CN109873257A - Reduce the capacitance compensation type grounding body and preparation method of earthing or grounding means impact impedance - Google Patents
Reduce the capacitance compensation type grounding body and preparation method of earthing or grounding means impact impedance Download PDFInfo
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- CN109873257A CN109873257A CN201910145731.8A CN201910145731A CN109873257A CN 109873257 A CN109873257 A CN 109873257A CN 201910145731 A CN201910145731 A CN 201910145731A CN 109873257 A CN109873257 A CN 109873257A
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- flow table
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Abstract
The invention discloses a kind of capacitance compensation type grounding bodies and preparation method for reducing earthing or grounding means impact impedance, including ground connection matrix and equal flow table, ground connection matrix both ends are covered with equal flow table, equal flow table is fixedly connected with ground connection matrix, being grounded matrix includes conductor and clad, clad is coated on outside conductor, the bonded earth electrode of the method for the present invention preparation, it will be highly conductive, high dielectric constant polymer material is coated on except metallic ground material, increase the dielectric constant of bonded earth electrode, capacitor equivalent to increase bonded earth electrode, it can play the role of reducing Transient grounding resistance well, also there is corrosion resistance simultaneously.
Description
Technical field
The invention belongs to technical field of high voltage, and in particular to a kind of capacitance compensation type for reducing earthing or grounding means impact impedance
Grounding body and preparation method.
Background technique
Earthing or grounding means is the critical facility of lightning protection, plays the key effect that lightning current is imported rapidly to the earth.It reduces
The impulse earthed resistance of earthing or grounding means is the key measure of lightning protection.Since the lightning current duration is short, containing a large amount of high fdrequency components,
The inductance for impacting lower grounding body acts on enhancing, causes impulse earthed resistance higher.The method of traditional reduction offset ground resistance
Mainly increase grounding body quantity, optimization grounding body position.Enhance for lower grounding body inductance effect is impacted, impedance ground
The problem of large percentage shared by middle induction reactance, it has been suggested that it is acted in earthing or grounding means and capacitor to reduce grounding body inductance, thus
Achieve the purpose that reduce Transient grounding resistance.But when the capacitor that parallel connection is concentrated, capacitor is embedded in underground, capacitor there are environment evils
It is bad, it is easily damaged, and difficult in maintenance.Construction workload is very big.
Summary of the invention
To solve the above-mentioned problems, the present invention provides a kind of capacitance compensation type ground connection for reducing earthing or grounding means impact impedance
Body and preparation method, for reducing the impulse earthed resistance of earthing or grounding means, structure is simple, convenient for the construction of grounding body.
In order to achieve the above objectives, a kind of capacitance compensation type grounding body packet reducing earthing or grounding means impact impedance of the present invention
Conductor, clad and equal flow table are included, the clad is coated on outside the conductor, and the equal flow table is centered on conductor, covering
On the outer end face at clad both ends, and the equal flow table is fixedly connected with clad.
Further, clad is made of conducting polymer, and the resistivity of the conducting polymer is 50 Ω of Ω m~100
M, relative dielectric constant are 10000~11000.
Further, conductor is cylindrical body, and the radius of the conductor is 1cm~3cm.
Further, equal flow table with a thickness of 1mm~2mm.
A kind of preparation method for the capacitance compensation type grounding body reducing earthing or grounding means impact impedance, comprising the following steps:
Step 1, in polypropylene matrix respectively addition account for total volume 20%~40% carbon black and account for total volume 5%~
10% CaCu3Ti4O12It is kneaded, melting temperature is 200 DEG C~240 DEG C, and mixing time is 20min~40min, is led
Electric polymer；
Step 2, the conducting polymer for preparing step 1 are coated to outside metallic conductor, form clad, the clad
With a thickness of 0.2m~0.3m；At room temperature cool down after to get to ground connection matrix；
Step 3 is fixedly connected with equal flow table, the both ends of equal flow table covering ground connection matrix at ground connection matrix both ends.
Further, in step 1, the partial size of the carbon black is 50nm~200nm, the CaCu3Ti4O12Partial size be
100nm~300nm.
Further, in step 2, the conductor is the cylindrical body that diameter is 1cm~3cm.
Further, in step 3, the equal flow table using steel or copper at.
Compared with prior art, the present invention at least has a technical effect beneficial below: the present invention is by highly conductive, Gao Jie electricity
The conducting polymer materials of constant are coated on except metal (steel, copper etc.) earthing material, increase the dielectric constant of grounding body, phase
When in the capacitor for increasing bonded earth electrode, capable of playing the role of reducing Transient grounding resistance well, while also there is corrosion resistant
Corrosion.
The conducting polymer materials that clad uses also have good ductility, therefore are convenient for the construction of grounding body.
The equal flow table in both ends plays the role of stream and pressure, if without flowing disk, electric current point in high dielectric constant polymer
Cloth is uneven, and electric current, which is concentrated mainly on around the metal bar of cladding, to be flowed, and equivalent capacitor will give a discount.
Detailed description of the invention
Fig. 1 is influence schematic diagram of the coating thickness to Transient grounding resistance；
Fig. 2 is influence schematic diagram of the relative dielectric constant to Transient grounding resistance；
Fig. 3 is the schematic diagram of grounding body of the present invention；
Fig. 4 is the test result of surge voltage variation when different coating thicknesses change；
In attached drawing: 1, metal bar, 2, clad, 3, equal flow table.
Specific embodiment
The following describes the present invention in detail with reference to the accompanying drawings and specific embodiments.
In the description of the present invention, it is to be understood that, term " center ", " longitudinal direction ", " transverse direction ", "upper", "lower",
The orientation or positional relationship of the instructions such as "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outside" is
It is based on the orientation or positional relationship shown in the drawings, is merely for convenience of description of the present invention and simplification of the description, rather than instruction or dark
Show that signified device or element must have a particular orientation, be constructed and operated in a specific orientation, therefore should not be understood as pair
Limitation of the invention.In addition, term " first ", " second " are used for description purposes only, it is not understood to indicate or imply opposite
Importance or the quantity for implicitly indicating indicated technical characteristic.Define " first " as a result, the feature of " second " can be bright
Show or implicitly include one or more of the features.In the description of the present invention, unless otherwise indicated, " multiple " contain
Justice is two or more.
The principle of the present invention are as follows: in the outer layer additional layer clad 2 of earth conductor, clad be 2 high dielectric constants and
Conductive substance, weakens the influence of the perceptual weight under high frequency to increase the equivalent capacity of earth conductor, coats layer capacitance
Calculation formula are as follows:S indicates that the cross-sectional area of clad, d indicate clad length, and ε is clad dielectric constant.It can
To find out the influence of the capacitor of clad by the thickness and dielectric constant of clad.It, can in order to increase the capacitor of earth conductor
It is realized in a manner of filling by using the substance of biggish coating thickness and high dielectric constant.Simultaneously because grounding body is also wanted
Play the role of the diffusing into soil, therefore the clad of grounding body should also have good conductive characteristic.In view of lower
Soil resistivity should be in 100 Ω m hereinafter, therefore the resistivity of grounding body clad 2 is less than 100 Ω m.
For principles above, the present invention realizes that a kind of reduction earthing or grounding means impact connects by mixing high dielectric constant material
The grounding body of ground impedance.
Referring to Fig. 3, a kind of capacitance compensation type grounding body reducing earthing or grounding means impact impedance includes ground connection matrix and flows
Disk, ground connection matrix both ends are covered with equal flow table 3, and equal flow table 3 is fixedly connected with ground connection matrix, and ground connection matrix includes conductor 1 and packet
Coating 2, clad 2 are coated on outside conductor 1.Wherein, conductor 1 is cylindrical body, and radius is 1cm~3cm；The thickness of equal flow table 3
For 1mm~2mm.Clad 2 is that resistivity is 50 Ω m, the conducting polymer that relative dielectric constant is 10000.
It uses a length for the horizontal grounding objects of L=50m, coats the material of differing dielectric constant in vitro in horizontal grounding,
Or the identical material of coating but the outer covering layer of different-thickness are tested, the radius of conductor 1 is R1=0.01m, conductor use
Earthing material be steel, use soil resistivity to be simulated for the uniform soil of 1000 Ω m.The lightning current waveform of simulation is
Double exponential waves of 2.6/50 μ s, dash current amplitude 10kA obtain Fig. 1 and Fig. 2 according to the test result of simulation.Fig. 1 and Fig. 2
The influence of transient characterisitics is impacted to earthing or grounding means for coating thickness and relative dielectric constant.It will be seen from figure 1 that make to coat
The equivalent capacity of layer plays the role of being substantially reduced ground resistance impedance under lightning current impact, and coating thickness is more than or equal to
0.2m.Due to the increase with coating thickness, the trend that Transient grounding resistance reduces slows down, it is therefore proposed that coating thickness exists
0.2m~0.3m is advisable.It can be seen that, the equivalent capacity of clad to be made to play to be substantially reduced and connect under lightning current impact by Fig. 2
The relative dielectric constant of the effect of ground resistance impedance, clad is not less than 10000.Due to the increase with relative dielectric constant,
The trend that Transient grounding resistance reduces slows down, while considering the cost of material, it is proposed that relative dielectric constant 10000~
11000 are advisable.
A kind of preparation method for the capacitance compensation type grounding body reducing earthing or grounding means impact impedance, comprising the following steps:
Step 1, preparation high dielectric constant, high conductivity polymer material: Zhan Jubing is added respectively in polypropylene matrix
Alkenyl body, carbon black and CaCu3Ti4O12Total volume 20%~40%, particle diameter be 50nm~200nm carbon black and account for totality
The CaCu of product 5%~10%, particle diameter 100nm~300nm3Ti4O12, it being kneaded, melting temperature is 200 DEG C~240 DEG C,
Mixing time is 20min~40min, obtains the conducting polymer of spare dielectric constant, high conductivity；
Step 2, the conducting polymer made from step 1 coat metallic conductor 1: at 200 DEG C~240 DEG C, step 1 being made
Standby conducting polymer is coated to outside metallic conductor 1 by extrusion apparatus, formed clad 2, clad 2 with a thickness of 0.2m~
0.3m；The ground connection matrix of metallic conductor is coated after cooling down at room temperature to high dielectric constant and high conductivity layer；Wherein,
The sectional area of conductor 1 by will by size of current determine, it is preferred that conductor 1 is the cylindrical body that diameter is 1cm~3cm.
The length that matrix is grounded made from step 2 is cut into 1m~2m by step 3, welds equal flow table at ground connection matrix both ends
3, the both ends of the equal covering of flow table 3 ground connection matrix, and shapes and sizes phase of its shapes and sizes with the longitudinal section of ground connection matrix
Together.
For equal flow table 3 centered on conductor 1, radius is the rosette of the thickness of clad, and reduction ground connection dress can be obtained
Set the grounding body of Transient grounding resistance.The equal selection steel of flow table 3 or copper, other materials or price height or anti-corrosion ability are bad.
Equal flow table 3 with a thickness of 1mm~2mm.
Embodiment 1
A kind of preparation method for the capacitance compensation type grounding body reducing earthing or grounding means impact impedance, comprising the following steps:
The preparation of step 1, conducting polymer
Add the carbon black that volume ratio is 30%, particle diameter 100nm, volume ratio respectively in appropriate polypropylene matrix
7.5%, the CaCu of particle diameter 200nm3Ti4O12It is kneaded, 240 DEG C of melting temperature, mixing time 30min is obtained spare
Dielectric constant, high conductivity polymer, resistivity is about 50 Ω m, and relative dielectric constant is about 10000.
Step 2 coats metallic conductor with conducting polymer
At 240 DEG C, in polymer overmold to the cylindrical steel earth conductor 1 of diameter 2cm prepared by step 1,
The cladding radius of polymer is 0.2m；It is led after cooling down at room temperature to get to high dielectric constant and high conductivity layer cladding metal
The compound ground connection matrix of body.
Ground connection matrix made from step 2 is cut into 1m long by step 3, in the welding of ground connection matrix both ends centered on metal bar
Radius be 0.2m, the equal flow table 3 with a thickness of 1mm.
Embodiment 2
A kind of preparation method for the capacitance compensation type grounding body reducing earthing or grounding means impact impedance, comprising the following steps:
The preparation of step 1, conducting polymer
Adding volume ratio respectively in appropriate polypropylene matrix is the 20%, carbon black of particle diameter 50nm, volume ratio 5%,
The CaCu of particle diameter 100nm3Ti4O12It is kneaded, 200 DEG C of melting temperature, mixing time 20min obtains spare dielectric
Constant, high conductivity polymer material.
Step 2, conducting polymer coat metallic conductor
At 200 DEG C, by the circular steel earth conductor of the polymer overmold prepared to diameter 2cm, thickness is coated
For 0.25m；The bonded earth electrode of metallic conductor is coated after cooling down at room temperature to high dielectric constant and high conductivity layer.
The above grounding body is cut into 1.5m long by step 3, welds radius 0.25m, the thickness centered on metal bar at both ends
The equal flow table 3 of 1mm.
Embodiment 3
A kind of preparation method for the capacitance compensation type grounding body reducing earthing or grounding means impact impedance, comprising the following steps:
The preparation of step 1, conducting polymer
Adding volume ratio respectively in appropriate polypropylene matrix is 40%, particle diameter, the carbon black of 200nm, volume ratio
10%, the CaCu of particle diameter 300nm3Ti4O12It is kneaded, 220 DEG C of melting temperature, mixing time 40min is obtained spare
Dielectric constant, high conductivity polymer material.
Step 2, conducting polymer coat metallic conductor
At 220 DEG C, by the circular steel earth conductor of the polymer overmold prepared to diameter 2cm, thickness is coated
0.3m；The bonded earth electrode of metallic conductor is coated after cooling down at room temperature to high dielectric constant and high conductivity layer.
The above grounding body is cut into 2m long by step 3, at both ends radius of the welding centered on metal bar be 0.3m, thickness
For the equal flow table 3 of 2mm.
Length to the test that the bonded earth electrode of preparation carries out, 1000 Ω m of soil resistivity, grounding body is 50m, is buried
If depth is 0.8m, the dash current wave used is double exponential waves of 2.6/50 μ s, amplitude 10kA.Different coating thicknesses become
In test result reference Fig. 4, Fig. 4 of surge voltage variation when change, L1 is not plus the earth conductor of clad is made in shock wave
Under, surge voltage versus time curve, L2 is the earth conductor that coating thickness is 0.05m under shock wave
Surge voltage versus time curve, L3 are that impacting under shock wave for the earth conductor that coating thickness is 0.1m is electric
Press versus time curve, L4 be the surge voltage under shock wave for the earth conductor that coating thickness is 0.2m at any time
Between change curve, L5 is the change of surge voltage at any time under shock wave for the earth conductor that coating thickness is 0.3m
Change curve, L6 is that the surge voltage under shock wave for the earth conductor that coating thickness is 0.4m changes with time song
Line, L7 are the surge voltage versus time curve under shock wave for the earth conductor that coating thickness is 0.5m, examination
Test the result shows that, the grounding body compare original steel earth conductor, have more well reduce impulse earthed resistance ability.Cut packet
The thickness of coating is bigger, and the ability for reducing impulse earthed resistance is stronger.
Claims (8)
1. a kind of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance, which is characterized in that including conductor (1), cladding
Layer (2) and equal flow table (3), the clad (2) are coated on the conductor (1) outside, during the equal flow table (3) with conductor (1) is
The heart is covered on the outer end face at clad (2) both ends, and the equal flow table (3) is fixedly connected with clad (2).
2. a kind of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 1, feature exist
In the clad (2) is made of conducting polymer, and the resistivity of the conducting polymer is the 50 Ω m of Ω m~100, opposite to be situated between
Electric constant is 10000~11000.
3. a kind of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 1, feature exist
In the conductor (1) is cylindrical body, and the radius of the conductor (1) is 1cm~3cm.
4. a kind of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 1, feature exist
In, the equal flow table (3) with a thickness of 1mm~2mm.
5. it is a kind of reduce earthing or grounding means impact impedance capacitance compensation type grounding body preparation method, which is characterized in that including with
Lower step:
Step 1, addition accounts for the carbon black of total volume 20%~40% and accounts for total volume 5%~10% respectively in polypropylene matrix
CaCu3Ti4O12It is kneaded, melting temperature is 200 DEG C~240 DEG C, and mixing time is 20min~40min, is obtained conductive poly-
Close object；
Step 2, the conducting polymer for preparing step 1 are coated to metallic conductor (1) outside, are formed clad (2), the clad
(2) with a thickness of 0.2m~0.3m；At room temperature cool down after to get to ground connection matrix；
Step 3 is fixedly connected equal flow table (3) at ground connection matrix both ends, the both ends of equal flow table (3) covering ground connection matrix.
6. a kind of preparation side of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 5
Method, which is characterized in that in step 1, the partial size of the carbon black is 50nm~200nm, the CaCu3Ti4O12Partial size be 100nm
~300nm.
7. a kind of preparation side of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 5
Method, which is characterized in that in step 2, the conductor (1) is the cylindrical body that diameter is 1cm~3cm.
8. a kind of preparation side of capacitance compensation type grounding body for reducing earthing or grounding means impact impedance according to claim 5
Method, which is characterized in that in step 3, the equal flow table (3) using steel or copper at.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112147463A (en) * | 2020-09-25 | 2020-12-29 | 云南电网有限责任公司红河供电局 | Method and device for reducing grounding impedance of transformer substation grounding grid by additionally arranging capacitor module |
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Application publication date: 20190611 |