JPS5836109A - Gas insulating cable - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas insulated cable with improved electrical characteristics.

In recent years, gas-insulated cables have been put into practical use as large-capacity power transmission cables, in which one insulating spacer is attached to a metal pipe conductor at predetermined intervals, the outer surface of the spacer is covered with a metal sheath, and the insulating gas is filled. Because gas insulated cables are not flexible, they cannot be rolled up onto drums or the like and transported in long lengths, and connection work at the installation site takes a long time. For this reason, recently, flexible gas insulated cables using stranded conductors and corrugated metal sheaths have been proposed.In such flexible gas insulated cables,
Storing a stranded wire conductor with an uneven surface on its outer circumferential surface exposed to the insulating gas inside the corrugated metal sheath via an insulating spacer is not undesirable in terms of insulation properties, and it is also difficult to fix it with an insulating spacer. Therefore, the cable conductor to be housed within the external corrugated metal sheath via an insulating spacer must be a stranded conductor. However, if the stranded wire conductor is stored bare inside the corrugated metal tube, the stranded wire conductor and the housing metal tube will come into contact with each other, resulting in a difference in actance between the two.

Circulating current flows and circuit loss occurs. To explain this in more detail, a 4000-mm copper stranded conductor (outside diameter 80φ)
) The loss generated in the conductor in a table with a 2111 thick aluminum tube placed over it is 137 times that of the same copper stranded conductor alone, as shown by the formula shown below. ! The conductor loss according to the formula f is as follows: (1) Calculation formula (r + jX) I + coX, k.

＝j Conductor storage metal tube resistance
Mutual reactance Therefore, 2 v = wl - w2 However, when calculating the circuit loss of the cable, rx = """,,'"X 102 (1 + 0.0
0393 x 70 )=x! L496 x 10”
” ”/mr2=mXlo” (1+o, oo4o3x
7o)=4tox1o/mX=2Xit)'Wh(d2/d,)-2X
10 X 100π1ra-= pro2 X 1
0" A/110 r1+r2=&25×10"(+"/m=stophiffl2
= 43e x lts" 2 pieces 1o3x16' = s16xIF' 2 w = 7.5zx1+o'
x" = eh496xLef' When the metal tube is coated and the stranded conductor in the metal tube is connected only at one arbitrary point so that no loop is formed between the stranded conductor and the sheathed metal tube,
When a steep surge enters a conductor, the propagation speed is different between the stranded conductor and the outer metal tube, causing problems such as overvoltage and dielectric breakdown in the conductor insulation coating between them, making it unsuitable. The present invention aims to solve the above-mentioned problems and provide a gas insulated cable with excellent electrical properties.

An example of this will be explained below. In the figure, an l#'i stranded conductor is shown, 2 is a semiconducting layer applied to the outer circumferential surface of the stranded conductor 1, and 3 is a semiconductive layer on the stranded conductor 1. Split type insulation in which corrugated metal conductor storage tubes and 4ti conductor storage tubes 3 are fixed at predetermined intervals after the semiconducting layer 2 is coated with extrusion coating or semiconductive tape wrapping, etc. Spacer 5 is a corrugated metal sheath on the outside, and an insulating gas 6 is inside the metal sheath 6.
The volume resistivity r required for the cable internal conductor in the gas insulated cable of the present invention constructed as described above is filled with -0. A semiconducting layer 2 with a layer thickness of about 1 to 2111 is placed on the stranded conductor 1 so that = 10° to 10'''n-ts.
It is desirable to apply 0 volume resistivity! If is within the above range, even if a steep surge wave invades the internal stranded conductor 1, the conductor 1 and the conductor storage tube 3 will be kept at the same potential and will have a high enough resistance to block the circulating current. However, f = lo
If it is more than 'n-(to), it is not preferable because a potential difference will occur.〇 The following table is as follows: Sample: Stranded wire conductor, , , 4000wj (outer diameter 8
0φ) Conductor The loss ratio between the loss results measured by applying a current of 10OA to each of the cable conductors of the invention and the loss ratio of the sample is shown.

According to the present invention, as described above, the semiconducting layer 2 is particularly formed on the internal stranded conductor 1, and the corrugated metal conductor storage tube 3 is formed thereon, so that it has excellent characteristics with less conductor-generated loss. gas insulated cable obtained

[Brief explanation of the drawing]

The figure is an explanatory diagram of main parts showing one embodiment of the present invention. 01: Twisted conductor 2: Semiconducting layer 3: Corrugated metal conductor storage tube 4: Insulating spacer 5 - Corrugated metal sheath 6I Insulating gas

Claims (1)

[Claims] A corrugated metal conductor storage tube is placed over a stranded conductor with a semiconducting layer applied to the outer circumferential surface, the conductor storage tube is fixed with an insulating spacer, and an insulating gas is filled in the corrugated metal sheath placed over the stranded conductor storage tube. A gas insulated cable characterized by: