JPH04303519A - Lighting insulator device - Google Patents

Abstract

PURPOSE:To improve the life of an element with the share voltage of the resistance element built in a lightning insulator reduced, and also to lighten the weight of and miniaturize an electric field relaxation ring with its coordinate position made pertinent, enabling application to an existing lightning insulator device. CONSTITUTION:The arrangement coordinate of an electric field relaxation ring 13, for making the share voltage of a resistance element 25 housed in a lightning insulator 5 below a given value, is set in a range in which the maximum charge rate of the resistance element 25 is set below a given value, and also a shape of the ring 13 is formed into a nearly elliptical shape.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention is capable of quickly discharging lightning surge current to the ground when it flows through a power transmission line, and suppressing and interrupting the following current to prevent ground faults. The purpose of this invention is to provide a lightning arrester device that can be used.

0002

[Prior Art] Conventionally, the ground side end of a lightning arrester containing a built-in resistance element with non-linear voltage-current characteristics was connected to a steel tower, and a power transmission line was supported at the energized side end of the lightning arrester. In the non-gap type lightning arrester device, when the lightning arrester deteriorates or becomes conductive due to an unexpected large-scale lightning surge current, the arc emitted from the lightning arrester is captured and the arc is removed. It is moved between the horns to prevent the entire lightning arrester from being separated.

0003

[Problem to be Solved by the Invention] Since the resistance element built into the lightning arrester is always kept in a energized state, the energization rate becomes larger on the energized side and the ground side than in the intermediate part,
Therefore, there is a problem that the voltage sharing ratio acting on the resistive element becomes high on the power supply side and the grounding side, the resistive element tends to deteriorate early, and the life of the lightning arrester is shortened.

[0004] In order to maintain the AC charging life of the resistive element to the same level as that of a C-characteristic lightning arrester (A.V.R 85%, 40°C, 100 years), it is necessary to suppress the shared potential.
A lightning arrester for 0kV requires a shield ring of approximately 2mφ. Therefore, in a 500 kV suspension type lightning arrester, it is necessary to design the ring coordinates and shape in consideration of this electric field relaxation element and the insulation clearance of the electric field relaxation ring with respect to the steel tower.

Therefore, we specifically compared the dimensions of the suspension device, tension device, and electric field relaxation ring of the V-hanging device of a 500kV suspended lightning arrester device with the horn of a conventional insulator device. Compared to the conventional horn, it protrudes approximately 200 mm in the direction of the railway line, and approximately 650 mm in the direction of the steel tower. Furthermore, compared to the conventional horn, the tension device protrudes approximately 600 mm toward the upper phase side and approximately 750 mm toward the jumper wire side in the line direction. Furthermore, compared to conventional horns, the V-hanging device has a distance of approximately 720 m in both the upper arm of the tower and the direction of the tower.
m protrudes. As a result, if an attempt is made to attach the electric field mitigation ring to an existing steel tower, a problem arises in that the insulation clearance is insufficient and the ring cannot be applied.

[0006] The purpose of the present invention is to reduce the charging rate of the resistance element to a predetermined value or less to improve the life of the lightning arrester, and to ensure insulation clearance with the existing steel tower, making it possible to apply it. The object of the present invention is to provide a lightning arrester device that can provide lightning protection.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention connects the ground side end of a lightning arrester insulator having a built-in resistance element with non-linear voltage-current characteristics to a steel tower, and an electric field relaxation ring for supporting a power transmission line on the energized side end of the insulator and reducing the share of voltage applied to the resistive element with respect to the energized side end and/or the grounding side end of the lightning arrester insulator; In the lightning arrester device in which the electric field relaxation ring is arranged, the arrangement coordinates of the electric field relaxation ring are set such that flashover between the lightning arrester and the electric field relaxation ring is prevented by the limiting voltage of the resistance element, and the charging rate of the resistance element is set to a predetermined value. The method used is to set the following coordinates.

[0008]

[Operation] This invention arranges the electric field relaxation ring at a coordinate position that takes into account the limiting voltage and charging rate of the resistive element, thereby reducing the charging rate of the resistive element to a predetermined value or less and improving the life of the resistive element. In addition, the size of the electric field relaxation ring can be set to the minimum necessary size, and the size and weight can be reduced. Furthermore, the electric field mitigation ring can be easily installed on an existing steel tower because it is easy to secure insulation clearance.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a tension device for a suspended lightning arrester device will be described below with reference to FIGS. 1 to 6. As shown in FIG. 2, a suspension insulator chain 4 and a large number of suspension type lightning arrester insulators 5 are connected in series to the support arm 1 of the steel tower via a ground side connection fitting unit 2. Suspended lightning arrester series 6 are connected in parallel to each other. Further, a power transmission line 8 is connected to the power supply side of the two insulator chains 4 and 6 via a power supply side connecting fitting unit 7. Note that a jumper wire (not shown) is connected to the connection fitting unit 7 on the power supply side.

As shown in FIG. 3, the ground side connecting fitting units 2, 2 have ground side arc rings 11, 11, respectively.
is supported. Similarly, the power supply side connection fitting unit 7,
The energizing side arc rings 12 , 12 are also supported on the energizing side arc rings 12 , 12 for catching creeping flashover of the suspended insulator series 4 or the suspended type lightning arrester series 6 and suppressing damage to the insulator series 4 , 6 . Arc rings 12, 12 are supported.

[0011] An electric field relaxation ring 13 having an elongated oval shape is supported on the energizing side connecting fitting unit 7 so as to surround the suspension insulator chain 4 and the suspension type lightning arrester chain 6. This electric field relaxation ring 13 is formed into an oblong shape as a whole by a first ring 14 and a second ring 15 , and both rings 14 , 15 are supported by a bracket 16 on the power supply side connecting fitting unit 7 .

Next, the structure of the suspension type lightning arrester 5 will be explained with reference to FIG. 6. This lightning arrester consists of an insulator body 21 and a cap fitting 22 fitted and fixed to the upper part of its head 21a with cement. A pin fitting 23 fitted into the head 21a and fixed with cement, and the insulator body 2
A resistance element 25 whose main material is zinc oxide and whose voltage-current characteristics are nonlinear is housed in a mounting head 24 integrally formed with 1.
It is composed of. Further, cap electrodes 26 and 27 are fitted and fixed to both upper and lower ends of the mounting head 24, and both electrodes are connected to the cap metal fitting 22 and the pin metal fitting 23 by lead wires 28 and 29, respectively.

Next, the setting of the coordinates of the electric field relaxation ring 13 in consideration of the electric field relaxation effect of the resistance element 25 built into the lightning arrester and the limiting voltage of the element will be explained with reference to FIG. Here, the limited voltage of the lightning arrester chain 6 refers to the voltage generated when a current flows through the lightning arrester chain. In FIG. 4, the X coordinate (mm) of the suspended lightning arrester chain 6 indicates the distance from the central axis O of the lightning arrester chain 6 to the side, and the Y coordinate (
mm) indicates the distance from the lower end of the energized side of the lightning arrester chain 6 to the ground side. The set coordinate T1 shown by the solid line in FIG. 4 takes into account the above-mentioned limiting voltage and indicates a region where flashover from the electric field relaxation ring 13 to the lightning arrester chain 6 does not occur when the maximum discharge current is applied.

Further, the setting coordinate T2 shown by a broken line in FIG. 4 is appropriate when the deterioration of the resistive element 25 is suppressed by setting the charging rate ε to 75% or less with respect to the maximum charging rate εmax (100%). Show coordinates. The electric field relaxation ring 13 is a single ring, and its material diameter is 60 mmφ. In this embodiment, the maximum charge rate ε acting on the resistance element 25 is
The coordinate position of the electric field relaxation ring 13 is set as the set coordinate T2 so that the electric field relaxation ring 13 is 75% or less.

To explain in more detail, the ○ and ● marks in FIG. 4 are analytical data, and the ○ marks indicate the case where the charging rate ε is equal to or less than 75%. Also, the ● mark indicates that the charging rate ε is 75%.
The above is shown. Furthermore, the △ and ▲ marks are test data, and the △ mark indicates that the charging rate ε is equal to or less than 75%,
▲ indicates that the charging rate ε is 75% or more. □ indicates the horn coordinates applied to normal insulators, and ■ mark indicates (coordinates of □ + increase in the diameter of the insulator) when the same concept as for normal insulators is used.

The relationship between the capacitance and charging rate between the electric field relaxation ring 13 and the lightning arrester chain 6 will now be explained. The capacitance between the air insulation distance between each lightning arrester 5 and the electric field relaxation ring 13 is the total capacitance between the opposing area of the ring 13 and each part between the lightning arrester 5,
This increased capacitance can reduce the charging rate acting on the resistive element 25, and can improve the life of the resistive element 25 in a constantly energized state.

FIG. 5 shows the relationship between the position of the resistive element 25 from the voltage application end and its voltage sharing ratio. As is clear from this graph, the voltage sharing ratio is high at the power supply side end and the grounding side end and low at the middle part. Therefore, based on this voltage sharing curve, the X coordinate, Y coordinate, and overall shape of the electric field relaxation ring 13 may be set so that the charging rate of each resistance element 25 becomes an appropriate value. Even when the electric field relaxation ring 13 is disposed on the ground side, the X coordinate, Y coordinate, and overall shape settings are the same.

Furthermore, as shown in FIG. 4, arranging the electric field relaxation ring 13 at the coordinate point where the set coordinates T1 and T2 intersect is advantageous from the viewpoint of reducing the weight and size of the ring 13; Appropriate coordinates may be selected in consideration of the installation location, suspension, tension, differences in V-suspended insulator devices, etc. In addition, in this embodiment, the electric field relaxation ring 13 is formed in an elliptical shape, so that by facing the short diameter part of the ring to the tower main body or other members, it can be arranged without reducing the insulation clearance with respect to the existing tower. can do. The shape of the electric field relaxation ring 13 can be modified as appropriate, such as a circular shape, depending on the conditions of use.

Next, an embodiment in which the present invention is embodied in a suspended lightning arrester device will be described with reference to FIGS. 7 to 9. Figure 7
As shown in FIG. 2, a suspension insulator chain 4 and a lightning arrester chain 6 are suspended and supported in parallel to each other at the lower part of the support arm 1 via a connecting fitting unit 2. Further, a power transmission line 8 is supported by a power supply side connection unit 7 at the lower end of both the insulator chains 4 and 6.

Furthermore, the grounding side connecting fitting unit 2 and the power supplying side connecting unit 7 are provided with grounding side arc rings 11, 11.
and energized side arc rings 12, 12 are supported, respectively. An electric field relaxation ring 13 having a substantially elliptical planar shape is horizontally supported on the power supply side connecting fitting unit 7 so as to surround both insulator chains 4 and 6. FIG. 9 shows the evaluation results of the ring coordinates in consideration of the electric field relaxation effect and limit voltage of the electric field relaxation ring 13 in this suspended type lightning arrester device.

In FIG. 9, the ring coordinates when the limiting voltage is taken into consideration are T1. Further, when considering the charging rate ε, the ring coordinates T2 and T3 are approximately perpendicular, and it is desirable to arrange the electric field relaxation ring 13 along the vertical line of the coordinate T2. Further, the diameter of the ring may be increased along the coordinate T3, but in order to make the ring small and lightweight, it is desirable to increase the diameter near the intersection of the coordinates T2 and T3.

Note that the present invention is not limited to the above-mentioned embodiments, and may be modified as desired without departing from the spirit of the present invention, such as applying the electric field relaxation ring of the present invention to a V-hanging type lightning arrester device. It is also possible to make it more concrete.

[0023]

Effects of the Invention As described in detail above, the present invention can reduce the charging rate of the resistance element built into the lightning arrester and improve the life of the element, and can also adjust the coordinate position of the electric field relaxation ring appropriately. This has the advantage of being able to reduce its weight and size, thereby ensuring insulation clearance with the steel tower or other members, and making it possible to apply it to existing lightning arrester devices.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an attached state of an electric field relaxation ring used in a tension device of a suspended lightning arrester device embodying the present invention.

FIG. 2 is a front view showing the entire tension device of the suspended lightning arrester device of the present invention.

FIG. 3 is a plan view of the lightning arrester device of FIG. 2;

FIG. 4 is an explanatory diagram of the set coordinates of the electric field relaxation ring in the tension device of the suspended lightning arrester device embodying the present invention.

FIG. 5 is a graph showing the position of the lightning arrester from the power supply end and the voltage sharing ratio.

FIG. 6 is a half-longitudinal cross-sectional view showing a suspended lightning arrester.

FIG. 7 is a front view showing an embodiment of the present invention in a suspended lightning arrester device.

8 is a right side view of the lightning arrester device of FIG. 7. FIG.

9 is an explanatory diagram showing the coordinates of an electric field relaxation ring in the lightning arrester device of FIG. 7. FIG.

[Explanation of symbols]

5 Suspended lightning arrester, 6 Suspended lightning arrester series, 13
Electric field relaxation ring, 14 first ring, 15 second ring.

Claims (1)

[Claims] 1. A grounding side end of a lightning arrester insulating a built-in resistance element with non-linear voltage-current characteristics is connected to the steel tower, and a power transmission line is supported on the energizing side end of the lightning arrester,
In the lightning arrester device, an electric field relaxation ring is arranged for reducing the sharing ratio of the voltage applied to the resistance element with respect to the charged side end and/or the grounding side end of the lightning arrester, the arrangement of the electric field relaxation ring. A lightning arrester characterized in that the coordinates are set at coordinates that prevent flashover between the lightning arrester and the electric field relaxation ring by the limiting voltage of the resistive element, and make the charging rate of the resistive element equal to or less than a predetermined value. Device.