CN113724948A - Lightning stroke resistance improving method for composite insulator and lightning stroke resistance composite insulator - Google Patents
Lightning stroke resistance improving method for composite insulator and lightning stroke resistance composite insulator Download PDFInfo
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- CN113724948A CN113724948A CN202111081979.6A CN202111081979A CN113724948A CN 113724948 A CN113724948 A CN 113724948A CN 202111081979 A CN202111081979 A CN 202111081979A CN 113724948 A CN113724948 A CN 113724948A
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- 239000012212 insulator Substances 0.000 title claims abstract description 145
- 239000002131 composite material Substances 0.000 title claims abstract description 114
- 238000000034 method Methods 0.000 title claims abstract description 38
- 208000025274 Lightning injury Diseases 0.000 title claims abstract description 29
- 230000015556 catabolic process Effects 0.000 claims abstract description 40
- 239000002184 metal Substances 0.000 claims abstract description 26
- 238000012360 testing method Methods 0.000 claims abstract description 18
- 238000012216 screening Methods 0.000 claims description 4
- 239000004020 conductor Substances 0.000 abstract description 23
- 239000000725 suspension Substances 0.000 abstract description 22
- 238000009413 insulation Methods 0.000 abstract description 7
- 239000011810 insulating material Substances 0.000 abstract description 4
- 230000000694 effects Effects 0.000 description 6
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- 238000007599 discharging Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000000576 coating method Methods 0.000 description 2
- 238000002679 ablation Methods 0.000 description 1
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- 230000003631 expected effect Effects 0.000 description 1
- 238000009422 external insulation Methods 0.000 description 1
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- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
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- 229910052573 porcelain Inorganic materials 0.000 description 1
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- H01B19/00—Apparatus or processes specially adapted for manufacturing insulators or insulating bodies
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- H—ELECTRICITY
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- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
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Abstract
A method for improving lightning stroke resistance of a composite insulator and a lightning stroke resistant composite insulator comprise the following steps: two end grading rings are respectively arranged at hardware fittings at two ends of the composite insulator; performing lightning strike resistance test on the composite insulator provided with the grading rings at the two ends to obtain a first breakdown voltage value curve; arranging an intermediate equalizing ring at the middle part of the composite insulator to obtain an improved composite insulator; changing the position of the middle equalizing ring at the middle part of the improved composite insulator, and carrying out lightning stroke resistance test to obtain a second breakdown voltage value curve; and determining the optimal position of the intermediate grading ring according to the first breakdown voltage value curve and the second breakdown voltage value curve, and fixing the intermediate grading ring at the optimal position. The invention avoids the trouble of ground insulation caused by the increase of the length of the insulator; because the suspension conductor is made of metal, the mechanical property is better than that of an insulating material, the metal structure of the suspension conductor cannot be ablated due to overlarge arc current even under frequent lightning strikes, and the trouble of frequently replacing insulators is avoided.
Description
Technical Field
The invention belongs to the technical field of high-voltage external insulation, and particularly relates to a method for improving lightning stroke resistance of a composite insulator and a lightning stroke resistant composite insulator.
Background
The 110kV composite insulator used by the existing power transmission line in a multi-thunder area generally has the problem of insufficient lightning resistance level, so that lightning trip accidents of the line are frequent. Not only can the unqualified composite insulator easily generate flashover, but also the insulator meeting the standard requirement has lightning flashover trip-out accidents, and the fundamental reason is that the dry arc distance of the 110kV composite insulator specified by the standard can not meet the insulation requirement of a thunderstorm area. In addition, in order to protect the insulator from being ablated by lightning arcs, grading rings are additionally arranged at two ends of the 110kV insulator in a thunderstorm area. Because the shielding depth of the grading rings has the effect of shortening the dry arc distance of the insulator, according to the operation experience and the test result of a manufacturer, after the two grading rings are additionally arranged, the lightning resistance level of the 110kV composite insulator is reduced by 8 percent compared with that before the grading rings are not additionally arranged, the probability of lightning trip accidents of the composite insulator in a multi-thunder area is increased, and the threat to the power transmission line is further increased.
To address such problems, several solutions have been proposed by the current scholars. The most mentioned method is to increase the length of the insulator, on the basis of the original length, the 110kV insulator is lengthened by 10-15% or 1-2 electric porcelain or glass insulators are connected in series at the tail end of the composite insulator, and the dry arc distance of the insulator is increased by the method so as to improve the lightning resistance level of the insulator. However, for the transmission line in operation, under the condition of not changing the structure of the transmission line tower, the length of the insulator is increased, so that the insulation distance between the insulator and the ground is directly shortened, and a series of problems of insulation to the ground can be caused. In other studies, students try to improve the lightning resistance level of the composite insulator by coating semiconductor coatings on the two-end grading rings, however, the method has not yet achieved the expected effect at present and has little effect on improving the lightning resistance level of the composite insulator.
Disclosure of Invention
Aiming at the defects of the existing method for improving the lightning-resistant level of the 110kV composite insulator, the invention provides a method for improving the lightning-resistant capability of the composite insulator and the lightning-resistant composite insulator by applying the discharge theory of the existence of the air gap of the suspended conductor. Namely, the lightning tolerance level of the composite insulator is improved by installing the suspension conductor in the middle of the composite insulator.
The method of the present invention is further described below, specifically as follows:
the invention provides a method and a device for improving the lightning stroke tolerance level of a 110kV composite insulator based on the discharge theory of an air gap with a suspension conductor. The lightning protection device aims to improve the lightning protection level of a 110kV insulator for a multi-thunder area by utilizing the effect of improving the lightning impulse voltage of an air gap through a spherical suspension conductor, and ensures the safe and stable operation of a power system.
The invention specifically adopts the following technical scheme:
a method for improving lightning stroke resistance of a composite insulator is characterized by comprising the following steps:
step 1: two end grading rings are respectively arranged at hardware fittings at two ends of the composite insulator;
step 2: performing lightning strike resistance test on the composite insulator provided with the grading rings at the two ends in the step 1 to respectively obtain breakdown voltage value curves of the composite insulator under positive and negative polarities;
and step 3: arranging an intermediate grading ring at the middle part of the composite insulator in the step 1 to obtain an improved composite insulator;
and 4, step 4: changing the position of the middle equalizing ring at the middle part of the improved composite insulator, and carrying out lightning stroke resistance test;
and 5: and determining the optimal position of the intermediate grading ring according to the breakdown voltage value curve obtained in the step 2 and the breakdown voltage value curve obtained in the step 4, and fixing the intermediate grading ring at the optimal position.
The invention further adopts the following preferred technical scheme:
and 2, respectively connecting a high-voltage lead and a ground wire to two ends of the composite insulator, and testing under the standard lightning impulse voltage of 1.2/50 mu s to respectively obtain breakdown voltage value curves under positive and negative voltages.
In step 3, the shielding depth of the used middle equalizing ring is 0.
In step 3, the middle equalizing ring comprises an outer ring and a middle connecting guide rod;
the connecting and guiding rod is a metal rod with one bent end, the non-bent end is fixed on the side wall of the inner circle of the outer ring, and the bent end faces the center of the inner circle;
when the two metal connecting guide rods are combined, the bent parts of the two metal connecting guide rods are combined to form a circular hole, and the inner diameter of the circular hole is consistent with the outer diameter of the composite insulator core rod.
step 401: respectively connecting a high-voltage wire and a ground wire to two ends of the improved composite insulator obtained in the step 3;
step 402: testing breakdown voltage values of the lightning impulse voltage under positive and negative polarities;
step 403: changing the position of the intermediate grading ring and returning to the step 401;
step 404: repeatedly executing the steps 401 and 403 to obtain the U of the improved composite insulator under the positive and negative polarities when the intermediate grading rings are at different positions50Breakdown voltage value curve.
And 5, screening out a position which can improve the positive polarity breakdown voltage of the composite insulator and simultaneously does not reduce the negative polarity breakdown voltage as the optimal position of the intermediate grading ring according to the two obtained breakdown voltage value curves.
And 5, screening out a position which can improve the positive-polarity breakdown voltage of the composite insulator and does not reduce the negative-polarity breakdown voltage as the optimal position of the intermediate grading ring according to the two obtained breakdown voltage value curves, and taking the position closest to the high-voltage end of the composite insulator as the optimal position of the intermediate grading ring.
The lightning stroke resistant composite insulator manufactured based on the composite insulator lightning stroke resistant capability improving method comprises hardware fittings, a core rod, an umbrella skirt, two end grading rings and an intermediate grading ring, and is characterized in that:
the two-end equalizing rings are respectively arranged at the hardware fittings at the two ends of the composite insulator;
the middle equalizing ring is arranged in the middle of the composite insulator and fixed on the core rod.
The middle equalizing ring comprises an outer ring and a middle connecting guide rod,
the middle connecting guide rod is a metal rod with one bent end, the non-bent end is fixed on the side wall of the inner circle of the outer ring, and the bent end faces the center of the inner circle;
the connecting guide rods are respectively arranged on two sides of the inner circle side wall of the outer ring, and the two metal connecting guide rods are fixed on the core rod through bolts.
The pipe diameter of the outer ring of the middle grading ring is larger than that of the grading rings at the two ends;
the inner diameter of the middle equalizing ring is larger than the outer diameters of the equalizing rings at the two ends.
The invention has the beneficial effects that:
(1) according to the invention, by applying the discharge theory of the suspension conductor, on the basis of the original 110kV composite insulator provided with the equalizing rings at two ends, the intermediate equalizing ring at the suspension potential is arranged in the middle of the insulator, and the breakdown voltage of the 110kV composite insulator under the lightning impulse is improved by utilizing the effect of improving the breakdown voltage of the air gap lightning impulse by using the spherical suspension conductor.
(2) The lightning stroke resistance improving method and the lightning stroke resistance composite insulator do not need to increase the length of the insulator, and avoid the trouble of ground insulation caused by the increase of the length of the insulator. Meanwhile, the suspension conductor is made of metal, so that the mechanical property of the suspension conductor is superior to that of an insulating material, the metal structure of the suspension conductor cannot be ablated due to overlarge arc current even under frequent lightning strikes, and the trouble of frequently replacing insulators is avoided.
Drawings
FIG. 1 is a flow chart of a method for improving lightning stroke resistance of a composite insulator according to the present invention.
Fig. 2 is a schematic structural view of the composite insulator with grading rings at two ends according to the present invention.
Figure 3 is a schematic diagram of an intermediate grading ring configuration for use with the present invention.
FIG. 4 is a wiring diagram for testing the lightning endurance of a 110kV composite insulator in an example of the invention.
Fig. 5 is a diagram of the relationship between the breakdown voltage and the position of the improved 110kV composite insulator with the positive and negative polarities of U50.
Fig. 6 is a schematic structural view of the lightning strike resistant composite insulator of the present invention.
Detailed Description
The method provided by the invention is based on the air gap floating conductor discharge theory, and the theory is applied to improving the lightning resistance level of the 110kV composite insulator. The present invention will be described in detail with reference to the following examples and accompanying drawings.
According to the discharge theory of the air gap with the suspension conductor, the spherical suspension conductor can effectively improve the positive polarity lightning impulse tolerance level of the gap in the partial area close to the positive polarity electrode. Because the arc ablation resistance and the mechanical property of the metal conductor are superior to those of the traditional insulating material, the metal conductor is applied to the design of an insulating device and has certain advantages. After the grading rings at two ends are installed on the composite insulator 1, lightning flashover is also carried out in the air. The method for improving the lightning resistance level of the air gap can be applied to design and improve the lightning resistance level of the composite insulator 1. Therefore, based on the characteristic that the gap lightning impulse voltage can be improved by the suspension conductor, the suspension conductor with large diameter such as the intermediate equalizing ring and the auxiliary metal shed at the suspension potential is arranged on the 110kV composite insulator, so that the discharge characteristic of the insulator under the positive polarity lightning impulse is improved, and the insulation level of the insulator is improved.
As shown in fig. 1, the method for improving lightning strike resistance of the composite insulator 1 of the present invention includes the steps of:
step 1: two end grading rings 2 are respectively arranged at two end fittings 101 of the composite insulator 1. Specifically, a 110kV composite insulator universal grading ring is adopted in the step 1, and the shielding depth is a certain (70 mm); and the outer diameter is larger than the maximum umbrella skirt diameter so as to realize the functions of shielding the hardware electric field, striking arcs and protecting the insulator umbrella skirt.
Preferably, in one embodiment of the invention, a 250mm outer diameter, 25mm pipe diameter fixed potential grading ring is used.
Step 2: and (3) performing lightning strike resistance test on the composite insulator 1 provided with the grading rings 2 at the two ends in the step (1) to respectively obtain breakdown voltage value curves of the composite insulator under positive and negative polarities.
Specifically, a high-voltage lead and a ground wire are respectively connected to two ends of the composite insulator 1, and the U of the composite insulator under positive and negative polarities is tested under the standard lightning impulse voltage of 1.2/50 mu s50Breakdown voltage value curve.
In one embodiment of the invention, a 110kV composite insulator model FXBW-110/70 was selected for testing. As shown in FIG. 2, the minimum arc distance is 1000mm, and the structure is a big umbrella shape and a small umbrella shape. Two ends of the electric potential equalizer are respectively provided with a fixed electric potential equalizing ring with the outer diameter of 250mm and the pipe diameter of 25 mm. And the two ends of the grounding wire are respectively connected with a high-voltage lead wire and a ground wire, and the U of the grounding wire under the two voltages of positive and negative polarities is tested under the standard lightning impulse voltage of 1.2/50 mu s50Breakdown voltage value.
And step 3: and arranging an intermediate equalizing ring 3 in the middle part of the composite insulator 1 to obtain the improved composite insulator. As shown in fig. 3, the intermediate grading ring 3 used in step 3 includes an outer ring 301 and an intermediate connection guide 302. The shielding depth of the intermediate grading ring 3 needs to be 0 to ensure that the intermediate connecting guide rod 302 of the intermediate grading ring 3 is wrapped in the outer ring 301.
The middle connecting guide rod 302 is a metal rod with one bent end, the non-bent end is fixed on the inner circle side wall of the outer ring 301, and the bent end faces the center of the inner circle. Two such intermediate connecting guide rods are respectively arranged on both sides of the inner circular side wall of the outer ring 301, and the two intermediate connecting guide rods 301 are fixed by bolts. When the two middle connecting guide rods 301 are combined, the bent parts are combined into a circular hole shape, and the inner diameter of the circular hole is consistent with the outer diameter of the core rod.
Moreover, the pipe diameter of the middle grading ring outer ring 301 is larger than the pipe diameters of the grading rings 2 at the two ends, so that the pipe diameter of the middle grading ring outer ring 301 is larger as possible and has no upper limit value from the viewpoint of lightning protection. The inner diameter of the middle equalizing ring 3 is larger than the outer diameters of the equalizing rings 2 at the two ends, and the difference between the inner diameter of the middle equalizing ring 3 and the outer diameters of the equalizing rings 2 at the two ends is not smaller than 2cm, so that the middle equalizing ring 3 is positioned in an electric field area formed by a connecting line between the equalizing rings 2 at the two ends, and the middle equalizing ring 3 can generate enough strong influence on the discharging process.
It should be noted that the outer diameter of the intermediate grading ring 3 and the pipe diameter of the outer ring 301 should also meet the requirement of being able to pass through the insulator shed 102 and the hardware 101, and the pipe diameter should be increased as much as possible to increase the voltage lifting range and shield the adverse effect of the intermediate connecting guide rod 302 on the discharge. Namely, the installation of the intermediate grading ring 3 is facilitated while the problem of the intermediate grading ring 3 itself in the lightning discharging process is ensured not to occur. However, the mechanical load bearing, the appearance and the mutual influence among the composite insulators 1 in actual use are comprehensively considered, the outer diameter of the middle equalizing ring 3 is not more than 500mm, and the pipe diameter of the outer ring is not more than 200 mm.
Preferably, in one embodiment of the invention, an intermediate grading ring with an outer diameter of 400mm and a pipe diameter of 90mm is used.
It should be noted that, in the present invention, an improved composite insulator can also be obtained by arranging an auxiliary metal shed. The size of the auxiliary metal umbrella skirt is similar to that of the intermediate grading ring, and the larger the diameter is, the better the diameter is. That is, the diameter of the metal shed should be larger than the outer diameter (250mm) of the equalizing ring common to both ends, but since the metal shed is solid, the design diameter should be slightly smaller than the intermediate equalizing ring in consideration of the actual mechanical load, and therefore, the diameter of the auxiliary metal shed is preferably 250mm to 400 mm.
And 4, step 4: and changing the position of the middle equalizing ring 3 in the middle part of the improved composite insulator, and performing lightning stroke resistance test. Specifically, as shown in fig. 4, the step includes the steps of:
step 401: respectively connecting a high-voltage wire and a ground wire to two ends of the improved composite insulator obtained in the step 3;
step 402: testing U of the lightning impulse under the standard lightning impulse voltage of 1.2/50 mu s under positive and negative polarities50A breakdown voltage value;
step 403: changing the position of the intermediate grading ring 3 and returning to the step 401;
step 404: the step 401-403 is repeatedly executed to obtain the U of the improved composite insulator under the positive and negative polarities when the intermediate grading ring 3 is at different positions50Breakdown voltage value curve.
In one embodiment of the invention, a 110kV composite insulator model FXBW-110/70 was selected for testing. As shown in FIG. 2, the minimum arc distance is 1000mm, and the structure is a big umbrella shape and a small umbrella shape. Two ends of the electric potential equalizer are respectively provided with a fixed electric potential equalizing ring with the outer diameter of 250mm and the pipe diameter of 25 mm. And partially in the middle thereofAnd setting an intermediate grading ring with the outer diameter of 400mm and the pipe diameter of 90mm to obtain the improved composite insulator. And connecting high-voltage lead and bottom wire at two ends, respectively, and testing U under standard lightning impulse voltage of 1.2/50 μ s50Breakdown voltage value.
And 5: and determining the optimal position of the intermediate grading ring 3 according to the breakdown voltage value curve obtained in the step 2 and the breakdown voltage value curve obtained in the step 4.
Specifically, according to the two obtained breakdown voltage value curves, the position which can improve the positive polarity breakdown voltage of the composite insulator 1 and simultaneously does not reduce the negative polarity breakdown voltage is screened out, and the position closest to the high-voltage end of the composite insulator 1 is selected as the optimal position of the intermediate grading ring 3.
As shown in fig. 5, in an embodiment of the present invention, when the intermediate grading ring 3 is disposed in a region (k is 4, which is a position about 25cm away from the positive polarity high voltage grading ring) of the center of the insulator biased toward the positive polarity high voltage electrode, the position can significantly improve the lightning withstand level of the 110kV insulator under the positive polarity voltage, and does not reduce the negative polarity breakdown voltage (a point circled by a dashed square frame in fig. 4), which is an optimal position for disposing the intermediate grading ring 3.
Compared with the prior art, the method can improve the lightning resistance level of the 110kV composite insulator under the condition of not increasing the length of the insulator; and the improved device adopts a detachable structure, only a customized intermediate equalizing ring needs to be additionally arranged on the produced standard 110kV composite insulator, the processing and the installation are simple and convenient, and any burden can not be added to the original composite insulator production process.
As shown in fig. 6, the invention further provides a lightning strike resistant composite insulator, which comprises a hardware 101, a core rod, an umbrella skirt 102, two end grading rings 2 and an intermediate grading ring 3.
The two-end grading rings 2 are respectively arranged at the hardware fittings 101 at the two ends of the composite insulator 1. And the outer diameter of the grading rings 2 at the two ends is larger than the maximum umbrella skirt diameter of the composite insulator 1 so as to realize the functions of shielding a hardware fitting electric field, striking an arc and protecting the umbrella skirt of the insulator. In one embodiment of the invention, the two-end grading ring is a 110kV insulator universal grading ring, and the shielding depth is 70 mm.
The intermediate grading ring 3 is provided in the middle part of the composite insulator 1 and comprises an outer ring 301 and an intermediate connecting rod 302. The shielding depth of the intermediate grading ring 3 needs to be 0 to ensure that the intermediate connecting guide rod 302 of the intermediate grading ring 3 is wrapped in the outer ring 301.
The middle connecting guide rod 302 is a metal rod with one bent end, the non-bent end is fixed on the inner circle side wall of the outer ring 301, and the bent end faces the center of the inner circle. Two such intermediate connecting guides 302 are respectively provided on both sides of the inner circular side wall of the outer ring 301, and the two intermediate connecting guides 301 are fixed by bolts. When the two middle connecting guide rods 302 are combined, the bent parts are combined into a circular hole shape, and the inner diameter of the circular hole is consistent with the outer diameter of the core rod. That is, the intermediate grading ring 3 is fixed to the core rod of the composite insulator 1 through the intermediate connection guide 302.
Moreover, the pipe diameter of the outer ring 301 of the middle equalizing ring is larger than the pipe diameters of the equalizing rings 2 at the two ends, the inner diameter of the middle equalizing ring 3 is larger than the outer diameters of the equalizing rings 2 at the two ends, and the difference between the inner diameter of the middle equalizing ring 3 and the outer diameters of the equalizing rings 2 at the two ends is not less than or equal to 2cm, so that the middle equalizing ring 3 is positioned in an electric field area formed by a connecting line between the equalizing rings 2 at the two ends, and the middle equalizing ring 3 can generate strong enough influence on the discharging process.
Preferably, in one embodiment of the invention, an intermediate grading ring with an outer diameter of 400mm and a pipe diameter of 90mm is used.
In addition, when the specific installation position of the intermediate grading ring 3 is determined, the specific installation position of the intermediate grading ring 3 can be determined in the manner of the step 2-5 in the lightning strike resistance capability improvement method of the composite insulator 1.
Preferably, in one embodiment of the present invention, an intermediate grading ring is disposed above the 4 th shed on the side of the composite insulator 1 near the high-voltage end.
According to the invention, by applying the discharge theory of the suspension conductor, on the basis of the original 110kV composite insulator provided with the equalizing rings at two ends, the intermediate equalizing ring at the suspension potential is arranged in the middle of the insulator, and the breakdown voltage of the 110kV composite insulator under the lightning impulse is improved by utilizing the effect of improving the breakdown voltage of the air gap lightning impulse by using the spherical suspension conductor.
The lightning stroke resistance improving method and the lightning stroke resistance composite insulator do not need to increase the length of the insulator, and the trouble of ground insulation caused by the increase of the length of the insulator is avoided. Meanwhile, the suspension conductor is made of metal, so that the mechanical property of the suspension conductor is superior to that of an insulating material, the metal structure of the suspension conductor cannot be ablated due to overlarge arc current even under frequent lightning strikes, and the trouble of frequently replacing insulators is avoided.
While the best mode for carrying out the invention has been described in detail and illustrated in the accompanying drawings, it is to be understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the scope of the invention should be determined by the appended claims and any changes or modifications which fall within the true spirit and scope of the invention should be construed as broadly described herein.
Claims (10)
1. A method for improving lightning stroke resistance of a composite insulator is characterized by comprising the following steps:
step 1: two end grading rings are respectively arranged at hardware fittings at two ends of the composite insulator;
step 2: performing lightning strike resistance test on the composite insulator provided with the grading rings at the two ends in the step 1 to respectively obtain first breakdown voltage value curves of the composite insulator under positive and negative polarities;
and step 3: arranging an intermediate grading ring at the middle part of the composite insulator in the step 1 to obtain an improved composite insulator;
and 4, step 4: changing the position of the middle grading ring at the middle part of the improved composite insulator, and carrying out lightning stroke resistance test to respectively obtain second breakdown voltage value curves of the middle grading ring under positive and negative polarities;
and 5: and determining the optimal position of the intermediate grading ring according to the first breakdown voltage value curve obtained in the step 2 and the second breakdown voltage value curve obtained in the step 4, and fixing the intermediate grading ring at the optimal position.
2. The method for improving lightning stroke resistance of the composite insulator according to claim 1, wherein the method comprises the following steps:
and 2, respectively connecting a high-voltage lead and a ground wire to two ends of the composite insulator, and testing under the lightning impulse voltage to respectively obtain breakdown voltage value curves under positive and negative polarities.
3. The method for improving lightning stroke resistance of the composite insulator according to claim 1, wherein the method comprises the following steps:
in step 3, the shielding depth of the used middle equalizing ring is 0.
4. The method for improving lightning stroke resistance of the composite insulator according to claim 1 or 3, wherein the method comprises the following steps:
in step 3, the middle equalizing ring comprises an outer ring and a middle connecting guide rod;
the connecting guide rod is a metal rod with one bent end, the non-bent end is fixed on the side wall of the inner circle of the outer ring, and the bent end faces the center of the inner circle;
when the two metal connecting guide rods are combined, the bent parts of the two metal connecting guide rods are combined to form a circular hole, and the inner diameter of the circular hole is consistent with the outer diameter of the composite insulator core rod.
5. The method for improving lightning stroke resistance of the composite insulator according to claim 4, wherein the method comprises the following steps:
step 4 comprises the following steps:
step 401: respectively connecting a high-voltage lead and a ground wire to two ends of the improved composite insulator obtained in the step 3;
step 402: respectively testing breakdown voltage values of the lightning impulse voltage under positive and negative polarities;
step 403: changing the position of the intermediate grading ring and returning to the step 401;
step 404: the steps 401 and 403 are repeatedly executed to obtain two voltages of the improved composite insulator with the positive and negative polarities when the intermediate grading rings are at different positionsLower U50Breakdown voltage value curve.
6. The method for improving lightning stroke resistance of the composite insulator according to claim 1 or 5, wherein the method comprises the following steps:
and 5, screening out a position which can improve the positive polarity breakdown voltage of the composite insulator and simultaneously does not reduce the negative polarity breakdown voltage as the optimal position of the intermediate grading ring according to the two obtained breakdown voltage value curves.
7. The method for improving lightning stroke resistance of the composite insulator according to claim 6, wherein the method comprises the following steps:
and 5, screening out a position which can improve the positive-polarity breakdown voltage of the composite insulator and does not reduce the negative-polarity breakdown voltage as the optimal position of the intermediate grading ring according to the two obtained breakdown voltage value curves, and taking the position closest to the high-voltage end of the composite insulator as the optimal position of the intermediate grading ring.
8. The method for improving the lightning stroke resistance of the composite insulator based on the claims 1-7 comprises hardware fittings, a core rod, an umbrella skirt, two-end grading rings and a middle grading ring, and is characterized in that:
the two-end equalizing rings are respectively arranged at the hardware fittings at the two ends of the composite insulator;
the middle equalizing ring is arranged in the middle of the composite insulator and fixed on the core rod.
9. The lightning strike resistant composite insulator of claim 8, wherein:
the middle equalizing ring comprises an outer ring and a middle connecting guide rod,
the middle connecting guide rod is a metal rod with one bent end, the non-bent end is fixed on the side wall of the inner circle of the outer ring, and the bent end faces the center of the inner circle;
the two connecting guide rods are respectively arranged on two sides of the inner circular side wall of the outer ring, and the two metal connecting guide rods are fixed on the core rod through bolts.
10. The lightning strike resistant composite insulator of claim 8 or 9, wherein:
the pipe diameter of the outer ring of the middle grading ring is larger than that of the grading rings at the two ends;
the inner diameter of the middle equalizing ring is larger than the outer diameters of the equalizing rings at the two ends.
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| CN202111081979.6A CN113724948A (en) | 2021-09-15 | 2021-09-15 | Lightning stroke resistance improving method for composite insulator and lightning stroke resistance composite insulator |
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| CN202111081979.6A CN113724948A (en) | 2021-09-15 | 2021-09-15 | Lightning stroke resistance improving method for composite insulator and lightning stroke resistance composite insulator |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114966360A (en) * | 2022-07-27 | 2022-08-30 | 成都光创联科技有限公司 | System and method for testing avalanche voltage of optical device |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114966360A (en) * | 2022-07-27 | 2022-08-30 | 成都光创联科技有限公司 | System and method for testing avalanche voltage of optical device |
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