JPH0757046B2 - Tightening method for power lines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention monitors sag in a tight line of a power transmission line with high accuracy, and efficiently and efficiently grasps fluctuations in sag economically and efficiently. It is related to the tight line construction method of the power transmission line that sets the degree.

[Prior Art] In recent years, the overhead power transmission lines have become ultra-higher in voltage, and the conductors have become larger in size, and the size of the towers has increased. On the other hand, the span between overhead lines tends to become longer.

With the increase in size of such overhead power transmission lines, some new problems have come to be exposed in the overhead lines, including their location conditions.

When an overhead power transmission line is installed, as shown in Fig. 5,
A predetermined design sag d is set so that excessive overhead line tension is not applied to the power transmission line 1 between the steel towers T ₁ and T ₂ , and so-called tight line work is performed to adjust the power transmission line 1 to the sag d during the overhead line. Is performed.

Conventionally, in order to perform this tight line work, a vertex 4 with a display scale as shown in Fig. 6 is installed on the tower T ₂ side, a compass 3 with a telescope is installed on the tower T ₁ side, and the vertex 4 is placed on the compass. By collimating from 3, the tension of the electric wire 1 was adjusted so that the transmission line 1 had a sag d, and the sag was set.

FIG. 4 is an explanatory diagram showing a tension adjustment state of the electric wire 1 in the wire tension work. The insulator string 2 is attached to the steel tower arm Ta, the cam along 5 is attached to the electric wire 1, the insulator string 2 and the cam along 5 are connected by pulleys 6 and 6, and the pulleys 6 and 6 are moved by the wire 7. adjust. In this way, the sag monitoring operator using the vertex and the tension adjusting operator using the pulley are in contact with each other while the sag d is maintained.
When it is confirmed that the above condition is satisfied, a strain clamp is attached to the end of the electric wire 1, and the electric wire 1 is connected to the insulator string 2.

[Problems to be Solved by the Invention] As described above, collimation to a vertex by a sag telescope is performed for tight line work, but as a result of a large tower and a large span, the collimation distance is extremely small. It became very long and I could not see the vertex properly. In particular, because the location conditions of power transmission lines have become severe and construction has often been carried out in mountainous areas, obstacles to the field of view such as fog and gas are likely to occur, or elements that make the collimation more difficult, such as backlighting. Is also increasing. Furthermore, since the electric wire has a multi-conductor structure of four or more conductors, it is uncertain which electric wire to look at when collimating, and there is a new problem that it cannot be distinguished.

For this reason, recently, there has been a great demand for a new tie wire construction method capable of setting the sag with high accuracy without collimation.

Also, when looking at the sag itself, the original sag is
As shown in FIG. 7, the sag d ₀ should be the observation point at P ₁ directly under the steel tower arm Ta, but the actual observation point is the tower leg P ₂ and the measured sag d ₁ is originally 7th for the sag d ₀ of
The error Δd shown in the figure occurs. This error increases as the size of the tower increases, so it is a value that cannot be ignored between towers with horizontal angles and large height differences.

In addition to this, it is necessary to correct by the outside temperature at the time of measurement,
Another problem is how to make that correction.

The object of the present invention is to eliminate the above-mentioned conventional collimation work for tight binding, while continuously measuring the sag with extremely high accuracy by an angle measuring device capable of correcting and monitoring the catenary angle of the wire in the tight binding. The purpose of the present invention is to provide a new overhead wire tension line construction method capable of performing a tension line work.

[Means for Solving the Problem] The present invention measures the angle by separately attaching a gyro capable of highly accurate angle measurement to an insulator string and an electric wire in a steel tower,
The result is input to the calculator to correct the catenary angle of the wire due to the weight of the insulator string, and the calculator separately inputs the previously known span length, height difference, temperature conditions, etc. The degree of sag is continuously calculated, and the degree of sag is efficiently set based on the result.

[Operation] If the catenary angle of the wire, the span length, and the height difference are determined, the wire sag is determined. However, even if only the catenary angle of the electric wire during the overhead wire work is measured with high accuracy, the correct sag cannot be obtained. This is because the insulator has a large weight and the catenary angle fluctuates accordingly. The influence of Insulators on the catenary depends on the composition of Insulators themselves, but it also depends on the height difference and span length of the tower, so it is not possible to measure it. By actually measuring, the change in the catenary angle of the wire can be known.By correcting this according to the program installed in the calculator in advance, the correct slack can be immediately calculated and displayed, and the wire tension can be adjusted according to the display. In this case, it is possible to set the sag with high efficiency and high accuracy.

[Embodiment] The present invention will be sequentially described below with reference to the drawings of embodiments.

FIG. 1 is an explanatory diagram showing the configuration of each element when the sag d of the electric wire 1 that is installed between the steel towers T ₁ and T ₂ is calculated by a calculation formula.

In FIG. 1, θ is the catenary angle (degree), S is the span length (m), h is the height difference (m) of the supporting points, and d is the sag (m).

The general formula for calculating the sag in the above configuration is as follows. (In the case of the lower tower) here, However, To: Horizontal tension w: Unit weight of wire From formulas (1) and (2) Since the span length S and the height difference h are known in the equation (3), the sag d is determined by the equation (3) as long as the catenary angle θ is determined.

However, as described above, the true θ shown in FIG. 1 cannot be found by simply measuring only the angle of the electric wire 1.
This is because the value varies depending on the weight of the insulator and the obtained value is not true θ.

In order to obtain the true correction value of θ,
It is explanatory drawing which shows the Example which concerns on this invention which attached the gyros 10a and 10b to the electric wire 1 and the insulator series 2, respectively, and connected these gyros 10a, 10b to the calculator 12 by the lead wires 11a, 11b.

The gyros 10a and 10b are required to be able to measure extremely minute angles, and a conventional mechanical gyro or an electric gyro may be used, but it is preferable to use an optical gyroscope using an optical fiber. . The optical gyroscope has a high degree of drift of 0.01 ° / S or less, has an extremely fast response speed, and is small and lightweight, so it can be mounted on a steel tower and mounted as shown in Fig. 2. Very convenient.

The actual catenary angle θ ₁ of the electric wire is measured by the gyro 10a, and the angle θ ₂ of the insulator is measured by the other gyro 10b. The corrected true catenary angle θ can be easily known by inputting these measurement results into a calculator for calculation. Accordingly, the sag d can be easily calculated by taking into consideration the span length S, the height difference h, which have been separately input, and the temperature condition and other necessary data, if necessary. The result can be displayed on the display device, and the operator can read the result directly and set the sag accurately to perform the tight-tie work.

Note that it is possible to wirelessly connect the gyro and the display, which makes it possible to further simplify the work.

Further, the technical idea of the present invention can be applied not only to a power transmission line but also to a wire rope overhead line and the like.

[Effects of the Invention] As described above, according to the cording method according to the present invention, the following excellent effects can be exhibited.

(1) No need to install or remove the vertex,
The man-hours and labor costs for that can be reduced.

(2) Since the sag can be directly read as a numerical value, the work efficiency can be greatly improved.

(3) If they are attached to each of the multiple conductors, the irregularities of the electric wires can be seen at a glance, and the adjustment work becomes significantly easier than in the conventional example.

(4) Since the wire slackness can be immediately corrected by a calculation for a disturbance factor such as the outside air temperature, the tight line accuracy can be greatly improved.

(5) If an optical fiber is used, there is no influence of induction, and it is possible to carry out the tight-tie work with one side live.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the elements necessary for the sag calculation, FIGS. 2 and 3 are explanatory diagrams showing a state in which the present invention is being carried out, and FIG. 4 is an explanatory diagram showing a wire tight working condition of an electric wire. FIG. 5 is an explanatory diagram showing a conventional sag measuring method, FIG. 6 is a sketch of a vertex, and FIG. 7 is an explanatory diagram showing the relationship between true sag and measured sag. 1: Electric wire, 2: Insulator series, 10a, 10b: Gyro, 12: Calculation display.

Claims (2)

[Claims] 1. A gyro capable of highly accurately measuring an angle is installed at a predetermined position of an electric wire and a predetermined position of an insulator string, and the angle measured by the gyro on the wire side and the angle measured by the gyro on the insulator string side are respectively set. By inputting the necessary data such as span length and height difference measured in advance into the calculator as well as inputting into the calculator, the fluctuation of the catenary angle of the wire due to the weight of the insulator is corrected and the calculation is displayed. Tightening method for power transmission lines that adjusts the slack while confirming the exact slack of the wires. 2. The method of tightening a power transmission line according to claim 1, wherein the gyro is an optical gyroscope.