JPS6010489B2 - Multi-conductor power transmission line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power transmission line for preventing the occurrence of gearlopping.

When wind hits an overhead power transmission line especially when it is covered with ice and snow, a so-called galloping phenomenon occurs in which the line oscillates vertically and horizontally, causing electrical accidents such as short circuits between phases of the line and damage to steel towers and connecting fittings. There is a risk that

For this reason, dampers are installed on power transmission lines to prevent these accidents from occurring. Each damper weighs several tens of kilograms, and many dampers must be installed on the power transmission line, making it an extremely dangerous task to install these dampers on the power transmission line stretched at high places. It is accompanied by Furthermore, in order to prevent galloping on power transmission lines, dampers must be individually designed and manufactured to match the galloping characteristics of each span between towers, and installation on power transmission lines also requires precise adjustment. The disadvantage is that the work required is very time-consuming.

The present invention particularly provides a multi-conductor power transmission line as claimed in the claims, which can prevent gearing without using a damper as described above in the multi-conductor power transmission line.

An embodiment of the present invention will be explained based on the drawings. , FIG. 1 shows a power transmission line in which one phase consists of four conductors.

In the figure, 1 and 2 are upper conductors in one phase, 1' and 2' are lower conductors in one phase, and conductors 1, 2, 1', and 2' are connected by a spacer 3. . In the secondary 4-conductor transmission line,
The difference between the tension of conductors 1' and 2' and that of conductors 1 and 2 is a few percent.
Therefore, there is almost no difference in tension between the upper and lower conductors, but the major feature of the present invention is that the tension on conductors 1' and 2' is less than half of the tension on conductors 1 and 2. be. This focuses on the fact that the vibration period changes when the tension of the elementary conductor changes, and by coarsely combining conductors with different tensions and shifting the twisting period and vertical vibration period of the line, it is possible to prevent the occurrence of galloping. This is what I did.

The inventor suspended 4-conductor steel-core aluminum stranded wires (410 ground ACSR) through load cells for tension detection in 140 test spans, and installed fins (artificial icing) to simulate icing over the entire length. When the conductor was installed and the tension variation in the conductor was investigated with respect to wind speed, the results shown in Figure 2 were obtained.

The fins are plates with a diameter of approximately 5 cm and are attached vertically over the entire length of each conductor, and the wind is measured at an average wind speed of 1 minute (unit: 's). According to Figure 2,
Let the tension on the upper conductors 1 and 2 be T, and the tension on the lower conductors 1' and 2' as T2. T, ;T2=25
When set to 00 [k9/row], the average wind speed for 10 minutes is approximately 13
It is recognized that the wire tension fluctuation due to galloping increases rapidly when the speed exceeds /s.

However, leaving the tension T, as it is, the tension T2 becomes T2=7.
If the wire is set to 5 ri, 40 u, 200 [k9/thread], the wire tension fluctuation due to gearing will not increase rapidly.
Therefore, it is recognized that the tension fluctuations in each conductor are significantly improved when the wind speed exceeds 13/s compared to the conventional case where T, ≠ T2. Furthermore, if a conductor with a high tensile strength is used for the elementary conductor that is subjected to a large tension T, it is efficient in terms of material strength. The natural vibration period of the above-mentioned four-conductor power transmission line used in the test is as shown in Table 1, and T, KiL = 2500 [
In the case of k9/thread, the vertical vibration period and twisting period match, and galloping is likely to occur, whereas
By reducing T2, the vertical vibration period of the phase does not match the twisting period, and the occurrence of galloping is suppressed.

[Table 1] Natural vibration period of 4-conductor power transmission line (however, T,
=2500 [K/article]) As mentioned above, the multi-conductor power transmission line of the present invention is not limited to a four-conductor power transmission line, and among the multi-conductors,
If the tension in at least one conductor is less than half of the tension in the other conductors, it will work.

Since tripping can be prevented, it is not only possible to avoid the dangerous work of reinstalling multiple dampers on a multi-conductor power transmission line after it has been suspended from a steel tower, but also to avoid electrical and mechanical accidents on the power transmission line. It is something that can be done.
Further, since there is no need to individually design and manufacture dampers that match the galloping characteristics of the power transmission line, the present invention is extremely effective.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a four-conductor power transmission line showing an embodiment of the present invention, and Fig. 2 is a correlation between average wind speed and wire tension fluctuation for a four-conductor steel-core aluminum stranded wire with artificial icing fins. It is a diagram. Note that 1, 2, 1', and 2' are conductors, and 3 is a substrate. car illustration 2

Claims (1)

[Claims] 1. A multi-conductor power transmission line that is connected by spacers etc. to form one phase, in which the tension of at least one element conductor is suspended to be less than half of the tension of the other element conductors. A multi-conductor power transmission line characterized by: 2. The multi-conductor power transmission line according to claim 1, wherein a high tensile strength conductor is used as the elementary conductor that shares high tension.