JPH1021758A - Power cable with tension member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cable cost and improve laying work by using an aluminum- coated stainless tape having an aluminum portion of a predetermined cross section area as a tension member and also as shielding layers so as to reduce the number of tapes. SOLUTION: In a cross-linking polyethylene insulation power cable, an aluminum-coated stainless tape 13 is wound on a cable core composed of a conductor 1, an inside semi-conductive layer 2, cross-linking polyethylene insulating material 3, and an outside semi-conductive layer 12 with protrusions of an extrusion coating layer. Further, a pressing tape 9, a vinyl sheath 10, and an ant proofing nylon layer 11 are successively laminated thereon. The tape 13 as a tension member functions as a shielding layer, and the aluminum portion thereof has a cross section in which an accident current can flow at an earth fault time. The tape 13 may be substituted with resin such as FRP or the like, or high tension metal having tensile strength equivalent thereto or more. Thereby, a conventional annealed copper wire, the pressing tape therefor, and an inside sheath are not required so that the cable becomes compact.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to power cable technology, and more particularly to a power cable having a tension member attached to a cross-linked polyethylene insulated power cable.

[0002]

2. Description of the Related Art Generally, when this type of power cable is laid underground, when it is laid in a tower rising section, a shaft, or an inclined section, an axial force generated by the self-weight of a falling difference and thermal expansion and contraction of the power cable itself. It is necessary to have a tensile force enough to withstand the stress. As a method of giving a sufficient tensile force to the power cable, a multi-point support method using cleats,
There is a method of applying a tension member (armor) and a method of moving a messenger wire along. On the other hand, when cables are laid and fixed in a place where cable laying space is limited, such as an environmentally-friendly tower, cleat mounting space is required. There is a limit to the application because the cable outer diameter becomes large.

On the other hand, in the case of a power cable with a tension member, since a single-point support can be provided by attaching a suspending device capable of withstanding the cable's own weight to the upper portion, a location such as an environmentally-friendly tower start-up section can be used. Has been adopted.

FIG. 2 shows the structure of a cross-linked polyethylene insulated power cable with a tension member, which has been conventionally used. The inner semi-conductive layer 2, the cross-linked polyethylene insulator 3, and the outer semi-conductive layer 4 are formed on a conductor 1. A soft copper wire 5 for flowing a return current in the event of a ground-fault is helically or corrugated on a cable core made of, a holding tape 6 is wrapped thereon, and an inner sheath 7 is provided thereon. ing. The inner sheath 7 is provided with a projection so as to maintain a sufficient surface pressure against a tension member described later and to have a sufficient tensile force on the cable. A stainless tape 8 as a tension member is wound around the outer surface of the inner sheath 7 with a projection. A holding tape 9 is wound on the stainless tape 8,
Further, a vinyl sheath 10 and a nylon termite-proof layer 11 are sequentially applied.

In an ordinary cross-linked polyethylene insulated power cable having no tension member, the inner sheath 7 for holding the surface pressure of the tension member, the stainless steel tape 8 as the tension member, and the pressing tape 9 become unnecessary.

[0006]

[Problems to be solved by the invention]

According to the prior art described above; FIG. 1; the power cable with tension member has the following problems. The cable outer diameter increases. The cable weight increases. Due to the large cable weight, the number of stainless tapes wound as tension members increases. The cost of the cable becomes very high due to the increase in the number of cable constituent materials and the number of manufacturing steps. Poor workability when laying cables.

Therefore, the problems to be solved by the present invention (objects)
Has provided a compact cross-linked polyethylene insulated power cable with a tension member by reducing the cable outer diameter and weight, and at the same time, reducing the cable price; reducing the number of tension members; and improving the workability when laying the cable. To provide a power cable with a tension member.

[0008]

[Means for Solving the Problems]

First means provided by the present invention; the power cable with a tension member uses an aluminum-coated stainless tape as a tension member for the cross-linked polyethylene insulated power cable, and the aluminum-coated stainless tape also serves as a shielding layer, and the ground portion is formed at the aluminum portion. The cross-sectional area that allows the flow of the fault current at the time of
This eliminates the need for conventionally used annealed copper wires and their holding tapes.

[0009] The second means provided by the present invention; the power cable with a tension member uses an aluminum-coated stainless tape as a tension member for the cross-linked polyethylene insulated power cable, and this aluminum-coated stainless tape is used for the outer semiconductive layer with projections. It is wrapped on the upper side, so that a sufficient tensile force can be secured to the cable without using the conventional inner sheath.

The aluminum-coated stainless tape can be replaced by a resin such as FRP having a tensile strength equal to or higher than that of the tape or a high-tensile metal. In this case, needless to say, it is necessary to satisfy necessary tensile strength and function as a shielding layer.

[0011]

FIG. 1 shows an embodiment of the present invention.
1 shows a structure of a power cable with a tension member embodying the first means and the second means of the present invention. Note that the same components as those in FIG. 2 are denoted by the same reference numerals as those in FIG. Incidentally, 1 is a conductor, 2 is an inner semiconductive layer, 3 is a cross-linked polyethylene insulator,
9 is a holding tape, 10 is a vinyl sheath, and 11 is a nylon termite-proof layer.

In this embodiment, the outer semiconductive layer applied on the cross-linked polyethylene insulator 3 is an extruded coating layer of the outer semiconductive layer 12 with projections, and the outer semiconductive layer 12 with projections is used as a tension member. It is formed by winding an aluminum-coated stainless steel tape 13.

[0013] Such aluminum-coated stainless steel tape 13
Use a material that functions as a shielding layer and has a cross-sectional area that allows an accident current to flow at the time of a ground fault in an aluminum portion.

The aluminum-coated stainless steel tape 13 is
Although the occupancy rate is improved by changing the flat square, it is also possible to use a normal round wire.

[0015]

According to the present invention as described above, a compact cross-linked polyethylene insulated power cable with a tension member is provided by reducing the outer diameter and weight of the cable, and at the same time, the cost of the cable is reduced; It is possible to achieve the intended problem (object) of providing this kind of power cable with a tension member that can improve workability when laying the cable. In addition, there is an advantage that the manufacturing cost is reduced and the cable manufacturing process is reduced by reducing the cable outer diameter and the cable weight.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a crosslinked polyethylene insulated power cable with a tension member embodying a first means and a second means of the present invention, according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a cross-linked polyethylene insulated power cable with a tension member as a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductor 2 inner semiconductive layer 3 crosslinked polyethylene insulator 9 holding tape 10 vinyl sheath 11 nylon termite layer 12 outer semiconductive layer with projection 13 aluminum coated stainless tape

Claims (2)

[Claims] 1. An aluminum-coated stainless steel tape is used as a tension member for a cross-linked polyethylene insulated power cable, and this aluminum-coated stainless steel tape is also used as a shielding layer, so that an accident current at the time of a ground fault can flow in an aluminum portion. A power cable with a tension member that has a large cross-sectional area. 2. A power cable with a tension member, wherein an aluminum-coated stainless tape is used as a tension member for a cross-linked polyethylene insulated power cable, and the aluminum-coated stainless tape is wound on an outer semiconductive layer with projections.