JP2009106089A - Method of repairing straight-line sleeve connection of overhead transmission line and structure of repaired portion of straight-line sleeve connection of overhead transmission line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a heat generation defect in connections of a straight-line sleeve may cause disconnection. <P>SOLUTION: The method of repairing the connections of the straight-line sleeve includes: winding an underlying armour rod around each end part of a transmission line, which is exposed at each side of the straight-line sleeve to which the transmission line is connected, to have a diameter nearly the same as the outer diameter of the straight-line sleeve;covering the straight-line sleeve and the underlying armour rod; and winding a finishing armour rod which is slightly shorter than the winding end of the underlying armour rods. In this method of repairing the connections of the straight-line sleeve for overhead transmission lines, 2L<SB>1</SB>+L<SB>0</SB>≥L<SB>2</SB>is satisfied, wherein L<SB>0</SB>is the length of the straight-line sleeve, L<SB>1</SB>is the winding length of the underlying armour rod, and L<SB>2</SB>is the winding length of the finishing armour rod. Also provided is repaired portions of the connections of the straight-line sleeve, which are manufactured by the method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for solving a heat generation problem caused by aging of a straight sleeve in an aerial transmission line installed between steel towers and a structure made by such a method.

In general, an overhead power transmission line is composed of a double structure consisting of a steel core part that is a tension member and an aluminum twisted wire part that is a current path, and is usually manufactured at a length of 1 to 2 km in a transmission line factory, and is wound around a drum. It is transported to the site, and a steel tower is used while connecting it at the site, and a wire of 3 to 6 km is drawn. However, since a connection point is made for each length of the drum, a linear sleeve is used.
That is, they are connected by a straight sleeve comprising a steel sleeve for compression connection of the steel core portion of the steel core aluminum stranded wire and an aluminum sleeve including the steel sleeve and compression connected over the aluminum wire portions on both sides thereof.

The steel sleeve is manufactured so that the outer diameter and length satisfy the mechanical strength, and the aluminum sleeve is manufactured so that the outer diameter and length satisfy the electrical and mechanical performance. To connect the transmission line with this compression straight sleeve, at the end of the transmission line to be connected, the aluminum wire is cut and removed, the inner steel core is exposed for a predetermined length, and the steel sleeve is exposed to the steel core. After being inserted and compressed, the aluminum sleeve previously communicated with the end of the power transmission line is moved to the outer periphery of the connecting portion, and the entire surface is compressed to complete the connection.
In such a connection portion of the linear sleeve, a failure due to heat generation occurs over a long period of time, and if left unattended, there is a concern that disconnection may occur. The cause of this is that the power transmission line also has a long-term transmission line twisted into the straight sleeve, infiltrating moisture from rainwater, etc., causing internal corrosion, increasing the electrical resistance, and the steel sleeve in the aluminum sleeve. It is thought that the main cause is a so-called construction failure in which the position of the center is eccentric from the center of the sleeve.
Japanese Patent Application Laid-Open No. 2002-218615 describes corrosion detection of an aluminum power transmission line, but does not describe any countermeasures.
JP2002-218615

Conventionally, in any case, the electrical resistance of the linear sleeve increases, the temperature of the sleeve rises, and this temperature rise further increases the electrical resistance. It is done.
If this state is left unattended, there is a risk of a serious accident in which the sleeve and the electric wire in the vicinity thereof are disconnected in the worst case due to thermal deterioration.

  As measures for preventing disconnection due to the above-described state, the entire span having the sleeve portion that has been heated conventionally is replaced with a new power transmission line, or the wires around 10 m before and after the heated sleeve are removed, and a new wire is inserted between them. The end portion and the remaining wire end portion were each repaired by compressing and connecting them using two sets of linear sleeves (each set consisting of a steel sleeve and an aluminum sleeve).

  When the entire span is replaced with a new transmission line, as illustrated in FIG. 1, the transmission line W is installed on the tension tower A, the suspension tower B, the suspension tower B, and the tension tower A, and the suspension tower B Assuming the case where the straight sleeve S is connected between B, in order to replace all the wires between the diameters with new wires due to the heat generated in the straight sleeve S, the power transmission is stopped, There is a problem that it takes more time and cost than new construction of overhead power transmission lines, such as removing existing power transmission lines, extending new wires, connecting them with wire, connecting with straight sleeves, retaining with clamping clamps, compression, etc. is there.

In order to solve the above problems, there is also a proposal that cuts a spanned wire including a heated straight sleeve and compresses and connects the existing wire remaining at both ends using an interrupted wire using a straight sleeve. However, since all of the above work is work on the transmission line between spans, it takes considerable labor and cost, and the surface and other parts are oxidized due to aging or chemical changes such as sulfidation and salt damage depending on the location. As a result, the contaminated existing electric wire and the connection sleeve are compressed and connected, and there is a concern that heat will be regenerated at the repair connection point in a relatively short time in the future.
It is an object of the present invention to provide a method and a structure that solves the problems caused by the prior art.

The present invention has been made as a result of intensive studies in order to achieve the above object. The outline of the present invention is an improvement of a straight sleeve connecting portion of an overhead power transmission line. The armor rod for the lower winding is wound so as to be substantially equivalent to the outer diameter of the linear sleeve, and then the surface of the linear sleeve and the armor rod for the lower winding is covered, and is slightly shorter than the winding end of the armor rod for the lower winding. A method for repairing a straight sleeve connecting portion of an overhead power transmission line, characterized by winding an armor rod for upper winding (Claim 1).
2. The linear sleeve connecting portion of the overhead power transmission line according to claim 1, wherein the winding length of the armor rod for lower winding covers a range in which the power transmission line is affected by the heat generated by the straight sleeve. (Claim 2).
When the length L ₀ of the linear sleeve, the winding length L ₁ of the armor rod for _the lower winding, and the winding length L _{2 of the} armor rod for _the upper winding are set so _that 2L 1 ₊ L ₀ ≧ L ₂ , 2. The method for repairing a linear sleeve connection portion of an overhead power transmission line according to claim 1, wherein the tapped end is attached shorter than the end portion of the armor rod for lower winding (Claim 3).
2. The linear sleeve of an overhead power transmission line according to claim 1, wherein the winding length of the upper winding armor rod wound on the lower winding armor rod is two or more pitches of the upper winding armor rod itself. A method of repairing the connecting portion (Claim 4).
The repair structure of the connecting portion is a straight sleeve of an overhead power transmission line that is repaired by any one of claims 1 to 3 (claim 5).

  In the present invention, the connection of the linear sleeve portion as described above is used in combination with the armor rod for the lower winding and the armor rod for the upper winding, so that the defective linear sleeve portion can be mechanically and electrically connected in a relatively short time. Can complete a strong connection.

  According to the present invention, by the method as described above, it is not necessary to separately stretch a new electric wire between the ribs, the electric wire between the spans is cut, a new connecting electric wire is not used, and the sleeve connection is not required. By simply wrapping the foam armor rod, it is possible to take measures against heat generation of the transmission line without requiring a special tool, and it prevents the transmission line thermally deteriorated due to heat generation and the decrease in tensile strength of the straight sleeve, Backing up by winding the lower wound armor rod and upper wound armor rod can satisfy the standard value of the tensile load. Furthermore, compared with the conventional technology, the construction time and cost can be reduced by an order of magnitude. It can be achieved, and the connection part produced by this construction method has various effects such as elimination of the fear of heat generation.

Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a conceptual diagram in the case where a transmission line is connected using two tension steel towers and two suspension towers, and the transmission lines are connected by a straight sleeve between the suspension towers. This figure is an example, and other cases can be easily analogized by those skilled in the art.
In the figure, A is a tensile steel tower, and B is a suspended steel tower, each having two units. The transmission line is indicated by W, and S is a straight sleeve.

FIG. 2 is a partial longitudinal sectional view showing an example of the connection structure of the linear sleeve S according to the present invention, and shows the external appearance of the linear sleeve in cross section. The straight sleeve S is usually crimped and connected to the transmission line using a steel sleeve on the inside and an aluminum sleeve on the outside.
In the present invention, the lower winding armor rod 1 is wound closely on the end of the straight sleeve S around the surface of the transmission line W exposed on both sides of the straight sleeve S, and then the straight sleeve S and the lower winding armor rod are wound. The upper armor rod 2 is wound around the surface of 1 and fixed. At this time, the upper winding armor rod 2 is slightly drawn by about several centimeters from the lower winding armor rod 1 to make it shorter.
The length of the straight sleeve S and L ₀ is the specifically, the winding length MZ for armor rods 1 and L _1, the winding length first volume armor rod 2 is taken as L _2, 2L 1 ₊ L ₀
≧ L ₂ is satisfied.
By winding the lower winding armor rod 1 and the upper winding armor rod 2 in this way, the DC resistance at 2L ₁ + L ₀ decreases, and the current flowing through the transmission line W and the straight sleeve S causes the lower winding armor rod 1 and the upper winding armor. Since the upper armor rod 2 is wound on the straight sleeve S, the outer diameter of the portion is increased, and the heat dissipation is increased. The effect of being able to significantly reduce the temperature rise of this portion can be obtained, and thermal degradation of the location can be prevented.

In this case, the winding length of the armor rod for lower winding should just cover the range in which the power transmission line is affected by the heat generated by the heat generated by the linear sleeve.
On the other hand, the tensile strength of the heat-degraded power transmission line W or the straight sleeve S is lower than the standard value, but the effect that the grip strength of the lower armor rod 1 and the upper armor rod 2 can be used to back up the tensile strength. Play.
In the case of 2L ₁ + L ₀ <L ₂ , the tip of the upper winding armor rod 2 jumps outward from the end of the lower winding armor rod 1, which is not preferable in terms of corona characteristics.
In addition, since the grip force of the lower armor rod 1 and the upper armor rod 2 is expected, if 2L ₁ + L ₀ <L ₂ , the amount of the upper armor rod protruding from the lower armor rod is unnecessary. Length.

Examples of the present invention will be described. FIG. 3 is an example of an XX cross-sectional view of FIG. 2, and shows a state where the lower winding armor rod 1 is tightly wound on the transmission line W and further the upper winding armor rod 2 is tightly wound thereon.
The actual armor rod may be one in which a plurality of armor rods are bundled in advance. In this way, the winding speed can be improved.
FIG. 4 shows a state in which the lower winding armor rod 1 is tightly wound around the power transmission line W, and the upper winding armor rod 2 is further roughly wound at appropriate intervals, for example, every other winding. By doing in this way, the armor rod 2 for upper windings can reduce the number of use, and can improve the heat dissipation effect by a space | gap.
Fig. 5 shows the length (L2) and pitch (P) of the upper armor rod wound on the lower armor rod. The length wound on the lower armor rod varies depending on the wire size. By setting the pitch to 2 pitches (2P) or more, it is possible to back up the tensile strength of the linear sleeve and ensure a predetermined tensile strength.
At this time, the total length (L2) of the armor rod for upper winding is 4P + L0 or more.

Another embodiment of the present invention will be described with reference to a longitudinal sectional view of another example showing a connection state on the straight sleeve (side view) of FIG. In the present embodiment, when the difference between the outer diameter of the linear sleeve and the outer diameter of the transmission line is large, when the size of the wire rod of the armor rod for lower winding is applied as a standard size, It is the partial longitudinal cross-sectional view which showed the outer appearance of the sleeve and others by the cross section. The straight sleeve S is usually crimped and connected to the transmission line using a steel sleeve on the inside and an aluminum sleeve on the outside.
In the present invention, the armature rods 1a (lower side) and 1b (upper side) for lower winding are in close contact with the ends of the linear sleeve S in a double winding state on the surface of the transmission line W exposed on both sides of the linear sleeve S. Then, the upper winding armor rod 2 is wound around and fixed to the surfaces of the linear sleeve S and the lower winding armor rod 1b. In this case, the twisting direction of the lower armor rod 1a (lower side) and 1b (upper side) may be the same as or opposite to the twisting direction. There is a concern that the armor rod for lower winding 1b (upper side) falls and the diameter decreases.

The double winding of the lower armor rod will be described in more detail. When the cross-sectional area of the transmission line is 810 mm ² and the outer diameter is 38.4 mm, the straight sleeve outer diameter is 68 mm, and the outer diameter difference is 29.6 mm. It becomes. To cope with this difference in outer diameter, an armor rod for lower volume is required to have an outer diameter of 14.8 mm. However, since such a rod is not actually produced, a standard outer diameter (5 to 10 mm) is required. ) Size is required to be double-wound, and implementation in accordance with this embodiment is required.
The upper armor rod 2 is slightly shorter than the lower armor rod 1 by about several centimeters. The length of the straight sleeve S and L ₀ is the specifically, the winding length of the second volume for armor rods 1a and 1b and L _1, the winding length first volume armor rod 2 is taken as L _2, 2L 1 ₊ L Satisfying ₀ ≧ L ₂ is as described above.

  In carrying out the present invention, the armor rod used can increase the friction and improve the tensile force by attaching plastic powder or the like to the inner surface. Also, an armor in which a plurality of spiral wires are joined with an adhesive. Construction can be performed in a short time by using the rod.

  The present invention can be applied to a power transmission line in any region because a preferable heat generation countermeasure can be taken by a very simple means.

In this invention, the conceptual diagram which shows the execution object The longitudinal cross-sectional view which shows the connection state on the linear sleeve (side view) in this invention An example of a sectional view taken along line XX in FIG. Another example of a sectional view taken along line XX in FIG. Explanatory drawing of the relationship between the pitch and length of the armor rod for upper winding The longitudinal cross-sectional view of another example which shows the connection state on the linear sleeve (side view) in this invention

Explanation of symbols

S Straight sleeve W Transmission line A Tensile tower B Suspended tower L ₀ Length L of straight sleeve S ₁ Winding length L of lower armor rod ₂ Winding length of upper armor rod P Pitch of upper armor rod 1 Lower volume Armor rod 1a (lower side) Armor rod 1b for lower volume (upper side) Armor rod 2 for lower volume Armor rod for upper volume

Claims (5)

In refurbishing the straight sleeve connection of the overhead power transmission line,
The armor rod for lower winding is wound around the exposed transmission line ends on both sides of the linear sleeve to which the power transmission line is connected so that the outer diameter of the linear sleeve is approximately equal to the outer diameter of the linear sleeve, and then the surface of the linear sleeve and the armor rod for lower winding are A method for repairing a linear sleeve connecting portion of an overhead power transmission line, comprising covering and winding an upper winding armor rod slightly shorter than a winding end of the lower winding armor rod.   2. The linear sleeve connecting portion of the overhead power transmission line according to claim 1, wherein the winding length of the armor rod for lower winding covers a range in which the power transmission line is affected by the heat generated by the straight sleeve. Repair method. When the length L ₀ of the linear sleeve, the winding length L ₁ of the armor rod for _the lower winding, and the winding length L _{2 of the} armor rod for _the upper winding are set so _that 2L 1 ₊ L ₀ ≧ L ₂ , The method for refurbishing a straight sleeve connecting portion of an overhead power transmission line according to claim 1, wherein the attached end is attached shorter than the end portion of the armor rod for lower winding.   2. The linear sleeve of an overhead power transmission line according to claim 1, wherein the winding length of the upper winding armor rod wound on the lower winding armor rod is two or more pitches of the upper winding armor rod itself. How to repair the connection. The structure of the repair part of the linear sleeve connection part of an aerial transmission line characterized by being repaired by any one of Claims 1-3.

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