CN113255976B - Grounding optimization design method for distribution line erection overhead ground wire - Google Patents
Grounding optimization design method for distribution line erection overhead ground wire Download PDFInfo
- Publication number
- CN113255976B CN113255976B CN202110514067.7A CN202110514067A CN113255976B CN 113255976 B CN113255976 B CN 113255976B CN 202110514067 A CN202110514067 A CN 202110514067A CN 113255976 B CN113255976 B CN 113255976B
- Authority
- CN
- China
- Prior art keywords
- ground
- line
- ground wire
- induced
- overvoltage
- 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.)
- Active
Links
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/04—Forecasting or optimisation specially adapted for administrative or management purposes, e.g. linear programming or "cutting stock problem"
- G06Q10/043—Optimisation of two dimensional placement, e.g. cutting of clothes or wood
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
- G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
- G06F16/29—Geographical information databases
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q50/00—Systems or methods specially adapted for specific business sectors, e.g. utilities or tourism
- G06Q50/06—Electricity, gas or water supply
Abstract
The invention relates to a grounding optimization design method for erecting an overhead ground wire of a distribution line, which comprises the following steps: establishing a distribution line induced lightning overvoltage Agrawal field line coupling model based on a finite difference time domain method; performing discrete transformation on the Agrawal field line coupling equation by a finite difference time domain method, and establishing a multi-conductor multi-order inductive lightning overvoltage calculation model; establishing an overhead ground wire model; according to the overhead ground wire model, calculating and comparing the induced lightning overvoltage of the non-ground wire line and the ground wire line, and obtaining the induced lightning overvoltage on the phase line by changing the ground conductivity and the ground resistance parameter of the overhead ground wire; the method comprises the steps of obtaining induced overvoltage on an insulator in an approximate mode, analyzing the influence relation of the earth conductivity and the induced overvoltage on the insulator when the grounding resistance changes, and determining whether resistance reduction measures need to be taken on an electric pole when the earth conductivity and the grounding resistance of the overhead ground wire change; if the induced overvoltage on the insulator is in a decreasing trend, resistance reduction measures are not needed, and the insulator is naturally grounded.
Description
Technical Field
The application relates to the technical field of distribution line lightning protection, in particular to a grounding optimization design method for erecting an overhead ground wire on a distribution line.
Background
The 10kV overhead distribution line has low insulation level and high failure rate caused by lightning stroke, wherein most failures are caused by lightning induced overvoltage generated on a lead when the ground or a building near the line is struck by lightning, so that the key for improving the reliability is to effectively reduce the number of times of induced overvoltage flashover of the line.
As early as the last century, researchers have proposed that ground wires are erected in overhead distribution lines to protect against lightning induced overvoltage, and the principle is to reduce the amplitude of the induced overvoltage on the wires by using the principle that the ground wires are drawn close to the zero potential of the wires and the ground. In engineering practice, protective measures for erecting ground wires are basically not adopted in distribution lines in China, and the reason for this is that different opinions exist on the actual protective effects of the measures. Therefore, it is necessary to conduct quantitative research on the protective effect of the installed ground in order to guide the engineering application of the measures.
The electric pole of the overhead distribution line is generally naturally grounded, has higher grounding resistance and increases along with the increase of the ground resistivity, and whether resistance reduction measures need to be taken on the electric pole or not is a key concern in engineering when the ground wire is erected to protect lightning induction overvoltage.
Disclosure of Invention
The application provides a grounding optimization design method for erecting an overhead ground wire of a power distribution line, which aims to solve the problem that whether resistance reduction measures are needed to be taken for an electric pole of the overhead power distribution line when the overhead ground wire is adopted to protect lightning induction overvoltage.
The technical scheme adopted by the application is as follows:
the invention provides a grounding optimization design method for erecting an overhead ground wire of a distribution line, which comprises the following steps:
establishing an Agrawal field line coupling model of the distribution line induced lightning overvoltage based on a time domain finite difference method;
according to the determined distribution line induced lightning overvoltage Agrawal field line coupling model, performing discrete transformation on an Agrawal field line coupling equation by a time domain finite difference method, and establishing a multi-conductor multi-stage induced lightning overvoltage calculation model;
establishing an overhead ground wire model according to the multi-order inductive lightning overvoltage calculation model;
according to the overhead ground wire model, calculating and comparing the induced lightning overvoltage of the non-ground wire line and the ground wire line, and obtaining the induced lightning overvoltage on the phase line of the ground wire line by changing the ground conductivity and the ground resistance parameter of the overhead ground wire;
the method comprises the steps of obtaining induced overvoltage on an insulator in an approximate mode, analyzing the influence relation of the earth conductivity and the induced overvoltage on the insulator when the grounding resistance changes, and determining whether resistance reduction measures need to be taken on an electric pole when the earth conductivity and the grounding resistance of the overhead ground wire change;
if the induced overvoltage on the insulator is in a decreasing trend, resistance reduction measures are not needed, and the insulator is naturally grounded.
Further, the establishing of the distribution line induced lightning overvoltage calculation model based on the time domain finite difference method comprises the following steps:
building a lightning electromagnetic field calculation model around the distribution line;
and coupling the lightning electromagnetic field to the conductor line to calculate the induced lightning overvoltage.
Further, the lightning electromagnetic field calculation model around the electric line comprises: the method comprises the steps of lightning channel back-strike model, space electromagnetic field calculation iterative model, boundary absorption and different medium processing.
Further, the multi-conductor multi-order inductive lightning overvoltage calculation model has the following expression:
(1) And [ L 'in the formula (2)' ij ]A unit inductance matrix for multiple conductors with self-inductance and mutual inductance taken into account, [ C ] i ' j ]In order to consider a unit inductance matrix with self-capacitance and mutual capacitance, the delta x and the delta t are respectively a space step length and a time step length; h is a total of i Is the conductor space height; e is a spatial vertical electric field;
the relationship between the capacitance matrix and the inductance matrix is as follows:
[C ij ′]＝μ 0 ε 0 [L ij ′] -1 (5)
in the formulae (3), (4) and (5), h represents the wire height, r represents the wire radius, and s ij Is the spacing between the wires.
Further, according to the overhead ground wire model, the induced lightning overvoltage of the non-ground wire line and the ground wire line is calculated and compared, and the relationship between the ground conductivity and the ground resistance in the induced lightning overvoltage on the phase line is obtained by changing the parameters of the ground conductivity and the ground resistance of the overhead ground wire:
(6) In the formula R e Represents a ground resistance, R 0 The ground body size is indicated and ρ is the soil resistivity.
Further, the ground resistor includes: the resistance of the grounding tower, the resistance of the grounding lead, the transition resistance between the tower grounding body and the accessed soil, and the current dissipation resistance of the tower grounding body to the ground are the maximum.
The technical scheme of the application has the following beneficial effects:
the invention discloses a grounding optimization design method for erecting an overhead ground wire of a distribution line, which comprises the following steps of: establishing an Agrawal field line coupling model of the distribution line induced lightning overvoltage based on a time domain finite difference method; according to the determined distribution line induced lightning overvoltage Agrawal field line coupling model, performing discrete transformation on an Agrawal field line coupling equation by a time domain finite difference method, and establishing a multi-conductor multi-stage induced lightning overvoltage calculation model; establishing an overhead ground wire model according to the multi-order inductive lightning overvoltage calculation model; according to the overhead ground wire model, calculating and comparing the induced lightning overvoltage of the non-ground wire line and the ground wire line, and obtaining the induced lightning overvoltage on the phase line by changing the ground conductivity and the ground resistance parameter of the overhead ground wire; the method comprises the steps of obtaining induced overvoltage on an insulator in an approximate mode, analyzing the influence relation of the earth conductivity and the induced overvoltage on the insulator when the grounding resistance changes, and determining whether resistance reduction measures need to be taken on an electric pole when the earth conductivity and the grounding resistance of the overhead ground wire change; if the induced overvoltage on the insulator is in a decreasing trend, resistance reduction measures are not needed, and the insulator is naturally grounded.
The model has good precision after verification, can accurately simulate the shielding effect on each phase of conductor when the ground conductivity and the ground resistance of the overhead ground wire change, and provides an analysis method for guiding the ground optimization design of the overhead ground wire of the distribution network.
Drawings
In order to more clearly explain the technical solution of the present application, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious to those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.
Fig. 1 is a model of calculating an electromagnetic field around a lightning channel in a grounding optimization design method for a distribution line overhead ground wire according to an embodiment of the present invention;
fig. 2 is a schematic spatial diagram of an Agrawal field-line coupling model of a ground optimization design method for erecting an overhead ground wire on a distribution line according to an embodiment of the present invention;
fig. 3 is a geometry of a multi-conductor of a grounding optimization design method for an overhead ground wire of a distribution line according to an embodiment of the present invention;
fig. 4 is an induced current flow diagram of a ground optimization design method for erecting an overhead ground wire of a distribution line according to an embodiment of the present invention;
fig. 5 illustrates induced overvoltage waveforms at a line endpoint of a method for optimizing ground for distribution line overhead ground wires according to an embodiment of the present invention;
fig. 6 is a graph showing changes in the induced voltage amplitude with the ground resistance in the ground optimization design method for the distribution line overhead ground wire according to the embodiment of the present invention.
Detailed Description
Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following examples do not represent all embodiments consistent with the present application. But merely as exemplifications of systems and methods consistent with certain aspects of the application, as recited in the claims.
The invention provides a grounding optimization design method for erecting an overhead ground wire of a distribution line, which comprises the steps of firstly calculating and comparing induced overvoltage of a non-ground wire line and a ground wire line, further calculating the induced overvoltage of the ground wire line by taking different ground conductivity and ground resistance values, and finally obtaining the grounding optimization design method for the distribution line.
The invention provides a spatial position optimization method for erecting an overhead ground wire of a distribution line, which mainly comprises two parts of establishing a distribution line induced lightning overvoltage calculation model based on a time domain finite difference method and establishing an overhead ground wire model through a multi-conductor induced lightning overvoltage calculation model.
The application provides a grounding optimization design method for erecting an overhead ground wire of a distribution line, which comprises the following steps:
s01: establishing a distribution line induced lightning overvoltage Agrawal field line coupling model based on a finite difference time domain method;
specifically, the method comprises the following steps:
building a lightning electromagnetic field calculation model around the distribution line;
and coupling the lightning electromagnetic field to the conductor line to calculate the induced lightning overvoltage.
As shown in FIG. 1, the lightning channel surrounding electromagnetic field calculation model based on the time domain finite difference method is generally divided into four parts, namely a lightning channel back-strike model, a space electromagnetic field calculation iteration model, boundary absorption and different medium processing.
The lightning strike-back channel is arranged at the axial symmetry position under the two-dimensional cylindrical coordinate system, and the lightning electromagnetic field calculation in the whole three-dimensional space can be simulated through axial symmetry processing. The electromagnetic field under the two-dimensional cylindrical coordinate system is divided into two groups of waveforms of TE and TM, and corresponds to different electromagnetic field components, wherein the components including a vertical electric field and a horizontal electric field are TM waves, and the Maxwell equation is as follows:
wherein, mu, epsilon, sigma and sigma m Respectively representing the permeability coefficient, relative dielectric constant, electrical loss and magnetic loss of space, E r Horizontal electric field, E z Is a vertical electric field and is provided with a plurality of electric fields,
is a direction angle magnetic field.
Continuing to perform time domain finite difference transformation on the formula, the following iterative equations can be obtained, and the propagation process of the electromagnetic field can be simulated through the three equations:
wherein i and j are only used for distinguishing the positions of the electromagnetic field components at different spatial grids, and have no practical physical meaning.
Therefore, the lightning electromagnetic field is mainly calculated in three steps, firstly, the initial value of the component of the whole space electromagnetic field is given, and meanwhile, the basic parameters such as the ground electric conductivity in the free space are set. And secondly, a time iteration process is carried out, and when the time is increased, the lightning current in the lightning strike-back channel model also changes in real time. And finally, calculating a vertical electric field around the lightning strike-back channel through a corresponding excitation formula, and diffusing the vertical electric field into a surrounding calculation space through an electromagnetic field iterative formula.
On the other hand, the vertical electric field and the horizontal electric field of any point in the free space are obtained through the lightning electromagnetic field calculation model, and then calculation is carried out through an Agrawal field line coupling method, so that induced lightning overvoltage on the line can be obtained, fig. 2 is a space schematic diagram of an Agrawal field line coupling model, wherein the left side is a lightning strike-back channel, and the right side is a set line model.
The Agrawal model equation can be expressed as follows:
in the above formula v s I is a scattered voltage, i is an induced current, L 'is an inductance per unit length, C' is a capacitance per unit length,
is the horizontal electric field, h is the phase conductor height, and t is the time.
The incident voltage is calculated by a vertical electric field, and since the vertical electric field varies little in value at a certain height, the following expression can be equivalent:
in the above formula
The vertical electric field generated at x for elements at height z in the lightning path,
the vertical electric field generated by the element at the bottom of the lightning channel at the position x, h is the height of the lightning channel, t is time, and z is the vertical height of a certain current element of the lightning strike-back channel.
The total induced lightning voltage has the following relation with the incident voltage and the scattering voltage:
v(x,t)＝v i (x,t)+v s (x,t)
based on the formula, the calculation of the induced lightning overvoltage v (x, t) is mainly divided into two steps, namely the calculation of the scattering voltage v s (x, t) and incident voltage v i (x,t)。
S02: according to the distribution line induced lightning overvoltage Agrawal field line coupling model determined in the S01, discrete transformation is carried out on an Agrawal field line coupling equation through a time domain finite difference method, and a multi-stage induced lightning overvoltage calculation model of a single conductor and multiple conductors is established;
the multi-conductor model is similar to the derivation process of the single-conductor model, the vector matrix can be formed by carrying out vector expansion on the single-conductor model and expanding basic vectors such as voltage and current, the effect of coupling between wires is supplemented and calculated by utilizing the inductance-capacitance matrix, and the Agrawal field line coupling-based multi-conductor vector matrix model can be obtained by the mode.
The multi-conductor multi-order inductive lightning overvoltage calculation model has the following expression:
in the formula of (L' ij ]For a unity inductance matrix between multiple conductors taking into account self and mutual inductance, [ C i ' j ]In order to consider a unit inductance matrix with self-capacitance and mutual capacitance, the delta x and the delta t are respectively a space step length and a time step length; h is a total of i Is the conductor space height; e is a space vertical electric field, k has no practical physical significance and is only used for distinguishing codes of different space positions in space;
the unity inductance matrix is composed of the inductance and mutual inductance between a plurality of conductors, and is expressed as follows:
each row represents the self-inductance of the conductor and the mutual inductance with other conductors, i = j represents the self-inductance of the conductor, i ≠ j represents the mutual inductance of the conductor with other conductors, and n represents the number of conductors.
Paul summarizes a calculation formula of self inductance and mutual inductance of the multiple conductors based on the coupling effect among the multiple conductors, and on the other hand, the following formula can be obtained due to the relationship between a capacitance matrix and an inductance matrix:
[C ij ′]＝μ 0 ε 0 [L ij ′] -1
wherein h represents the wire height, r represents the wire radius, s ij Is the spacing between the wires, mu 0 Is the permeability coefficient of vacuum ∈ 0 Is the dielectric constant in vacuum.
The calculation process of the multi-conductor Agrawal model is similar to that of the single-conductor Agrawal model, and the main difference is that an inductance-capacitance matrix is determined according to the positions of conductors, and the coupling effect between the conductors is reflected to the calculation. Meanwhile, the electric field excitation on each conductor needs to be respectively selected according to the position of the conductor, so that the induced lightning overvoltage on the multiple conductors can be accurately calculated.
S03: establishing an overhead ground wire model according to the multi-order inductive lightning overvoltage calculation model;
due to the fact that the overhead ground wire and the lead are also in coupling effect, the coupling effect mechanism of the overhead ground wire and the lead is the same as the mechanism of the lead, the overhead ground wire model is also suitable for a multi-conductor field wire coupling model, and the overhead ground wire can be regarded as a certain phase in the multi-conductor model.
The multi-conductor field line coupling model based on the overhead ground wire can simulate the overhead ground wire by only grounding the end point of a certain phase conductor. As shown in fig. 3, the overhead ground wire is grounded at the end point, and therefore the ground point potential becomes 0, which corresponds to the application of a negative voltage to the ungrounded overhead ground wire to counteract the induced lightning overvoltage, and this negative voltage, due to the coupling effect between the overhead ground wire and the conductor, will generate a coupling voltage on the phase conductor by the coupling effect, thereby reducing the induced lightning overvoltage on the phase conductor.
S04: according to the overhead ground wire model, firstly, calculating and comparing the induced lightning overvoltage of the non-ground wire line and the ground wire line, and further, obtaining the induced lightning overvoltage on the phase line of the ground wire line by changing the ground conductivity and the ground resistance parameter of the overhead ground wire;
s03, an overhead ground wire model is established based on the multi-conductor coupling model, at the moment, the overhead ground wire is ideally grounded, namely, the ground resistance is 0, and the ideal ground, namely, the ground conductivity is infinite. S04 further changes these parameters and studies were performed.
The root cause of the influence of the grounding resistance value on the induced voltage on the line is the influence of the lossy earth on the tower grounding resistance.
The grounding resistance of the tower comprises the following four components: the resistance of the grounding pole tower, the resistance of a grounding lead, the transition resistance between a pole tower grounding body and the accessed soil, and the current dissipation resistance of the pole tower grounding body to the ground are the maximum, and the current dissipation resistance is generally ignored for other three types of resistance.
From the distribution of the ground resistance, 90% or more of the resistance is distributed in the soil around the ground body. Thus, the ground resistance R e Is equal to the potential difference U between the tower and the remote ground zero potential surface e With the direct or mains current I flowing through e In a ratio of
R e ＝U e /I e
In the formula R e Represents a ground resistance, R 0 The size of the ground mass is indicated and ρ is the resistivity of the soil.
It can be seen that the tower grounding resistance is related to the size of the grounding body and the soil resistivity ρ, and the grounding resistance is positively related to the soil resistivity.
The method can change the ground resistance value of the soil according to the actually measured soil resistivity range of the line tower, and substitutes the parameters into the lightning induced overvoltage calculation model to obtain the relationship that the waveform of the lightning induced overvoltage changes along with the change of the ground resistance value when the conductivity of the soil is different.
S05: the method comprises the steps of obtaining induced overvoltage on an insulator when no ground wire exists and when a ground wire exists in an approximate mode, analyzing the influence relation between the earth conductivity and the induced overvoltage on the insulator when the ground resistance changes, and determining whether resistance reduction measures need to be taken on an electric pole when the earth conductivity and the ground resistance of an overhead ground wire change;
s06: if the induced overvoltage on the insulator is in a decreasing trend, resistance reduction measures are not needed, and the insulator can be naturally grounded.
As shown in fig. 4, for the non-grounded line, since no induced current flows into the ground through the tower, the top of the pole is substantially equal to the ground, and the voltage borne by the insulator is the conductor-to-ground voltage (in the case of no ground). For the line with the ground wire, neglecting the voltage drop between the ground wire and the insulator pin, the voltage born by the insulator is the potential difference between the conducting wire and the ground wire (in the case of the ground wire).
Insulator voltage: the principle can be equivalent to the potential difference between the lead and the ground wire, and the induced lightning overvoltage waveform between the lead and the ground wire can be obtained through the simulation calculation and is obtained by subtraction.
According to the calculation result of fig. 5, the two are compared to see that the highest induced overvoltage amplitude borne by the insulator of the line with the ground wire is lower than that of the line without the ground wire, that is, the effectiveness of the overvoltage protection of the induced lightning is further verified by arranging the overhead ground wire on the distribution network. And the analysis of the induced overvoltage on the phase line and the overhead ground wire when the obtained earth electric conductivity and the ground resistance change can be further converted into analysis of the influence of the overvoltage on the insulator, so as to obtain a new change rule.
Through the simulation calculation, the ground conductivity and whether resistance reduction measures are required to be taken on the electric pole when the grounding resistance of the overhead ground wire changes can be analyzed, and the grounding optimization design of the overhead ground wire is further obtained.
Fig. 6 shows the calculated amplitude of the induced overvoltage of the ground wire, the highest induced overvoltage of the ground wire, and the variation curve of the highest induced overvoltage amplitude borne by the insulator with the ground resistance. According to the simulation result of fig. 6, the highest induced overvoltage amplitude of the conductor to the ground increases with the increase of the grounding resistance, but the highest overvoltage amplitude borne by the insulator decreases with the increase of the grounding resistance, and the analysis reason is that the highest induced overvoltage amplitude of the conductor to the ground is the same as the highest induced overvoltage amplitude of the conductor to the ground, and the highest induced overvoltage amplitude increases with the increase of the grounding resistance, but the increase trend of the highest induced overvoltage amplitude of the conductor to the ground is more obvious. Therefore, when the ground wire is adopted to protect the induced overvoltage, the resistance reduction measures are not needed to be taken for the electric pole, and the electric pole is naturally grounded.
The model has good precision after verification, can accurately simulate the shielding effect on each phase of conductor when the ground conductivity and the ground resistance of the overhead ground wire change, and provides an analysis method for guiding the ground optimization design of the overhead ground wire of the distribution network.
The detailed description provided above is only a few examples under the general concept of the present application, and does not constitute a limitation to the scope of the present application. Any other embodiments extended according to the scheme of the present application without inventive efforts will be within the scope of protection of the present application for a person skilled in the art.
Claims (6)
1. The ground optimization design method for the distribution line erected overhead ground wire is characterized by comprising the following steps:
establishing an Agrawal field line coupling model of the distribution line induced lightning overvoltage based on a time domain finite difference method;
according to the determined distribution line induced lightning overvoltage Agrawal field line coupling model, performing discrete transformation on an Agrawal field line coupling equation by a time domain finite difference method, and establishing a multi-conductor multi-stage induced lightning overvoltage calculation model;
establishing an overhead ground wire model according to the multi-order inductive lightning overvoltage calculation model;
according to the overhead ground wire model, calculating and comparing the induced lightning overvoltage of the non-ground wire line and the ground wire line, and obtaining the induced lightning overvoltage on the phase line of the ground wire line by changing the ground conductivity and the ground resistance parameter of the overhead ground wire;
the method comprises the steps of obtaining induced overvoltage on an insulator in an approximate mode, analyzing the influence relation of ground conductivity and grounding resistance on the induced overvoltage on the insulator when the ground conductivity changes, and determining whether resistance reduction measures need to be taken on an electric pole when the ground conductivity and the grounding resistance of an overhead ground wire change;
if the induced overvoltage on the insulator is in a decreasing trend, resistance reduction measures are not needed, and the insulator is naturally grounded.
2. The method for optimally designing the grounding of the overhead ground wire for the distribution line erection according to claim 1, wherein the establishing of the distribution line induced lightning overvoltage calculation model based on the finite difference time domain method comprises the following steps:
building a lightning electromagnetic field calculation model around the distribution line;
and coupling the lightning electromagnetic field to the conductor line to calculate the induced lightning overvoltage.
3. The method of claim 2, wherein the model for calculating the lightning electromagnetic field around the electrical line comprises: the method comprises the steps of lightning channel back-strike model, space electromagnetic field calculation iterative model, boundary absorption and different medium processing.
4. The optimal design method for grounding of overhead ground wires for distribution line construction according to claim 3, wherein the expression of the multi-conductor multi-stage induced lightning overvoltage calculation model is as follows:
(1) And [ L 'in the formula (2)' ij ]A unit inductor matrix [ C 'with self inductance and mutual inductance considered among multiple conductors' ij ]In order to consider a unit inductance matrix with self-capacitance and mutual capacitance, the delta x and the delta t are respectively a space step length and a time step length; h is i Is the conductor space height; e is a spatial vertical electric field;
the relationship between the capacitance matrix and the inductance matrix is as follows:
[C ij ′]＝μ 0 ε 0 [L ij ′] -1 (5)
in the formulae (3), (4) and (5), h represents the wire height, r represents the wire radius, and s ij The spacing between the wires.
5. The method of claim 1, wherein the induced lightning overvoltage of the non-ground line and the ground line is calculated and compared according to the overhead ground line model, and the ground conductivity and the ground resistance of the phase line are related as follows in the induced lightning overvoltage by changing the ground conductivity and the ground resistance parameters of the overhead ground line:
(6) In the formula R e Represents a ground resistance, R 0 The size of the ground mass is indicated and ρ is the resistivity of the soil.
6. The method of claim 5, wherein the ground resistance comprises: the resistance of the grounding tower, the resistance of the grounding lead, the transition resistance between the tower grounding body and the accessed soil, and the current dissipation resistance of the tower grounding body to the ground are the maximum.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110514067.7A CN113255976B (en) | 2021-05-12 | 2021-05-12 | Grounding optimization design method for distribution line erection overhead ground wire |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110514067.7A CN113255976B (en) | 2021-05-12 | 2021-05-12 | Grounding optimization design method for distribution line erection overhead ground wire |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113255976A CN113255976A (en) | 2021-08-13 |
| CN113255976B true CN113255976B (en) | 2023-01-24 |
Family
ID=77222878
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110514067.7A Active CN113255976B (en) | 2021-05-12 | 2021-05-12 | Grounding optimization design method for distribution line erection overhead ground wire |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113255976B (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103714239A (en) * | 2013-11-15 | 2014-04-09 | 贵州电力试验研究院 | Method for computing lightning induced voltages of insulators of low-voltage lines when earth is struck by lightning |
| CN104850738A (en) * | 2015-04-29 | 2015-08-19 | 重庆大学 | Method for calculating lightning induction voltage of overhead power line tower |
| CN109711088A (en) * | 2019-01-15 | 2019-05-03 | 国网湖北省电力有限公司电力科学研究院 | A kind of distribution line lightning induced voltage calculation method of Electromagnetic field |
| CN112036005A (en) * | 2020-07-21 | 2020-12-04 | 广东电网有限责任公司广州供电局 | Method and device for calculating lightning induction voltage |
-
2021
- 2021-05-12 CN CN202110514067.7A patent/CN113255976B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103714239A (en) * | 2013-11-15 | 2014-04-09 | 贵州电力试验研究院 | Method for computing lightning induced voltages of insulators of low-voltage lines when earth is struck by lightning |
| CN104850738A (en) * | 2015-04-29 | 2015-08-19 | 重庆大学 | Method for calculating lightning induction voltage of overhead power line tower |
| CN109711088A (en) * | 2019-01-15 | 2019-05-03 | 国网湖北省电力有限公司电力科学研究院 | A kind of distribution line lightning induced voltage calculation method of Electromagnetic field |
| CN112036005A (en) * | 2020-07-21 | 2020-12-04 | 广东电网有限责任公司广州供电局 | Method and device for calculating lightning induction voltage |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113255976A (en) | 2021-08-13 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yang et al. | Numerical study of lightning-induced currents on buried cables and shield wire protection method | |
| Silveira et al. | Lightning overvoltage due to first strokes considering a realistic current representation | |
| CN104850738B (en) | Lightning induced voltage computational methods at overhead power transmission line line pole tower | |
| Gholami Farkoush et al. | Investigation and optimization of grounding grid based on lightning response by using ATP-EMTP and genetic algorithm | |
| Shariatinasab et al. | The effect of grounding system modeling on lightning-related studies of transmission lines | |
| Cao et al. | Lightning surge analysis of transmission line towers with a hybrid FDTD-PEEC method | |
| Salari et al. | Comparative analysis of 2-and 3-D methods for computing electric and magnetic fields generated by overhead transmission lines | |
| Markovski et al. | Fast and accurate transient analysis of large grounding systems in multilayer soil | |
| Rizk et al. | Investigation of lightning electromagnetic fields on underground cables in wind farms | |
| Guo et al. | A three‐dimensional direct lightning strike model for lightning protection of the substation | |
| Hu et al. | A new optimization design for grounding grid | |
| Rizk et al. | Influence of highly resistive ground parameters on lightning-induced overvoltages using 3-D FDTD method | |
| Kherif et al. | Investigation of horizontal ground electrode's effective length under impulse current | |
| CN110895300A (en) | Lightning protection performance analysis method for graphite grounding device of power transmission line tower | |
| Zhang et al. | Study of induced overvoltage on solar arrays | |
| CN113255976B (en) | Grounding optimization design method for distribution line erection overhead ground wire | |
| Rizk et al. | Induced voltages on overhead line by return strokes to grounded wind tower considering horizontally stratified ground | |
| CN111859714A (en) | Power frequency electric field intensity calculation method and system and power frequency electric field shielding device | |
| Zou et al. | Transient simulation model for a lightning protection system using the approach of a coupled transmission line network | |
| Li et al. | Thin-wire models for inclined conductors with frequency-dependent losses | |
| Viola et al. | Finite-difference time-domain simulation of towers cascade under lightning surge conditions | |
| CN113255975B (en) | Space position optimization method for overhead ground wire erected on distribution line | |
| CN112036005A (en) | Method and device for calculating lightning induction voltage | |
| Zhang et al. | Backflashover performance evaluation of the partially grounded scheme of overhead lines with fully composite Pylons | |
| Huang et al. | A distributed modelling method of the transmission tower and transient response analysis of lightning wave process |
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 |