A calculation method and device for power frequency electric field above a building

Abstract

The present invention discloses a method and device for calculating the power-frequency electric field above a building. The method comprises: using a pre-established AC overhead line model and a simulated charge method to determine a field intensity distribution curve at a preset ground height; determining distortion coefficient fitting curves for buildings of different sizes using a fitting formula based on calculation results of distortion coefficient curves for buildings of different sizes; and calculating the power-frequency field intensity amplitude at the preset height above the building using the building's distortion coefficient fitting curve and the field intensity distribution curve at the preset ground height, combined with the distance between the building and an equivalent single conductor.

Description

Technical Field

[0001] The present invention relates to the field of power frequency electric field calculation, and more particularly to a method and device for calculating the power frequency electric field above a building. Background Art

[0002] At present, my country is vigorously building a strong and intelligent power grid with ultra-high voltage power grid as the backbone network and coordinated development of power grids at all levels. The line mileage is huge, especially the AC ultra-high voltage and ultra-high voltage power grids, which form complex "ring networks" in various places. While transmitting electric energy, there are also electromagnetic environment problems such as power frequency electric fields, power frequency magnetic fields, audible noise and radio interference.

[0003] Residential platforms are important and frequented areas for residents. According to the assessment requirements of the "Technical Guidelines for Environmental Impact Assessment of Transmission and Transformation Projects" (HJ24-2014), AC transmission line design must consider the power-frequency electric field at a height of 1.5 meters above the ground in the vicinity of the line and at environmentally sensitive points above residential platforms to ensure that it does not exceed the required limits. HJ24-2014 only provides methods for predicting the power-frequency electric field at ground level. For predicting the electric field above buildings, methods generally use spatial predictions (e.g., if the building is 3 meters high, the power-frequency electric field is predicted at 4.5 meters) or methods that raise the ground level (e.g., if the building is 3 meters high, the ground level is raised by 3 meters). Neither method accurately calculates the electric field strength above the building. Alternatively, simulated charge methods or finite element methods can be used to predict these electric fields. However, these methods require specific modeling and analysis, requiring models for buildings of varying sizes and different lines. This makes them inefficient for large-scale predictions, such as line design, and their application is limited.

[0004] Therefore, existing methods for calculating the power frequency electric field above buildings have problems of poor calculation accuracy and low efficiency. Summary of the Invention

[0005] Aiming at the technical problems of poor calculation accuracy and low efficiency in the existing methods for calculating the power frequency electric field above a building, the present invention provides a method and device for calculating the power frequency electric field above a building.

[0006] According to one aspect of the present invention, a method for calculating the power frequency electric field above a building is provided, comprising:

[0007] Using a pre-established AC overhead line model and the simulated charge method, the field strength distribution curve at a preset height above the ground is determined;

[0008] According to the calculation results of the distortion coefficient curve of the building size, the distortion coefficient fitting curve of buildings of different sizes is determined using the fitting formula;

[0009] The power frequency field strength amplitude at a preset height above the building is calculated by using the distortion coefficient fitting curve of the building and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single conductor.

[0010] Optionally, a pre-established AC overhead line model and a simulated charge method are used to determine a field strength distribution curve at a preset height above the ground, including:

[0011] Using the pre-established AC overhead line model, the radius of the equivalent single conductor of the transmission line is calculated;

[0012] Based on the radius of the equivalent single conductor, the simulated charge method is combined with the mirror method to set simulated linear charges inside the equivalent single conductor and at symmetrical positions with the ground as the baseline. Matching points are selected on the surface of the equivalent single conductor to calculate the simulated linear charge density in the equivalent single conductor.

[0013] Based on the simulated linear charge density in the equivalent single wire, the electric field intensity component parallel to the ground (x) and the electric field intensity component perpendicular to the ground (y) at a preset height above the ground are calculated;

[0014] The electric field strength distribution curve at a preset height above the ground is determined based on the electric field strength component in the direction parallel to the ground (x) and the electric field strength component in the direction perpendicular to the ground (y).

[0015] Optionally, before determining the distortion coefficient fitting curves for buildings of different sizes using a fitting formula based on the calculation results of the distortion coefficient curves for buildings of different sizes, the method further includes:

[0016] Establish building examples of certain types and sizes, and establish field models corresponding to the building examples of each type and size;

[0017] Calculate the electric field strength above the building based on the field model and finite element method;

[0018] According to the electric field intensity above the building and the given uniform electric field value, the calculation result of the distortion coefficient curve above the building is determined.

[0019] Optionally, according to calculation results of the distortion coefficient curves of buildings of different sizes, a fitting formula is used to determine the distortion coefficient fitting curves of buildings of different sizes, including:

[0020] According to the calculation results of the distortion coefficient curves of buildings of different sizes, the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes are determined;

[0021] Determine the functional relationship between the maximum and minimum calculated values of the distortion coefficient and the building height and building length using curve fitting;

[0022] The maximum fitting value and the minimum fitting value of the distortion coefficient are determined using the functional relationship;

[0023] According to the maximum fitting value and the minimum fitting value of the distortion coefficient, the distortion coefficient fitting curve of the upper surface of the building is obtained by using quadratic function fitting.

[0024] Optionally, the power frequency field intensity amplitude at the preset height above the building is calculated using a distortion coefficient fitting curve of the building and a field intensity distribution curve at a preset height above the ground, in combination with the distance between the building and an equivalent single conductor, including:

[0025] According to the distance between the building and the equivalent single wire, the distortion coefficient fitting curve of the building is translated;

[0026] The power frequency electric field intensity amplitude at a preset height above the building is calculated based on the distortion coefficient fitting curve of the translated building and the field strength distribution curve at a preset height above the ground.

[0027] According to another aspect of the present invention, there is provided a device for calculating the power frequency electric field above a building, comprising:

[0028] A first determination module is used to determine a field intensity distribution curve at a preset height above the ground using a pre-established AC overhead line model and a simulated charge method;

[0029] The second determining module is used to determine the distortion coefficient fitting curves of buildings of different sizes using a fitting formula according to the calculation results of the distortion coefficient curve of the building size;

[0030] The calculation module is used to calculate the power frequency field strength amplitude at a preset height above the building by using the distortion coefficient fitting curve of the building and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single wire.

[0031] Optionally, the first determining module is specifically configured to:

[0032] Using the pre-established AC overhead line model, the radius of the equivalent single conductor of the transmission line is calculated;

[0033] Based on the radius of the equivalent single conductor, the simulated charge method is combined with the mirror method to set simulated linear charges inside the equivalent single conductor and at symmetrical positions with the ground as the baseline. Matching points are selected on the surface of the equivalent single conductor to calculate the simulated linear charge density in the equivalent single conductor.

[0034] Based on the simulated linear charge density in the equivalent single wire, the electric field intensity component in the parallel ground (x) direction and the electric field intensity component in the y direction at a preset height above the ground are calculated;

[0035] The ground field strength distribution curve at a preset height on the ground is determined based on the electric field strength component in the direction parallel to the ground (x) and the electric field strength component in the direction y.

[0036] Optionally, the device further includes a third determining module, configured to:

[0037] Establish building examples of certain types and sizes, and establish field models corresponding to the building examples of each type and size;

[0038] Calculate the electric field strength above the building based on the field model and finite element method;

[0039] According to the electric field intensity above the building and the given uniform electric field value, the calculation result of the distortion coefficient curve above the building is determined.

[0040] Optionally, the second determining module is specifically configured to:

[0041] According to the calculation results of the distortion coefficient curves of buildings of different sizes, the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes are determined;

[0042] Determine the functional relationship between the maximum and minimum calculated values of the distortion coefficient and the building height and building length using curve fitting;

[0043] The maximum fitting value and the minimum fitting value of the distortion coefficient are determined using the functional relationship;

[0044] According to the maximum fitting value and the minimum fitting value of the distortion coefficient, the distortion coefficient fitting curve of the upper surface of the building is obtained by using quadratic function fitting.

[0045] Optionally, the computing module is specifically configured to:

[0046] According to the distance between the building and the equivalent single wire, the distortion coefficient fitting curve of the building is translated;

[0047] The power frequency electric field intensity amplitude at a preset height above the building is calculated based on the distortion coefficient fitting curve of the translated building and the field strength distribution curve at a preset height above the ground.

[0048] According to another aspect of the present invention, a computer-readable storage medium is provided, wherein the storage medium stores a computer program, and the computer program is used to execute the method according to any one of the above aspects of the present invention.

[0049] According to another aspect of the present invention, an electronic device is provided, comprising: a processor; a memory for storing instructions executable by the processor; and the processor for reading the executable instructions from the memory and executing the instructions to implement the method described in any one of the above aspects of the present invention.

[0050] Therefore, the present invention first uses a pre-established AC overhead line model and a simulated charge method to determine the field intensity distribution curve at a preset height above the ground. Then, based on the calculated results of the distortion coefficient curves for buildings of different sizes, a fitting formula is used to determine the distortion coefficient fitting curves for buildings of different sizes. Finally, the distortion coefficient fitting curve of the building and the field intensity distribution curve at the preset height above the ground are used in combination with the distance between the building and the equivalent single conductor to calculate the power frequency electric field intensity amplitude at the preset height above the building. The present invention does not require the establishment of different building models for buildings of different sizes. Instead, it only requires the use of a formula fitting method to calculate the distortion coefficient fitting curve for the building size after the building is placed in a uniform electric field. After calculating the distortion coefficient fitting curve of the building, the calculation of the power frequency electric field above the building is simplified. The power frequency electric field intensity amplitude at the preset height above the building can be calculated by combining the distance between the building and the equivalent single conductor, and using the distortion coefficient fitting curve of the building and the field intensity distribution curve at the preset height above the ground, thereby greatly improving calculation efficiency. Therefore, the present invention proposes a method for predicting the power-frequency electric field on a building's upper surface based on distortion coefficients and a fitting formula. This method can efficiently and accurately calculate the power-frequency electric field intensity amplitude at a preset height above the building. Therefore, it can meet large-scale electric field prediction needs while ensuring accurate calculations. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] A more complete understanding of exemplary embodiments of the present invention may be obtained by referring to the following drawings:

[0052] Figure 1 1 is a flow chart of a method for calculating the power frequency electric field above a building provided by an exemplary embodiment of the present invention;

[0053] Figure 2 is a schematic diagram of a specific circuit model provided by an exemplary embodiment of the present invention;

[0054] Figure 3 is a schematic diagram of a building model provided by an exemplary embodiment of the present invention;

[0055] Figure 4 is a schematic diagram of a uniform electric field domain model provided by an exemplary embodiment of the present invention;

[0056] Figure 5 is a schematic diagram of a distortion coefficient fitting curve K provided by an exemplary embodiment of the present invention;

[0057] Figure 6 1 is a schematic diagram of an electric field intensity distribution calculation curve, an electric field intensity translation curve, and a final calculation result at a preset height above the ground provided by an exemplary embodiment of the present invention;

[0058] Figure 7 is a comparison diagram of measured values and predicted values of the power frequency electric field above a building provided by an exemplary embodiment of the present invention;

[0059] Figure 8 1 is a schematic structural diagram of a device for calculating the power frequency electric field above a building provided by an exemplary embodiment of the present invention;

[0060] Figure 9 This is a structure of an electronic device provided by an exemplary embodiment of the present invention. DETAILED DESCRIPTION

[0061] Below, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein.

[0062] It should be noted that the relative arrangement of components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

[0063] Those skilled in the art will understand that the terms "first" and "second" in the embodiments of the present invention are only used to distinguish different steps, devices or modules, and neither represent any specific technical meaning nor indicate the necessary logical order between them.

[0064] It should also be understood that, in the embodiments of the present invention, “a plurality of” may refer to two or more than two, and “at least one” may refer to one, two or more than two.

[0065] It should also be understood that any component, data or structure mentioned in the embodiments of the present invention can generally be understood as one or more, unless explicitly limited or otherwise indicated in the context.

[0066] In addition, the term "and / or" in this invention merely describes an association relationship between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Furthermore, the character " / " in this invention generally indicates that the related objects are in an "or" relationship.

[0067] It should also be understood that the description of the various embodiments of the present invention focuses on the differences between the various embodiments, and the same or similar aspects thereof can be referenced with each other. For the sake of brevity, they will not be described one by one.

[0068] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0069] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0070] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0071] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0072] Embodiments of the present invention can be applied to electronic devices such as terminal devices, computer systems, and servers, and can operate in conjunction with numerous other general-purpose or specialized computing system environments or configurations. Examples of well-known terminal devices, computing systems, environments, and / or configurations suitable for use with terminal devices, computer systems, servers, and other electronic devices include, but are not limited to, personal computer systems, server computer systems, thin clients, thick clients, handheld or laptop devices, microprocessor-based systems, set-top boxes, programmable consumer electronics, network personal computers, minicomputer systems, mainframe computer systems, and distributed cloud computing technology environments including any of the above.

[0073] Electronic devices such as terminal devices, computer systems, and servers can be described in the general context of computer system-executable instructions (such as program modules) executed by a computer system. Generally, program modules can include routines, programs, object programs, components, logic, data structures, etc., which perform specific tasks or implement specific abstract data types. Computer systems / servers can be implemented in a distributed cloud computing environment, where tasks are performed by remote processing devices linked via a communication network. In a distributed cloud computing environment, program modules can be located on local or remote computing system storage media, including storage devices.

[0074] Exemplary Methods

[0075] Figure 1 FIG. 1 is a flow chart of a method for calculating the power frequency electric field above a building provided by an exemplary embodiment of the present invention. This embodiment can be applied to electronic devices, such as Figure 1 As shown, the method 100 for calculating the power frequency electric field above a building includes the following steps:

[0076] Step 101 : Using a pre-established AC overhead line model and a charge simulation method, a field intensity distribution curve at a preset height above the ground is determined.

[0077] In an embodiment of the present invention, at a predetermined height above the ground, for example, but not limited to, 1.5 meters above the ground, an AC overhead line model can be established using existing methods before determining the electric field strength distribution curve at that height. Subsequently, the established AC overhead line model and the simulated charge method are used to calculate the power frequency electric field distribution at 1.5 meters above the ground, thereby determining the electric field strength distribution curve at that height.

[0078] Optionally, a pre-established AC overhead line model and a simulated charge method are used to determine the field strength distribution curve at a preset height above the ground, including: using a pre-established AC overhead line model to calculate the radius of an equivalent single conductor of the transmission line; based on the radius of the equivalent single conductor, using the simulated charge method in combination with the mirror method, setting simulated line charges in the equivalent single conductor and at symmetrical positions with the ground as the baseline, selecting matching points on the surface of the equivalent single conductor, and calculating the simulated line charge density in the equivalent single conductor; calculating the electric field strength component in the direction parallel to the ground (x) and the electric field strength component in the direction perpendicular to the ground (y) at a preset height above the ground based on the simulated line charge density in the equivalent single conductor; and determining the field strength distribution curve at a preset height above the ground based on the electric field strength component in the direction parallel to the ground (x) and the electric field strength component in the direction perpendicular to the ground (y).

[0079] In this embodiment of the present invention, step 101 specifically includes the following sub-steps:

[0080] Step 1011: Using the formula Calculate the radius R of the equivalent single conductor of the transmission line i Where R is the splitting radius of an equivalent single conductor, in meters; n is the number of splits; and r is the radius of the equivalent single conductor, in meters.

[0081] Step 1012: Based on the radius of the equivalent single wire, the simulated charge method combined with the mirror method is used to set the simulated linear charge density in the equivalent single wire and at a symmetrical position with the ground as the baseline, and the matching points are selected on the surface of the equivalent single wire. Calculate the simulated linear charge density λ1, λ2, …, λ in the equivalent single wire N Among them, U j is the potential value; P ji is the point coefficient matrix; i is the simulated linear charge density.

[0082] Step 1013: Use the simulated linear charge densities λ1, λ2, ..., λ N , solve the x and y direction electric field intensity components at the preset height of the ground Among them, M xi is the electric field strength coefficient value in the direction parallel to the ground (x); M yiis the electric field intensity coefficient in the y direction. And using the formula The electric field intensity amplitude at the preset height on the ground is solved to obtain the field intensity distribution curve at the preset height on the ground.

[0083] Step 102: According to the calculation results of the distortion coefficient curves of buildings of different sizes, the distortion coefficient fitting curves of buildings of different sizes are determined by a fitting formula.

[0084] Optionally, before determining the distortion coefficient fitting curves of buildings of different sizes using a fitting formula based on the calculation results of the distortion coefficient curves of buildings of different sizes, the method further includes: establishing calculation examples of buildings of certain types and sizes, and establishing field models corresponding to the calculation examples of buildings of each type and size; calculating the electric field strength above the building based on the field model and the finite element method; and determining the calculation results of the distortion coefficient curve above the building based on the electric field strength above the building and a given uniform electric field value.

[0085] Optionally, based on the calculation results of the distortion coefficient curves of buildings of different sizes, a fitting formula is used to determine the distortion coefficient fitting curves of buildings of different sizes, including: determining the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes based on the calculation results of the distortion coefficient curves of buildings of different sizes; using curve fitting to determine the functional relationship between the maximum calculated value and the minimum calculated value of the distortion coefficient and the building height and the building length; using the functional relationship to determine the maximum fitting value and the minimum fitting value of the distortion coefficient; and using quadratic function fitting to obtain the distortion coefficient fitting curve of the upper surface of the building based on the maximum fitting value and the minimum fitting value of the distortion coefficient.

[0086] In this embodiment of the present invention, step 102 specifically includes the following sub-steps:

[0087] Step 1021: If the building distortion coefficient formula has not been fitted, create 3956 examples of building sizes, including building heights h ranging from 3m to 12m in steps of 0.2m, and building lengths d ranging from 3m to 20m in steps of 0.2m. Then, establish a field model for these buildings placed in a uniform electric field. Otherwise, proceed directly to Step 1024.

[0088] Step 1022: Use the finite element method to solve the electric field intensity distribution E above the building cal , and use the formula k=E cal / E sd Obtain the calculation results of the distortion coefficient curve above the building, and obtain the maximum calculated value k of the distortion coefficient through the calculation results of the distortion coefficient curve max and the minimum calculated value k min , where E cal is the calculated value of the power frequency electric field, E sd is the uniform electric field value.

[0089] Step 1023: Obtain the maximum calculated value k of the distortion coefficient by curve fitting max and the minimum calculated value k min Functional relationship k between building height h and building length d max =f1(h,d),k min =f2(h,d).

[0090] Step 1024: Obtain the maximum fitting value and the minimum fitting value k of the distortion coefficient using the functional relationship max =f1(h,d),k min =f2(h,d), and the distortion coefficient fitting curve of the upper surface of the building is obtained by quadratic function fitting K=4·(k max -k min ) / d 2 ·x 2 +k min .

[0091] Step 103 , using the distortion coefficient fitting curve of the building and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single wire, calculate the power frequency electric field strength amplitude at a preset height above the building.

[0092] Optionally, the distortion coefficient fitting curve of the building size and the field strength distribution curve at a preset height above the ground are used, combined with the distance between the building and the equivalent single conductor, to calculate the amplitude of the power frequency electric field strength at a preset height above the building, including: translating the distortion coefficient fitting curve of the building according to the distance between the building and the equivalent single conductor; and calculating the amplitude of the power frequency electric field strength at a preset height above the building based on the distortion coefficient fitting curve of the translated building and the field strength distribution curve at a preset height above the ground.

[0093] In this embodiment of the present invention, step 103 specifically includes the following sub-steps:

[0094] Step 1031: Shift the distortion coefficient fitting curve according to the relative position relationship between the building and the equivalent single wire.

[0095] Step 1032: Multiply the translated distortion coefficient fitting curve K by the power frequency electric field intensity distribution E at a preset height above the ground to obtain the power frequency electric field intensity amplitude at a preset height above the building.

[0096] The following will be combined Figures 2 to 7 , giving the best embodiment of the specific application of the present invention:

[0097] The present invention provides a method for calculating the power frequency electric field above a building. The calculation object of the specific embodiment is: a double-circuit 1000kV DC transmission line on the same tower, using 8 split equivalent single conductors, the sub-equivalent single conductor model is JL1 / G1A-630 / 55, the sub-equivalent single conductor diameter is 34.3mm, the split spacing is 40cm, and the double-circuit line is arranged in reverse phase sequence; the building is 3m high, 6m long and wide, and is 15m away from the equivalent single conductor (such as Figure 3 The specific steps are as follows:

[0098] Step 1: Establish AC overhead line model (such as Figure 2 The ground electric intensity distribution is solved using the simulated charge method.

[0099] Specifically, the equivalent single wire splitting radius is R = 0.4 / 2 / sin(pi / 8) = 0.5226m, and the equivalent radius R i =0.5226·(8×0.01715 / 0.5226) 1 / 8 =0.4422m.

[0100] The potential value and the simulated linear charge density λ1, λ2, ..., λ in the equivalent single wire are established by using the mirror method. N And use the known potential point on the surface of the equivalent single wire as the matching point Calculate the linear charge density λ1,λ2,…,λ N .

[0101] Then, the linear charge densities λ1, λ2, ..., λ N , solve the x, y direction electric field intensity components at the preset height of the ground Combined use Solve the electric field intensity amplitude at the preset height of the ground, and the calculation results are as follows Figure 5 shown.

[0102] Step 2: Solve the distortion coefficient fitting value.

[0103] Specifically, when the building distortion coefficient formula fitting has not been performed, a total of 3956 building size calculation examples are established, with building height h ranging from 3m to 12m, with a step length of 0.2m, and building length d ranging from 3m to 20m, with a step length of 0.2m. A field model is then established in which the building is placed in a uniform electric field, as shown in the following example: Figure 4 shown.

[0104] The finite element method is used to solve the electric field intensity distribution E above the building. cal , and use the distortion coefficient fitting formula k max =f1(h,d),k min =f2(h,d), calculate the maximum fitting value and minimum fitting value k of the distortion coefficientmax =f1(h,d)=1.561,k min =f2(h,d)=1.548. Using the maximum and minimum fitting values of the above distortion coefficients, the fitting curve distribution of the distortion coefficient on the upper surface of the building is solved as follows: K=4·(k max -k min ) / d 2 ·x 2 +k min =0.001444·x 2 +1.548m, the distortion coefficient fitting curve and the result of finite element calculation are compared as shown in the figure below. Figure 6 shown.

[0105] Step 3: Calculate the amplitude of the power frequency electric field strength at the preset height of the building (1.5m height)

[0106] Since the building is 15m away from the equivalent single conductor, its position is at x = 32m and the center point is at x = 35m. Therefore, it is necessary to shift the distortion coefficient fitting curve to the right by 35m and then multiply it by the electric field strength E at the preset height above the ground (at a height of 1.5m) to obtain the power frequency electric field strength amplitude (predicted value) at the preset height above the building (at a height of 1.5m).

[0107] If the position of the building and the equivalent single conductor changes, a new prediction result can be obtained by translating the distortion coefficient fitting curve, which greatly improves the calculation efficiency. The comparison between the prediction result and the measured result is as follows: Figure 7 As shown, the accuracy of this method is proved.

[0108] Therefore, the present invention first uses a pre-established AC overhead line model and a simulated charge method to determine the field intensity distribution curve at a preset height above the ground. Then, based on the calculated results of the distortion coefficient curves for buildings of different sizes, a fitting formula is used to determine the distortion coefficient fitting curves for buildings of different sizes. Finally, the distortion coefficient fitting curve of the building and the field intensity distribution curve at the preset height above the ground are used in combination with the distance between the building and the equivalent single conductor to calculate the power frequency electric field intensity amplitude at the preset height above the building. The present invention does not require the establishment of different building models for buildings of different sizes. Instead, it only requires the use of a formula fitting method to calculate the distortion coefficient fitting curve for the building size after the building is placed in a uniform electric field. After calculating the distortion coefficient fitting curve of the building, the calculation of the power frequency electric field above the building is simplified. The power frequency electric field intensity amplitude at the preset height above the building can be calculated by combining the distance between the building and the equivalent single conductor, and using the distortion coefficient fitting curve of the building and the field intensity distribution curve at the preset height above the ground, thereby greatly improving calculation efficiency. Therefore, the present invention proposes a method for predicting the power-frequency electric field on a building's upper surface based on distortion coefficients and a fitting formula. This method can efficiently and accurately calculate the power-frequency electric field intensity amplitude at a preset height above the building. Therefore, it can meet large-scale electric field prediction needs while ensuring accurate calculations.

[0109] Exemplary devices

[0110] Figure 8 FIG. 1 is a schematic diagram of a structure of a power frequency electric field calculation device above a building provided by an exemplary embodiment of the present invention. Figure 8 As shown, the apparatus 800 includes:

[0111] A first determining module 810 is configured to determine a field intensity distribution curve at a preset height above the ground using a pre-established AC overhead line model and a simulated charge method;

[0112] The second determining module 820 is configured to determine the distortion coefficient fitting curves for buildings of different sizes using a fitting formula based on the calculation results of the distortion coefficient curves of the building sizes;

[0113] The calculation module 830 is used to calculate the power frequency field strength amplitude at a preset height above the building by using the distortion coefficient fitting curve of the building and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single wire.

[0114] Optionally, the first determining module 810 is specifically configured to:

[0115] Using the pre-established AC overhead line model, the radius of the equivalent single conductor of the transmission line is calculated;

[0116] Based on the radius of the equivalent single conductor, the simulated charge method is combined with the mirror method to set simulated linear charges inside the equivalent single conductor and at symmetrical positions with the ground as the baseline. Matching points are selected on the surface of the equivalent single conductor to calculate the simulated linear charge density in the equivalent single conductor.

[0117] Based on the simulated linear charge density in the equivalent single wire, the electric field intensity component parallel to the ground (x) and the electric field intensity component perpendicular to the ground (y) at a preset height above the ground are calculated;

[0118] The ground field strength distribution curve at a preset height on the ground is determined based on the electric field strength component in the direction parallel to the ground (x) and the electric field strength component in the direction perpendicular to the ground (y).

[0119] Optionally, the device further includes a third determining module, configured to:

[0120] Establish building examples of certain types and sizes, and establish field models corresponding to the building examples of each type and size;

[0121] Calculate the electric field strength above the building based on the field model and finite element method;

[0122] According to the electric field intensity above the building and the given uniform electric field value, the calculation result of the distortion coefficient curve above the building is determined.

[0123] Optionally, the second determining module 820 is specifically configured to:

[0124] According to the calculation results of the distortion coefficient curves of buildings of different sizes, the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes are determined;

[0125] Determine the functional relationship between the maximum and minimum calculated values of the distortion coefficient and the building height and building length using curve fitting;

[0126] The maximum fitting value and the minimum fitting value of the distortion coefficient are determined using the functional relationship;

[0127] According to the maximum fitting value and the minimum fitting value of the distortion coefficient, the distortion coefficient fitting curve of the upper surface of the building is obtained by using quadratic function fitting.

[0128] Optionally, the calculation module 830 is specifically configured to:

[0129] According to the distance between the building and the equivalent single wire, the distortion coefficient fitting curve of the building is translated;

[0130] The power frequency electric field intensity amplitude at a preset height above the building is calculated based on the distortion coefficient fitting curve of the translated building and the field strength distribution curve at a preset height above the ground.

[0131] The power-frequency electric field calculation device 800 above a building according to an embodiment of the present invention corresponds to the power-frequency electric field calculation method 100 above a building according to another embodiment of the present invention, and will not be described in detail herein.

[0132] Exemplary electronic devices

[0133] Figure 9 The electronic device according to an exemplary embodiment of the present invention may be configured as either or both of the first and second devices, or as a standalone device independent of the first and second devices. The standalone device may communicate with the first and second devices to receive collected input signals from the devices. Figure 9 FIG2 is a block diagram of an electronic device according to an embodiment of the present invention. Figure 9 As shown, the electronic device 90 includes one or more processors 91 and a memory 92 .

[0134] The processor 91 may be a central processing unit (CPU) or other forms of processing units having data processing capabilities and / or instruction execution capabilities, and may control other components in the electronic device to perform desired functions.

[0135] The memory 92 may include one or more computer program products, which may include various forms of computer-readable storage media, such as volatile memory and / or non-volatile memory. The volatile memory may, for example, include random access memory (RAM) and / or cache memory (cache), etc. The non-volatile memory may, for example, include read-only memory (ROM), a hard disk, a flash memory, etc. One or more computer program instructions may be stored on the computer-readable storage medium, and the processor 91 may run the program instructions to implement the method for information mining of historical change records and / or other desired functions of the software program of each embodiment of the present invention described above. In one example, the electronic device may further include: an input device 93 and an output device 94, which are interconnected via a bus system and / or other forms of connection mechanisms (not shown).

[0136] In addition, the input device 93 may also include, for example, a keyboard, a mouse, and the like.

[0137] The output device 94 can output various information to the outside. The output device 94 can include, for example, a display, a speaker, a printer, a communication network and a remote output device connected thereto.

[0138] Of course, to simplify, Figure 9Only some of the components related to the present invention in the electronic device are shown, and components such as a bus, an input / output interface, etc. are omitted. In addition, the electronic device may further include any other appropriate components according to specific application scenarios.

[0139] Exemplary computer program products and computer-readable storage media

[0140] In addition to the above-mentioned methods and devices, an embodiment of the present invention may also be a computer program product, which includes computer program instructions, which, when executed by a processor, enable the processor to execute the steps of the method for information mining of historical change records according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0141] The computer program product may be written in any combination of one or more programming languages to implement the operations of embodiments of the present invention, including object-oriented programming languages such as Java, C++, and conventional procedural programming languages such as C or similar programming languages. The program code may be executed entirely on the user's computing device, partially on the user's computing device, as a stand-alone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server.

[0142] In addition, an embodiment of the present invention may also be a computer-readable storage medium having computer program instructions stored thereon, which, when executed by a processor, enables the processor to execute the steps of the method for information mining of historical change records according to various embodiments of the present invention described in the above "Exemplary Method" section of this specification.

[0143] The computer-readable storage medium can adopt any combination of one or more readable media. The readable medium can be a readable signal medium or a readable storage medium. The readable storage medium can, for example, include but is not limited to a system, system or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination thereof. More specific examples (non-exhaustive list) of readable storage media include: an electrical connection with one or more wires, a portable disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0144] The basic principles of the present invention have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in the present invention are merely illustrative and non-limiting, and should not be construed as necessarily possessed by each embodiment of the present invention. Furthermore, the specific details disclosed above are provided for illustrative purposes and to facilitate understanding, and are not intended to be limiting. These details do not necessarily limit the present invention to being implemented using these specific details.

[0145] Each embodiment in this specification is described in a progressive manner, with each embodiment focusing on its differences from the other embodiments. References to the same or similar parts between the various embodiments are sufficient. For system embodiments, since they largely correspond to method embodiments, their description is relatively simple. For relevant parts, references to the description of the method embodiments are sufficient.

[0146] The block diagrams of the devices, systems, equipment, and systems involved in the present invention are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, systems, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "including," "comprising," "having," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0147] The method and system of the present invention may be implemented in many ways. For example, the method and system of the present invention may be implemented by software, hardware, firmware, or any combination of software, hardware, and firmware. The above sequence of steps for the method is for illustration only, and the steps of the method of the present invention are not limited to the sequence specifically described above, unless otherwise specified. In addition, in some embodiments, the present invention may also be implemented as a program recorded in a recording medium, which includes machine-readable instructions for implementing the method according to the present invention. Thus, the present invention also covers recording media that store programs for executing the method according to the present invention.

[0148] It should also be noted that, in the system, device and method of the present invention, each component or each step can be decomposed and / or recombined. These decompositions and / or recombinations should be regarded as equivalent schemes of the present invention. The above description of the disclosed aspects is provided to enable any technician in this field to make or use the present invention. Various modifications to these aspects will be very obvious to those skilled in the art, and the general principles defined here can be applied to other aspects without departing from the scope of the present invention. Therefore, the present invention is not intended to be limited to the aspects shown here, but according to the widest scope consistent with the principles disclosed here and novel features.

[0149] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present invention to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for calculating the power frequency electric field above a building, characterized in that: include: Using a pre-established AC overhead line model and the simulated charge method, the field strength distribution curve at a preset height above the ground is determined; According to the calculation results of the distortion coefficient curve of the building size, the distortion coefficient fitting curve of buildings of different sizes is determined using the fitting formula; Calculate the power frequency field strength amplitude at a preset height above the building by using the building's distortion coefficient fitting curve and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single conductor; Wherein, before determining the distortion coefficient fitting curves of buildings of different sizes using the fitting formula based on the calculation results of the distortion coefficient curves of buildings of different sizes, the following steps are also included: Establish building examples of certain types and sizes, and establish field models corresponding to the building examples of each type and size; Calculate the electric field strength above the building based on the field model and finite element method; According to the electric field strength above the building and the given uniform electric field value, the calculation result of the distortion coefficient curve above the building is determined; According to the calculation results of the distortion coefficient curves of buildings of different sizes, the distortion coefficient fitting curves of buildings of different sizes are determined using fitting formulas, including: According to the calculation results of the distortion coefficient curves of buildings of different sizes, the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes are determined; Determine the functional relationship between the maximum and minimum calculated values of the distortion coefficient and the building height and building length using curve fitting; The maximum fitting value and the minimum fitting value of the distortion coefficient are determined using the functional relationship; According to the maximum fitting value and the minimum fitting value of the distortion coefficient, the distortion coefficient fitting curve of the upper surface of the building is obtained by using quadratic function fitting; The power frequency field strength amplitude at a preset height above the building is calculated by using the distortion coefficient fitting curve of the building and the field strength distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single conductor, including: According to the distance between the building and the equivalent single wire, the distortion coefficient fitting curve of the building is translated; The power frequency electric field intensity amplitude at a preset height above the building is obtained by multiplying the distortion coefficient fitting curve after translation with the power frequency electric field intensity distribution at a preset height above the ground.

2. The method according to claim 1, characterized in that Using a pre-established AC overhead line model and the simulated charge method, the field strength distribution curve at a preset height above the ground is determined, including: Using the pre-established AC overhead line model, the radius of the equivalent single conductor of the transmission line is calculated; Based on the radius of the equivalent single conductor, the simulated charge method is combined with the mirror method to set simulated linear charges inside the equivalent single conductor and at symmetrical positions with the ground as the baseline. Matching points are selected on the surface of the equivalent single conductor to calculate the simulated linear charge density in the equivalent single conductor. Calculate the electric field intensity component parallel to the ground and the electric field intensity component perpendicular to the ground at a preset height based on the simulated linear charge density in the equivalent single wire; The electric field strength distribution curve at a preset height on the ground is determined based on the electric field strength component in the direction parallel to the ground and the electric field strength component in the direction perpendicular to the ground.

3. A device for calculating the power frequency electric field above a building, characterized in that: include: A first determination module is used to determine a field intensity distribution curve at a preset height above the ground using a pre-established AC overhead line model and a simulated charge method; The second determining module is used to determine the distortion coefficient fitting curves of buildings of different sizes using a fitting formula according to the calculation results of the distortion coefficient curve of the building size; A calculation module is used to calculate the power frequency field intensity amplitude at a preset height above the building by using the distortion coefficient fitting curve of the building and the field intensity distribution curve at a preset height above the ground, combined with the distance between the building and the equivalent single conductor; The device further includes a third determining module, configured to: Establish building examples of certain types and sizes, and establish field models corresponding to the building examples of each type and size; Calculate the electric field strength above the building based on the field model and finite element method; According to the electric field strength above the building and the given uniform electric field value, the calculation result of the distortion coefficient curve above the building is determined; The second determining module is specifically configured to: According to the calculation results of the distortion coefficient curves of buildings of different sizes, the maximum calculated value and the minimum calculated value of the distortion coefficient of buildings of different sizes are determined; Determine the functional relationship between the maximum and minimum calculated values of the distortion coefficient and the building height and building length using curve fitting; The maximum fitting value and the minimum fitting value of the distortion coefficient are determined using the functional relationship; According to the maximum fitting value and the minimum fitting value of the distortion coefficient, the distortion coefficient fitting curve of the upper surface of the building is obtained by using quadratic function fitting; The computing module is specifically used for: According to the distance between the building and the equivalent single wire, the distortion coefficient fitting curve of the building is translated; The power frequency electric field intensity amplitude at a preset height above the building is obtained by multiplying the distortion coefficient fitting curve after translation with the power frequency electric field intensity distribution at a preset height above the ground.

4. The device according to claim 3, characterized in that The first determination module is specifically configured to: Using the pre-established AC overhead line model, the radius of the equivalent single conductor of the transmission line is calculated; Based on the radius of the equivalent single conductor, the simulated charge method is combined with the mirror method to set simulated linear charges inside the equivalent single conductor and at symmetrical positions with the ground as the baseline. Matching points are selected on the surface of the equivalent single conductor to calculate the simulated linear charge density in the equivalent single conductor. Calculate the electric field intensity component parallel to the ground and the electric field intensity component perpendicular to the ground at a preset height based on the simulated linear charge density in the equivalent single wire; The electric field strength distribution curve at a preset height on the ground is determined based on the electric field strength component in the direction parallel to the ground and the electric field strength component in the direction perpendicular to the ground.

5. A computer-readable storage medium, characterized in that The storage medium stores a computer program, and the computer program is used to execute the method according to any one of claims 1-2.

6. An electronic device, characterized in that: The electronic device comprises: processor; a memory for storing instructions executable by the processor; The processor is configured to read the executable instructions from the memory and execute the instructions to implement the method according to any one of claims 1 to 2.

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