Method for constructing magnetic field model during maintenance of high-voltage circuit breaker in transformer substation

Abstract

This invention provides a method for constructing a magnetic field model during the maintenance of high-voltage circuit breakers in substations, belonging to the field of magnetic field technology for high-voltage circuit breakers in substations. The method includes constructing a spatial model of the substation; obtaining and calibrating the spatial coordinates of the high-voltage circuit breakers in the substation; and obtaining the magnetic induction intensity generated at the high-voltage circuit breakers by energized conductors in the substation based on the spatial coordinates of the high-voltage circuit breakers. The method for constructing a magnetic field model during the maintenance of high-voltage circuit breakers in substations provided by this invention constructs a spatial model of the substation and marks the coordinates of the high-voltage circuit breakers and energized conductors. Based on the coordinates of the energized conductors and the high-voltage circuit breakers, the induced electromotive force generated by the power frequency magnetic field in the substation on the high-voltage circuit breakers can be calculated, thereby determining the actual induced current flowing during the test, improving the accuracy and precision of testing the opening and closing times of high-voltage circuit breakers.

Description

Technical Field

[0001] This invention relates to the field of magnetic field technology for high-voltage circuit breakers in substations, and specifically to a method for constructing a magnetic field model during the maintenance of high-voltage circuit breakers in substations. Background Technology

[0002] Substations typically have multiple high-voltage circuit breakers installed to maintain their stable and safe operation. As crucial electrical components in substation operation, the opening and closing performance of high-voltage circuit breakers is a key focus of maintenance.

[0003] Currently, the testing of the opening and closing performance of high-voltage circuit breakers generally involves measuring their operating time. Existing methods typically involve installing a coupling device on the grounding wire on one side of the high-voltage circuit breaker to couple an induced current onto that wire, and then placing an induced current receiver on the grounding wire on the other side of the circuit breaker to obtain the circuit breaker's opening and closing time. However, in substations, the power frequency magnetic field generated during conduction can affect the value of the induced current, thus reducing the accuracy and precision of the high-voltage circuit breaker opening and closing time test.

[0004] In the process of realizing this invention, the inventors of this application discovered that the above-mentioned solutions in the prior art have the drawback of low measurement accuracy and precision. Summary of the Invention

[0005] The purpose of this invention is to provide a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation. This method has the functions of high measurement accuracy and precision.

[0006] To achieve the above objectives, embodiments of the present invention provide a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation, comprising:

[0007] Construct a spatial model of the substation;

[0008] The spatial coordinates of the high-voltage circuit breakers in the substation are obtained for calibration.

[0009] Based on the spatial coordinates of the high-voltage circuit breaker, the magnetic induction intensity generated at the high-voltage circuit breaker by the live conductor in the substation is obtained.

[0010] Based on the magnetic induction intensity, the induced electromotive force of the closed circuit at the high-voltage circuit breaker is obtained;

[0011] The high-voltage circuit breaker is inspected based on the induced electromotive force.

[0012] Optionally, obtaining the magnetic induction intensity generated at the high-voltage circuit breaker by a live conductor in the substation based on the coordinates of the high-voltage circuit breaker includes:

[0013] Obtain the coordinates of the start and end points of the charged conductor;

[0014] The magnetic flux density of the charged conductor at the high-voltage circuit breaker is calculated according to formula (1).

[0015]

[0016] in, Let μ be the magnetic flux density of the charged conductor at the high-voltage circuit breaker, μ0 be the free permeability, and μ0 = π·10 -7 H / m, i ab R is the current flowing through the charged conductor. Length, θ is the distance from the current element to the high-voltage circuit breaker. a Let θ be the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor. b The angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and end points of the energized conductor.

[0017] Optionally, calculating the magnetic flux density of the charged conductor at the high-voltage circuit breaker according to formula (1) further includes:

[0018] Calculate the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor according to formula (2).

[0019]

[0020] Wherein, sin(θ) a Let ) be the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; T be the perpendicular point of the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; and A be the starting point of the energized conductor. AT l represents the displacement between the starting point and the perpendicular point of the charged conductor. ZA This refers to the displacement of the starting point of the high-voltage circuit breaker and the energized conductor.

[0021] Optionally, calculating the magnetic flux density of the charged conductor at the high-voltage circuit breaker according to formula (1) further includes:

[0022] Calculate the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor according to formula (3).

[0023]

[0024] Wherein, sin(θ) b Let B be the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and end points of the energized conductor, and let Z be the spatial coordinates of the high-voltage circuit breaker. AB l represents the displacement of the starting and ending points of the charged conductor. AT l represents the displacement between the starting point and the perpendicular point of the charged conductor. ZB This refers to the displacement of the termination point of the high-voltage circuit breaker and the energized conductor.

[0025] Optionally, the direction of the magnetic field at the high-voltage circuit breaker can be as shown in formulas (4) and (5).

[0026]

[0027]

[0028] in, The unit vector is the direction of the magnetic field. Let be the unit vector of the line connecting the start and end points of the charged conductor. The unit vector of the line connecting the high-voltage circuit breaker and the termination point of the energized conductor. Let be the vector of the line connecting the start and end points of the charged conductor. Let be the vector of the line connecting the high-voltage circuit breaker and the termination point of the energized conductor. Let X be the unit vector of the X-axis in the spatial coordinate system of the substation. Let be the unit vector along the Y-axis in the spatial coordinate system of the substation. Let x be the unit vector along the Z-axis in the spatial coordinate system of the substation. a Let y be the value of point A on the X-axis. a Let z be the value of point A on the Y-axis. a Let x be the value of point A on the Z-axis. b Let y be the value of point B on the x-axis. b Let z be the value of point B on the Y-axis. b Let x be the value of point B on the Z-axis, x be the value of the high-voltage circuit breaker on the X-axis, y be the value of the high-voltage circuit breaker on the Y-axis, and z be the value of the high-voltage circuit breaker on the Z-axis.

[0029] Optionally, obtaining the induced electromotive force of the closed loop at the high-voltage circuit breaker based on the magnetic induction intensity includes:

[0030] The induced electromotive force of the closed loop is calculated according to formula (6).

[0031]

[0032] Where ε is the induced electromotive force of the closed loop, B is the magnetic induction intensity, and S is the area of ​​the closed loop.

[0033] Optionally, constructing a spatial model of a substation includes:

[0034] The busbars, incoming and outgoing lines of the substation, and the connecting wires between the equipment are simplified into several straight wires.

[0035] The main power distribution equipment of the substation is simplified to a linear conductor;

[0036] The metal supports of the electrical equipment in the substation are simplified into multiple straight conductors.

[0037] Optionally, the busbars, incoming and outgoing lines of the substation, and the connecting wires between equipment can be simplified into several straight conductors, including:

[0038] Calculate the equivalent radius of the split conductor according to formula (7).

[0039]

[0040] Among them, R e R is the equivalent radius, n is the radius of the split conductor, and r is the radius of the sub-conductor of the split conductor.

[0041] On the other hand, the present invention provides a computer-readable storage medium storing instructions for being read by a machine to cause the machine to perform any of the construction methods described above.

[0042] Through the above technical solution, the method for constructing a magnetic field model for high-voltage circuit breaker maintenance in substations provided by the present invention constructs a spatial model of the substation and marks the coordinates of the high-voltage circuit breaker and the energized conductor. Based on the coordinates of the energized conductor and the high-voltage circuit breaker, the induced electromotive force generated by the power frequency magnetic field in the substation on the high-voltage circuit breaker can be calculated, thereby determining the actual induced current flowing during the test, which improves the accuracy and precision of the high-voltage circuit breaker opening and closing time test.

[0043] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0044] The accompanying drawings are provided to further illustrate embodiments of the present invention and form part of the specification. They are used together with the following detailed description to explain the embodiments of the present invention, but do not constitute a limitation thereof. In the drawings:

[0045] Figure 1 This is a flowchart of a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation, according to one embodiment of the present invention.

[0046] Figure 2 This is a flowchart illustrating the process of obtaining the magnetic induction intensity of a charged conductor at a high-voltage circuit breaker in a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation, according to an embodiment of the present invention.

[0047] Figure 3 This is a simplified model diagram of a metal support in a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation according to an embodiment of the present invention. Detailed Implementation

[0048] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0049] Figure 1 This is a flowchart illustrating a method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation, according to one embodiment of the present invention. Figure 1 In this context, the construction method may include:

[0050] In step S10, a spatial model of the substation is constructed. CDEGS software, developed by SES Inc. of Canada, is a powerful tool for solving engineering problems related to power system grounding, electromagnetic fields, and electromagnetic interference. CDEGS can calculate the grounding potential, conductor potential, and electromagnetic field generated by a network of charged conductors at any location above or below ground during normal, fault, lightning, and transient processes. CDEGS can also build computational models for exposed and insulated metal pipes, metal conductors, various cables, and conductor networks buried in complex soil structures. Substation switchyards contain numerous devices, including a large number of high-voltage circuit breakers, current and voltage transformers, surge arresters, and their corresponding metal grounding supports. Substations contain a large number of different devices, and current flows through many widely distributed areas. Therefore, directly studying and analyzing the power frequency magnetic field within the substation switchyard presents challenges such as large computational loads, complex magnetic field superposition, and complex equipment model building. In actual substation switchyard operations, various electrical devices play different roles. During simulation calculations, it's difficult to model all devices completely. Therefore, when establishing a 3D model of the substation switchyard, it's necessary to screen the electrical devices, ignoring those with minimal impact on the magnetic field. When modeling the electrical equipment, while meeting actual engineering requirements and minimizing magnetic field distribution errors, the electrical equipment in the substation is simplified in its modeling. The simplification principle is as follows:

[0051] 1. The busbars, substation incoming and outgoing lines, and the conductors connecting the equipment are all simplified into a number of straight conductors of finite length. Since the conductor length is finite, the sag effect of the conductor is ignored, the conductor is regarded as an ideal conductor, the loss on the line is not calculated, and the current flowing through the conductor does not change along the line.

[0052] 2. During modeling and analysis, the influence of insulating media such as insulating porcelain bushings and ceramic shells of electrical equipment in the switchyard on the power frequency magnetic field in the switchyard is negligible;

[0053] 3. When modeling, the main power distribution devices such as circuit breakers, disconnect switches, grounding switches, current transformers, and voltage transformers will be simplified according to their actual shape characteristics and geometric dimensions, and various linear conductors will be used to replace them, and corresponding boundary conditions will be set.

[0054] 4. The metal supports used to support electrical equipment such as high-voltage circuit breakers in the substation switchyard are simulated using multi-strand straight conductors. When setting boundary conditions, the potential of these conductors is set to zero.

[0055] 5. The substation ground is flat, the grounding resistance is very small and not considered, and the earth surface potential is set to zero, so it is regarded as a conductor.

[0056] During the actual on-site measurement, the height of the measurement point was 1.5m. Therefore, when setting up the power frequency magnetic field observation surface of CDEGS, the height was set to 1.5m.

[0057] In step S11, the spatial coordinates of the high-voltage circuit breaker in the substation are obtained for calibration.

[0058] In step S12, the magnetic induction intensity generated at the high-voltage circuit breaker by the energized conductor in the substation is obtained based on the spatial coordinates of the high-voltage circuit breaker. Specifically, the magnitude of the power frequency magnetic field at the high-voltage circuit breaker can be determined based on the coordinates of the energized conductor and the high-voltage circuit breaker.

[0059] In step S13, the induced electromotive force of the closed circuit at the high-voltage circuit breaker is obtained based on the magnetic induction intensity.

[0060] In step S14, the high-voltage circuit breaker is inspected based on the induced electromotive force. Specifically, after obtaining the induced electromotive force generated by the power frequency magnetic field on the high-voltage circuit breaker, the actual induced current generated by the coupling device on the high-voltage circuit breaker circuit can be obtained. The accurate opening and closing time characteristics of the high-voltage circuit breaker can then be determined based on this induced current.

[0061] In steps S10 to S14, a spatial model of the substation, along with the coordinates of the high-voltage circuit breaker and the energized conductor, is first constructed. Based on these coordinates, the magnetic induction intensity of the power frequency magnetic field on the high-voltage circuit breaker circuit is determined, allowing for the calculation of the magnitude of the induced current generated by the power frequency magnetic field in the high-voltage circuit breaker circuit. By removing the induced current generated by the power frequency magnetic field on the high-voltage circuit breaker circuit, the actual coupling current of the coupling device can be obtained. This induced current can then be used to determine the time performance of the high-voltage circuit breaker's opening and closing, facilitating subsequent maintenance by personnel.

[0062] Traditional testing of the opening and closing time performance of high-voltage circuit breakers typically involves installing a coupling device on the grounding wire on one side of the circuit breaker to couple an induced current onto the grounding wire, and then installing an induced current receiver on the grounding wire on the other side of the circuit breaker to obtain the circuit breaker's opening and closing time. However, in substations, the power frequency magnetic field generated during conduction can affect the value of the induced current, thus reducing the accuracy and precision of the high-voltage circuit breaker opening and closing time test. However, in this embodiment of the invention, a substation model is constructed to obtain the induced electromotive force generated by the substation's power frequency magnetic field on the high-voltage circuit breaker. This allows for the determination of the actual induced current flowing during the test, improving the accuracy and precision of the high-voltage circuit breaker opening and closing time test.

[0063] In this embodiment of the invention, in order to obtain the magnetic induction intensity generated by the energized conductor at the high-voltage circuit breaker in the substation, it is also necessary to calculate the coordinates of the high-voltage circuit breaker and the coordinates of the energized conductor in the substation. Specific steps can be as follows: Figure 2 As shown. Specifically, in Figure 2 In this context, the construction method may include:

[0064] In step S20, the coordinates of the starting point and the ending point of the charged conductor are obtained.

[0065] In step S21, the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting point and the ending point of the energized conductor is calculated according to formula (2).

[0066]

[0067] Wherein, sin(θ) a Let ) be the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker, and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; T is the perpendicular point of the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; A is the starting point of the energized conductor; l AT l represents the displacement of the starting point and perpendicular point of the charged conductor. ZA This refers to the displacement of the starting point of the high-voltage circuit breaker and the energized conductor.

[0068] In step S22, the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and termination points of the energized conductor is calculated according to formula (3).

[0069]

[0070] Wherein, sin(θ) b Let B be the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker, and the line connecting the high-voltage circuit breaker and the start and end points of the energized conductor; let Z be the spatial coordinate of the high-voltage circuit breaker; and let l be the sine of the angle between the line connecting the termination point of the energized conductor and the line connecting the start and end points of the energized conductor. AB l represents the displacement of the starting and ending points of the charged conductor. AT l represents the displacement of the starting point and perpendicular point of the charged conductor. ZB This refers to the displacement of the termination point of the high-voltage circuit breaker and the energized conductor.

[0071] In step S23, the magnetic induction intensity of the charged conductor at the high-voltage circuit breaker is calculated according to formula (1).

[0072]

[0073] in, Let μ be the magnetic flux density of a charged conductor at a high-voltage circuit breaker, and μ0 be the permeability of free space, where μ0 = π·10⁻⁶. -7 H / m, i ab R is the current flowing through the charged conductor. Length, Let θ be the distance from the current element to the high-voltage circuit breaker. a Let θ be the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker, and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor. b The angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and end points of the energized conductor.

[0074] In a static magnetic field, a current-carrying conductor segment is called a current element. To obtain the static magnetic field B generated by different current-carrying conductors, it is necessary to first find the formula for calculating the elemental magnetic field dB generated by the current element. Let the current flowing through the conductor be I, and any directed segment on the current-carrying conductor be represented by the vector dl (dl is in the same direction as the current). Then, the current-carrying segment can be quantitatively described by Idl (Idl corresponds to the point charge q). Because the current needs to exist in a closed loop, a constant current element will not exist alone, and the magnetic field of a constant current element cannot be measured by experiment. Since the magnetic field also follows the superposition principle, the magnetic field of any shape of current-carrying conductor can be superimposed by the magnetic field vector sum of all segments. The elemental magnetic field dB generated by the current element Idl can be expressed by formula (8) (SI).

[0075]

[0076] Where dB is the elemental magnetic field, Idl is the current element, r is the distance between the current element Idl and the high-voltage circuit breaker in space, and e r Let Idl be the unit vector pointing from the current element Idl to the coordinates of the high-voltage circuit breaker in space. This is the SI expression for Coulomb's law. Specifically, the magnetic field generated by a current element at any point Z(x, y, z) in space can be expressed as shown in equation (9).

[0077]

[0078] in, Let I be the magnetic field excited by the current element, dl be the source current, dl be the differential of the source current, and μ0 be the free permeability, where μ0 = π·10 -7 H / m, Let θ be the distance from the current element to the high-voltage circuit breaker in space, and θ be the distance between dl and dl. The included angle.

[0079] Calculate the magnetic induction intensity generated by any segment of length on the spatial coordinate position of the high-voltage circuit breaker according to formula (10).

[0080]

[0081] in, Let r be the magnetic induction intensity generated by the high-voltage circuit breaker at its coordinate position in space, r0 be the unit vector of dl pointing to point Z, and r be the distance of dl pointing to point Z. After substituting the variables in formula (10), formula (1) can be obtained.

[0082] Furthermore, the direction of the power frequency magnetic field generated by a charged conductor can be shown in formulas (4) and (5).

[0083]

[0084]

[0085] in, It is the unit vector representing the direction of the magnetic field. Let be the unit vector of the line connecting the start and end points of a charged conductor. The unit vector of the line connecting the high-voltage circuit breaker and the termination point of the energized conductor. Let be the vector connecting the start and end points of a charged conductor. The vector connecting the high-voltage circuit breaker and the termination point of the live conductor. Let X be the unit vector along the X-axis in the spatial coordinate system of the substation. Let be the unit vector along the Y-axis in the spatial coordinate system of the substation. x is the unit vector along the Z-axis in the spatial coordinate system of the substation. a Let y be the value of point A on the X-axis. a Let z be the value of point A on the Y-axis. a Let x be the value of point A on the Z-axis. b Let y be the value of point B on the x-axis. b Let z be the value of point B on the Y-axis. b Let x be the value of point B on the Z-axis, x be the value of the high-voltage circuit breaker on the X-axis, y be the value of the high-voltage circuit breaker on the Y-axis, and z be the value of the high-voltage circuit breaker on the Z-axis.

[0086] In this embodiment of the invention, in order to obtain the induced electromotive force of the closed loop at the high-voltage circuit breaker, it is also necessary to convert the magnetic induction intensity generated by the power frequency magnetic field. Specifically, the induced electromotive force of the closed loop is calculated according to formula (6).

[0087]

[0088] Where ε is the induced electromotive force of the closed loop, B is the magnetic flux density, and S is the area of ​​the closed loop.

[0089] In this embodiment of the invention, since the height of the busbars and incoming / outgoing lines in the substation switchyard is much greater than the geometric dimensions between the split conductors, the split conductors are considered as a single conductor in actual engineering simulation modeling. The equivalent radius of the split conductors can be calculated according to formula (7).

[0090]

[0091] Among them, R e Let R be the equivalent radius, n be the number of splits in the split conductor, and r be the radius of the sub-conductors of the split conductor. Typically, due to the weight of the conductor itself, the conductor will form a certain curvature between the two support points when the transmission distance is long, making the conductor appear curved. However, in the substation switchyard, the distance between the two support points of the conductor is small, and the conductor has almost no sag effect. Therefore, its influence on the power frequency magnetic field can be ignored. Ignoring the sag effect will not significantly affect the distribution of the power frequency magnetic field in the simulation results.

[0092] Furthermore, this embodiment of the invention also includes the construction of a metallic grounding model. Specifically, there are numerous metallic grounding bodies within the switchyard. Some of these metallic grounding bodies are conductor supports, while others are support columns for equipment such as high-voltage circuit breakers, disconnect switches, and current transformers. The parts of these supports that contact the ground are metallic columns, while the electrical equipment on them is made of non-metallic ceramic. These metallic columns will affect the distribution of the power frequency electromagnetic field within the substation switchyard. When simplifying the modeling, these metallic supports also need to be modeled to consider their impact on the electromagnetic field distribution within the switchyard, making the result approximate the actual power frequency magnetic field distribution within the substation switchyard. When modeling the metallic supports, the insulating portion above the supports is ignored, and only the impact of the metallic grounding body on the surrounding power frequency electromagnetic field is considered. The model structure of the metallic grounding body is simplified during modeling, and multiple cylindrical conductors are used to simulate the model structure of the metallic supports. When setting parameters, the radius of the metallic supports is set to 0.15m, and the potential of the metallic supports is set to zero. The height of the metal supports for different electrical equipment is also different: the height of the metal supports for disconnecting switches, high-voltage circuit breakers, grounding switches, current transformers and voltage transformers is set at 5.1m, 4m, 5.1m and 3.2m respectively.

[0093] Taking a substation for on-site testing of induced current as an example, the 500kV switchyard has two busbars and twelve outgoing lines. The conductor type is 4×LGJ400-35 steel-cored aluminum stranded wire with an equivalent radius of 0.204m. The intersection of the longitudinal extension of the two busbars and the transverse extension of the outgoing line endpoints is set as the origin of the coordinate system. The horizontal direction is set as the X-axis, the vertical direction as the Y-axis, and the direction perpendicular to the ground as the Z-axis. The length of each busbar in the x-axis direction is set to 168m, and the height of the busbar is 16.2m. The three phases A, B, and C are spaced 6.5 meters apart, with phase C on the right. Each busbar is arranged in the order of phase C, phase B, and phase A. The coordinates of the three phases A, B, and C on the y-axis of the first busbar are set to 37, 30.5, and 24, respectively; the coordinates of the three phases A, B, and C on the y-axis of the second busbar are set to 133, 126.5, and 120, respectively. Each outgoing line is 143m long along the y-axis, with a 7.5m spacing between phases and a height of 23m. The C phase of the six outgoing lines is positioned at x-axis coordinates of 15.5, 43.5, 71.5, 99.5, 127.5, and 155.5, respectively. The corresponding B and A phases are moved 7.5m along the positive x-axis, while other settings remain unchanged. The height of the two incoming lines is 25m, with an 8m spacing between A and B phases and a 14m spacing between B and C phases. A simplified model of the metal supports below the conductors is shown below. Figure 3 As shown.

[0094] On the other hand, the present invention also provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores instructions for being read by a machine to cause the machine to execute any of the above-described construction methods.

[0095] Through the above technical solution, the method for constructing a magnetic field model for high-voltage circuit breaker maintenance in substations provided by the present invention constructs a spatial model of the substation and marks the coordinates of the high-voltage circuit breaker and the energized conductor. Based on the coordinates of the energized conductor and the high-voltage circuit breaker, the induced electromotive force generated by the power frequency magnetic field in the substation on the high-voltage circuit breaker can be calculated, thereby determining the actual induced current flowing during the test, which improves the accuracy and precision of the high-voltage circuit breaker opening and closing time test.

[0096] Those skilled in the art will understand that embodiments of this application 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 embodied 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0101] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0102] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0103] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0104] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for constructing a magnetic field model during the maintenance of a high-voltage circuit breaker in a substation, characterized in that, include: Construct a spatial model of the substation; The spatial coordinates of the high-voltage circuit breakers in the substation are obtained for calibration. Based on the spatial coordinates of the high-voltage circuit breaker, the magnetic induction intensity generated at the high-voltage circuit breaker by the live conductor in the substation is obtained. Based on the magnetic induction intensity, the induced electromotive force of the closed circuit at the high-voltage circuit breaker is obtained; The high-voltage circuit breaker is inspected based on the induced electromotive force. Based on the coordinates of the high-voltage circuit breaker, the magnetic induction intensity generated by the energized conductor at the high-voltage circuit breaker in the substation is obtained, including: Obtain the coordinates of the start and end points of the charged conductor; The magnetic flux density of the charged conductor at the high-voltage circuit breaker is calculated according to formula (1). in, Let μ be the magnetic flux density of the charged conductor at the high-voltage circuit breaker, μ0 be the free permeability, and μ0 = π·10 -7 H / m, i ab R is the current flowing through the charged conductor. Length, θ is the distance from the current element to the high-voltage circuit breaker. a Let θ be the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor. b The angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and termination points of the energized conductor. Based on the magnetic induction intensity, obtaining the induced electromotive force of the closed circuit at the high-voltage circuit breaker includes: The induced electromotive force of the closed loop is calculated according to formula (6). Where ε is the induced electromotive force of the closed loop, B is the magnetic induction intensity, and S is the area of ​​the closed loop; Constructing a spatial model of a substation includes: The busbars, incoming and outgoing lines of the substation, and the connecting wires between the equipment are simplified into several straight wires. The power distribution equipment of the substation is simplified to a linear conductor; The metal supports of the electrical equipment in the substation are simplified into multiple straight conductors.

2. The construction method according to claim 1, characterized in that, The calculation of the magnetic flux density of the charged conductor at the high-voltage circuit breaker according to formula (1) also includes: Calculate the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor according to formula (2). Wherein, sin(θ) a Let ) be the sine of the angle between the line connecting the starting point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; T be the perpendicular point of the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor; and A be the starting point of the energized conductor. AT l represents the displacement between the starting point and the perpendicular point of the charged conductor. ZA This refers to the displacement of the starting point of the high-voltage circuit breaker and the energized conductor.

3. The construction method according to claim 2, characterized in that, The calculation of the magnetic flux density of the charged conductor at the high-voltage circuit breaker according to formula (1) also includes: Calculate the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the starting and ending points of the energized conductor according to formula (3). Wherein, sin(θ) b Let B be the sine of the angle between the line connecting the termination point of the energized conductor and the high-voltage circuit breaker and the line connecting the high-voltage circuit breaker and the start and end points of the energized conductor, and let Z be the spatial coordinates of the high-voltage circuit breaker. AB l represents the displacement of the starting and ending points of the charged conductor. AT l represents the displacement between the starting point and the perpendicular point of the charged conductor. ZB This refers to the displacement of the termination point of the high-voltage circuit breaker and the energized conductor.

4. The construction method according to claim 3, characterized in that, The direction of the magnetic field at the high-voltage circuit breaker is shown in formulas (4) and (5). in, The unit vector is the direction of the magnetic field. Let be the unit vector of the line connecting the start and end points of the charged conductor. The unit vector of the line connecting the high-voltage circuit breaker and the termination point of the energized conductor. Let be the vector of the line connecting the start and end points of the charged conductor. Let be the vector of the line connecting the high-voltage circuit breaker and the termination point of the energized conductor. Let X be the unit vector of the X-axis in the spatial coordinate system of the substation. Let be the unit vector along the Y-axis in the spatial coordinate system of the substation. Let x be the unit vector along the Z-axis in the spatial coordinate system of the substation. a Let y be the value of point A on the X-axis. a Let z be the value of point A on the Y-axis. a Let x be the value of point A on the Z-axis. b Let y be the value of point B on the x-axis. b Let z be the value of point B on the Y-axis. b Let x be the value of point B on the Z-axis, x be the value of the high-voltage circuit breaker on the X-axis, y be the value of the high-voltage circuit breaker on the Y-axis, and z be the value of the high-voltage circuit breaker on the Z-axis.

5. The construction method according to claim 1, characterized in that, The busbars, incoming and outgoing lines, and connecting wires between equipment in the substation are simplified into several straight wires, including: Calculate the equivalent radius of the split conductor according to formula (7). Among them, R e R is the equivalent radius, n is the radius of the split conductor, and r is the radius of the sub-conductor of the split conductor.

6. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores instructions that are read by a machine to cause the machine to perform the construction method as described in any one of claims 1 to 5.

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