CN112595938A - Method for evaluating adaptability of graphite-based flexible grounding device of overhead transmission line tower - Google Patents
Method for evaluating adaptability of graphite-based flexible grounding device of overhead transmission line tower Download PDFInfo
- Publication number
- CN112595938A CN112595938A CN202011395935.6A CN202011395935A CN112595938A CN 112595938 A CN112595938 A CN 112595938A CN 202011395935 A CN202011395935 A CN 202011395935A CN 112595938 A CN112595938 A CN 112595938A
- Authority
- CN
- China
- Prior art keywords
- graphite
- grounding device
- based flexible
- transmission line
- flexible grounding
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
The invention discloses an evaluation method for adaptability of an overhead transmission line tower grounding device, which comprises the steps of establishing a power frequency finite element model and a lightning impulse finite element model of the environment soil where the grounding device and the grounding device are located; acquiring a power frequency grounding resistor and an impulse grounding resistor of the grounding device according to the model; if the power frequency grounding resistance does not meet the grounding design requirement, the grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; if the single-phase power frequency short circuit is met, inputting the power frequency grounding resistance and the impulse grounding resistance into an overhead transmission line model of the grounding device under the corresponding voltage class, and acquiring the single-phase power frequency short circuit and the current passing through the grounding device when the tower is struck by lightning; and taking the current as a boundary condition, carrying out simulation calculation to obtain the temperature rise of the grounding device, wherein if the temperature rise of the grounding device meets the design requirement, the grounding device is suitable for the overhead transmission line tower, and otherwise, the grounding device is not suitable for the overhead transmission line tower. The invention aims to evaluate the adaptability of the grounding device in the application of an overhead transmission line tower.
Description
Technical Field
The invention belongs to the technical field of lightning protection grounding, and particularly relates to an assessment method for adaptability of an overhead transmission line tower graphite-based flexible grounding device.
Background
The tower grounding body is an important ring in lightning protection of overhead transmission lines, and the excessively high grounding resistance can reduce the lightning-resistant level of a line and increase the flashover rate of the line, so that the safe and stable operation of a power system is influenced. Traditional grounding materials such as galvanized steel, copper-clad steel and the like are widely applied to grounding of power systems, but in actual operation, the traditional grounding body has the problems of poor corrosion resistance, poor contact with soil, easy manual damage and the like. Aiming at the defects of the traditional material grounding body in practical application, the graphite-based flexible material with excellent corrosion resistance and soil compatibility is gradually applied to the overhead transmission line tower grounding body, but the application of the graphite-based flexible grounding device in a circuit still has the adaptability problem.
Specifically, the resistivity of the graphite-based flexible grounding device is higher than that of the traditional metal grounding material, and the body resistance is higher, so that the power frequency grounding resistance and the impulse grounding resistance of the tower can be influenced. Secondly, because the overhead transmission line has high voltage level and large transmission capacity, when a single-phase grounding short circuit occurs through a tower, the current passing through the grounding body is large, meanwhile, the line is erected in the field and is easy to be struck by lightning, and high-amplitude lightning current flows through the tower grounding body. The graphite-based flexible grounding device contains chemical fibers, adhesives and other substances, and the working temperature is not more than 160 ℃, so that the temperature rise of the graphite-based flexible grounding device when a large current passes through the graphite-based flexible grounding device must be evaluated. However, at present, there is no method for performing adaptive evaluation on the model selection and design of the graphite-based flexible grounding device, and therefore, whether the graphite-based flexible grounding device is suitable for the corresponding voltage-class power transmission line tower cannot be judged.
Disclosure of Invention
The invention provides an assessment method for the adaptability of a graphite-based flexible grounding device of an overhead transmission line tower, aiming at assessing the adaptability of the graphite-based flexible grounding device in the application of the overhead transmission line tower and providing a basis for the model selection and design optimization of the graphite-based flexible grounding device.
In order to solve the technical problems, the invention is realized by the following technical scheme:
an assessment method for adaptability of an overhead transmission line tower graphite-based flexible grounding device comprises the following steps:
establishing a power frequency finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device, and establishing a lightning impulse finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device;
acquiring a power frequency grounding resistance of the graphite-based flexible grounding device according to the power frequency finite element model, and acquiring an impulse grounding resistance of the graphite-based flexible grounding device according to the lightning impulse finite element model;
comparing the power frequency grounding resistance with a power frequency grounding resistance design value under a voltage level corresponding to the graphite-based flexible grounding device; when the power frequency grounding resistance is larger than the design value of the power frequency grounding resistance, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; when the power frequency grounding resistance is not larger than the design value of the power frequency grounding resistance, inputting the power frequency grounding resistance and the impulse grounding resistance into an overhead transmission line model of the graphite-based flexible grounding device under the corresponding voltage level;
obtaining the current of the overhead transmission line passing through the graphite-based flexible grounding device when the overhead transmission line is in a single-phase power frequency short circuit and the current of the overhead transmission line passing through the graphite-based flexible grounding device when the overhead transmission line is struck by lightning;
taking the current passing through the graphite-based flexible grounding device when the single-phase power frequency is in short circuit as a terminal boundary condition of the power frequency finite element model to obtain a first volume loss density; taking the current passing through the graphite-based flexible grounding device when the tower is struck by lightning as a terminal boundary condition of the lightning impulse finite element model to obtain a second volume loss density;
calculating a first temperature rise of the graphite-based flexible grounding device according to the first volume loss density and the specific heat capacity of the graphite-based flexible grounding device; calculating a second temperature rise of the graphite-based flexible grounding device according to the second volume loss density and the specific heat capacity of the graphite-based flexible grounding device;
comparing the first temperature rise and the second temperature rise to a temperature rise threshold of the graphite-based flexible grounding device; when at least one of the first temperature rise and the second temperature rise is larger than the temperature rise threshold value, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; and when the first temperature rise and the second temperature rise are not greater than the temperature rise threshold value, the graphite-based flexible grounding device is suitable for the overhead transmission line tower under the corresponding voltage class.
Further, the establishing process of the power frequency finite element model and the lightning impulse finite element model is as follows:
and establishing a three-dimensional model of the graphite-based flexible grounding device, introducing the three-dimensional model into finite element simulation software, and establishing a model of the environmental soil where the graphite-based flexible grounding device is located by using the finite element simulation software according to the embedding depth of the graphite-based flexible grounding device to obtain a power frequency finite element model and a lightning impulse finite element model.
Further, the method for obtaining the power frequency grounding resistance of the graphite-based flexible grounding device according to the power frequency finite element model comprises the following steps: and setting the resistivity of the environment soil where the graphite-based flexible grounding device is located as a fixed value, and solving in a frequency domain by adopting a current field to obtain the power frequency grounding resistance.
Further, the method for obtaining the impulse grounding resistance of the graphite-based flexible grounding device according to the lightning impulse finite element model comprises the following steps:
and setting the resistivity of the soil in the environment where the graphite-based flexible grounding device is located as a hierarchical interpolation function related to the electric field strength, and solving in a time domain by adopting a current field and a magnetic field coupled multi-physical field to obtain the impulse grounding resistance.
Further, the method for establishing the overhead transmission line model comprises the following steps:
establishing the overhead transmission line model by using ATP-EMTP;
the overhead transmission line model comprises an overhead line, a tower and a lightning current source, wherein the overhead line adopts a JMarti frequency response model in an LCC module in ATP-EMTP, the tower adopts a multi-wave impedance model, and the lightning current source adopts a double-exponential model for simulation.
Further, calculating a first temperature rise of the graphite-based flexible grounding device according to the first volume loss density and the specific heat capacity of the graphite-based flexible grounding device, wherein a specific formula is as follows:
wherein, PmaxMaximum volume loss density of graphite material in flexible graphite-based earthing device, unit W/m3；
Δ t-duration of power frequency short circuit current in units of s;
cm-the specific heat capacity of the graphitic material, in J/(kg. DEG C);
rho-density of graphite material, unit kg/m3。
Further, calculating a second temperature rise of the graphite-based flexible grounding device according to the second volume loss density and the specific heat capacity of the graphite-based flexible grounding device, wherein a specific formula is as follows:
wherein, PiVolume loss density of graphite material in unit W/m corresponding to ith time step in graphite-based flexible grounding device3；
N is the total number of time steps,
t is the lightning current duration in units of s;
Δ t-time domain simulation time step, unit s;
cm-the specific heat capacity of the graphitic material, in J/(kg. DEG C);
rho-density of graphite material, unit kg/m3。
Further, the finite element simulation software is COMSOL Mutiphysics finite element simulation software.
Compared with the prior art, the invention has at least the following beneficial effects: the invention provides an assessment method for adaptability of a graphite-based flexible grounding device of an overhead transmission line tower. The modeling calculation can be carried out on any type of graphite-based flexible grounding device by combining the calculation advantages of finite element simulation software and electromagnetic transient simulation software, and the adaptability is wide. The evaluation method can be used for calculating and evaluating the whole set of complete graphite-based flexible grounding device, and has the advantages of low cost, flexibility, convenience, design and construction reasonability guarantee and the like compared with the test which has high cost and difficult implementation and can only evaluate partial structure of the graphite-based flexible grounding device. The optimization and improvement of the graphite grounding device model selection and design before the engineering construction are facilitated to a certain extent, and the method has important significance for reducing the lightning flashover rate of the overhead transmission line and avoiding unreasonable engineering construction.
In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a flow chart of an evaluation method of adaptability of an overhead transmission line tower graphite-based flexible grounding device according to the invention;
FIG. 2 is a three-dimensional model of a graphite-based flexible grounding device according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of the relationship between soil conductivity and soil electric field strength provided by an embodiment of the present invention;
fig. 4 is a 220kV overhead transmission line model provided in the embodiment of the present invention.
In the figure: 1-armouring down lead; 2-spark-plug type grounding module; 3-graphite resistance reducing cloth; 4-horizontal flexible grounding body.
Detailed Description
To make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As a specific embodiment of the present invention, a method for evaluating the adaptability of a graphite-based flexible grounding device for an overhead transmission line tower, includes:
establishing a power frequency finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device, and establishing a lightning impulse finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device;
specifically, the establishing process of the power frequency finite element model and the lightning impulse finite element model is as follows: the method comprises the steps of establishing a three-dimensional model of the graphite-based flexible grounding device by utilizing Solidworks, introducing the three-dimensional model into finite element simulation software, and establishing a model of the environment soil where the graphite-based flexible grounding device is located by utilizing the finite element simulation software according to the embedding depth of the graphite-based flexible grounding device to obtain a power frequency finite element model and a lightning impulse finite element model.
The method comprises the following steps of obtaining the power frequency grounding resistance of the graphite-based flexible grounding device according to a power frequency finite element model, and specifically comprises the following steps: and setting the resistivity of the environment soil where the graphite-based flexible grounding device is located as a fixed value, and solving in a frequency domain by adopting a current field to obtain the power frequency grounding resistance.
Acquiring impulse grounding resistance of the graphite-based flexible grounding device according to the lightning impulse finite element model, wherein the specific acquisition method comprises the following steps: the resistivity of the soil in the environment where the graphite-based flexible grounding device is located is set as a layered interpolation function related to the electric field intensity, and the impulse grounding resistance is obtained by solving in a time domain by adopting a current field and a magnetic field coupled multi-physical field.
Illustratively, a three-dimensional model diagram of a 220kV overhead transmission line near-area tower grounding device shown in fig. 2 is established in Solidworks software, the graphite-based flexible grounding device is applied to a region with soil resistivity of 0-300 omega-m, and the maximum allowable power frequency grounding resistance is 10 omega. The graphite-based flexible grounding device mainly comprises an armored graphite down lead 1, a horizontal flexible grounding body 4, graphite resistance reducing cloth 3 and a spark plug type grounding module 2, and engineering simplification is carried out on the model according to the actual size of each part.
And (3) introducing the three-dimensional model of the graphite-based flexible grounding device into COMSOL Mutiphysics finite element software, and arranging a soil domain around the grounding device. When current passes through the grounding body, the graphite-based flexible grounding device is used as the center and uniformly diffuses to the surrounding soil, the soil domain is in a hemisphere shape, and the grounding device is buried 0.6m below the soil surface. The radius of the soil area is set to be more than 10 times of the maximum diagonal length of the grounding device, so that the calculation result can be guaranteed to be basically accurate, and the radius is set to be 500m in the embodiment.
And setting the hemispherical surface of the soil domain as the ground potential, and taking the upper end of the armored down lead as a current injection point. The electrical conductivity, relative permittivity and relative permeability are set according to the characteristics of different materials, and in this embodiment, the electrical conductivity, relative permittivity and relative permeability of the graphite are respectively 5 × 104S/m, 15 and 1. When the power frequency grounding resistance is calculated, the soil conductivity is considered as a fixed value which does not change along with the field intensity and is 0.00333S/m; when calculating the impulse grounding resistance, the soil conductivity is set to vary with the field strength, and the relationship between the soil conductivity and the soil field strength is shown in fig. 3. And the power frequency grounding resistance is 9.256 omega, and the impulse grounding resistance is 7.234 omega.
Comparing the power frequency grounding resistance with a power frequency grounding resistance design value under a voltage level corresponding to the graphite-based flexible grounding device; when the power frequency grounding resistance is larger than the design value of the power frequency grounding resistance, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; when the power frequency grounding resistance is not larger than the design value of the power frequency grounding resistance, inputting the power frequency grounding resistance and the impulse grounding resistance into an overhead transmission line model of the graphite-based flexible grounding device under the corresponding voltage level; the system comprises an overhead line, a tower, a lightning current source and a power supply, wherein the overhead line adopts a JMarti frequency response model in an LCC module in ATP-EMTP, the tower adopts a multi-wave impedance model, and the lightning current source adopts a double-exponential model for simulation.
And obtaining the current of the overhead transmission line passing through the graphite-based flexible grounding device when the single-phase power frequency is short-circuited and the current passing through the graphite-based flexible grounding device when the tower is struck by lightning according to the overhead transmission line model.
Illustratively, the power frequency ground resistance of the graphite-based flexible grounding device in the embodiment is 9.256 Ω, which is smaller than the design value of the power frequency ground resistance. A220 kV overhead transmission line model is built in ATP-EMTP electromagnetic transient calculation software and is shown in figure 4. In this embodiment, parameters of the 220kV overhead transmission line were selected in the investigation. The length of the overhead transmission line is 200km, and the transmission capacity is 121 MW. The line tower is a single-loop tangent tower, the tower is simulated by adopting a multi-wave impedance model, and the grounding device is simulated by using a grounding resistor. When a single-phase power frequency short circuit occurs in the line, the grounding resistance is set to 9.256 omega; when the tower is struck by lightning, the grounding resistance is set to 7.234 omega. Through simulation calculation, the amplitude of the single-phase power frequency short-circuit current passing through the graphite-based flexible grounding device is 1743A, the amplitude of the lightning current passing through the graphite-based flexible grounding device is 176.250kA, and the waveform is 2.8/10.7 mu s. The double exponential function of lightning current is:
I＝-389620×(e-547679t-e-145777t)。
taking the current passing through the graphite-based flexible grounding device when the single-phase power frequency is in short circuit as a terminal boundary condition of a power frequency finite element model to obtain a first volume loss density; and taking the current passing through the graphite-based flexible grounding device when the tower is struck by lightning as a terminal boundary condition of the lightning impulse finite element model to obtain a second volume loss density.
Calculating a first temperature rise of the graphite-based flexible grounding device according to the first volume loss density and the specific heat capacity of the graphite-based flexible grounding device; and calculating the second temperature rise of the graphite-based flexible grounding device according to the second volume loss density and the specific heat capacity of the graphite-based flexible grounding device.
Illustratively, the terminal current amplitude of the power frequency finite element model is set to 1743A, and the terminal current of the lightning impulse finite element model is set to a double exponential function with a current amplitude of 189.020kA and a waveform of 2.8/10.7 mus. The specific heat capacity of the graphite was 710J/(. degree. C. kg), and the density was 2000kg/m3. Short circuit currents and lightning currents have a short duration of action and are therefore considered to be thermally insulating between different materials. The longest power frequency short-circuit current lasts 0.5s, and the maximum value of the first volume loss density is 7.6 multiplied by 10 according to simulation results7W/m3The first maximum temperature rise is then:
the lightning current lasts 50 mus, the time domain simulation time step length is 1 mus, then
The second maximum temperature rise is:
under the power frequency short circuit current with the duration time of 0.04s, the maximum temperature rise of the graphite grounding device is not more than 26.761 ℃; under the lightning impulse current, the maximum temperature rise of the graphite grounding device is not more than 74.360 ℃.
Comparing the first temperature rise and the second temperature rise with a temperature rise threshold of the graphite-based flexible grounding device; when at least one of the first temperature rise and the second temperature rise is larger than the temperature rise threshold value, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; when the first temperature rise and the second temperature rise are not larger than the temperature rise threshold value, the graphite-based flexible grounding device is suitable for the overhead transmission line tower under the corresponding voltage class.
Illustratively, in the embodiment, the temperature rise of the graphite-based flexible grounding device under the conditions of power frequency short circuit and lightning large current does not exceed 120 ℃, and the graphite-based flexible grounding device is suitable for a near-area tower of a 220kV overhead transmission line.
Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (8)
1. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower is characterized by comprising the following steps of:
establishing a power frequency finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device, and establishing a lightning impulse finite element model of the environment soil comprising the graphite-based flexible grounding device and the graphite-based flexible grounding device;
acquiring a power frequency grounding resistance of the graphite-based flexible grounding device according to the power frequency finite element model, and acquiring an impulse grounding resistance of the graphite-based flexible grounding device according to the lightning impulse finite element model;
comparing the power frequency grounding resistance with a power frequency grounding resistance design value under a voltage level corresponding to the graphite-based flexible grounding device; when the power frequency grounding resistance is larger than the design value of the power frequency grounding resistance, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; when the power frequency grounding resistance is not larger than the design value of the power frequency grounding resistance, inputting the power frequency grounding resistance and the impulse grounding resistance into an overhead transmission line model of the graphite-based flexible grounding device under the corresponding voltage level;
obtaining the current of the overhead transmission line passing through the graphite-based flexible grounding device when the overhead transmission line is in a single-phase power frequency short circuit and the current of the overhead transmission line passing through the graphite-based flexible grounding device when the overhead transmission line is struck by lightning;
taking the current passing through the graphite-based flexible grounding device when the single-phase power frequency is in short circuit as a terminal boundary condition of the power frequency finite element model to obtain a first volume loss density; taking the current passing through the graphite-based flexible grounding device when the tower is struck by lightning as a terminal boundary condition of the lightning impulse finite element model to obtain a second volume loss density;
calculating a first temperature rise of the graphite-based flexible grounding device according to the first volume loss density and the specific heat capacity of the graphite-based flexible grounding device; calculating a second temperature rise of the graphite-based flexible grounding device according to the second volume loss density and the specific heat capacity of the graphite-based flexible grounding device;
comparing the first temperature rise and the second temperature rise to a temperature rise threshold of the graphite-based flexible grounding device; when at least one of the first temperature rise and the second temperature rise is larger than the temperature rise threshold value, the graphite-based flexible grounding device is not suitable for the overhead transmission line tower under the corresponding voltage class; and when the first temperature rise and the second temperature rise are not greater than the temperature rise threshold value, the graphite-based flexible grounding device is suitable for the overhead transmission line tower under the corresponding voltage class.
2. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower according to claim 1, wherein the power frequency finite element model and the lightning impulse finite element model are established in the following processes:
and establishing a three-dimensional model of the graphite-based flexible grounding device, introducing the three-dimensional model into finite element simulation software, and establishing a model of the environmental soil where the graphite-based flexible grounding device is located by using the finite element simulation software according to the embedding depth of the graphite-based flexible grounding device to obtain a power frequency finite element model and a lightning impulse finite element model.
3. The method for evaluating the adaptability of the overhead transmission line tower graphite-based flexible grounding device according to claim 1, wherein the method for obtaining the power frequency grounding resistance of the graphite-based flexible grounding device according to the power frequency finite element model comprises the following steps: and setting the resistivity of the environment soil where the graphite-based flexible grounding device is located as a fixed value, and solving in a frequency domain by adopting a current field to obtain the power frequency grounding resistance.
4. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower according to claim 1, wherein the method for obtaining the impulse grounding resistance of the graphite-based flexible grounding device according to the lightning impulse finite element model comprises the following steps:
and setting the resistivity of the soil in the environment where the graphite-based flexible grounding device is located as a hierarchical interpolation function related to the electric field strength, and solving in a time domain by adopting a current field and a magnetic field coupled multi-physical field to obtain the impulse grounding resistance.
5. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower according to claim 1, wherein the method for establishing the overhead transmission line model comprises the following steps:
establishing the overhead transmission line model by using ATP-EMTP;
the overhead transmission line model comprises an overhead line, a tower and a lightning current source, wherein the overhead line adopts a JMarti frequency response model in an LCC module in ATP-EMTP, the tower adopts a multi-wave impedance model, and the lightning current source adopts a double-exponential model for simulation.
6. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower according to claim 1, wherein a first temperature rise of the graphite-based flexible grounding device is calculated according to the first volumetric loss density and the specific heat capacity of the graphite-based flexible grounding device, and the specific formula is as follows:
wherein, PmaxMaximum volume loss density of graphite material in flexible graphite-based earthing device, unit W/m3；
Δ t-duration of power frequency short circuit current in units of s;
cm-the specific heat capacity of the graphitic material, in J/(kg. DEG C);
rho-density of graphite material, unit kg/m3。
7. The method for evaluating the adaptability of the graphite-based flexible grounding device of the overhead transmission line tower according to claim 1, wherein a second temperature rise of the graphite-based flexible grounding device is calculated according to the second volumetric loss density and the specific heat capacity of the graphite-based flexible grounding device, and the specific formula is as follows:
wherein, PiVolume loss density of graphite material in unit W/m corresponding to ith time step in graphite-based flexible grounding device3；
N is the total number of time steps,
t is the lightning current duration in units of s;
Δ t-time domain simulation time step, unit s;
cm-the specific heat capacity of the graphitic material, in J/(kg. DEG C);
rho-density of graphite material, unit kg/m3。
8. The method for evaluating the adaptability of the overhead transmission line tower graphite-based flexible grounding device as claimed in claim 2, wherein the finite element simulation software is COMSOL Mutiphysics finite element simulation software.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011395935.6A CN112595938B (en) | 2020-12-03 | 2020-12-03 | Method for evaluating adaptability of graphite-based flexible grounding device of pole tower of overhead transmission line |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011395935.6A CN112595938B (en) | 2020-12-03 | 2020-12-03 | Method for evaluating adaptability of graphite-based flexible grounding device of pole tower of overhead transmission line |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112595938A true CN112595938A (en) | 2021-04-02 |
| CN112595938B CN112595938B (en) | 2023-08-22 |
Family
ID=75187754
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011395935.6A Active CN112595938B (en) | 2020-12-03 | 2020-12-03 | Method for evaluating adaptability of graphite-based flexible grounding device of pole tower of overhead transmission line |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112595938B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114280411A (en) * | 2021-11-19 | 2022-04-05 | 中国电建集团河北省电力勘测设计研究院有限公司 | Test method for obtaining high-frequency response of cable |
Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101114999B1 (en) * | 2010-10-11 | 2012-03-06 | (주)옴니엘피에스 | A device for assessing the length of carbon ground electrode module based on a two-level distributed parameter circuit model and the method thereof |
| CN102928673A (en) * | 2012-10-25 | 2013-02-13 | 清华大学 | Method for acquiring impulse grounding resistance |
| CN103293451A (en) * | 2013-05-24 | 2013-09-11 | 华南理工大学 | Method of estimating lightning protection of high-voltage transmission line pole/tower earthing device |
| CN104931793A (en) * | 2015-06-10 | 2015-09-23 | 国网上海市电力公司 | Substation grounding grid grounding resistance acquisition method |
| CN105182084A (en) * | 2015-07-02 | 2015-12-23 | 国家电网公司 | Method for obtaining impulse impedance of grounding device through low lightning current impulse test |
| CN106569038A (en) * | 2016-09-28 | 2017-04-19 | 国网山西省电力公司阳泉供电公司 | Method for testing impulse grounding resistance of pole of power transmission line |
| CN108445297A (en) * | 2018-04-18 | 2018-08-24 | 中国石油天然气集团有限公司 | The monitoring method and system of Resistance of Grounding Grids |
| CN109635360A (en) * | 2018-11-21 | 2019-04-16 | 宁波恒晨电力建设有限公司 | Lightning Strike Risk Evaluation method and device based on cascade emulation |
| CN110895300A (en) * | 2019-10-12 | 2020-03-20 | 国网安徽省电力有限公司经济技术研究院 | Lightning protection performance analysis method for graphite grounding device of power transmission line tower |
-
2020
- 2020-12-03 CN CN202011395935.6A patent/CN112595938B/en active Active
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101114999B1 (en) * | 2010-10-11 | 2012-03-06 | (주)옴니엘피에스 | A device for assessing the length of carbon ground electrode module based on a two-level distributed parameter circuit model and the method thereof |
| CN102928673A (en) * | 2012-10-25 | 2013-02-13 | 清华大学 | Method for acquiring impulse grounding resistance |
| CN103293451A (en) * | 2013-05-24 | 2013-09-11 | 华南理工大学 | Method of estimating lightning protection of high-voltage transmission line pole/tower earthing device |
| CN104931793A (en) * | 2015-06-10 | 2015-09-23 | 国网上海市电力公司 | Substation grounding grid grounding resistance acquisition method |
| CN105182084A (en) * | 2015-07-02 | 2015-12-23 | 国家电网公司 | Method for obtaining impulse impedance of grounding device through low lightning current impulse test |
| CN106569038A (en) * | 2016-09-28 | 2017-04-19 | 国网山西省电力公司阳泉供电公司 | Method for testing impulse grounding resistance of pole of power transmission line |
| CN108445297A (en) * | 2018-04-18 | 2018-08-24 | 中国石油天然气集团有限公司 | The monitoring method and system of Resistance of Grounding Grids |
| CN109635360A (en) * | 2018-11-21 | 2019-04-16 | 宁波恒晨电力建设有限公司 | Lightning Strike Risk Evaluation method and device based on cascade emulation |
| CN110895300A (en) * | 2019-10-12 | 2020-03-20 | 国网安徽省电力有限公司经济技术研究院 | Lightning protection performance analysis method for graphite grounding device of power transmission line tower |
Non-Patent Citations (3)
| Title |
|---|
| T.ZHENG 等: "Fault analysis for lightning stroke-caused string fracture of 500kV line porcelain insulators", 《THE 16TH IET INTERNATIONAL CONFERENCE ON AC AND DC POWER TRANSMISSION》, pages 15 - 18 * |
| 邓长征: "线路杆塔接地装置冲击特性及试验系统的研究", 《中国博士学位论文全文数据库工程科技Ⅱ辑》, no. 1, pages 042 - 35 * |
| 黄欢 等: "杆塔冲击接地阻抗的有限元分析", 《高压电器》, vol. 55, no. 4, pages 217 - 222 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114280411A (en) * | 2021-11-19 | 2022-04-05 | 中国电建集团河北省电力勘测设计研究院有限公司 | Test method for obtaining high-frequency response of cable |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112595938B (en) | 2023-08-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Mokhtari et al. | An improved circuit-based model of a grounding electrode by considering the current rate of rise and soil ionization factors | |
| CN103293451B (en) | A kind of appraisal procedure of high-voltage transmission line pole tower earthing device lightning protection characteristic | |
| Rizk et al. | Investigation of lightning electromagnetic fields on underground cables in wind farms | |
| CN111679103A (en) | High-voltage cable water-blocking tape electrical performance test system based on three-electrode method | |
| CN110309546B (en) | Method for evaluating impact grounding impedance influence of power transmission line grounding device | |
| CN112595938A (en) | Method for evaluating adaptability of graphite-based flexible grounding device of overhead transmission line tower | |
| CN112924763B (en) | Method for evaluating transient electric shock below high-voltage alternating-current transmission line | |
| Puttarach et al. | Substation grounding grid analysis with the variation of soil layer depth method | |
| CN110895300A (en) | Lightning protection performance analysis method for graphite grounding device of power transmission line tower | |
| Araneo et al. | Hybrid and pi-circuit approaches for grounding system lightning response | |
| Zhang et al. | Onset electric field of soil ionisation around grounding electrode under lightning | |
| Fernández et al. | Simulation of current distribution in a wind turbine blade using the FDTD method | |
| Viola et al. | Finite-difference time-domain simulation of towers cascade under lightning surge conditions | |
| CN114824846B (en) | Short conductor-based power transmission pole tower grounding method | |
| CN111985109A (en) | Lightning protection effective size coefficient evaluation method for horizontal grounding body at different temperatures | |
| CN105572510A (en) | DC power transmission line corona loss test method based on corona cage | |
| Araneo et al. | Transient response of grounding systems of wind turbines under lightning strikes | |
| Li | Lightning Response Transient Characteristics of Substation Grounding Grid in Multilayer Horizontal Stratified Earth Model Considering Soil Ionization Effect | |
| de Azevedo et al. | Transient analysis of power transmission towers above lossy ground with frequency dependent electrical parameters considering the water content of soil | |
| CN112821095B (en) | Method for reducing impact grounding impedance and non-equal-diameter grounding device | |
| CN112083252B (en) | Method for evaluating maximum economic size coefficient of horizontal layered under-soil grounding device | |
| Song et al. | Model for prediction of characteristics of lightning breakdown channels in soil in the presence of a buried cable | |
| Gonos | Experimental study of transient behaviour of grounding grids using scale models | |
| Othman et al. | Simulation of 33kV String Insulators Using Finite Element Method (FEM) | |
| Rondon et al. | Influence of grounding system modeling on transient analysis of transmission lines due to direct lightning strike |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |