Power cable

Patent metadata

Field	Value
Publication number	US-10217547-B1
Application number	US-201815873205-A
Country	US
Kind code	B1
Filing date	Jan 17, 2018
Priority date	Aug 30, 2017
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A power cable to be provided inside a steel pipe that is electrically connected to a reference potential node, includes 3 transmission cables, 3 ground buses making contact with outer peripheral surfaces of adjacent transmission cables and arranged at 3-fold rotationally symmetrical positions with respect to a center of the transmission cables in a cross sectional view, a binder covering the ground buses and the transmission cables, and a jacket provided to overlap the binder. The transmission cables have outer diameters to inscribe a first circle having a radius corresponding to a radius of a second, envelope circle of the power cable having a maximum radius inside the steel pipe, but excluding thicknesses of the binder and the jacket. The ground buses have outer diameters to project outwardly of an envelope closed curve of the transmission cables, but less than or equal to a diameter of the first circle.

First claim

What is claimed is:

1. A power cable to be provided inside a steel pipe that is electrically connected to a reference potential node, the power cable comprising:
three transmission cables respectively including one of three conductor wires configured to transmit 3-phase alternating current power, an insulating layer covering the one of the three conductor wires, and a semiconductive layer covering the insulating layer and forming an outer peripheral surface of one of the three transmission cables, wherein the three transmission cables are arranged at three-fold rotationally symmetrical positions with respect to a center of the three transmission cables in a cross sectional view in a state in which the semiconductive layers of adjacent transmission cables of the three transmission cables make contact with each other, and wherein the cross sectional view is taken in a direction perpendicular to a longitudinal direction of the power cable;
three ground buses respectively having an outer peripheral surface that is made of a conductor and is in direct contact with the outer peripheral surfaces of two adjacent transmission cables of the three transmission cables, and arranged at three-fold rotationally symmetrical positions with respect to the center of the three transmission cables in the cross sectional view;
a binder made of an insulator and in direct contact with and covering both the outer peripheral surfaces of the three ground buses and the outer peripheral surfaces of the three transmission cables; and
a jacket made of an insulator and in direct contact with an outer peripheral surface of the binder to overlap the binder,
wherein the three transmission cables have outer diameters so as to inscribe a first circle that has a radius in the cross sectional view corresponding to a radius of a second, envelope circle of the power cable having a maximum radius inside the steel pipe, but excluding thicknesses of the binder and the jacket, and
wherein the three ground buses have outer diameters such that the three ground buses project in a radial direction from the center, outwardly of an envelope closed curve of the three transmission cables surrounding the outer peripheral surfaces of the three transmission cables in the cross sectional view, but the outer diameters of the three ground buses are less than or equal to a diameter of the first circle.

2. The power cable as claimed in claim 1 , wherein the three ground buses have the outer diameters such that the outer peripheral surfaces of the three ground buses inscribe the first circle.

3. The power cable as claimed in claim 1 , wherein both ends of each of the three ground buses are electrically connected to a potential node equal to a potential of the reference potential node.

4. The power cable as claimed in claim 2 , wherein both ends of each of the three ground buses are electrically connected to a potential node equal to a potential of the reference potential node.

5. The power cable as claimed in claim 1 , wherein the three transmission cables in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center through which a virtual center line passes, while being twisted around the virtual center line.

6. The power cable as claimed in claim 5 , wherein the three ground buses in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center, while being twisted around the three transmission cables.

7. The power cable as claimed in claim 2 , wherein the three transmission cables in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center through which a virtual center line passes, while being twisted around the virtual center line.

8. The power cable as claimed in claim 7 , wherein the three ground buses in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center, while being twisted around the three transmission cables.

9. The power cable as claimed in claim 3 , wherein the three transmission cables in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center through which a virtual center line passes, while being twisted around the virtual center line.

10. The power cable as claimed in claim 9 , wherein the three ground buses in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center, while being twisted around the three transmission cables.

11. The power cable as claimed in claim 4 , wherein the three transmission cables in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center through which a virtual center line passes, while being twisted around the virtual center line.

12. The power cable as claimed in claim 11 , wherein the three ground buses in the cross sectional view maintain the 3-fold rotationally symmetrical positions with respect to the center, while being twisted around the three transmission cables.

13. The power cable as claimed in claim 1 , wherein each of the three ground buses is made up of a plurality of wires that are twisted to form a single wire.

14. The power cable as claimed in claim 1 , wherein each of the three ground buses is a bare conductor wire.

15. The power cable as claimed in claim 1 , further comprising:
a resin member made of an insulator and filling gaps between the three transmission cables and the three ground buses, inside of the binder.

16. The power cable as claimed in claim 1 , further comprising:
a resin member made of an insulator and filling gaps between the three transmission cables and the three ground buses, inside of the binder,
wherein the resin member is in direct contact with the outer peripheral surfaces of the three transmission cables, the outer peripheral surfaces of the three ground buses, and an inner peripheral surface of the binder.

17. The power cable as claimed in claim 1 , wherein the three transmission cables respectively further include a conductor screen provided between the one of the three conductor wires and the insulating layer.

18. The power cable as claimed in claim 1 , wherein the three transmission cables respectively further include an insulator screen provided between the insulating layer and the semiconductive layer.

19. The power cable as claimed in claim 1 , wherein the three transmission cables respectively further include
a conductor screen provided between the one of the three conductor wires and the insulating layer, and
an insulator screen provided between the insulating layer and the semiconductive layer.

Assignees

• Sumitomo Electric Industries

Inventors

• Kaneda Taiki
• Mashio Shoji

Classifications

• H01B7/225

  forming part of an outer sheath · CPC title

• H01B9/02 Primary

  with screens or conductive layers, e.g. for avoiding large potential gradients · CPC title

• H01B11/02

  Cables with twisted pairs or quads · CPC title

• H01B7/20

  Metal tubes, e.g. lead sheaths · CPC title

• H01B9/028

  with screen grounding means, e.g. drain wires · CPC title