A method and system for constructing GIS data models for power grid objects

Abstract

This invention discloses a method and system for constructing a GIS data model for power grid objects. The method includes: collecting power plant data to design a power grid GIS data model for the power plants; expanding the power plant GIS data model by designing GIS data models for ordinary lines and complex lines, and improving the GIS data model for complex lines based on the ordinary line model; and processing the expanded complex line GIS data model using the nearest neighbor method. This invention uses the nearest neighbor method to select the branch points of the lines, minimizing the length of the branch lines, which conforms to practical applications and avoids excessively long lines or line overlay affecting the display effect. Simultaneously, the nearest neighbor method in the model eliminates the need for data integration, effectively saving the workload of developers and engineers.

Description

Technical Field

[0001] This invention relates to the field of power grid modeling technology, and in particular to a method and system for constructing GIS data models for power grid objects. Background Technology

[0002] Power grid GIS (Geographic Information System) visualization platforms based on geographic information technology have been widely used in smart grid systems, covering multiple aspects such as power generation, transmission, substation, distribution, and consumption. Among these, power grid dispatching has the greatest demand for and widest application of geographic information visualization platforms. Modules such as external meteorological information, fault location, and comprehensive new energy display in the new generation of power grid dispatching systems all require the support of GIS visualization technology. As a fundamental component of the power grid GIS visualization system, the power grid GIS data model plays a crucial role in data organization, management, and querying, and is fundamental to ensuring the stable operation of the power grid GIS visualization system.

[0003] Currently, GIS data in power grid dispatching systems mainly includes substation, power plant, and converter station data, as well as transmission line data, primarily consisting of transmission towers and AC / DC lines. This data is stored in a dedicated relational database for the power grid in the form of relational tables. Spatial and attribute data are stored as a unified whole within the relational database without separate distinction. Therefore, spatial data stored in the relational database cannot be used directly and requires complex integration processing before it can be applied to the power grid GIS visualization system. This hinders rapid loading of spatial data and results in high costs. Furthermore, the complex logical structure between multiple relational tables often leads to duplicate data, causing data redundancy.

[0004] Moreover, in the context of the construction of the new generation of power grid dispatching system, the existing power grid GIS data model construction methods and devices based on the D5000 system are no longer able to meet the requirements of the new power system due to their low efficiency and lack of scalability. In order to better adapt to the construction of the new generation of power grid dispatching system, it is necessary to design a new GIS data model oriented towards power grid objects. Summary of the Invention

[0005] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0006] In view of the aforementioned existing problems, this invention is proposed. Therefore, this invention provides a GIS data model construction method for power grid objects, to solve the problems of data redundancy, low efficiency, and lack of scalability in power grid dispatching systems in practical applications.

[0007] To address the aforementioned technical problems, this invention provides the following technical solution: a method for constructing a GIS data model for power grid objects, comprising:

[0008] By collecting data from power plants and substations, a power grid GIS data model for power plants and substations is designed.

[0009] The power grid GIS data model of the plant is extended, and power grid GIS data models for ordinary lines and complex lines are designed respectively. The power grid GIS data model for complex lines is improved based on the power grid GIS data model for ordinary lines.

[0010] The nearest neighbor method was used to process the expanded complex power grid GIS data model.

[0011] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, the plant data includes: power plant data, substation data, and converter station data.

[0012] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, the method includes: designing a power grid GIS data model for power plants and substations, comprising:

[0013] The power plant data, substation data, and converter station data are treated as a single object, with the plant / station number, plant / station name, plant / station type, plant / station voltage level, longitude, latitude, and grid ID as the design information.

[0014] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, the design of a power grid GIS data model for ordinary power lines includes:

[0015] Ordinary power lines are usually connected in series with multiple tower points in sequence. The line has only one starting point and one ending point and no branch lines.

[0016] Based on the definition of ordinary lines mentioned above, all ordinary lines in the power grid are treated as a single object. The power grid GIS data model of ordinary lines is designed sequentially according to the line number, line name, line voltage level, coordinates of the starting and ending power plants, coordinates of the towers, and tower coordinates.

[0017] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, the design of a power grid GIS data model for complex lines includes:

[0018] Complex power grid lines include T-connected lines and Π-connected lines;

[0019] Based on the definitions of T-connected lines and Π-connected lines, T-connected lines and Π-connected lines are regarded as the same power grid object. The power grid GIS data model of complex lines is designed according to the line number, line name, line voltage level, branch point coordinates, line starting station coordinates, line ending station coordinates, line T connection ending point coordinates, and tower coordinates.

[0020] Among them, the T-connection line is a T-shaped line model, which usually includes one starting point, two ending points and one branch point. The branch point is a special point on the main line, and the branch point connects to other substations; the Π-connection line includes one starting point and multiple ending points. The Π-connection line will branch off two branches on the main line, and the line model presents a Π shape.

[0021] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, the method involves processing the expanded complex power grid GIS data model using the nearest neighbor method, including:

[0022] Find the point on the main line that is closest to the third-party substation, and use this point as a branch point of the main line to connect with the third-party substation.

[0023] As a preferred embodiment of the GIS data model construction method for power grid objects described in this invention, it further includes:

[0024] The tower line is considered as several line segments, and the nearest point is calculated for each line segment;

[0025] The nearest point is calculated for each line segment using the azimuth method, which calculates the azimuth angle from point C to endpoints A and B of line segment AB. Based on the different azimuth angles, AC, BC, and the perpendicular line from C to AB are determined. Based on the line segment with the shortest distance among the three lines, each line segment is iterated in turn to find the shortest distance point.

[0026] A GIS data model construction system for power grid objects includes:

[0027] The power grid GIS data model design module for power plants and substations designs a power grid GIS data model for power plants and substations by collecting power plant and substation data.

[0028] The power grid GIS data model design module for ordinary and complex lines extends the power grid GIS data model of the substations, designs power grid GIS data models for ordinary and complex lines respectively, and improves the power grid GIS data model for complex lines based on the power grid GIS data model for ordinary lines.

[0029] The power grid GIS data model processing module for complex lines uses the nearest neighbor method to process the expanded power grid GIS data model for complex lines.

[0030] A computer device includes a memory and a processor, the memory storing a computer program, wherein the processor executes the computer program to implement any step of the method described above.

[0031] A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements any step of the above-described method.

[0032] Compared with existing technologies, the beneficial effects of this invention are as follows: This invention collects power plant data and designs a power grid GIS data model for power plants; it expands the power grid GIS data model of power plants by designing power grid GIS data models for ordinary lines and complex lines respectively, and improves the power grid GIS data model for complex lines based on the power grid GIS data model for ordinary lines; it uses the nearest neighbor method to process the expanded power grid GIS data model for complex lines; this invention uses the nearest neighbor method to select the branch points of the lines, which can minimize the length of the branch lines, conforming to the actual application situation and avoiding the impact of excessively long lines or line overlay on the display effect; at the same time, the nearest neighbor method applied to the model can eliminate the data integration step, effectively saving the workload of developers and engineers. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0034] Figure 1 This is a flowchart illustrating the overall process of constructing a GIS data model for power grid objects according to an embodiment of the present invention.

[0035] Figure 2 This is a power plant model design diagram of the GIS data model construction method for power grid objects according to an embodiment of the present invention;

[0036] Figure 3 This is a design diagram of a general line data model for a GIS data model construction method for power grid objects according to an embodiment of the present invention;

[0037] Figure 4 This is a complex line data model design diagram of the GIS data model construction method for power grid objects according to an embodiment of the present invention;

[0038] Figure 5This is a schematic diagram showing the simulated line display result of the GIS data model construction method for power grid objects according to an embodiment of the present invention;

[0039] Figure 6 This diagram shows a comparison between a traditional model and the model of the present invention for a GIS data model construction method for power grid objects, as described in an embodiment of the present invention. Detailed Implementation

[0040] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail 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 them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0041] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0042] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0043] This invention is described in detail with reference to the schematic diagrams. When detailing the embodiments of this invention, for ease of explanation, the cross-sectional views illustrating the device structure may be partially enlarged, not adhering to the usual scale. Furthermore, the schematic diagrams are merely examples and should not be construed as limiting the scope of protection of this invention. In actual fabrication, the three-dimensional spatial dimensions of length, width, and depth should be included.

[0044] Furthermore, in the description of this invention, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In addition, the terms "first," "second," or "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] Unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" in this invention should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; similarly, they can refer to mechanical connections, electrical connections, or direct connections, or indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] Example 1

[0047] Reference Figures 1 to 5 This is the first embodiment of the present invention, which provides a method for constructing a GIS data model for power grid objects, including:

[0048] S1. By collecting data from power plants and substations, design a power grid GIS data model for power plants and substations;

[0049] Furthermore, the plant and station data includes power plant data, substation data, and converter station data;

[0050] It should be noted that because the above three types of power plant data share similar characteristics, power plant data, substation data, and converter station data are treated as a single object. The power plant number, name, type, voltage level, longitude, latitude, and grid ID are used as design information for reference. Figure 2 ;

[0051] S2. Expand the power grid GIS data model of the plant and substation, design power grid GIS data models for ordinary lines and complex lines respectively, and improve the power grid GIS data model for complex lines based on the power grid GIS data model for ordinary lines.

[0052] Furthermore, ordinary lines are usually connected in series with multiple tower points in sequence, and the line has only one starting point and one ending point, with no branch lines;

[0053] Based on the definition of ordinary power lines mentioned above, all ordinary power lines in the power grid are treated as a single object. A power grid GIS data model for these ordinary power lines is designed sequentially according to the line number, line name, line voltage level, coordinates of the starting and ending substations, and tower coordinates. (Refer to...) Figure 3 ;

[0054] Furthermore, complex power grid lines include T-connected lines and Π-connected lines;

[0055] Furthermore, based on the definitions of T-connected and Π-connected lines, these lines are treated as the same power grid object. A complex power grid GIS data model is designed using information such as line number, line name, line voltage level, branch point coordinates, starting and ending substation coordinates, T-connection endpoint coordinates, and tower coordinates. (Refer to...) Figure 4 ;

[0056] It should be noted that a T-connection line is a T-shaped line model, which usually includes one starting point, two ending points and one branch point. The branch point is a special point on the main line, and the branch point connects to other substations. A Π-connection line includes one starting point and multiple ending points. A Π-connection line will branch off two branches on the main line, and the line model presents a Π shape.

[0057] S3. Process the expanded complex power grid GIS data model using the nearest neighbor method;

[0058] Furthermore, find a point on the main line that is closest to the third-party substation, and use this point as a branch point of the main line to connect with the third-party substation;

[0059] Furthermore, the tower line is considered as several line segments, and the nearest point is calculated for each line segment;

[0060] The nearest point is calculated for each line segment using the azimuth method, which calculates the azimuth angle from point C to endpoints A and B of line segment AB. Based on the different azimuth angles, AC, BC, and the perpendicular line from C to AB are determined. Based on the line segment with the shortest distance among the three lines, each line segment is iterated in turn to find the shortest distance point.

[0061] It should be noted that due to the lack of data collection, the power grid dispatch center cannot obtain the geographical coordinates of the T-connection line branch points, and therefore cannot accurately display the T-connection lines. To compensate for the problems caused by the lack of data, the power grid dispatch system developers generally select the midpoint of the main line as the branch point to connect with the third-party substation, i.e., the center point method. The advantage of this method is that the selection of the branch point is simple and fast, and does not require complex calculations. Although this method is simple and efficient, it is poor in terms of line display effect. On the one hand, the branch lines connected by the center point method may overlap with the main line in the graphic display, causing confusion in the line display. On the other hand, when the line is too long, it will also cause the branch line to be too long, affecting the display effect, see Figure (5-b).

[0062] It should be noted that the nearest neighbor method can minimize the length of the branch lines, which is in line with the actual situation and avoids the display effect being affected by excessively long lines or line overlays, as shown in Figure (5-a); where the points where branch lines 1 and 2 intersect with the main line are the branch points.

[0063] Furthermore, this embodiment also provides a GIS data model construction system for power grid objects, including:

[0064] The power grid GIS data model design module for power plants and substations designs a power grid GIS data model for power plants and substations by collecting power plant and substation data.

[0065] The power grid GIS data model design module for ordinary and complex lines extends the power grid GIS data model of the substations, designs power grid GIS data models for ordinary and complex lines respectively, and improves the power grid GIS data model for complex lines based on the power grid GIS data model for ordinary lines.

[0066] The power grid GIS data model processing module for complex lines uses the nearest neighbor method to process the expanded power grid GIS data model for complex lines.

[0067] This embodiment also provides a computer device applicable to the GIS data model construction method for power grid objects, including:

[0068] The system includes a memory and a processor. The memory stores computer-executable instructions, and the processor executes these instructions to implement the GIS data model construction method for power grid objects as proposed in the above embodiments.

[0069] The computer device can be a terminal, comprising a processor, memory, communication interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, carrier networks, NFC (Near Field Communication), or other technologies. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0070] This embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, it implements the GIS data model construction method for power grid objects as proposed in the above embodiments.

[0071] The storage medium proposed in this embodiment and the data storage method proposed in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0072] Example 2

[0073] Reference Figure 6 This is the second embodiment of the present invention, which provides a method for constructing a GIS data model for power grid objects, including:

[0074] Building a spatial database based on PostGIS;

[0075] Next, configure the PostgreSQL environment;

[0076] It should be noted that PostgreSQL is an object-relational database management system, and environment variables need to be configured before using PostgreSQL;

[0077] Next, run StackBuilder to install PostGIS, with the installation path being the root directory of PostgreSQL, and complete the installation of PostGIS;

[0078] Furthermore, based on the designed three model structures—plant, ordinary line, and complex line—corresponding spatial database structures are built sequentially to facilitate data storage and maintenance.

[0079] Data collection and storage;

[0080] Furthermore, data from power plants, substations, and converter stations are collected using surveying and mapping geographic information data acquisition technology, and the data is entered into the database according to the plant / station number, plant / station name, plant / station type, plant / station voltage level, longitude, latitude, and the ID of the power grid to which it belongs.

[0081] Furthermore, the data for ordinary power lines is entered into the database. The line type is confirmed; if it is an ordinary line, the line table is linked based on the starting and ending power station IDs. The latitude and longitude of the power station are obtained using the table query function, and the latitude and longitude data of the towers are obtained from the tower table based on the line ID to which the tower belongs. The ordinary line data is then entered into the database sequentially according to information such as line number, line name, line voltage level, starting and ending power station coordinates, and tower coordinates.

[0082] Furthermore, complex line data is entered into the database; the line type is confirmed, and if it is a complex line, the terminal ID of the T-connection line or Π-connection line is extracted from the T-connection line or Π-connection line table. Based on the ID information, the latitude and longitude coordinates of the terminal power station are obtained. The latitude and longitude coordinates of the branch point are determined using the latitude and longitude set of ordinary lines and the nearest point method. Then, the complex line data is entered into the database in the following order: line number, line name, line voltage level, branch point coordinates, line start coordinates, line end coordinates, branch line end coordinates 1, branch line end coordinates 2, and tower coordinates.

[0083] Establish spatial topological relationships;

[0084] Furthermore, the data is loaded into the database using ArcGIS software, and then the topology tools in ArcGIS software are used to establish topological relationships for all the loaded power grid spatial data and store the topological relationships to facilitate the query and retrieval of spatial data.

[0085] Power grid map design;

[0086] Furthermore, the collected and stored data is loaded into spatial data visualization software, and then the power grid map is designed, mainly including the icons and color rendering of substations, power plants, and converter stations, the color and style rendering of lines, and the design of map backgrounds.

[0087] Power grid map publishing and display;

[0088] Mapnike technology is used to publish power grid map services. The published map services can be loaded and displayed via the web, enabling the application of GIS data models for power grid objects.

[0089] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of this application can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0090] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0091] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0092] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0093] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0094] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A method for constructing a GIS data model for power grid objects, characterized in that, include: By collecting data from power plants and substations, a power grid GIS data model for power plants and substations is designed. The power grid GIS data model of the aforementioned substation is extended, and power grid GIS data models for ordinary lines and complex lines are designed separately. The power grid GIS data model for complex lines is then improved based on the ordinary line model. Specifically, the design of the power grid GIS data model for ordinary lines includes: Ordinary power lines are usually connected in series with multiple tower points in sequence. The line has only one starting point and one ending point and no branch lines. Based on the definition of ordinary lines mentioned above, all ordinary lines in the power grid are treated as a single object. The power grid GIS data model of ordinary lines is designed in sequence according to the line number, line name, line voltage level, coordinates of the starting and ending power plants, coordinates of the ending power plants, and tower coordinates. Design a GIS data model for a power grid with complex lines, including: Complex power grid lines include T-connected lines and Π-connected lines; Based on the definitions of T-connected lines and Π-connected lines, T-connected lines and Π-connected lines are regarded as the same power grid object. The power grid GIS data model of complex lines is designed according to the line number, line name, line voltage level, branch point coordinates, line starting station coordinates, line ending station coordinates, branch line ending coordinates, and tower coordinates. Among them, the T-connection line is a T-shaped line model, which includes one starting point, two ending points and one branch point. The branch point is a special point on the main line, and the branch point connects to other substations; the Π-connection line includes one starting point and multiple ending points. The Π-connection line will branch off two branches on the main line, and the line model presents a Π shape. The nearest neighbor method is used to process the power grid GIS data model of the expanded complex line. Specifically, it includes finding a point on the main line that is closest to a third-party substation and using this point as a branch point of the main line to connect with the third-party substation.

2. The GIS data model construction method for power grid objects as described in claim 1, characterized in that, The plant data includes: power plant data, substation data, and converter station data.

3. The GIS data model construction method for power grid objects as described in claim 1 or 2, characterized in that, Design a power grid GIS data model for power plants and substations, including: The power plant data, substation data, and converter station data are treated as a single object, with the plant number, plant name, plant type, plant voltage level, longitude, latitude, and grid ID as the design information.

4. The GIS data model construction method for power grid objects as described in claim 3, characterized in that, Also includes: The tower line is considered as several line segments, and the nearest point is calculated for each line segment; The nearest point is calculated for each line segment using the azimuth method, which calculates the azimuth angle from point C to endpoints A and B of line segment AB. Based on the different azimuth angles, AC, BC, and the perpendicular line from C to AB are determined. Based on the line segment with the shortest distance among the three lines, each line segment is iterated in turn to find the shortest distance point.

5. A GIS data model construction system for power grid objects, applied to the method described in any one of claims 1-4, characterized in that, include: The power grid GIS data model design module for power plants and substations collects power plant and substation data and designs a power grid GIS data model for power plants and substations. The power grid GIS data model design module for ordinary and complex lines extends the power grid GIS data model of the substations, designs power grid GIS data models for ordinary and complex lines respectively, and improves the power grid GIS data model for complex lines based on the power grid GIS data model for ordinary lines. The power grid GIS data model processing module for complex power lines uses the nearest neighbor method to process the expanded power grid GIS data model for complex power lines.

6. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that: When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 4.

7. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 4.

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