A method and device for arranging mixed-voltage collector lines in onshore wind farms

Abstract

This invention discloses a method and apparatus for arranging mixed-voltage collector lines in onshore wind farms, belonging to the field of wind farm collector line design. The method includes the following steps: obtaining information such as the location and total number of wind turbine units; obtaining the number of collector lines of each type when the total cost of the collector lines is minimized; clustering the wind turbine units in the wind farm into several wind turbine clusters; obtaining the load power of the wind turbine clusters and allocating the collector lines of the corresponding voltage level to the wind turbine clusters; adjusting the wind turbine clusters so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector lines in that wind turbine cluster; generating a minimum spanning tree for each wind turbine cluster to obtain the shortest connection line between the wind turbine units. The arrangement method provided in this application optimizes the overall arrangement of collector lines in the wind farm, reduces the total number and total length of collector lines, thereby improving the convenience of operation and maintenance and the reliability of the wind power generation system.

Description

Technical Field

[0001] This invention relates to the field of wind farm power collection line design, and more specifically, to a method and apparatus for arranging mixed-voltage power collection lines in onshore wind farms. Background Technology

[0002] As wind power technology matures, high-quality onshore wind resources have been largely exhausted, and wind farms are shifting towards areas with low wind speeds or long-distance power transmission. If large-scale wind farms built in low-wind-speed areas still use the traditional mainstream 35kV voltage level collection lines, it will lead to an increase in circuits and a longer power transmission distance. This will not only increase the cost of collection line cables and result in higher line losses, but also increase the complexity of operation and maintenance and reduce the reliability of the system.

[0003] If wind farms adopt 66kV voltage level collector lines, the number of circuits will be significantly reduced, the power carrying capacity of a single line will be increased, and the total cable length will also be significantly reduced. Compared with the mainstream 35kV voltage level collector lines, using higher voltage level 66kV collector lines can increase the reliability and safety of the lines. Not only will power loss be reduced, but voltage drop can also be effectively controlled. Furthermore, the collector line structure is simpler, the total cable length is reduced, line fault problems will be better resolved, and the reliability of the collector system will be improved.

[0004] Currently, 66kV voltage level collector lines have been widely used in offshore wind farms, but there are no practical application cases in onshore wind farms. This is because if an onshore wind farm uses a 66kV collector line scheme throughout, although it has advantages in reducing the number of circuits, saving cable costs, and controlling voltage drop, the investment in step-up transformer equipment will be significantly increased. On the other hand, although the mainstream 35kV collector line scheme has higher cable investment costs, the key component of this scheme—the medium-voltage transformer—is relatively mature and mass-produced. Therefore, the 35kV collector line scheme has a considerable advantage in the cost of step-up transformer equipment.

[0005] Therefore, how to simplify the line structure, reduce line losses, and improve the safety and reliability of the collection lines while controlling the total cost is a major problem that needs to be solved for long-distance collection systems in large onshore wind farms. Summary of the Invention

[0006] The purpose of this invention is to solve the technical problems of high cable cost and low system reliability in existing wind farms that use traditional mainstream 35kV voltage level collector lines, and to propose a method and device for arranging mixed voltage collector lines in onshore wind farms.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] The first aspect of this invention provides a method for arranging mixed-voltage power collection lines in onshore wind farms, the method comprising the following steps:

[0009] Obtain the total number of wind turbines M in the wind farm, the location information of M wind turbines, the location information of the booster station, and the total load of M wind turbines;

[0010] Based on the formula for calculating the total cost of collector lines, the number of 35kV collector lines and the number of 66kV collector lines are calculated when the total cost C of collector lines is the lowest.

[0011] Based on the K-means clustering algorithm, the M wind turbines are clustered into K wind turbine clusters according to their location information, the number of 35kV collection lines, and the number of 66kV collection lines.

[0012] Calculate and obtain the load power of K wind turbine clusters respectively, and distribute the 35kV and 66kV collector lines to the corresponding wind turbine clusters according to the load power of the K wind turbine clusters.

[0013] Adjust the wind turbine clusters so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector lines in that wind turbine cluster.

[0014] Based on the Prim algorithm, with the booster station as the initial node, a minimum spanning tree is generated for each wind turbine cluster to obtain the shortest connection line between wind turbines in the wind turbine cluster.

[0015] Furthermore, the total cost of the collection line is calculated as follows:

[0016]

[0017] In the formula: α is the number of 35kV collector lines; β is the number of 66kV collector lines; K is the K value of the K-means clustering algorithm; C is the total cost of the collector lines; C SUB For electrical equipment costs; C CABLE For line laying costs; C 35kV Cost of a single 35kV collector line step-up transformer cluster; C 66kV Cost of a single 66kV collector line step-up transformer cluster; C MV Cost of laying a single 35kV collector line; C HV Cost of laying a single 66kV collector line; L i The length of a single 35kV collector line; C iunit Cost per unit length of a 35kV collector line; L j The length of a single 66kV collector line; C junitCost per unit length of a 66kV collector line; S 35kV The maximum wind turbine capacity for each 35kV collection line; S 66kV M represents the maximum wind turbine capacity of each 66kV collection line; M represents the total number of wind turbines in the wind farm; and s represents the rated capacity of a single wind turbine.

[0018] Furthermore, based on the K-means clustering algorithm, according to the location information of M wind turbine units, the number of 35kV collection lines, and the number of 66kV collection lines, the M wind turbine units are clustered into K wind turbine clusters. The steps include:

[0019] K wind turbines are randomly selected from M wind turbines to obtain K cluster centers;

[0020] Calculate the distance between each of the M wind turbine units and the K cluster centers, and assign each wind turbine unit to the cluster center with the closest distance to it to form a wind turbine cluster;

[0021] Repeat the step of assigning wind turbine units to the nearest cluster center until there are no wind turbine units among the M wind turbine units that have not been assigned to a cluster center, thus obtaining K wind turbine unit clusters.

[0022] Furthermore, the step of calculating the distance between each of the M wind turbine units and the K cluster centers includes:

[0023] Establish a coordinate system with the location of the booster station as the origin;

[0024] Convert the coordinates of each wind turbine in the coordinate system into a turbine vector, where the turbine vector of the i-th wind turbine is:

[0025] Convert the coordinates of each cluster center in the coordinate system to a cluster center vector, where the cluster center vector of the j-th cluster center is:

[0026] Based on angle calculation formula: Calculate the angle θ between the unit vector of the wind turbine and the cluster center vector of the cluster center, and calculate the angle between the unit vector of each wind turbine and the cluster center vector of the K cluster centers respectively;

[0027] Based on the distance calculation formula, the distance between the wind turbine and the cluster center is calculated according to the included angle θ, and the distance between each wind turbine and K cluster centers is calculated separately.

[0028] Furthermore, the distance calculation formula is:

[0029]

[0030] In the formula: Let D be the unit vector of the i-th wind turbine; i θ is the distance between the i-th wind turbine and the cluster center; θ is the angle between the turbine vector of the i-th wind turbine and the cluster center vector of the cluster center.

[0031] Furthermore, the steps of calculating and obtaining the load power of K wind turbine clusters respectively, and distributing the 35kV and 66kV collector lines to the corresponding wind turbine clusters according to the load power of the K wind turbine clusters, include:

[0032] Obtain the number of wind turbines, m, in each of the K wind turbine clusters;

[0033] The load power of the wind turbine cluster is calculated based on the number of wind turbines m in the wind turbine cluster and the rated capacity s of a single wind turbine.

[0034] Obtain the load power of K wind turbine clusters, and sort the K wind turbine clusters in ascending order of load power to obtain the wind turbine cluster sequence;

[0035] Alpha 35kV collector lines are assigned to the α wind turbine clusters with the lowest load power in the wind turbine cluster sequence; after the 35kV collector lines are assigned, β 66kV collector lines are assigned to the remaining wind turbine clusters in the wind turbine cluster sequence.

[0036] Furthermore, the step of adjusting the wind turbine clusters so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector lines in that wind turbine cluster includes:

[0037] The load power of the wind turbine cluster is compared with the maximum capacity of the collector lines in the wind turbine cluster. If the load power of the wind turbine cluster exceeds the maximum capacity of the collector lines in the wind turbine cluster, it is determined that the wind turbine cluster is in an overload state. Then, the wind turbine in the wind turbine cluster that is farthest from the cluster center is assigned to the nearest adjacent wind turbine cluster that is not in an overload state.

[0038] Repeat the step of assigning the wind turbine cluster furthest from the cluster center to the nearest adjacent wind turbine cluster that is not overloaded, until there are no overloaded wind turbine clusters among the K wind turbine clusters.

[0039] Furthermore, the step of generating a minimum spanning tree for each wind turbine cluster based on the Prim algorithm, using the booster station as the initial node, to obtain the shortest connection line between wind turbines in the wind turbine cluster, includes:

[0040] Based on the location information of M wind turbine units, an undirected weighted graph T = (V, W) is constructed for each wind turbine cluster in the K wind turbine clusters, and the distance indicated by each line segment in the undirected weighted graph is obtained; where V in the undirected weighted graph is the set of all wind turbine units in the wind turbine cluster, and W is the set of line segments connecting each pair of wind turbine units in the wind turbine cluster.

[0041] Based on Prim's algorithm, a minimum spanning tree is generated for the undirected weighted graph, with all wind turbines in the wind turbine cluster as vertices. The line segments in the minimum spanning tree are subsets of W in the undirected weighted graph, and the minimum spanning tree is an acyclic graph.

[0042] Repeat the steps described above, which use all wind turbines in a wind turbine cluster as vertices to generate a minimum spanning tree for the undirected weighted graph based on the Prim algorithm, until there are no wind turbine clusters among the K wind turbine clusters that have not generated a minimum spanning tree.

[0043] Furthermore, the step of generating a minimum spanning tree for the undirected weighted graph based on Prim's algorithm, using all wind turbines in the wind turbine cluster as vertices, includes:

[0044] Select the booster station as the initial selected vertex;

[0045] Select the vertex that is closest to the already selected vertex in the undirected weighted graph to obtain the updated selected vertices;

[0046] From the unselected vertices in the undirected weighted graph, select the vertex that is closest to the selected vertex to obtain the updated selected vertices; stop the selection when all vertices in the undirected weighted graph are selected vertices, and obtain the minimum spanning tree.

[0047] A second aspect of the present invention provides a hybrid voltage collection line layout device for onshore wind farms, comprising: a location acquisition module, wherein the location acquisition module is used to acquire the location information of wind turbine generators and the location information of booster stations in the wind farm;

[0048] The unit clustering optimization module is used to cluster wind turbines into K wind turbine clusters based on the location information of the wind turbines using the K-means clustering algorithm.

[0049] A load determination module is used to determine whether the load power of the wind turbine cluster exceeds a preset limit.

[0050] A mixed-voltage scheme adjustment module is used to adjust the number of wind turbines in a wind turbine cluster when the load power of the wind turbine cluster exceeds a preset limit, so as to reduce the load power of the wind turbine cluster below the preset limit.

[0051] The minimum spanning tree iteration module is used to generate the minimum spanning tree of each of the K wind turbine clusters based on the Prim algorithm, thereby obtaining the topological connection method between the wind turbines in each wind turbine cluster.

[0052] The beneficial effects of this invention are as follows: Compared with the traditional method of using a single 35kV voltage level collector line, the mixed-voltage collector line layout method provided in this application for onshore wind farms can significantly reduce the total cable length, construction cost, and power loss during power transmission under rated operating conditions. By optimizing the overall layout of collector lines in wind farms, the total number and length of collector lines are reduced, thereby improving the convenience of operation and maintenance and the reliability of wind power generation systems. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of a method for arranging mixed-voltage collection lines in an onshore wind farm, provided in an embodiment of the present invention.

[0054] Figure 2 A schematic diagram showing the optimal wiring method between wind turbine units when a wind farm uses a dual-circuit 35kV voltage level collector line.

[0055] Figure 3 This diagram illustrates the optimal wiring method between wind turbine units when using mixed-voltage collection lines in a wind farm. Detailed Implementation

[0056] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0057] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0058] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0059] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0060] To improve the reliability and safety of power transmission through collection lines and reduce the overall cost of collection lines, please refer to [link / reference needed]. Figure 1 As shown, this embodiment of the invention provides a method for arranging mixed-voltage collection lines in onshore wind farms. In practical applications, this method is used to determine the quantity ratio of collection lines of different voltage levels based on the coordinate positions of wind turbines in the wind farm and the layout requirements of collection lines, connecting the wind turbines in the wind farm to the collection lines of the corresponding voltage levels; and obtaining the overall collection line layout with the lowest total cost. It should be noted that the maximum capacity of wind turbines that can be connected by collection lines of different voltage levels is different. In this embodiment, each double-circuit 35kV voltage level collection line is designed to withstand a maximum wind turbine capacity of 60MW, and each double-circuit 66kV voltage level collection line is designed to withstand a maximum wind turbine capacity of 110MW.

[0061] The main steps in arranging mixed-voltage collector lines for onshore wind farms are as follows:

[0062] Obtain the total number of wind turbines M in the wind farm, the location information of M wind turbines, the location information of the booster station, and the total load of M wind turbines.

[0063] In this step, the location information of the wind turbine and the substation can be the geographical location of the wind turbine and the substation, or the location of the wind farm on the plane coordinates.

[0064] Based on the formula for calculating the total cost of collector lines, the number of 35kV collector lines and the number of 66kV collector lines are calculated when the total cost C of collector lines is minimized.

[0065] In this step, the total cost of the collector line is calculated as follows:

[0066]

[0067] In the formula: α is the number of 35kV collector lines; β is the number of 66kV collector lines; K is the K value of the K-means clustering algorithm; C is the total cost of the collector lines; C SUB For electrical equipment costs; C CABLE For line laying costs; C 35kV Cost of a single 35kV collector line step-up transformer cluster; C 66kV Cost of a single 66kV collector line step-up transformer cluster; C MV Cost of laying a single 35kV collector line; C HV Cost of laying a single 66kV collector line; L i The length of a single 35kV collector line; C iunit Cost per unit length of a 35kV collector line; L j The length of a single 66kV collector line; C junit Cost per unit length of a 66kV collector line; S 35kV The maximum wind turbine capacity for each 35kV collection line; S 66kV M represents the maximum wind turbine capacity of each 66kV collection line; M represents the total number of wind turbines in the wind farm; and s represents the rated capacity of a single wind turbine.

[0068] Understandably, a 35kV collector line step-up transformer cluster represents the set of step-up transformers for all wind turbine units on a corresponding 35kV collector line. The number of 35kV collector lines matches the number of 35kV collector line step-up transformer clusters. Similarly, a 66kV collector line step-up transformer cluster represents the set of step-up transformers for all wind turbine units on a corresponding 66kV collector line. The number of 66kV collector lines matches the number of 66kV collector line step-up transformer clusters. Obtaining the number of 35kV and 66kV collector lines is to determine the K-value of the K-means clustering algorithm, i.e., to determine the number of wind turbine clusters that can be obtained after clustering; α·S 35kV β·S represents the sum of the maximum capacities of all 35kV collector lines in this embodiment. 66kVM represents the sum of the maximum capacities of all 66kV collector lines, and M·s represents the total load of M wind turbine units in the wind farm.

[0069] Based on the K-means clustering algorithm, the M wind turbines are clustered into K wind turbine clusters according to their location information, the number of 35kV power lines, and the number of 66kV power lines.

[0070] In this step, K wind turbines are first randomly selected from M wind turbines to obtain K cluster centers; where K is the sum of the number of 35kV collector lines and the number of 66kV collector lines.

[0071] Calculate the distance between each of the M wind turbine units and the K cluster centers. As one embodiment of this application, when calculating the distance between each wind turbine unit and the K cluster centers, firstly, a coordinate system is established using the location of the booster station as the origin; then, the coordinates of each wind turbine unit in the coordinate system are converted into a unit vector. Schematic, the unit vector of the i-th wind turbine unit is: Convert the coordinates of each cluster center in the coordinate system to a cluster center vector. The cluster center vector of the j-th cluster center is: Based on angle calculation formula: Calculate the angle θ between the turbine vector of the target wind turbine and the cluster center vector of the target cluster center. Repeat the above steps to calculate the angle between the turbine vector of the target wind turbine and the cluster center vectors of the K cluster centers. Based on the distance calculation formula, calculate the distance between the target wind turbine and the target cluster center, and further calculate the distance between the target wind turbine and the K cluster centers.

[0072] In the above technical solution, the distance calculation formula is:

[0073]

[0074] In the formula: Let D be the unit vector of the i-th wind turbine; i θ is the distance between the i-th wind turbine and the cluster center; θ is the angle between the turbine vector of the i-th wind turbine and the cluster center vector of the cluster center.

[0075] Since all the collection lines in a wind farm must be connected to the booster station, and all the booster stations are centrally located in a preset position, the clusters generated by the K-means clustering algorithm using the above distance calculation method are elongated, which optimizes the capacity of the wind turbines in each cluster. Compared with the circular clusters generated by the original K-means clustering using Euclidean distance clustering, the distance between wind turbines can be further reduced.

[0076] After obtaining the distance between the target wind turbine and the K cluster centers, the target wind turbine is assigned to the cluster center with the closest distance to it, forming a wind turbine cluster. The step of assigning the target wind turbine to the cluster center with the closest distance is repeated until there are no wind turbines among the M wind turbines that have not been assigned to a cluster center, thus obtaining K wind turbine clusters.

[0077] Calculate and obtain the load power of K wind turbine clusters respectively, and distribute the 35kV and 66kV collector lines to the corresponding wind turbine clusters according to the load power of the K wind turbine clusters.

[0078] In this step, firstly, the number of wind turbines m in each of the K wind turbine clusters is obtained; based on the number of wind turbines m in the wind turbine cluster and the rated capacity s of a single wind turbine, the load power of the wind turbine cluster is calculated; further, the load power of the K wind turbine clusters is obtained, and the K wind turbine clusters are sorted in order of load power from low to high to obtain the wind turbine cluster sequence; α 35kV collector lines are assigned to the α wind turbine clusters with the lowest load power in the wind turbine cluster sequence; after the 35kV collector lines are assigned, β 66kV collector lines are assigned to the remaining wind turbine clusters in the wind turbine cluster sequence.

[0079] After the α 35kV collector lines and β 66kV collector lines are matched one-to-one with the wind turbine clusters, the wind turbine clusters are adjusted so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector lines in that wind turbine cluster.

[0080] In this step, the load power of the target wind turbine cluster is first compared with the maximum capacity of the collector lines in that cluster. If the load power of the target wind turbine cluster exceeds the maximum capacity of the collector lines, the cluster is considered overloaded. The wind turbine furthest from the cluster center is then moved to the nearest, non-overloaded cluster. This reduces the total number of wind turbines in the target cluster, thus decreasing its load power. This process is repeated until no K wind turbine clusters are overloaded, at which point the adjustment is complete.

[0081] After adjusting the number of wind turbines in each of the K wind turbine clusters, the resulting K wind turbine clusters are determined as a mixed-voltage collection line clustering scheme. Furthermore, based on the Prim algorithm, with the substation as the initial node, a minimum spanning tree is generated for each wind turbine cluster to obtain the shortest connection line between wind turbines in the wind turbine cluster.

[0082] In this step, firstly, based on the location information of M wind turbine units, an undirected weighted graph T = (V, W) of each wind turbine cluster in the K wind turbine clusters is constructed, and the distance indicated by each line segment in the undirected weighted graph is obtained; where V in the undirected weighted graph is the set of all wind turbine units in the wind turbine cluster, and W is the set of line segments connecting each pair of wind turbine units in the wind turbine cluster;

[0083] Based on Prim's algorithm, a minimum spanning tree is generated for the undirected weighted graph, with all wind turbines in the target wind turbine cluster as vertices. The line segments in the minimum spanning tree are subsets of W in the undirected weighted graph, and the minimum spanning tree is an acyclic graph.

[0084] More specifically, taking the steps of generating the minimum spanning tree for any wind turbine cluster as an example: First, select the booster station as the initial selected vertex; select the vertex closest to the selected vertex in the undirected weighted graph to obtain the updated selected vertex; from the unselected vertices in the undirected weighted graph, select the vertex closest to the selected vertex to obtain the updated selected vertex; stop the selection when all vertices in the undirected weighted graph are selected vertices, and obtain the minimum spanning tree of the wind turbine cluster.

[0085] Repeat the above steps until there are no wind turbine clusters in the K wind turbine clusters that have not generated a minimum spanning tree; obtain the optimal layout scheme of the mixed voltage collection line for onshore wind farms.

[0086] Compared with the traditional method of using a single 35kV voltage level collector line, the mixed-voltage collector line layout method provided in this application can significantly reduce the total cable length, construction cost, and power loss during power transmission under rated operating conditions in the wind farm. By optimizing the overall layout of the collector lines in the wind farm, the total number and total length of the collector lines are reduced, thereby improving the convenience of operation and maintenance and the reliability of the wind power generation system.

[0087] This invention also provides an onshore wind farm hybrid voltage collection line layout device in this embodiment, including: a location acquisition module, a turbine clustering optimization module, a load judgment module, a hybrid voltage scheme adjustment module, and a minimum spanning tree iteration module; wherein, the location acquisition module is used to acquire the location information of wind turbines and the location information of the booster station in the wind farm; the turbine clustering optimization module is used to cluster wind turbines into K wind turbine clusters based on the location information of the wind turbines using the K-means clustering algorithm; the load judgment module is used to determine whether the load power of the wind turbine cluster exceeds a preset limit; the hybrid voltage scheme adjustment module is used to adjust the number of wind turbines in the wind turbine cluster when the load power of the wind turbine cluster exceeds the preset limit, so as to reduce the load power of the wind turbine cluster below the preset limit; the minimum spanning tree iteration module is used to generate the minimum spanning tree of each wind turbine cluster based on the Prim algorithm for each of the K wind turbine clusters, and obtain the topological connection method between the wind turbines in each wind turbine cluster. When using the onshore wind farm mixed-voltage collector line layout device provided in the above embodiments to arrange onshore wind farm mixed-voltage collector lines, the above functions can be allocated to corresponding functional modules as needed. That is, the internal structure of the onshore wind farm mixed-voltage collector line layout device can be divided into different functional modules to complete all or part of the functions described above. In addition, the onshore wind farm mixed-voltage collector line layout device and the onshore wind farm mixed-voltage collector line layout method embodiments provided in the above embodiments belong to the same concept. The specific implementation process is detailed in the method embodiments and will not be repeated here.

[0088] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for arranging mixed-voltage collector lines in an onshore wind farm, characterized in that, The method includes the following steps: Obtain the total number of wind turbines M in the wind farm, the location information of M wind turbines, the location information of the booster station, and the total load of M wind turbines; Based on the formula for calculating the total cost of collector lines, the number of 35kV collector lines and the number of 66kV collector lines are calculated when the total cost C of collector lines is the lowest. Based on the K-means clustering algorithm, the M wind turbines are clustered into K wind turbine clusters according to their location information, the number of 35kV collection lines, and the number of 66kV collection lines. Calculate and obtain the load power of K wind turbine clusters respectively, and distribute the 35kV and 66kV collector lines to the corresponding wind turbine clusters according to the load power of the K wind turbine clusters. Adjust the wind turbine clusters so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector lines in that wind turbine cluster. Based on the Prim algorithm, with the booster station as the initial node, a minimum spanning tree is generated for each wind turbine cluster to obtain the shortest connection line between wind turbines in the wind turbine cluster.

2. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 1, characterized in that, The total cost of the collector line is calculated as follows: In the formula: α is the number of 35kV collector lines; β is the number of 66kV collector lines; K is the K value of the K-means clustering algorithm; C is the total cost of the collector lines; C SUB For electrical equipment costs; C CABLE For line laying costs; C 35kV Cost of a single 35kV collector line step-up transformer cluster; C 66kV Cost of a single 66kV collector line step-up transformer cluster; C MV Cost of laying a single 35kV collector line; C HV Cost of laying a single 66kV collector line; L i The length of a single 35kV collector line; C iunit Cost per unit length of a 35kV collector line; L j The length of a single 66kV collector line; C junit Cost per unit length of a 66kV collector line; S 35kV The maximum wind turbine capacity for each 35kV collection line; S 66kV M represents the maximum wind turbine capacity of each 66kV collection line; M represents the total number of wind turbines in the wind farm; and s represents the rated capacity of a single wind turbine.

3. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 2, characterized in that, The K-means clustering algorithm is used to cluster the M wind turbines into K wind turbine clusters based on their location information, the number of 35kV power lines, and the number of 66kV power lines. The steps include: K wind turbines are randomly selected from M wind turbines to obtain K cluster centers; Calculate the distance between each of the M wind turbine units and the K cluster centers, and assign each wind turbine unit to the cluster center with the closest distance to it to form a wind turbine cluster; Repeat the step of assigning wind turbine units to the nearest cluster center until there are no wind turbine units among the M wind turbine units that have not been assigned to a cluster center, thus obtaining K wind turbine unit clusters.

4. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 3, characterized in that, The steps for calculating the distance between each of the M wind turbine units and the K cluster centers include: Establish a coordinate system with the location of the booster station as the origin; Convert the coordinates of each wind turbine in the coordinate system into a turbine vector, where the turbine vector of the i-th wind turbine is: Convert the coordinates of each cluster center in the coordinate system to a cluster center vector, where the cluster center vector of the j-th cluster center is: Based on angle calculation formula: Calculate the angle θ between the unit vector of the wind turbine and the cluster center vector of the cluster center, and calculate the angle between the unit vector of each wind turbine and the cluster center vector of the K cluster centers respectively; Based on the distance calculation formula, the distance between the wind turbine and the cluster center is calculated according to the included angle θ, and the distance between each wind turbine and K cluster centers is calculated separately.

5. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 4, characterized in that, The distance calculation formula is: In the formula: Let D be the unit vector of the i-th wind turbine; i θ is the distance between the i-th wind turbine and the cluster center; θ is the angle between the turbine vector of the i-th wind turbine and the cluster center vector of the cluster center.

6. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 3, characterized in that, The steps of calculating and obtaining the load power of K wind turbine clusters respectively, and distributing the 35kV and 66kV collector lines to the corresponding wind turbine clusters according to the load power of the K wind turbine clusters, include: Obtain the number of wind turbines, m, in each of the K wind turbine clusters; The load power of the wind turbine cluster is calculated based on the number of wind turbines m in the wind turbine cluster and the rated capacity s of a single wind turbine. Obtain the load power of K wind turbine clusters, and sort the K wind turbine clusters in ascending order of load power to obtain the wind turbine cluster sequence; Alpha 35kV collector lines are assigned to the α wind turbine clusters with the lowest load power in the wind turbine cluster sequence; after the 35kV collector lines are assigned, β 66kV collector lines are assigned to the remaining wind turbine clusters in the wind turbine cluster sequence.

7. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 6, characterized in that, The step of adjusting the wind turbine cluster so that the load power of any wind turbine cluster does not exceed the maximum capacity of the collector line in that wind turbine cluster includes: The load power of the wind turbine cluster is compared with the maximum capacity of the collector lines in the wind turbine cluster. If the load power of the wind turbine cluster exceeds the maximum capacity of the collector lines in the wind turbine cluster, it is determined that the wind turbine cluster is in an overload state. Then, the wind turbine in the wind turbine cluster that is farthest from the cluster center is assigned to the nearest adjacent wind turbine cluster that is not in an overload state. Repeat the step of assigning the wind turbine cluster furthest from the cluster center to the nearest adjacent wind turbine cluster that is not overloaded, until there are no overloaded wind turbine clusters among the K wind turbine clusters.

8. The method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 1, characterized in that, The method based on Prim's algorithm, using the substation as the initial node, generates a minimum spanning tree for each wind turbine cluster to obtain the shortest connection line between wind turbines in the cluster. The steps include: Based on the location information of M wind turbine units, an undirected weighted graph T = (V, W) is constructed for each wind turbine cluster in the K wind turbine clusters, and the distance indicated by each line segment in the undirected weighted graph is obtained; where V in the undirected weighted graph is the set of all wind turbine units in the wind turbine cluster, and W is the set of line segments connecting each pair of wind turbine units in the wind turbine cluster. Based on Prim's algorithm, a minimum spanning tree is generated for the undirected weighted graph, with all wind turbines in the wind turbine cluster as vertices. The line segments in the minimum spanning tree are subsets of W in the undirected weighted graph, and the minimum spanning tree is an acyclic graph. Repeat the steps described above, which use all wind turbines in a wind turbine cluster as vertices to generate a minimum spanning tree for the undirected weighted graph based on the Prim algorithm, until there are no wind turbine clusters among the K wind turbine clusters that have not generated a minimum spanning tree.

9. A method for arranging mixed-voltage collector lines in an onshore wind farm according to claim 8, characterized in that, The step of generating a minimum spanning tree for an undirected weighted graph based on Prim's algorithm, using all wind turbines in a wind turbine cluster as vertices, includes: Select the booster station as the initial selected vertex; Select the vertex that is closest to the already selected vertex in the undirected weighted graph to obtain the updated selected vertices; From the unselected vertices in the undirected weighted graph, select the vertex that is closest to the selected vertex to obtain the updated selected vertices; stop the selection when all vertices in the undirected weighted graph are selected vertices, and obtain the minimum spanning tree.

10. A mixed-voltage collector line arrangement device for onshore wind farms, characterized in that, include: A location acquisition module is used to acquire the location information of wind turbines and substations in a wind farm. The unit clustering optimization module is used to cluster wind turbines into K wind turbine clusters based on the location information of the wind turbines using the K-means clustering algorithm. A load determination module is used to determine whether the load power of the wind turbine cluster exceeds a preset limit. A mixed-voltage scheme adjustment module is used to adjust the number of wind turbines in a wind turbine cluster when the load power of the wind turbine cluster exceeds a preset limit, so as to reduce the load power of the wind turbine cluster below the preset limit. The minimum spanning tree iteration module is used to generate the minimum spanning tree of each of the K wind turbine clusters based on the Prim algorithm, thereby obtaining the topological connection method between the wind turbines in each wind turbine cluster.

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