JPS589487Y2 - Ultra high voltage overhead power transmission line - Google Patents

Description

[Detailed explanation of the invention] This invention uses electrostatic induction, corona noise (corona generates a faint buzzing noise that makes people in the vicinity feel uncomfortable), corona noise (corona causes radio waves to be transmitted to communication equipment, etc.), This relates to ultra-high voltage overhead power transmission lines intended to prevent wind noise, etc.

In 1000 KV class ultra-high voltage overhead power transmission lines, the potential gradient in the vicinity is high and electrostatic induction is large, so multiple ground shielding wires are required.

However, if there are road crossing points or buildings, the ground clearance of the shield line needs to be high, and the height of the steel tower will be 100 to 150 meters.

Also, corona noise is a phenomenon that occurs due to the high electric field strength on the surface of the wire, but in order to prevent corona, it is preferable that the conductor diameter is large, and for this reason, the diameter of the conductor is preferably large.
A conductor is constructed of about six multi-conductor power transmission lines, and the apparent diameter of the conductor reaches 1 to 1.5 m.

However, corona during rain occurs when water droplets adhere to the conductor surface, creating protrusions, and corona is generated from these protrusions, making it extremely difficult to countermeasures against corona noise.

On the other hand, in multi-conductor power transmission lines, wind causes Karman vortex vibration, which generates wind noise, and countermeasures against this are difficult.

The purpose of the present invention is to reduce or prevent the electrostatic induction, corona noise, corona noise, and wind noise of the above-mentioned ultra-high voltage power transmission line.

The gist of the present invention is to place an insulator with a low dielectric constant such as SF6 gas around the conductor, thereby suppressing the generation of corona even if the potential gradient of the conductor is high. The purpose is to achieve the above-mentioned purpose by using the sheath, the sheath and the ground, or the shared voltage between the phases.

An embodiment of the present invention will be described with reference to the drawings.

The electrically negative gas 4, such as SF6 gas, has a dielectric strength significantly greater than that of air, and even at 1 atmosphere has an insulating performance two to three times that of air.

Also, since it is a gas, its dielectric constant is extremely small, and is equal to the dielectric constant of a vacuum, E.

There is almost no difference. The sheath 2 encloses the electrically negative gas 4 described above and fixes the insulating spacer 3 that supports the center conductor 1.

Further, the sheath 2 is suspended from a structure such as a gate-shaped iron structure 6 via a metal fitting by an insulator such as an insulator 5.

In this way, the strong potential gradient on the conductor is surrounded and insulated by the electrically negative gas, and the sheath potential is not zero potential, so the generation of corona between the conductor and the sheath can be prevented.

Further, since the sheath 2 is divided into voltages lower than the power transmission voltage, there is almost no corona generation outside the sheath, and there is very little electrostatic induction near the ground.

Further, since the sheath 2 has a large outer diameter, the wind noise has a very low frequency, and no audible sound is generated.

According to the present invention, the above-mentioned excellent effects can be obtained.

This invention is effective when used locally in areas where corona noise, electrostatic induction, and wind noise are problems in ultra-high-voltage power transmission, and also reduces the distance between phases when leading into and out of power transmission and substation surfaces. It can be applied as a so-called narrow line spacing device.

Further, a coupling capacitor may be added between the sheath and the ground potential, that is, a gate-shaped iron structure, etc., in order to adjust the potential of the sheath.

According to the above-mentioned procedure, regarding 100 OKV class power transmission line,
More specifically, it will be as follows.

The capacitance between the conductor and sheath varies depending on the size, but
300PF/m, and the equivalent capacitance between the sheath and the ground (strictly speaking, it also includes capacitance between three phases, but the influence is small) is 100PF/m.

Therefore, the sheath 1000KV/4X--=430 sleeve voltages.

In addition, 200 PF for a 100 m long device, i.e. 20
If a coupling capacitor of 0 PF/m is added, approximately - of the transmission voltage is applied to the sheath, and the reduction effect is remarkable.

[Brief explanation of drawings]

The figure is an explanatory diagram showing an embodiment of the present invention. 1: Power transmission conductor, 2; Sheath, 3; Insulating spacer, 4
; Electrically negative scum; 5; Suspension insulator; 6; Portable steel structure.

Claims (1)

[Claims for Utility Model Registration] 1. In an ultra-high voltage overhead power transmission line having a center conductor 1 and a sheath 2, the distance between the center conductor 1 and the sheath 2 is maintained by a spacer 3 and an electrically negative gas 4 is filled. An ultra-high voltage overhead power transmission line characterized in that the sheath 2 is separated by an insulator 5 from a structure 6 at earth potential. 2. The ultra-high voltage overhead power transmission line according to the preceding item, characterized in that the sheath 2 is separated from the earth potential structure 6 by an insulator 5 via a capacitor.