JPS62139210A - Power cable - Google Patents

Abstract

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

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power cable with reduced sheath loss. In particular, by using a sheath with low conductivity such as stainless steel, eddy currents in the sheath can be reduced. This was designed to compensate for the lack of ground fault capacity in a structure designed to reduce losses.

[Conventional technology and its problems] If stainless steel is used instead of aluminum or the like in order to reduce the eddy current of the sheath, the flexibility will deteriorate, and if the sheath is made thinner to improve flexibility, , ground fault capacity is insufficient.

In order to solve these problems, a structure has been proposed in which a conductor coated with formal resin O polyimide resin is applied between the metal sheath and the cable insulator (
(See Japanese Patent Publication No. 60-38804).

However, when using an insulated conductor, the conductor and metal sheath are insulated by the sheathing material, and the potentials are not the same, so if a surge voltage enters, for example, a discharge can occur between them. There is a possibility that

[Means for Solving the Problems] The present invention, as shown in FIG. ,
This is an attempt to solve the above problem.

[Description] (1) The cable insulator 14 is used to include the outer semiconducting layer 16.

(2) The conductor 40 having a semiconducting material is a conductor 42 coated with a semiconducting material 44, as shown in FIG.

The conductor 42 is mainly made of copper, and the semiconductor 44 is made of semiconductive rubber or plastic, semiconductive foamed rubber or foamed plastic, copper oxide film, or the like.

(3) Also, "arranging" the conductor 40 provided with a semiconducting material may be (i) spirally wound as shown in Figure 3, or (i) corrugated with a long pitch as shown in Figure 4. It is used in the sense that it is okay to add vertically.

Further, the winding method may be either close winding or coarse winding.

(In particular, if foamed rubber or plastic is used for the semiconductor material 44, and its thickness and outer diameter are appropriate), there will be a gap between the cable core 10 and the metal sheath 20 even when the cable core 10 is most contracted. I can't do it, and cable core 10
When the cable core 10 expands to the maximum, it is possible to absorb the expansion, thereby preventing the cable core 10 from sliding down on a slope.

In addition, 50 in FIG. 1 indicates a semiconductive holding tape, and 52 indicates a corrosion protection layer.

[Actions and effects of the invention] (1) The conductor 42 compensates for the lack of ground fault capacity.

(2) Since the conductor 42 and the metal sheath 20 are in contact with each other via the semiconductor 44, the conductor 42 and the metal sheath 20 are at equal potential, and no discharge occurs even if a surge voltage enters.

(3) Since the semiconductor 44 is interposed between the adjacent conductors 42, no radio waves flow between them, and therefore eddy currents are reduced.

(4) Concentration of current on some conductors 42 in the event of a ground fault is alleviated.

[Brief explanation of drawings]

FIG. 1 is a detailed explanatory diagram of the present invention, FIG. 2 is a cross-sectional view of a conductor 40 provided with a semiconductive material, and FIGS. 3 and 4 illustrate a method of arranging the conductor 40 provided with a semiconductive material. Explanatory diagram. lO: Cable core 14: Cable insulator 16: External semiconducting layer

Claims (1)

[Claims] A power cable having a metal sheath, characterized in that a conductor whose surface is provided with a semiconductive material is disposed between the metal sheath and the cable insulator.