efficiency of device identification comparison.

[0118] Step 3: Construct spatial index tree R-tree:

[0119] Using all the atomic elements in the CAD drawing, a spatial index tree R-tree is constructed, which can quickly locate all atomic elements in the CAD drawing that have overlapping intersection relationship with the given rectangular coordinates.

[0120] Step 4: Obtain the to-be-identified sub-graph G1:

[0121] The to-be-identified sub-graph G1 is a to-be-identified device composed of part of the equipment in the entire CAD drawing, which can simplify the identification step, improve the identification efficiency and accuracy, and is a key step to complete the equipment matching identification.

[0122] As shown in Figure 4 is a group of composite pictures, in which A shows an example device 1, and the corresponding all index elements are shown in B. Device 1 is a multi-level index, in which the first-level index is index element a, and the second-level index is index element b. Similarly, D and E are multi-level index diagrams of device 2 and device 2, respectively, in which index element a is the first-level index of device 2, and index element c is the second-level index of device 2.

[0123] Suppose that there are only Figure 4 two devices with the first-level index of index element a. Then there must be a radius R, such that there is a circle C1 with the center of index element a and R as the radius, and for any angle of device 1 or device 2 containing this index element a, all atomic elements of the device are just in the circle C1. Then the radius R is called the retrieval radius of element a.

[0124] In order to facilitate calculation, the minimum circumscribed rectangle of circle C1 is taken as the basis for subsequent calculation, that is, a square with a length and width of 2R. In actual calculation of R, the retrieval radius Ri of each current device can be calculated for each first-level index element i, and the maximum value of all Ri is taken as the retrieval radius R.

[0125] For each index element a, a retrieval radius R is set, which means that all atomic elements of all possible devices containing this index element should be found in the circle with the index element as the center and R as the radius. By setting the retrieval radius R, a retrieval rectangle with the index element a as the center is constructed, which has a length and width of 2R and a center of a. The to-be-retrieved graph G-Si is retrieved in the R-tree, so as to obtain the to-be-identified sub-graph G1. A device can have multiple retrieval index elements, and there may be overlap and redundancy in the retrieval rectangle. Only the index rectangle calculation for the index element that can only be successfully retrieved for the first time in the retrieval tree can avoid this problem.

[0126] Step 5: Equipment identification matching:

[0127] From the root node of the S-Tree, match judgment is performed on G1 until the leaf node to determine whether G1 is a device in the set S. Specifically, for a to-be-identified subgraph G1, match judgment is performed in sequence from the root node Root of the search comparison tree. If the node element can be matched in G1, the left subtree is entered to continue node matching, and if it cannot be matched, the right subtree is entered to perform node matching, until the entered subtree is a leaf node (denoted as Node1). At this time, it can be determined that subgraph G1 can be one of the two cases of the device represented by this leaf node or not any device in set S. According to Node1, the corresponding device G-S1 is obtained, and it is judged whether G-S1 is a subgraph of subgraph G1, including nodes and topological relations. If yes, G1 is identified as device S1, and if not, it means that there is no corresponding device.

[0128] As shown in Figure 3 , the method flow of device matching search for any device is as follows:

[0129] S5.1: Convert all devices in the CAD drawing into atomic elements, and build a spatial index tree R-tree;

[0130] S5.2: According to the index elements in the search comparison tree S-tree, obtain the corresponding to-be-identified subgraph G;

[0131] S5.3: According to the to-be-identified subgraph G and the search comparison tree S-tree, search comparison is performed to determine possible devices, and then full-quantity atomic element matching judgment is performed on the possible devices to ensure that all atomic elements of the device can be found in the to-be-identified subgraph G;

[0132] (1) The matching judgment condition is:

[0133] Geometric feature comparison: Compare the geometric features of the device atomic elements with the atomic elements in the drawing.

[0134] Position relationship check: Check whether the position relationship of the two atomic elements meets the preset condition, such as distance, angle, etc.

[0135] Matching mark: If the atomic elements in the drawing meet the matching condition, mark them as candidate matching atomic elements.

[0136] S5.4: Matching verification

[0137] Topological relationship check: For all atomic elements marked as candidate matching, check whether their topological relationship conforms to the expected layout of the device.

[0138] Consistency verification: Verify whether the overall layout of the candidate matching atomic elements is consistent with the layout of the device atomic elements.

[0139] S5.5: Match Result Recording

[0140] Successful Match: If all device atomic elements can find suitable matches in the drawing and the overall layout is consistent, record the matching result of the device.

[0141] Information Recording: Record the device name, type, coordinate information in the drawing and the list of matched atomic elements of the successful match.

[0142] S5.6: Match Failure Processing

[0143] Skip Device: If the device atomic elements cannot find suitable matches in the drawing, or the accuracy of the match is lower than the preset threshold, skip the current device and continue to match the next device.

[0144] Optimization Suggestions: Record the reasons for the failure of the match and provide suggestions for subsequent method optimization.

[0145] S5.7: End of Matching Loop

[0146] Traversal Complete: When all devices have been tried to match, or the predetermined number of matching times has been reached, end the matching loop.

[0147] Result Output: Output all successfully matched devices and their related information.

[0148] Through the above steps, the accurate matching of a single device in the drawing can be realized, thereby providing accurate data basis for subsequent three-dimensional model construction and device management.

[0149] Step 6: Match Result Output:

[0150] After completing the matching of all devices, record and output the information of all the devices found, including device name, type, position coordinates, etc. Specifically including:

[0151] Result Recording: When all device matching is completed, record all the devices found and their coordinate information.

[0152] Information Output: Output the recognition result to the designated file or system for subsequent three-dimensional model construction and management.

[0153] The substation device identification system based on engineering design drawings of the present application comprises:

[0154] Device set acquisition and graph data structuring module: read all possible substation devices in the existing configuration, denoted as set S. The information of the devices can include the name, type, and constituent atomic elements of the device, so as to facilitate subsequent matching and identification. In order to improve the identification efficiency and accuracy, each device Si in set S is represented by graph data structure, and according to the global device atomic element distribution, the atomic elements with obvious characteristics and high specificity in device Si are set as first-level index elements. According to actual needs, multiple levels of index elements can be set.

[0155] Search comparison tree S-Tree module: based on the graph data structure G-S, a search comparison tree S-Tree is constructed. Specifically, all index elements in G-S are obtained, and a search comparison tree is constructed according to the characteristics of the index elements representing the devices. The search comparison tree is a binary tree, and the leaf nodes represent the substation devices, and the non-leaf nodes represent the index elements. The search comparison tree can filter the possible substation devices with the least number of comparisons.

[0156] Spatial index tree R-tree module: all atomic elements in the CAD drawing are used to construct a spatial index tree R-tree. The tree can quickly locate all atomic elements in the CAD drawing that have overlapping and intersecting relationships with the given rectangular coordinates.

[0157] Acquisition module of subgraph G1 to be identified: the subgraph G1 to be identified is composed of part of the devices in the CAD drawing, which can simplify the identification steps and improve the identification efficiency and accuracy.

[0158] Device identification and matching module: starting from the root node of S-Tree, G1 is matched and judged until the leaf node, to determine whether G1 is a device in set S.

[0159] Matching result output module: after completing all device matching, record and output all the device information found, including device name, type, position coordinates, etc.

Claims

1. A method for identifying substation equipment based on engineering design drawings, characterized in that: include: Equipment set acquisition and graph data structuring: Read all possible substation equipment from the existing configuration, recorded as set S, perform graph data structured representation on each device Si in set S, and select atomic elements in device Si as index elements based on the global distribution of atomic elements of the equipment; construct a retrieval comparison tree S-Tree based on the graph data structure GS; use all atomic elements in the CAD drawing to construct a spatial index tree R-tree; obtain the subgraph G1 to be identified: set a retrieval radius R for each index element a, and by setting the retrieval radius R, construct a retrieval rectangle centered on the index element, with a length and width of 2R and a center of a, search the graph G-Si to be retrieved in the R-tree, and thus obtain the subgraph G1 to be identified; equipment identification and matching; output matching results.

2. A method for identifying substation equipment based on engineering design drawings according to claim 1, characterized in that: The graph data structured representation of each device Si in the set S is specifically as follows: the index element list is a multi-level index ordered queue, each device has at least one index element, and the index element is an atomic element.

3. A method for identifying substation equipment based on engineering design drawings according to claim 2, characterized in that: The retrieval comparison tree S-Tree is constructed based on the graph data structure GS, specifically: all index elements in GS are obtained, and a retrieval comparison tree is constructed according to the characteristics of the equipment they can represent. Its leaf nodes represent the equipment in the substation, and other nodes represent index elements.

4. The method for identifying substation equipment based on engineering design drawings according to claim 1, characterized in that: The spatial index tree R-tree can quickly locate all atomic elements in the CAD drawing that have an overlapping and crossing relationship with the given rectangular coordinates.

5. The method for identifying substation equipment based on engineering design drawings according to claim 1, characterized in that: The sub-graph G1 to be identified is a device to be identified consisting of a portion of devices obtained from the entire CAD drawing.

6. The method for identifying substation equipment based on engineering design drawings according to claim 1, characterized in that: The device identification and matching is specifically as follows: for a subgraph G1 to be identified, matching judgment is performed in sequence starting from the root node Root of the search comparison tree; if the node element can be matched in G1, then enter the left subtree to continue node matching; if it cannot be matched, then enter the right subtree to continue node matching until the subtree entered is a leaf node, recorded as Node1, and ends; according to Node1, obtain the corresponding device G-S1, and judge whether G-S1 is a subgraph of the subgraph G1; if so, identify G1 as device S1, if not, it means that the corresponding device does not exist.

7. A method for identifying substation equipment based on engineering design drawings according to claim 6, characterized in that: In the device identification and matching, the method for performing device matching search for any device is as follows: Convert all devices in the CAD drawing into atomic elements and build a spatial index tree R-tree; According to the index element in the search comparison tree S-tree, the corresponding subgraph G to be identified is obtained; Possible devices are identified by performing a search and comparison between the subgraph G to be identified and the search and comparison tree S-tree. All atomic elements of the possible devices are matched to ensure that all atomic elements of the device can be found in the subgraph G to be identified. Match verification: For all atomic elements marked as candidate matches, check whether the topological relationship between them conforms to the expected layout of the device; and verifying whether the overall layout of the candidate matching atomic elements is consistent with the layout of the device atomic elements; Matching result record: If all device atomic elements can find suitable matches in the drawing and the overall layout is consistent, the matching result of the device will be recorded; the name, type, coordinate information in the drawing and the list of matched atomic elements of the successfully matched device will also be recorded; Matching failure processing: If the device atomic element fails to find a suitable match in the drawing, or the matching accuracy is lower than the preset threshold, the current device will be skipped and the next device will be matched; End of matching cycle: When all devices have been matched, or the predetermined matching limit is reached, the matching cycle ends and all successfully matched devices and their related information are output.

8. The method for identifying substation equipment based on engineering design drawings according to claim 1, characterized in that: The matching result output is specifically as follows: after completing the matching search for all devices, all the found devices and coordinate information are recorded, and the recognition results are output to a specified file or system.

9. A substation equipment identification system based on engineering design drawings, characterized in that: include: Device set acquisition and graph data structuring module: Read all possible substation devices from the existing configuration, recorded as set S, perform graph data structured representation on each device Si in set S, and select atomic elements in device Si as index elements based on the global distribution of atomic elements of the devices; Retrieval comparison tree S-Tree module: Based on the graph data structure GS, construct the retrieval comparison tree S-Tree; Spatial index tree R-tree module: uses all atomic elements in CAD drawings to build a spatial index tree R-tree; The module for obtaining the subgraph G1 to be identified sets a search radius R for each index element a. By setting the search radius R, a search rectangle with a length and width of 2R and a center of a is constructed with the index element as the center. The subgraph G-Si to be identified is retrieved in the R-tree to obtain the subgraph G1 to be identified. Device identification and matching module and matching result output module: device identification and matching and matching result output.

Images