JPS5914216A - Aerial transmission line - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to J! This invention relates to an overhead power transmission line that prevents the generation of noise and the generation of rona noise caused by raindrops.

The problem of noise (abbreviated as AN) on power transmission lines should be taken into consideration when determining the conductor configuration of overhead power transmission lines, which have been increasing in capacity in recent years. There are two major installations and one summary.

For example, FIG. 1 shows an example of the configuration of a conventional overhead power transmission line designed to prevent the generation of wind noise.
A plurality of preformed rods (metal wires) 2 are open spirally wound at the same pitch on the outer circumferential surface of a stranded conductor 1 having a circular Li-plane shape. For example, the preformed rod 2 wound in an open spiral shape substantially collapses the outer peripheral shape of the power transmission line into a non-circular shape, thereby making it possible to reduce noise.

However, in the power transmission line with the above configuration, when it rains (=I
W rainwater tends to accumulate as water droplets at the lower part of the spirally wound preformed rod 2 (indicated by line A in the figure '2#), which increases the number of discharge points, and the rainwater that tends to form water droplets. Due to poor mobility (fluidity), etc., there has been a problem of increased corona damage, especially AN.

In addition, as shown in FIG. 2, in order to reduce the AN of the power transmission line with the above configuration, the number of wire-formed rods 2 wound in an open spiral on the stranded conductor 1 is increased. For example, a preform A-mud formed by closely contacting two preformed rods 2 [a plurality of rods 1 to 3 are arranged in phase with each other on the outer circumferential surface of the stranded conductor 1 as in the case of Fig. 1. It has been proposed that the wires are wound in an open spiral at the same pitch with different pitches. However, if an overhead power transmission line with this configuration is used, rainwater during rainfall will accumulate (infiltrate) in the contact grooves between the bracing rods 2, which are in close contact with each other, resulting in water droplets becoming large. However, in this structure, the number of wires increases to 1.1 and 2 windings (the number of windings increases to There were four major drawbacks.

The present invention (j) was made in view of the above circumstances, and can reduce both AN and wind noise, and increase the number of major prizes by 1r3<
The objective is to provide new overhead power transmission lines that will never occur before.

The present invention will now be described with reference to the drawings.

FIG. 3 shows an embodiment of the present invention. + = b, and a plurality of stranded wires 5, which are made by twisting a plurality of thin aluminum wires 4 on the outer circumferential surface of the stranded conductor 1, are further shifted in transport -C
As shown in FIG. 1, each thin aluminum wire 4 that is wound into an open spiral in the same bit to form the above-mentioned stranded wire 5 has a rough surface 41 with minute irregularities, and Rough surface 1
The surface exhibits a surface state in which a hydrophilic film 42 is formed on top of the film 41.

In addition, when carrying out this invention, the finely uneven rough surface 41 on the surface of the thin aluminum wire 4 is
Is it by blasting 1'fl such as ~, Sand Plus 1~, steel wire, steel wool, etc.? Mechanical methods such as polishing, fluoride acid, fluoride
It can be formed by a chemical method such as immersion treatment using an aqueous solution of dichloromethane, ammonium fluoride, hydrochloric acid, etc., and it is preferable that the surface roughness is usually around several microns.

Further, the hydrophilic film/12 on the uneven surface 41 can be formed by spraying boiling water, pressurized steam, steam added with ammonia or amines, etc. on the rough surface 41, but the fine wire on which the rough surface 41 is formed 4 in such an atmosphere, or the rough surface 41 is anodized, or the
It is possible to obtain a Boehmai 1 coating, an anodized coating, or a Cronay 1 coating.

1- In the overhead power transmission line having the configuration of the embodiment described above, the stranded conductor (4
The stranded wire 5 is wound in an open spiral on the 1- of the +1 (11), and the cross-sectional outer peripheral shape of the wire is substantially broken into a non-circular shape. Like the conventional one shown, it reduces the wind noise level by 1 m,
Particularly during rain, rainwater adhering to the stranded wires 5 is taken into the strands 5 through the gaps between the twisted aluminum wires 4, and the fine uneven rough surface 41 on the surface of each thin aluminum wire 4. The capillary phenomenon on the right actively promotes the flow and diffusion of rainwater to the surrounding area, and the surface tension of the rainwater that prevents the surface area from contracting and rising into a spherical shape increases the hydrophilic bamboo skin 111. ! By reducing the affinity of the water molecules of 42, it is effectively prevented that rainwater remains in the form of granular water droplets on the surface of the stranded wire 5 for a long time. In some cases, the sound level is significantly reduced.

Next, a specific configuration example of the present invention will be explained.

[Specific Example 1] As shown in Figures 5 and 6, the nominal cross-sectional area is 810 m.
The outer periphery of an AC8R type stranded conductor 1 with a diameter of 1.m2 is treated with an uneven surface and a hydrophilic coating. The overhead power transmission line of the present invention was constructed by winding a stranded wire 51 formed by twisting together 19 fine aluminum wires 41 of 1 mm in an open spiral shape with a pitch of 11 = 100 mm. The AN characteristics and the 1001-1z hum sound level were measured for the power transmission line of the present invention and a comparative electric wire C having the same structure. ANN13
For measurement 1, the length of each sample above is 3 as shown in Figure 8.
+n, water injection m approximately 30 w/K, N'-
i") o Hong M (7) 11'7W wo Test test S to Q, conducted under a row A'1 set at a distance of 5 m and an elevation angle of 30 degrees from the horizontal direction. Also, 1001-
The measurement of the 1z hum sound level was carried out under the same conditions as in the measurement of the AN characteristics, except that the microphone M was set in a horizontal direction when viewed from the sample S as shown in FIG. Figure 7 shows the measurement results of the LAN characteristics at the heavy rain level and the equivalent light rain level under the above-mentioned ¥1 each.
:da, 100]-17 The measurement results at Hamabatake level are not shown in Figure 9.

As can be seen from these figures, the overhead power transmission line according to the present invention has AN characteristics comparable to that of the comparative electric wire, which has a shape desirable for reducing AN, and is effective as a countermeasure against AN.

[Specific Example 2] As shown in Table 1, sea urchin has a nominal cross-sectional area of 410 mm2.
Regarding the target electric wire (AC3R type stranded conductor) of 10 mm2, there are two types of wires: ■ A wire without any countermeasures as it is, ■ A spirally wound single breform rod corresponding to a conventional product, and ■ A spirally wound stranded wire as an example of the present invention. Makishi 1. : Six cuttings of each type shown in the table were constructed, and the IIIA M level was measured. The measurement results for the 1/3 octave band level are shown in Table 1, the frequency characteristics of the wind noise of the 410 mm2 target wire are shown in Figure 11, and the frequency characteristics of the wind noise of the 810 mm2 target wire are shown in Figure 12. .

From the J measurement results shown in these tables and figures, it can be seen that the overhead power transmission line of the present invention can achieve the same level of wind noise reduction effect as the power transmission line with conventional wind noise countermeasures.

As shown in Examples 1 and 2 above, the overhead power transmission line of the present invention is capable of dealing with both AN and wind noise.

As explained above, according to the overhead power transmission line of the present invention, the cross-sectional outer peripheral shape of the wire is changed to a substantially non-circular shape by the stranded wires wound in an open spiral on the stranded wire conductor. This makes it possible to reduce wind noise, and in particular, the spirally wound strands have a surface condition in which a hydrophilic film is formed on the rough surface with minute irregularities. Since it is made of thin aluminum wires, rainwater does not become granular water droplets and accumulate on the surface of the twisted wires, so the AN level can be effectively reduced. The twisted wire to be wound is the conventional 111
Since the weight can be made to be the same as or less than that of a preformed rod wrapped around the body, effects such as no increase in the weight of the power transmission line can be obtained.

[Brief explanation of the drawing]

Figure 1 is a side view of a power transmission line with conventional wind noise countermeasures.
Fig. 2 is a side view of a power transmission line with conventional anti-noise countermeasures and AN countermeasures, Fig. 3 is a side view showing an embodiment of the present invention, and Fig. 4 is an enlarged cross-section of the same essential parts. FIG. 5 is a detailed explanation diagram of the present invention, and FIG. 6 is a vr-
Figure 7, a cross-sectional view of the vr line, shows the measurement results of the AN characteristics.
The graph, Figure 8, shows the measurement conditions for AN characteristics? l Explanatory diagram, Figure 9 shows the measurement results of 100Hz hum sound level.
Graph, Figure 10 is an explanatory diagram showing the measurement conditions of 100Hz hum sound level, Figure 11 is a graph showing the measurement results of the frequency characteristics of wind noise for a target electric wire of 410 mm2, and Figure 12 is an explanatory diagram showing the measurement conditions of a 100Hz hum sound level. li about electric wires
It is a graph which shows the measurement result of the frequency characteristic f'l of t noise. 1...Twisted wire conductor, 1...Aluminum thin wire,
/11...Rough rough surface, 42...Hydrophilic film, 5...Open spiral wound stranded wire. Applicant: Fujikura Electric Cable Co., Ltd. 1

Claims (1)

[Claims] A plurality of thin aluminum wires (4) have a surface state in which a hydrophilic film (42) is formed on a finely uneven rough surface (41).
1. An overhead power transmission line characterized in that a twisted M wire (5) of (5) is wound in an open spiral on a twisted wire conductor (1).