JP2012248525A - Polymer insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer insulation capable of suppressing partial discharge even under a contamination wet condition, and suppressing the generation of tracking or erosion.SOLUTION: A sheath 12 is formed with shades 12A and 12B for covering an FRP core 11 sharing a mechanical load and ensuring a surface leakage distance required for insulation performance. A terminal fitting 13 provided at an end part of the FRP core 11 is connected to a building such as a steel tower or an electric wire. In a predetermined range from the terminal fitting on an electric charging end side, a ratio of a shade diameter and a drum diameter is made to be 2.87 or less. Or, semiconductive processing is performed on the whole surface of a body portion except for the shade portion of a surface of the sheath.

Description

  The present invention relates to a polymer insulator using an organic insulator as an insulating material.

  In general, porcelain is used as an insulating material for an insulator, but a polymer insulator using an organic insulator is also used in consideration of light weight and earthquake resistance. FIG. 3 is a structural diagram showing an example of a conventional polymer insulator for power transmission.

  As shown in FIG. 3, the polymer insulator includes an FRP (Fiber-glass Reinforced Plastics) core 11 that shares a mechanical load, a rubber sheath 12 that protects the FRP core 11 from ultraviolet rays, ozone, and the like, a steel tower, and the like. And a metal terminal 13 for connecting to a charging part such as an electric wire. A plurality of long and short shade portions 12A and 12B are formed on the body portion of the outer jacket 12 to ensure a surface leakage distance necessary for insulation performance during fouling and wetness. The cap portion 12A has a longer business trip length than the cap portion 12B. Such a polymer insulator is light and strong against impact, and has characteristics such as excellent insulation properties when wet due to water repellency of the outer rubber surface.

  Here, the silicone rubber composition for high voltage electrical insulators used for the jacket is improved, and even under conditions exposed to severe air pollution, salt damage or climate, water absorption resistance, weather resistance, water repellency, Some polymer insulators have excellent high voltage electrical characteristics such as dirtiness, voltage resistance, tracking resistance, arc resistance, and erosion resistance (see, for example, Patent Document 1).

JP 2007-180044 A

  However, since an organic insulator such as rubber or epoxy resin is used as the outer cover 12, deterioration over time due to ultraviolet rays, ozone, water, electric discharge, etc. cannot be avoided. In particular, there is a concern about the deterioration of the outer jacket due to the discharge when the soil is wet.

That is, when a fouling substance such as sea salt adheres to the surface of the jacket 12 and gets wet, the surface resistance R decreases, and a leakage current I flows under electric power. When the leakage current I flows, Joule heat RI ² is generated and the wet surface is dried, but it is not uniformly dried. The part where it is difficult to dry occurs. Since the leakage current I flowing the same current from the voltage application end to the ground terminal, the Joule heat RI ² generated in dry and high resistance point is greater than the lower other part of the resistance, increasing the drying proceeds, the other part Compared to many orders of magnitude greater resistance. Since the voltage applied to the entire insulator is distributed in proportion to the resistance distribution on the surface, the shared voltage of the dry zone where the surface resistance is high becomes very high, and the insulation of the air on the surface of the part breaks down and partial discharge occurs. appear.

  When such partial discharge occurs, the surface rubber or the like of the outer jacket 12 may be overheated under a condition where oxygen is insufficient, and tracking (conductive path) occurs. Further, if oxygen is sufficiently supplied, erosion (insulating erosion) may occur. When tracking occurs, the insulating function of the insulator is lost, and when the erosion is generated and the FRP core 11 is exposed, the insulator may break off due to brittle fracture.

  An object of the present invention is to provide a polymer insulator capable of suppressing partial discharge even under fouling and wet conditions and suppressing generation of tracking and erosion.

  The polymer insulator according to the first aspect of the present invention includes a FRP core that shares a mechanical load, and a body portion that covers the FRP core and has a cap portion for securing a surface leakage distance necessary for insulation performance while maintaining a gap. And a terminal metal fitting provided at an end of the FRP core and connected to a structure such as a steel tower or an electric wire, and in a predetermined range from the terminal metal fitting on the charging end side, The ratio of the diameter of the cap portion (cap portion diameter) to the diameter of the trunk portion of the outer jacket (trunk diameter) is 2.87 or less.

  The polymer insulator according to the invention of claim 2 includes an FRP core that shares a mechanical load, and a jacket that covers the FRP core and has a cap portion for securing a surface leakage distance necessary for insulation performance. The FRP core is provided with a structure such as a steel tower and a terminal fitting connected to an electric wire, and semi-conductive treatment is performed on the entire surface of the body portion excluding the shade portion of the outer cover surface. It is characterized by having given.

  According to the first aspect of the present invention, since the ratio of the cap diameter to the trunk diameter is set to 2.87 or less within a predetermined range from the terminal fitting on the charging end side, the partial discharge voltage is increased even under the fouling and wet conditions. Can hold. Accordingly, the discharge can be suppressed and the occurrence of tracking and erosion can be suppressed.

  According to the second aspect of the present invention, since the entire surface of the body portion excluding the cap portion is subjected to the semiconductive process on the surface of the jacket, the concentration of potential distribution on the body portion of the jacket surface can be reduced. Thereby, the partial discharge voltage can be kept high. Accordingly, the discharge can be suppressed and the occurrence of tracking and erosion can be suppressed.

1 is a structural diagram showing an example of a polymer insulator according to Embodiment 1 of the present invention. FIG. 6 is a structural diagram showing an example of a polymer insulator according to Embodiment 2 of the present invention. The structural diagram which shows an example of the polymer insulator for the conventional power transmission.

  First, the background to the present invention will be described. The applicant applied the same silicone rubber to the surfaces of the same length of power transmission polymer insulator and porcelain long insulator, and conducted an artificial accelerated deterioration test. As a result, it was understood that the polymer for power transmission is likely to generate a discharge and deteriorate easily.

  As a factor that polymer insulators are likely to deteriorate, a difference in trunk diameter and a difference in cap shape can be considered. Therefore, various polymer insulators and porcelain insulators were prepared, the same silicone rubber was applied to the entire surface, and an artificial accelerated deterioration test was conducted.

Table 1 shows the dimensions and shapes of three types of polymer insulators (transmission polymer insulators, SP insulators (station post insulators), polymer insulator tubes), and two types of porcelain insulators (porcelain aero insulators and porcelain JIS insulators). It is the table | surface which showed.

  As a result of the artificial accelerated deterioration test, it was found that only the insulator for the power transmission polymer is likely to deteriorate even with the same cap shape, the same jacket material, and the same length.

  Based on Table 1, it was decided to extract the point where the polymer for power transmission, which is likely to generate electric discharge, is structurally different from other insulators. As a result, we have found that the power transmission polymer insulator has a smaller body diameter than other insulators.

  As shown in Table 1, the diameter / body diameter of the power transmission polymer insulator is 4.08, the diameter / body diameter of the SP insulator is 2.34, and the diameter / body diameter of the polymer insulator pipe is 1.25, porcelain The diameter of the aero long insulator is 2.87, the diameter of the porcelain JIS long insulator is 2.00, and the diameter of the power transmission polymer insulator is 4 and the diameter of the insulator is 4. The diameter of the insulator / body diameter of other insulators, which are less likely to generate electric discharge, is 2.87 or less.

  Therefore, in the present invention, it is considered that the barrel diameter is increased and the ratio of the cap diameter / trunk diameter is set to 2.87 or less, and that the potential is concentrated at the charging end of the insulator and discharge is likely to occur. Taking into consideration, we studied to alleviate the concentration of potential distribution at the charging end of the insulator.

  Based on the above examination results, an embodiment of the present invention will be described. FIG. 1 is a structural diagram showing an example of a polymer insulator according to Embodiment 1 of the present invention. In the polymer insulator according to the first embodiment, the ratio of the shade diameter to the trunk diameter is 2.87 or less in a predetermined range from the terminal fitting 13 on the charging end side with respect to the conventional power transmission polymer insulator shown in FIG. It is what. The same elements as those in FIG. 3 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 1, the polymer insulator for power transmission is a rod-shaped insulator having terminal fittings 13 at both ends, and the lower side in the figure is a charging end for supporting the electric wire. In a predetermined range from the terminal fitting 13 on the charging end side, the barrel diameter is increased so that the ratio of the shade diameter to the trunk diameter is 2.87 or less. This is because the polymer insulator is rod-shaped, and the potential concentrates on the charging end that supports the wire. Therefore, to reduce further concentration of potential due to drying on the trunk, which is particularly susceptible to deterioration at the charging end. It is.

  As described above, in Embodiment 1, it is considered that if the electric field of the charging end body portion is relaxed, it is possible to suppress deterioration such that the polymer affects the life of the insulator. The body diameter of 5 pitches (about 30 cm) of 12A and 12B was changed from about 26 mm to about 46 mm, and the ratio of the shade diameter to the body diameter was about 2.3. When the cap diameter / trunk diameter is about 2.3, the SP insulator (caps diameter / trunk diameter 2.34) and the porcelain aero long insulator (caps diameter / trunk diameter 2.87) are less likely to cause discharge. The shade diameter / trunk diameter is a small value, and the trunk diameter is large. Therefore, it is difficult to generate discharge. Here, the value of the shade diameter / body diameter is 2.87 or less in the embodiment of the present invention. This is because the diameter of the porcelain aero long trunk, where the partial discharge is difficult to occur, is set to 2.87 or less.

  FIG. 2 is a structural diagram showing an example of a polymer insulator according to Embodiment 2 of the present invention. The polymer insulator according to the second embodiment is different from the conventional polymer insulator for power transmission shown in FIG. 3 in that a semiconductive treatment 14 is applied to the entire surface of the body portion except for the cap portions 12A and 12B on the outer cover surface. It is a thing. The same elements as those in FIG. 3 are denoted by the same reference numerals, and redundant description is omitted.

  As shown in FIG. 2, the semiconductive treatment 14 is applied to the entire surface of the body portion except the shade portions 12A and 12B, of the surface of the jacket of the polymer insulator.

For the polymer insulators of Embodiment 1, Embodiment 2 and the conventional example of the present invention, a partial discharge test was conducted under a fouling wet condition to investigate a partial discharge start voltage. The results are shown in Table 2.

  As shown in Table 2, partial discharge was started at the charging end at a voltage of 70 kV with a conventional polymer for power transmission. In the polymer insulator of the first embodiment, partial discharge was started at a portion having a small body diameter at a voltage of 120 kV, and in the polymer insulator of the second embodiment, partial discharge was started at a voltage application end semiconductive treatment end portion at a voltage of 100 kV.

  As described above, in the case of the insulator having a thickened body diameter of the first embodiment, it is 1.7 times or more, and in the case of the polymer having a semiconductive body part of the second embodiment, which is 1.4 times or more, excellent. A partial discharge suppressing effect was observed, and the polymer insulator insulation deterioration preventing effect was confirmed.

DESCRIPTION OF SYMBOLS 11 ... FRP core, 12 ... Jacket | cover, 12A, 12B ... Shade part, 13 ... Terminal metal fitting, 14 ... Semiconductive material

Claims (2)

An FRP core that shares the mechanical load;
An outer cover formed on the body portion with a gap between the cap portions for covering the FRP core and securing a surface leakage distance necessary for insulation performance;
The FRP core is provided at the end of the FRP core with a structure such as a steel tower and a terminal fitting connected to an electric wire,
A polymer insulator characterized in that the ratio of the shade diameter to the trunk diameter is 2.87 or less in a predetermined range from the terminal fitting on the charging end side. An FRP core that shares the mechanical load;
A jacket on which the cap portion for covering the FRP core and securing a surface leakage distance necessary for insulation performance is formed;
The FRP core is provided at the end of the FRP core with a structure such as a steel tower and a terminal fitting connected to an electric wire,
A polymer insulator characterized in that a semiconductive treatment is applied to the entire surface of the body part excluding the shade part among the surface of the jacket.

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