An intelligent design method for secondary electrical cables in a substation

Abstract

The object of the present invention is to provide an intelligent design method for secondary electrical cables in a substation. The method includes: constructing an intelligent design model for cables based on the positions of the cables and the cable channels; using the A* algorithm to calculate the optimal path for cable laying according to the intelligent design model for cables; and using an automatic cable arrangement algorithm to lay cables according to the optimal path for cable laying. The present invention can achieve cable path planning, cable laying, floor area ratio verification, etc., realize refined design, study the digital handover form of the optical cable laying results, and hand over the data in compliance with the specified data format to the owner. Furthermore, the optical cable laying results are applied to the whole life cycle management process such as the construction, construction, management and operation and maintenance of the substation. It has high social and economic value.

Description

Technical Field

[0001] The present invention relates to the technical field of power engineering design, and particularly relates to an intelligent design method for secondary electrical cables in a substation. Background Art

[0002] Cable laying refers to the process of laying and installing cables along a surveyed route to form a cable line. According to the usage scenarios, it can be divided into several laying methods such as overhead, underground (duct and direct burial), underwater, wall, and tunnel. Reasonably selecting the cable laying method is very important for ensuring the transmission quality, reliability, construction, and maintenance of the line. Direct burial laying is to directly bury the cable underground, which has the advantages of low investment, convenient construction, and good heat dissipation conditions, and is the most economical and widely used laying method. However, direct burial laying is vulnerable to the erosion of corrosive substances in the ground, and it is inconvenient to find faults and repair cables, especially when the soil freezes in winter, the accident repair is very difficult. Cable trench laying is applicable to the production devices in power plants, substations, and general industrial and mining enterprises. However, cable trench laying is not suitable for areas with too high groundwater levels. Cable tunnel laying is convenient for maintenance and repair, abnormal phenomena are relatively easy to be found during operation, and it is not easily damaged by the outside world, and at the same time it can accommodate more cables. However, it has serious water seepage, and explosive mixtures heavier than air entering the tunnel will threaten safety. This method is applicable to the main power lines with low groundwater levels and concentrated distribution cables, and generally more than 30 large-section cables are laid.

[0003] Currently, the design of the secondary electrical specialty is mainly based on the schematic diagrams and panel terminal diagrams provided by manufacturers, and the connection from terminal to terminal is manually completed using CAD tools; by using certain design tools, the terminal strip wiring table, cable inventory, information table, etc. are automatically generated based on the schematic diagrams. In the 1990s, the Northwest Electric Power Design Institute developed a cable length measurement software based on two-dimensional topological relationships. After 2005, commercial cable laying software based on new technologies emerged. These cable laying software only include basic laying functions, and the software installation and use are cumbersome and complex, various errors will occur during the process, some data are incompatible, and the feedback cycle of the software company for problems is relatively long, which is difficult to meet the time requirements of production. It is necessary to improve the means of cable laying, develop relevant software according to actual needs, improve production efficiency, and meet the design requirements of substation projects.

[0004] The existing software mainly focuses on the design stage, with the main goal of calculating and statistics the cable routing and cable quantity, and cannot visually display information such as cable cores and nodes, making it difficult to meet the needs of engineering cable data in the construction and operation and maintenance stages. Therefore, in view of the data requirements of cable construction and operation and maintenance in substation construction, it is necessary and urgent to establish a visual and digital optimized design system. Summary of the Invention

[0005] The object of the present invention is to provide an intelligent design method for secondary electrical cables in a substation, which can achieve cable path planning, cable laying, floor area ratio verification, etc., realize refined design, study the digital transfer form of the optical cable laying results, and transfer the data in compliance with the specified format to the owner. Furthermore, the optical cable laying results are applied to the whole life cycle management process of substation construction, construction, management and operation and maintenance, etc., with high social and economic value.

[0006] An intelligent design method for secondary electrical cables in a substation includes:

[0007] Construct a cable intelligent design model according to the position of the cable and the cable channel;

[0008] Use the A* algorithm to calculate the optimal path of cable laying according to the cable intelligent design model;

[0009] Use the cable automatic arrangement algorithm to lay the cables according to the optimal path of cable laying.

[0010] Preferably, the construction of the cable intelligent design model according to the position of the cable and the cable channel includes:

[0011] Fix the position of the cable;

[0012] Take the path of the cable channel as the edge, the length of the path as the weight, and the intersection points between the paths as the nodes to construct the cable intelligent design model.

[0013] Preferably, the use of the A* algorithm to calculate the optimal path of cable laying according to the cable intelligent design model includes:

[0014] Mark the starting point and calculate the estimated cost value of the first path from the starting point to the end point;

[0015] The estimated cost value is expressed as F(n) = G(n) + H(n), where G(n) is the actual cost from the initial state to state n in the cable intelligent design model; H(n) is the estimated cost of the best path from state n to the target state;

[0016] Select the intermediate point with the lowest estimated cost value of the first path as the starting point for the next path planning;

[0017] Traverse each point until reaching the end point from the initially marked starting point.

[0018] Preferably, the use of the cable automatic arrangement algorithm to lay the cables according to the optimal path of cable laying includes:

[0019] Lay the cables along the optimal path in trenches, on different sides and in different layers;

[0020] Use the cable automatic arrangement algorithm to adjust the cables after classified laying.

[0021] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0022] Obtain the positions of the cable path center line and the switchgear cabinet.

[0023] Calculate on which side of the path the switchgear cabinet is located through the spatial vector algorithm. Let a be one end of the switchgear cabinet, b be the other end of the switchgear cabinet, and λ be the length of the switchgear cabinet.

[0024] Calculate the positional relationship between points a and b and the cable path center line.

[0025] When points a and b are on the same side of the center line, determine on which side of the cable the switchgear cabinet is located. When points a and b are on different sides of the center line, determine the lengths occupied by λ at both ends of the center line respectively.

[0026] The length occupied by λ at one end of the center line is expressed as:

[0027] Where is the abscissa of point a, is the ordinate of point a, is the abscissa of the intersection point of the switchgear cabinet and the center line, is the ordinate of the intersection point of the switchgear cabinet and the center line;

[0028] When laying the cable on the connection channel of the end device, select the bracket close to the end of the switchgear cabinet to lay the cable. Obtain the coordinates of the cable, calculate the distances between the cable coordinates and points a and b, and select the point with a smaller distance to start laying the cable.

[0029] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0030] When laying on the switching path, select the same-side bracket;

[0031] When laying on the layer rack, lay the cable in the outer direction relative to the already laid cable. Obtain the position data of the already laid cable, and design the installation position of the cable to be laid according to the position data of the already laid cable.

[0032] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0033] Determine the number of buried pipes according to the number of cables passing through the center line of the buried pipe. Select the buried pipe specification to determine the inner diameter of the buried pipe and the maximum number of columns of the buried pipe arrangement, and calculate the width and height of the rectangular arrangement of the buried pipe.

[0034] The width of the rectangular arrangement of the buried pipe is expressed as:

[0035]

[0036] The height of the buried pipes arranged in a rectangle is expressed as:

[0037]

[0038] where r is the inner diameter of the buried pipe, is the number of horizontally buried pipes, and m is the number of vertically buried pipes.

[0039] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0040] Sort the cables according to the laying algorithm, stack the cables on the layer rack, take the maximum cable diameter in each stacked layer as the layer height of this stacked layer, and the starting calculation position of the next stacked layer is the height offset from the maximum diameter cable in the previous stacked layer;

[0041] Calculate the laying quantity of the cables according to the volume ratio set on the channel;

[0042] The volume ratio of one layer rack is expressed as:

[0043]

[0044] where, is the length of one layer rack, is the width of one layer rack, is the radius of the i-th cable, is the length of the i-th cable, and n is the number of cables;

[0045] When one layer rack is laid to the volume ratio, search for the laying position on another eligible layer rack and lay it, and calculate the actual laying position on the layer rack;

[0046] When the cable volume ratio of one layer rack reaches the upper limit, find the next eligible layer rack to place.

[0047] An intelligent design system for secondary electrical cables in a substation includes:

[0048] A cable model generation module, which is used to construct a cable intelligent design model according to the position of the cables and the cable channel;

[0049] A cable path generation module, which is used to calculate the optimal path of cable laying according to the cable intelligent design model by using the A* algorithm;

[0050] A cable laying design module, which is used to lay the cables according to the optimal path of cable laying by using the cable automatic arrangement algorithm.

[0051] An electronic device includes: a chip, a processor, and a memory. The memory is used to store computer program code, and the computer program code includes computer instructions. When the chip executes the computer instructions, the electronic device executes an intelligent design method for secondary electrical cables in a substation.

[0052] The beneficial effects of the present invention are as follows: 1. A mathematical model is constructed based on graph theory. The path of the cable channel is regarded as an edge, the length of the path is used as the weight, and the intersection points between the paths are used as nodes to construct a graph data structure. Furthermore, the application of the shortest path search algorithm can be used to implement the laying of optical cables; 2. The A* algorithm is used to find the optimal path for the cable. The conventional cable laying algorithm is the Dijkstra algorithm, whose main feature is to expand layer by layer outward from the starting point until the end point is reached. However, since it traverses and calculates a large number of nodes, its efficiency is low.

[0053] The present invention uses the A* algorithm to implement cable laying. As a static and heuristic algorithm, the A* algorithm has the advantage of high efficiency compared to other static path algorithms such as Dijkstra; 3. The cable automatic arrangement algorithm is adopted to digitally and automatically lay and arrange the cables in the substation. It can automatically lay the cables in a standardized layered and volume-divided manner, and can also avoid cable intersections according to the actual situation, which can greatly improve the safety and stability of the power project. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] The drawings here are incorporated into the specification and form a part of this specification, marking the embodiments that conform to the present invention and are used together with the specification to explain the principles of the present invention.

[0055] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without creative labor.

[0056] Figure 1 It is a schematic flowchart of an intelligent design method for secondary electrical cables in a substation according to the present invention;

[0057] Figure 2 It is a schematic diagram of the cable topology structure according to the present invention;

[0058] Figure 3 It is a schematic diagram of the cable layer rack structure according to the present invention;

[0059] Figure 4 It is a schematic diagram of the mathematical model structure of the cable path center line and the switch cabinet according to the present invention;

[0060] Figure 5 Schematic diagram of cable laying on different sides of the present invention;

[0061] Figure 6 Schematic diagram of cable laying in layers of the present invention;

[0062] Figure 7 Schematic diagram of cable volume ratio calculation of the present invention;

[0063] Figure 8 Schematic diagram of the hardware structure of an electronic device of the present invention. Detailed implementation manners

[0064] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0065] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0066] In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0067] At present, the design of the secondary electrical specialty is mainly based on the schematic diagrams and panel terminal diagrams provided by manufacturers, and the connection from terminal to terminal is manually completed using CAD tools; certain design tools are used to automatically generate terminal strip wiring tables, cable lists, information tables, etc. based on the schematic diagrams. In the 1990s, the Northwest Electric Power Design Institute developed a cable length measurement software based on two-dimensional topological relationships. After 2005, commercial cable laying software based on new technologies emerged. These cable laying software only include basic laying functions, and the software installation and use are cumbersome and complex, various errors will occur during the process, some data is incompatible, and the software company has a long feedback cycle for problems, which is difficult to meet the time requirements of production. It is necessary to improve the means of cable laying, develop relevant software according to actual needs, improve production efficiency, and meet the design requirements of substation projects.

[0068] The existing software mainly focuses on the design stage, with the main goal of calculating and statistics the cable routing and cable quantity, and cannot intuitively display information such as cable cores and nodes, which is difficult to meet the needs of engineering cable data in the construction and operation and maintenance stages. Therefore, it is necessary and urgent to establish a visual and digital optimized design system for the data requirements of cable construction and operation and maintenance in substation construction.

[0069] This invention constructs a mathematical model based on graph theory. The path of the cable channel is regarded as an edge, the length of the path is used as a weight value, and the intersection points between paths are used as nodes to construct a graph data structure. Then, the shortest path search algorithm can be applied to realize the application of optical cable laying; the A* algorithm is used to find the optimal path of the cable. The conventional cable laying algorithm is the Dijkstra algorithm, whose main feature is to expand layer by layer outward from the starting point until it reaches the end point. However, since it traverses and calculates many nodes, its efficiency is low. This invention uses the A* algorithm to realize cable laying. As a static and heuristic algorithm, the A* algorithm has the advantage of high efficiency compared with other static path algorithms such as Dijkstra; the cable automatic arrangement algorithm is used to digitally and automatically lay and arrange the cables in the substation, which can automatically lay the cables in a standardized stratified and sectionalized manner, and can also avoid the cable intersections according to the actual situation, which can greatly improve the safety and stability of power projects.

[0070] Embodiment 1

[0071] An intelligent design method for secondary electrical cables in a substation includes:

[0072] S100, constructing a cable intelligent design model according to the position of the cable and the cable channel;

[0073] The laying positions of the cable lines include indoor and outdoor, and are commonly found in places such as buildings, factories, and underground pipelines.

[0074] Indoor laying positions include: Walls: The common power supply method for cable lines is to lay them longitudinally on the walls to meet the electricity demand in different places, such as household power sockets. Floor: In commercial, hotel, hospital and other places, multiple cable lines often need to be laid to meet different uses. The cable lines laid on the floor are usually protected to prevent people from stepping on them. Cable tray: This kind of facility is usually used in indoor computer rooms, factories, terminals, etc. It has high safety, can support the laying of cable lines stably for a long time, and can be replaced or maintained at any time. Outdoor laying positions include: Large construction sites: In places such as highway, bridge, high-speed rail construction where conventional construction is required, cable lines often need to be laid temporarily to support the construction. Underground pipelines: Due to the large depth and good protection performance of the pipelines, cable lines are often used in underground pipelines to provide functions such as power supply, communication, and television. Buried: Cable lines are often used for underground burial in outdoor public places, such as parking lots, parks, squares, etc., to cooperate with public power sources. In the embodiments of the present invention, the design is mainly aimed at the laying of outdoor cables.

[0075] As a preferred embodiment, the cable intelligent design model is a mathematical model. Since the position of the cable remains unchanged, a static model is selected to simulate the cable laying. The static model means that the relationships between the quantities of the system to be described do not change with time and are generally expressed by algebraic equations. The position of the cable is regarded as a point in the cable intelligent design model, and then specific relationships between each point in the cable intelligent design model are established based on graph theory. The points represent the positions of cable laying, and the lines connecting two points represent the relationship between the corresponding two cables.

[0076] S200, calculate the optimal path of cable laying according to the cable intelligent design model by using the A* algorithm;

[0077] The A* algorithm is a kind of heuristic search algorithm. It is an algorithm that finds the lowest passing cost for a path with multiple nodes on a graphic plane. The A* algorithm, like the Dijkstra algorithm, can find the shortest path; and like the BFS, it conducts heuristic search. The core part of the A* algorithm lies in the design of its evaluation function: f(n)=g(n)+h(n), where f(n) is the evaluation value of each possible exploration point, and it consists of two parts: one part is g(n), which represents the cost from the starting search point to the current point (usually represented by the depth of a certain node in the search tree). The other part, that is, h(n), represents the most important part in heuristic search, that is, the evaluation value from the current node to the target node. The quality of the design of h(n) directly affects whether the heuristic algorithm with this kind of heuristic function can be called the A* algorithm. A sufficient condition for a heuristic algorithm with the strategy of f(n)=g(n)+h(n) to become the A* algorithm is that there exists an optimal path from the starting point to the end point on the search tree.

[0078] The problem domain is finite. The search cost value of the children nodes of all nodes > 0. When the above conditions are all satisfied, a heuristic algorithm with the strategy of f(n)=g(n)+h(n) can become the A* algorithm and will surely find the optimal solution.

[0079] The basic steps of the A* algorithm include: putting the starting node S into the OPEN list and setting the CLOSE list to be empty. At the beginning of the algorithm: If the OPEN list is not empty, take a node n from the head of the list; if it is empty, the algorithm fails. Determine whether n is the target solution. If so, find a solution (continue to search or terminate the algorithm). Expand all the successor nodes of n, that is, the nodes (children nodes) that can be directly associated with n. If they are not in the CLOSE list, put them into the OPEN list, put n into the CLOSE list, and at the same time calculate the estimated value f(n) of each successor node. Sort the OPEN list according to f(x), with the smallest one at the head of the list. Repeat the algorithm and go back to 1. The connection between the A* algorithm and the breadth-first, depth-first, and Dijkstra algorithms is that when g(n)=0, the algorithm is similar to DFS; when h(n)=0, the algorithm is similar to BFS. And at the same time, if h(n) is 0, only g(n) needs to be calculated, that is, the shortest path from the starting point to any vertex n is found, and it is transformed into a single-source shortest path problem, that is, the Dijkstra algorithm. This can be obtained by setting h(n) to 0 or g(n) to 0 in the specific process of the above A* search tree.

[0080] S300, adopt the cable automatic arrangement algorithm to lay cables according to the optimal path of cable laying.

[0081] Code for laying of electric power engineering cables. When selecting electric wires and cables, attention should generally be paid to the selection of the types and specifications (conductor cross-sections) of electric wires and cables. Selection of the type of electric wire and cable: When selecting electric wires and cables, the uses, laying conditions and safety should be considered; according to different uses, power cables, overhead insulated cables, control cables, etc. can be selected; according to different laying conditions, general plastic insulated cables, steel tape armored cables, steel wire armored cables, anti-corrosion cables, etc. can be selected; according to safety requirements, non-flammable cables, flame-retardant cables, halogen-free flame-retardant cables, fire-resistant cables, etc. can be selected. Selection of the specifications of electric wires and cables: When determining the use specifications (conductor cross-sections) of electric wires and cables, the selection conditions such as heat generation, voltage loss, economic current density, mechanical strength, etc. should generally be considered. In this application, the cable automatic arrangement algorithm can intelligently select the cable laying method according to the types of cables to be erected, cable models, erection environments, etc. on the cable laying path, such as laying in layers, laying on different sides or laying in different trenches. When selecting electric wires and cables, comprehensive consideration should be given according to the uses of the cables, cable laying conditions and safety. According to different uses of the cables, power cables, overhead insulated cables, control cables, etc. can be selected; according to different laying conditions, general plastic insulated cables, steel tape armored cables, steel wire armored cables, anti-corrosion cables, etc. can be selected; according to safety requirements, non-flammable cables, flame-retardant cables, halogen-free flame-retardant cables, fire-resistant cables, etc. can be selected. Ensure the rationality and safety of cable laying. Digital cable laying can reduce the possibility of more errors, and can also save the time of manual design and improve the cable laying efficiency.

[0082] Preferably, constructing a cable intelligent design model according to the position of the cable and the cable channel includes:

[0083] Fixing the position of the cable;

[0084] Cables are used for transmitting and distributing electric energy. Cables are often used in urban underground power grids, outgoing lines from power stations, internal power supply in industrial and mining enterprises, and underwater transmission lines across rivers and seas. The cable laying method is adjusted according to local conditions and is determined by on-site conditions such as the position of electrical equipment, outgoing line method, groundwater level height, and layout of process equipment. If control cables need to be led to the centralized control room, they should be preferably laid overhead. 6kV cables are laid in tunnels or conduits. When the groundwater level is relatively high, they need to be laid overhead or in conduits. For 380V cables, when the elevation difference between the two ends of the equipment is zero, they are laid in tunnels, trenches or conduits; when one end of the equipment is above and the other end is below, partial overhead laying can be adopted; when the groundwater level is relatively high, overhead cables should be used. The power cable line should ensure safe operation, be convenient for maintenance according to the power supply needs, and fully consider the ground environment, soil data and various underground road facilities to save costs and facilitate construction and other comprehensive factors to determine an economically reasonable line route.

[0085] Take the path of the cable channel as the edge, the length of the path as the weight, and the intersection points between the paths as the nodes to construct a cable intelligent design model.

[0086] The selection of the cable channel needs to save investment and try to choose the path with the shortest distance. The cable path should be selected in combination with the long-term plan and avoid the places that need to be constructed according to the plan as much as possible. The number of times the cable path crosses various pipelines, railways and other power cables should be minimized. Inside the building, the number of times crossing the walls and the floor of the building should be minimized.

[0087] To ensure the safe operation of the cable from being damaged by environmental factors, the cable should not be affected by external mechanical forces, chemical corrosion, vibration, geothermal heat, etc. When there are drainage ditches, gas pipelines, main water supply pipes, weak current lines, etc. on one side of the road, the power cable should be laid on the other side of the road. The directly buried cable should avoid the places that need to be excavated on the upper layer of the planned building to prevent the cable from being damaged and corroded. The directly buried cable must be armored and protected against corrosion. In the plane design, try to choose a short and straight path as much as possible. Manholes should be set when using concrete pipe blocks or pipe rows for laying, and manhole wells should also be set at the places where the cable branches, turns, in the catch basin and where there is a large elevation difference in the area. The distance between manhole wells is not more than 50m. Try to avoid and reduce crossing underground pipelines (including heat pipelines, up and down water pipelines, gas pipelines), highways, railways and communication cables. The selection of the cable laying method generally needs to be considered from three aspects: saving investment, convenient construction and safe operation. The direct burial of the cable is the most convenient for construction, the lowest in cost and better in heat dissipation, and should be preferred. When determining the cable structure, the expansion plan should be combined and spare supports and holes should be reserved.

[0088] The graph data structure is composed of two elements: vertices and edges. The path of the cable channel can be regarded as an edge, the length of the path as the weight, and the intersection points between the paths as the nodes to construct the graph data structure. Then, the shortest path search algorithm can be applied to realize the application of optical cable laying. The relevant mathematical model is as Figure 2 shown in a typical weighted directed graph.

[0089] Preferably, using the A* algorithm to calculate the optimal path of cable laying according to the cable intelligent design model includes:

[0090] Mark the starting point and calculate the estimated cost value of the first path from the starting point to the end point;

[0091] The estimated cost value is expressed as F(n) = G(n) + H(n), where G(n) is the actual cost from the initial state to state n in the cable intelligent design model; H(n) is the estimated cost of the best path from state n to the target state;

[0092] Select the intermediate point with the lowest estimated cost value of the first path as the starting point for the next path planning;

[0093] Traverse each point until reaching the end point from the initially marked starting point.

[0094] The A* algorithm is used to find the optimal path of the optical cable. The conventional cable laying algorithm is the Dijkstra algorithm, whose main feature is to expand layer by layer outward from the starting point until reaching the end point. The Dijkstra algorithm can obtain the optimal solution of the shortest path, but due to the large number of nodes it traverses and calculates, its efficiency is low.

[0095] This software uses the A* algorithm to implement cable laying:

[0096] As a static, heuristic algorithm, the A* algorithm has the advantage of high efficiency compared to other static path algorithms such as Dijkstra. The basis for choosing the A* algorithm for cable laying: The path nodes in cable laying belong to static nodes and do not change dynamically, meeting the static characteristics of the A* algorithm; The greatest advantage of the A* algorithm lies in its search speed, and the cable laying path nodes are relatively not particularly complex (the branches of each node generally do not exceed 4), so the impact on the search accuracy can be ignored, and the search speed has a significant improvement compared to the Dijkstra algorithm; During the process of finding the cable laying path, not only the distance factor between two nodes needs to be considered, but also some other additional influencing factors such as cable type and floor area ratio need to be considered. This characteristic is very suitable for the heuristic algorithm because we can influence its estimated cost by controlling the heuristic function (for example, the cost of two nodes that do not meet the floor area ratio requirements can be set to infinity). When there are more influencing factors in the future, the algorithm can be better extended. A topological structure based on graph theory is constructed according to cable trenches, buried pipes and electrical equipment, and node numbers are automatically generated. These node numbers will ultimately also be reflected in the cable inventory, used to describe which nodes a cable passes through, as shown in Figure 3.

[0097] Preferably, using the cable automatic arrangement algorithm to lay cables according to the optimal path of cable laying includes:

[0098] Lay the cables in trenches, on different sides and in different layers along the optimal path;

[0099] Separate trench laying means burying different types of cables in different cable trenches. A cable trench is an underground conduit used for laying and replacing power or telecommunications cable facilities. It is also the enclosure structure for the laid cable facilities, with pipe structure forms such as rectangular, circular, and arched. Cable brackets are installed in the cable trench. Cable brackets are usually made of metal materials and are fixed to the trench wall by welding or screws. The cables are supported by the brackets and kept at a certain distance from the trench bottom. Fire prevention measures are usually taken for the cables in the cable trench, including painting fireproof coatings, blocking and isolating, etc. Commonly used cable trenches include underground cable trenches, cable tunnels, direct cable burial, and cable pipe threading. Cable tunnels and direct cable burial are widely used. In substation engineering, commonly used cable trenches include cable tunnels, above-ground cable trenches, and underground cable trenches. Cable tunnels are used for power cables, and above-ground and underground cable trenches are used for control cables. Sometimes cable pipe threading is used locally.

[0100] When laying cables, a cable rack is also needed to lay the cables in layers. A cable rack is a device used to support and fix cables, usually made of metal. The main function of the cable rack is to ensure the stability of the cables during the laying process, preventing the cables from sagging or being damaged. It is usually installed in environments such as underground or trenches with harsh conditions, so it needs to have performance characteristics such as anti-corrosion, fire prevention, waterproof, high temperature resistance, high strength, and long life to ensure the safety of the cable system. Laying the cables in layers can ensure the safety and stability of the cable system.

[0101] The purpose of separate side laying of cables is to avoid the cables passing through too many complex environments during the laying process. If the cables are buried along the roadside or the edge of a building, they need to be laid in a straight line. Cable direction signs should be set at every 20m at the turning points and straight sections.

[0102] The cable automatic arrangement algorithm is used to adjust the cables after classified laying.

[0103] Cable trench laying refers to a cable installation method of laying cables in a pre-built cable trench. It is applicable to cable line paths with relatively light ground load, such as sidewalks, factory sites, etc.

[0104] Cable trenches generally adopt concrete or brick structures, and their tops are covered with covers. The cover surface can be flush with the ground for easy opening, or slightly lower than the ground with a layer of cement painted on the cover to prevent the cover from being uneven with the ground and rainwater from entering the cable trench. According to the number of cables laid, the cables can be placed singly on the bottom of the cable trench, or placed in layers on the brackets in the cable trench. Most use the latter form. The cables placed in layers have longitudinal and transverse spacings. Cable brackets can be installed on one side or both sides of the cable trench according to the number of cables laid. There is a certain width of passage between the brackets on both sides or between the brackets and the side wall of the cable trench (single-sided brackets). In order to prevent fire, yellow sand can also be filled in the cable trench.

[0105] For each shelf of the upper bracket on the cable channel, the types of cables that can be placed can be set, and a cable specification library is established to store cables with general specifications and their corresponding cable types, outer diameters, voltage levels and other parameters. When a cable is laid, when the automatic arrangement algorithm is applied, it is judged which types of cables can be placed on each layer. Only optical cables can be arranged on the shelves with matching types, as Figure 4 shown.

[0106] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0107] Obtain the position of the center line of the cable path and the switchgear cabinet;

[0108] Calculate on which side of the path the switchgear cabinet is located through the space vector algorithm. Let a be one end of the switchgear cabinet, b be the other end of the switchgear cabinet, and λ be the length of the switchgear cabinet;

[0109] Calculate the positional relationship between point a and point b and the center line of the cable path;

[0110] When point a and point b are on the same side of the center line, judge on which side of the cable the switchgear cabinet is located. When point a and point b are on different sides of the center line, judge the lengths occupied by λ at both ends of the center line respectively;

[0111] The length occupied by λ at one end of the center line is expressed as:

[0112] where is the abscissa of point a, is the ordinate of point a, is the abscissa of the intersection point of the switchgear cabinet and the center line, is the ordinate of the intersection point of the switchgear cabinet and the center line;

[0113] When the cable is laid on the connection channel of the end device, it is laid on the bracket closer to the end of the switchgear cabinet. Obtain the coordinates of the cable, calculate the distances between the cable coordinates and points a and b, and start laying the cable from the point with the smaller distance. Optical cables are preferentially arranged on the brackets on the side of the switchgear cabinet. Establish a mathematical model of the path center line and the switchgear cabinet, calculate on which side of the path the switchgear cabinet is located through the space vector algorithm, and this rule needs to be preferentially considered during the laying process. The mathematical model is as Figure 5 shown. When the cable is laid on the connection channel of the end device, it is preferentially laid on the bracket closer to the end switchgear cabinet

[0114] Preferably, the adjustment of the cables after classified laying by using the cable automatic arrangement algorithm includes:

[0115] When laying on a switching path, select the bracket on the same side;

[0116] When laying on the shelf, lay the cable in the outer direction relative to the already laid cable, obtain the position data of the already laid cable, and design the installation position of the cable to be laid according to the position data of the already laid cable.

[0117] Optical cable intersection avoidance algorithm. When laying on the switching path, it will tend to select the same-side support, and when laying on the shelf, it will tend to lay the cable in the outer direction relative to the already laid cable so that the laid cables will not intersect. The specific algorithm process is as Figure 6 shown. When laying the cable, it achieves the avoidance effect by preferentially selecting the same-side position for laying.

[0118] Preferably, the cable automatic arrangement algorithm is used to adjust the cables after classified laying, including:

[0119] Determine the number of buried pipes according to the number of cables passing through the center line of the buried pipe, select the buried pipe specification to determine the inner diameter of the buried pipe and the maximum number of columns of the buried pipe arrangement, and calculate the width and height of the buried pipe arranged in a rectangle;

[0120] The width of the buried pipe arranged in a rectangle is expressed as:

[0121]

[0122] The height of the buried pipe arranged in a rectangle is expressed as:

[0123]

[0124] where r is the inner diameter of the buried pipe, is the number of horizontal buried pipes, and m is the number of vertical buried pipes.

[0125] As another preferred embodiment, the present invention determines the number of buried pipes DPC according to the number of cables passing through the center line of the buried pipe, selects the buried pipe specification to determine the inner diameter of the buried pipe Dn and the maximum number of columns of the buried pipe arrangement MC, calculates the width and height of the buried pipe arranged in a rectangle. When the buried pipe is less than one row, its width is DPC * Dn and its height is Dn. Otherwise, the width is Dn * MC and the height is the rounded-up number DPR * Dn of DPC / MC. The arrangement direction of the buried pipe is arranged from bottom to top and from left to right in sequence.

[0126] Preferably, the cable automatic arrangement algorithm is used to adjust the cables after classified laying, including:

[0127] Sort the cables according to the laying algorithm. The cables are stacked on the shelf. The maximum cable diameter in each stacked layer is used as the layer height of this stacked layer. The starting calculation position of the next stacked layer is the height offset from the maximum diameter cable in the previous stacked layer;

[0128] Calculate the laying quantity of the cable according to the volume ratio set on the channel;

[0129] The floor area ratio of each layer rack is expressed as:

[0130]

[0131] where is the length of each layer rack, is the width of each layer rack, is the radius of the i-th cable, is the length of the i-th cable, and n is the number of cables;

[0132] When each layer rack is laid to the floor area ratio, it will search for the laying position on another eligible layer rack and perform the laying, and calculate the actual laying position on the layer rack;

[0133] When the floor area ratio of the cables on a layer rack reaches the upper limit, search for the next eligible layer rack to place them.

[0134] Calculation of the floor area ratio of optical cables in the channel. For the cables laid on the layer rack, the cables are sorted according to the laying algorithm, the cables are stacked on the layer rack, and the maximum cable diameter in each stacked layer is used as the floor height of this stacked layer. The starting calculation position of the next stacked layer is the height offset from the maximum diameter cable in the previous stacked layer, as Figure 7 shown. When calculating by the laying algorithm, the laying quantity of the cables is controlled according to the floor area ratio set on the channel. When each layer rack is laid to the floor area ratio, it will search for the laying position on another eligible layer rack and perform the laying, and calculate the actual laying position on the layer rack. When the floor area ratio of a certain layer of cables reaches the upper limit, then this layer cannot be placed, and it is necessary to search for another eligible layer rack to place them.

[0135] Embodiment 2

[0136] An intelligent design system for secondary electrical cables in a substation, comprising:

[0137] A cable model generation module, used to construct an intelligent design model of cables according to the positions of the cables and the cable channels;

[0138] A cable path generation module, used to calculate the optimal path of cable laying according to the intelligent design model of cables by using the A* algorithm;

[0139] A cable laying design module, used to perform cable laying according to the optimal path of cable laying by using the cable automatic arrangement algorithm.

[0140] Embodiment 3

[0141] An electronic device includes: a chip, a processor, and a memory. The memory is used to store computer program code, and the computer program code includes computer instructions. When the chip executes the computer instructions, the electronic device executes an intelligent design method for secondary electrical cables in a substation.

[0142] Reference Figure 8 , the electronic device 2 includes a processor 21, a memory 22, an input device 23, and an output device 24. The processor 21, the memory 22, the input device 23, and the output device 24 are coupled through a connector. The connector includes various interfaces, transmission lines, buses, etc., and the embodiments of the present invention do not limit this. It should be understood that in various embodiments of the present invention, coupling means being interconnected in a specific manner, including being directly connected or indirectly connected through other devices. For example, they can be connected through various interfaces, transmission lines, buses, etc.

[0143] The processor 21 can be one or more graphics processing units (GPUs). When the processor 21 is a single GPU, the GPU can be a single-core GPU or a multi-core GPU. Optionally, the processor 21 can be a processor group composed of multiple GPUs, and multiple processors are coupled to each other through one or more buses. Optionally, the processor can also be other types of processors, etc., and the embodiments of the present invention do not limit this.

[0144] The memory 22 can be used to store computer program instructions and various computer program codes including the program code for executing the solution of the present invention. Optionally, the memory includes but is not limited to random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or compact disc read-only memory (CD-ROM), and the memory is used for relevant instructions and data.

[0145] The input device 23 is used to input data and / or signals, and the output device 24 is used to output data and / or signals. The output device 24 and the input device 23 can be independent devices or an integrated device.

[0146] The beneficial effects of the present invention are as follows: 1. A mathematical model is constructed based on graph theory. The path of the cable channel is regarded as an edge, the length of the path is used as the weight value, and the intersection points between the paths are regarded as nodes to construct a graph data structure. Furthermore, the application of the shortest path search algorithm can be used to realize the laying of optical cables; 2. The A* algorithm is used to search for the optimal path of the cable. The conventional cable laying algorithm is the Dijkstra algorithm, whose main feature is to expand layer by layer outward from the starting point until the end point is reached. However, due to the large number of nodes it traverses and calculates, its efficiency is low.

[0147] The present invention uses the A* algorithm to realize cable laying. As a static and heuristic algorithm, the A* algorithm has the advantage of high efficiency compared with other static path algorithms such as Dijkstra; 3. The cable automatic arrangement algorithm is adopted to digitally and automatically lay and arrange the cables in the substation. It can automatically lay the cables in a standardized layered and classified manner, and can also avoid the cable intersections according to the actual situation, which can greatly improve the safety and stability of the power project.

[0148] The above are only the specific implementation manners of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather will conform to the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for intelligent design of secondary cables for substation electrical systems, characterized in that: include: Build a cable intelligent design model based on the cable location and cable channel; The A* algorithm is used to calculate the optimal path for cable laying based on the cable intelligent design model; Use automatic cable arrangement algorithm to lay cables according to the optimal cable laying path; The automatic cable arrangement algorithm intelligently selects the cable laying method based on the cable type, cable model, and installation environment required on the cable laying path. When selecting wires and cables, it comprehensively considers the cable's purpose, cable laying conditions, and safety. The cable laying method is also determined based on the location of electrical equipment, the way the cables are routed, the height of the groundwater level, and the arrangement of process equipment; The method of using an automatic cable arrangement algorithm to lay cables according to an optimal cable laying path includes: Lay the cables in trenches, sides and layers along the optimal path; The cables laid out in categories are adjusted using an automatic cable arrangement algorithm, and the adjustment includes: (1) Obtain the position of the center line of the cable path and the screen cabinet, and calculate the positional relationship between the center line and the endpoints of the screen cabinet; if the endpoints of the screen cabinet are on the same side of the center line, determine which side of the cable the screen cabinet is located on; if the endpoints of the screen cabinet are on different sides of the center line, determine the length of the screen cabinet at both ends of the center line; when laying the cable on the end device connection channel, choose to lay it on the bracket close to the endpoints of the screen cabinet, obtain the coordinates of the cable, calculate the distance between the cable coordinates and the endpoints of the screen cabinet, and choose the point with the smallest distance to start laying the cable; (2) When laying cables on a switching path, select the bracket on the same side; when laying cables on a shelf, lay the cables in the outer direction relative to the cables that have already been laid, obtain the position data of the cables that have already been laid, and design the installation position of the cables to be laid based on the position data of the cables that have already been laid; The specific algorithm for avoiding optical cable intersections is: path distance * path distance weight coefficient + bracket side * bracket side weight coefficient + shelf * shelf weight coefficient + shelf placement position weight {placement stacking layer * stacking layer weight coefficient + distance to the corresponding laying position in the current stacking layer * stacking layer distance weight coefficient}; (3) Determine the number of buried pipes based on the number of cables passing through the center line of the buried pipes, select the buried pipe specifications to determine the buried pipe inner diameter and the maximum number of rows of buried pipes, and calculate the width and height of the buried pipes arranged in a rectangular shape; (4) Arrange the cables according to the laying algorithm and stack them on the shelves. The largest cable diameter in each stacked layer is used as the layer height of the stacked layer. The starting calculation position of the next stacked layer is the height of the cable with the largest diameter offset from the previous stacked layer. The laying quantity of cables is calculated according to the volume ratio set on the channel. When a shelf is laid to the volume ratio, the laying position will be found on another shelf that meets the conditions and the cables will be laid. The actual laying position on the shelf will be calculated. When the cable volume ratio of a shelf reaches the upper limit, the next shelf that meets the conditions will be found for placement.

2. The intelligent design method for substation electrical secondary cables according to claim 1, characterized in that: The construction of the cable intelligent design model according to the cable position and the cable channel includes: Fix the position of the cable; The paths of cable channels are taken as edges, the lengths of the paths as weights, and the intersections between the paths as nodes to construct an intelligent cable design model.

3. The intelligent design method for substation electrical secondary cables according to claim 1, characterized in that: The method of using the A* algorithm to calculate the optimal path for cable laying according to the cable intelligent design model includes: Mark the starting point and calculate the estimated cost of the first path from the starting point to the end point; The estimated cost value is expressed as F(n) = G(n) + H(n), where G(n) is the actual cost from the initial state to state n in the cable intelligent design model; H(n) is the estimated cost of the optimal path from state n to the target state; Select the middle point with the lowest estimated cost on the first path as the starting point for the next path planning; Iterate through each point until you reach the end point from the initially marked starting point.

4. A substation electrical secondary cable intelligent design system designed according to any one of claims 1 to 3, characterized in that: include: Cable model generation module, used to build a cable intelligent design model based on the cable location and cable channel; The cable path generation module is used to calculate the optimal path for cable laying based on the cable intelligent design model using the A* algorithm; The cable laying design module is used to lay cables according to the optimal cable laying path using an automatic cable arrangement algorithm.

5. An electronic device, characterized in that: include: A chip, a processor and a memory, wherein the memory is used to store computer program code, the computer program code includes computer instructions, and when the chip executes the computer instructions, the electronic device executes a substation electrical secondary cable intelligent design method according to any one of claims 1 to 3.

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