JPH09308109A - Power supply using overhead earth-wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To extend the nominal span of aerial earths, and increase the electromotive force of an overhead earth-wire, and cover the power of apparatuses annexed to a pylon. SOLUTION: Overhead earth-wires 1 and 2 are supported by a wedge-type anchor clamp 3, and further the wedge-type anchor clamp 3 is supported by a center tightening plate 8 through one sheet of link 4, a vernier metal fitting 5, an insulator 6, and a right angle clevis 7. A free overhead earth-wire 9 positioned inside the anchor clamp 3 is fixed to the clamp frame 1 supported on an insulating plate 13 on the tightening plate 8 through an insulating plate 13, by means of a jumper clamp 12. As a result, the overhead earth-wires 1 and 2 are insulated from a pylon and the nominal span increases.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply device installed on an overhead ground wire to secure a power source for an aviation obstacle light installed on a transmission tower.

[0002]

2. Description of the Related Art As already proposed in Japanese Patent Publication No. 55-27530, an aerial land installed in parallel with a power transmission line for the purpose of securing a power source for an aviation obstruction light installed in a power transmission tower. Attempts have been made to connect a CT to the line and extract and utilize the induced current generated by the current of the power transmission main line.

[0003]

By the way, the flow of the induced current in the case of a power transmission line having two overhead ground wires is as shown in FIG. That is, since the induced currents are generated in the overhead ground wires 1L and 2L corresponding to the current phases of the adjacent main lines, respectively, depending on the phase difference between the main lines, between the overhead ground wires 1L and 2L. However, the phases of the generated currents deviate from each other. Further, e in the figure is the induced electromotive force of the overhead ground wire, and Z is the primary impedance of the power source CT. R1 and R2 are resistances of a ground arm that connects the overhead ground wires 1L and 2L to a steel tower, and R3 is a ground resistance of the steel tower. Here, the ground resistance R3 usually has a value of about 10Ω, while the ground arm resistances R1 and R2 have a value of about 10 mΩ. Therefore, the current generated due to the phase shift flows between the overhead ground wires 1L and 2L via the ground arm rather than the ground side. Therefore, the induced current flows through the impedance of the overhead ground wire and the ground arm resistance as the output impedance. If a CT for extracting the power source is installed on the overhead ground wire, the induced current decreases due to the increased impedance. . As a result, there is a limit to the electric power that can be obtained by simply installing the CT for taking out the electric power source, and it has been difficult to take out sufficient electric power to be supplied to an aviation obstruction light, monitoring equipment, and the like.

[0004]

In order to solve the above problems, the present invention is to connect a power CT to one or two overhead ground wires installed in parallel with a power transmission line. In an electric power supply device using an overhead ground wire for extracting induced current generated in an electric field, insulation is provided by the overhead ground wire supporting portion of one or more steel towers on both front and rear sides or one side supporting the overhead ground wire to which the power CT is connected. It is characterized in that the overhead ground wire is supported via a member. As a result, the apparent span of the aerial ground wire to which the power supply CT is connected is extended multiple times,
The power obtained from the power supply CT is increased.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of an insulating portion of an overhead ground wire according to the present invention. As shown in the figure, the overhead ground wires 1 and 2 stretched between the steel towers are supported by a wedge-shaped strain clamp 3, and the wedge-shaped strain clamp 3 further includes a single link 4, a vernier metal fitting 5, an insulator 6, It is supported by a central tension plate 8 via a right-angled clevis 7. The tight-tie plate 8 is supported and fixed to the tower main body by a ground arm (not shown). The free overhead ground wire 9 located inside the detention clamp 3 is fixed by a jumper clamp 12 to the upper surface of a clamp base 11 standing on the tension wire plate 8.

The clamp base 11 and the tension wire plate 8
Insulating plate 13 is mounted on insulation plate 13 and then clamp base 11 is attached in order to insulate them from each other. In this way, by supporting the overhead ground wire, which should originally be electrically connected to the steel tower, through the insulating member, the overhead ground wire is electrically insulated from the steel tower. As a result, with respect to the overhead ground wire, the apparent span is extended, and as a result, the induced electromotive force in the overhead ground wire is increased by the lengthened span.

Table 1 is a comparative example obtained by calculating the electric power generated when the overhead ground wire shown in FIG. 1 is insulated by a simulation of the ground wire current by EMTP analysis.

[0008]

[Table 1]

The analysis conditions are such that the UHV transmission line steel tower having the configuration shown in FIG. 2 is arranged like the induced current analysis model of the transmission line shown in FIG. 3, and the number of steel towers between substations is 10 5
50m, 2-line operation of main line power flow of 700A (effective value),
The ground resistance of the substation is 0.1Ω and the ground resistance of the steel tower is 10Ω.
Ω, 10 mΩ for a tower that does not insulate the arm resistance of the tower,
It is set to 1 kΩ for an insulating steel tower. Where C
Regarding the conversion efficiency of T, it has been confirmed by an experiment that the conversion efficiency is 65% to 90% when the load impedance capable of extracting the maximum power is connected to the secondary side when the primary current is 50 to 200 A. The efficiency was set to 65%, and the obtained electric power was calculated by the following formula.

[0010]

(Equation 1) (Power obtained) = (CT primary side input) × 0.65 (CT primary side input) = (CT primary side impedance)
× (Overhead ground wire current) ²

FIG. 4 shows an example of mounting the power source CT on the steel tower. As shown in FIG.
It is supported by the ground arm 14 by a support structure substantially similar to. The ground arm 14 has a support fitting 15
Is attached, and two CTs are fixed to the tip thereof. An overhead ground wire 17, 1 is attached to the CT via a fixing bracket 16.
8 is inserted. Overhead ground wire 17 inserted in CT,
18 is wired to the ground arm 14 side and grounded directly to the tower main body or via a joint box (not shown).

FIG. 5 shows another example of mounting the power supply CT. In this case, two CTs are fixed in the middle of the ground arm 14, and the joint box 19 is installed in the steel tower 21. FIG. 6 shows another mounting example of the power CT. In this case, at the position of No. 2 arm 22 of the tower 21, two C
The T and John Into box 19 are fixed.
In addition, in the above-described embodiment, an example in which the power CT is connected to the two overhead ground wires has been described, but the same effect can be obtained by similarly insulating the one ground overhead wire.

[0013]

As described above, according to the present invention, the apparent span of the overhead ground wire is extended by insulating the supporting portion of the steel tower that supports the overhead ground wire to which the power CT is connected. As a result, the electromotive force of the overhead ground wire increases, and the electric power of the equipment attached to the steel tower can be sufficiently supplied.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an overhead ground wire insulating portion according to an embodiment of the present invention.

FIG. 2 is a configuration diagram of a steel tower used in the analysis model of the embodiment according to the present invention.

FIG. 3 is a diagram showing an induced current analysis model according to an embodiment of the present invention.

FIG. 4 is a diagram showing a mounting example of a power supply CT according to an embodiment of the present invention.

FIG. 5 is a diagram showing another mounting example of the power supply CT in the embodiment according to the present invention.

FIG. 6 is a diagram showing another mounting example of the power CT in the embodiment according to the present invention.

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 1, Overhead ground wire 3 Wedge-type detention clamp 4 1 link 5 Vernier metal fitting 6 Insulator 7 Right angle clevis 8 Tightening plate 9 Overground ground wire 11 Clamping base 12 Jumper clamp 13 Insulation plate 14 Ground arm 15 Supporting metal fitting 16 Fixing metal fitting 17 , 18 overhead ground wire 19 joint box 21 steel tower 22 2nd arm

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Osamu Naganuma 1-7-1 Yurakucho, Chiyoda-ku, Tokyo Toko Electric Co., Ltd. (72) Masanori Isozaki 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo East Inside Kyoden Electric Co., Ltd. (72) Inventor Hiroshi Nakamura 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Inside Tokyo Electric Power Co., Inc.

Claims (1)

[Claims] 1. A 1 or 2 installed in parallel with a power transmission line
In a power supply device using an aerial ground wire that connects an aerial ground wire to a power CT to take out an induced current generated in the aerial ground wire, one of the front and rear sides or one side supporting the aerial ground wire to which the power CT is connected is connected. A power supply device using an aerial ground wire, wherein the aerial ground wire is supported via an insulating member at an aerial ground wire supporting portion of one or more steel towers.