Connection method and structure between grounding electrode diversion center terminal tower and diversion cable

Abstract

The present invention relates to the field of grounding electrode technology, and discloses a connection method and structure between a grounding electrode diversion center terminal tower and a drainage cable. For a grounding electrode that connects a diversion center terminal tower and a drainage cable through a main cable, the present invention peels off the outer protective layer to the inner insulation layer at one end of the main cable layer by layer to form a step-shaped section, and connects the conductor layer exposed at the step-shaped section to a metal connecting plate connected to the drainage cable, and connects the other end of the main cable to the diversion center terminal tower; the present invention improves the connection structure between the grounding electrode diversion center terminal tower and the drainage cable, improves the direct surface insulation capacity of the armor layer and the main cable, and effectively solves the circulation problem of the armor layer of the grounding electrode main cable.

Description

Technical Field

[0001] The invention relates to the technical field of grounding electrodes, and in particular to a connection method and structure between a grounding electrode diversion center terminal tower and a drainage cable. Background Art

[0002] As an important part of DC engineering, grounding electrodes provide a path for ground current and unbalanced current. Existing grounding electrodes include shallow buried grounding electrodes, vertical grounding electrodes and deep well grounding electrodes.

[0003] When constructing the grounding electrode, the feeding element is generally buried 3 to 5 meters underground. In the cable well near the feeding element, the feeding element is connected to the main cable through the drainage cable, and then the main cable is collected to the diversion center terminal tower, where the drainage cable is connected to the main cable through a metal connecting plate in the cable well. The main cable transmits the current from the diversion center terminal tower to the cable well, and then the drainage cable transmits the current to each feeding element.

[0004] The structure of the main cable is, from outside to inside, an outer protective layer, an armor layer, an inner shielding layer, an inner insulating layer, and a cable core made of copper conductor (i.e., a conductor layer). During the design and construction of the grounding electrode project, in order to ensure the safety of the grounding electrode operation and maintenance personnel, the armor layer of the main cable is generally grounded on-site at the diversion center terminal tower, and the main cable armor layer is kept insulated from the ground in the cable well. In order to prevent the main cable armor layer from connecting to the ground, the main cable, metal connection plate, and drainage cable are usually placed in a prefabricated concrete structure, and epoxy resin is filled in the concrete structure. The epoxy resin is used for waterproofing to prevent the main cable armor layer from connecting to the ground through water. During the construction phase, the cable core at one end of the main cable is usually stripped out and exothermally welded to the metal connection plate, where the section from the outer protective layer of the main cable to the inner insulating layer forms a "┛" structure with the cable core. The other end of the main cable is connected to the busbar of the diversion center terminal tower through a cable joint, and the armor layer of the main cable is connected to the grounding grid of the diversion center terminal tower through the cable joint down conductor.

[0005] During actual operation, since the cable well is buried 2 to 3 meters underground, water is easily accumulated in the cable well, which will affect the insulation performance of the epoxy resin in the cable well, causing the main cable armor layer to be connected to the earth through water, so that the main cable armor layer is grounded at two points in the cable well and the terminal tower of the diversion center. In this case, the surface potential will be raised during grounding operation, and the resulting surface potential difference will cause current to flow through the armor layer, seriously threatening the operation safety of the main cable. Summary of the invention

[0006] The present invention provides a connection method and structure between a grounding electrode diversion center terminal tower and a drainage cable. When epoxy resin in a cable well is damaged, a main cable may be grounded at two points in the cable well and the diversion center terminal tower, which may cause a circulating current. The present invention improves the connection structure between the grounding electrode diversion center terminal tower and the drainage cable, and solves the technical problem of how to reduce the circulating current of the main cable armor layer.

[0007] A first aspect of the present invention provides a method for connecting a grounding electrode diversion center terminal tower and a drainage cable, wherein the grounding electrode is connected to the diversion center terminal tower and the drainage cable through a main cable, and the main cable is composed of an outer protective layer, an armor layer, an inner shielding layer, an inner insulating layer and a conductor layer from the outside to the inside, and the connection method comprises:

[0008] Peel off the outer protective layer to the inner insulation layer at one end of the main cable layer by layer to form a step-shaped section;

[0009] The conductor layer exposed at the step-shaped section is connected to the metal connecting plate connected to the drainage cable, and the other end of the main cable is connected to the drainage center terminal tower.

[0010] According to an achievable manner of the first aspect of the present invention, the step of stripping the outer protective layer to the inner insulating layer at one end of the main cable layer by layer includes:

[0011] The outer protective layer, armor layer, inner shielding layer and inner insulating layer of one end of the main cable are peeled off layer by layer, and the length of the exposed armor layer, inner shielding layer, inner insulating layer and / or conductor layer is not less than 20 mm.

[0012] According to an achievable manner of the first aspect of the present invention, the connecting the other end of the main cable to the diversion center terminal tower comprises:

[0013] Cut off the armor layer at the other end of the main cable.

[0014] According to an achievable manner of the first aspect of the present invention, the cutting off of the armor layer at the other end of the main cable comprises:

[0015] The cut-off length of the armor layer at the other end of the main cable should be no less than 300mm.

[0016] According to an achievable manner of the first aspect of the present invention, the connecting the other end of the main cable to the diversion center terminal tower further includes:

[0017] The exposed conductor layer at the other end of the main cable is connected to the diversion center terminal tower through a cable connector.

[0018] The second aspect of the present invention provides a connection structure between a grounding electrode diversion center terminal tower and a drainage cable, wherein the grounding electrode is connected to the diversion center terminal tower and the drainage cable through a main cable, and the main cable is composed of an outer protective layer, an armor layer, an inner shielding layer, an inner insulating layer and a conductor layer from the outside to the inside, and the connection structure is:

[0019] The outer protective layer to the inner insulating layer at one end of the main cable are peeled off layer by layer to form a step-shaped section, and the conductor layer exposed at the step-shaped section is connected to the metal connecting plate connected to the drainage cable; the other end of the main cable is connected to the diversion center terminal tower.

[0020] According to an achievable manner of the second aspect of the present invention, the length of the armor layer, the inner shielding layer, the inner insulating layer and / or the conductor layer exposed at the stepped section is not less than 20 mm.

[0021] According to one implementation of the second aspect of the present invention, the armor layer at the other end of the main cable is cut off.

[0022] According to an achievable manner of the second aspect of the present invention, the armor layer at the other end of the main cable is cut off by a length of not less than 300 mm.

[0023] According to an achievable manner of the second aspect of the present invention, the exposed conductor layer at the other end of the main cable is connected to the diversion center terminal tower through a cable connector.

[0024] It can be seen from the above technical solutions that the present invention has the following advantages:

[0025] The present invention connects the grounding electrode of the diversion center terminal tower and the drainage cable through the main cable, peels off the outer protective layer to the inner insulating layer at one end of the main cable layer by layer to form a step-shaped section, and connects the conductor layer exposed at the step-shaped section to the metal connecting plate connected to the drainage cable, and connects the other end of the main cable to the diversion center terminal tower; the present invention improves the connection structure between the grounding electrode diversion center terminal tower and the drainage cable, enhances the direct surface insulation capacity of the armor layer and the main cable, and can effectively solve the circulation problem of the armor layer of the grounding electrode main cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1A schematic diagram of an existing main cable stripping structure provided for an optional embodiment of the present invention;

[0028] Figure 2 A flow chart of a method for connecting a grounding electrode diversion center terminal tower and a drainage cable provided as an optional embodiment of the present invention;

[0029] Figure 3 A schematic diagram of a main cable stripped into a stepped section according to an optional embodiment of the present invention.

[0030] Reference numerals:

[0031] 1-outer protective layer; 2-armor layer; 3-inner shielding layer; 4-inner insulation layer; 5-conductor layer. DETAILED DESCRIPTION

[0032] The embodiment of the present invention provides a connection method and structure between a grounding electrode diversion central terminal tower and a diversion cable, which is used to solve the technical problem of how to reduce the circulating current of the main cable armor layer.

[0033] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] In the existing grounding electrode, the diversion center terminal tower is connected to the drainage cable through the main cable, and the main cable is composed of an outer protective layer 1, an armor layer 2, an inner shielding layer 3, an inner insulating layer 4 and a conductor layer 5 from the outside to the inside.

[0035] In the prior art, in order to prevent the main cable armor layer 2 from being connected to the ground, the connection method between the drainage center terminal tower and the drainage cable is:

[0036] The main cable, metal connection plate and drainage cable are placed in a prefabricated concrete structure, and epoxy resin is filled in the concrete structure to prevent the main cable armor layer 2 from being connected to the ground through water. During the construction phase, the cable core at one end of the main cable is usually stripped out and exothermally welded to the metal connection plate, where the section from the main cable outer protective layer 1 to the inner insulating layer 4 forms a "┛" structure with the cable core, such as Figure 1 shown.

[0037] Under this structure, the accumulated water in the cable well will affect the insulation performance of the epoxy resin in the cable well, causing the main cable armor layer 2 to be connected to the ground through the water, so that the main cable armor layer 2 is grounded at two points in the cable well and the diversion center terminal tower. In this case, the surface potential will be raised during grounding operation, and the resulting surface potential difference will cause current to flow through the armor layer 2, seriously threatening the operation safety of the main cable.

[0038] In order to reduce or avoid the circulation of the armor layer 2, the present invention improves the connection structure between the grounding electrode diversion center terminal tower and the drainage cable.

[0039] A first aspect of the present invention provides a method for connecting a grounding electrode diversion central terminal tower and a drainage cable.

[0040] See also Figure 2 , Figure 2 A flow chart of a method for connecting a grounding electrode diversion central terminal tower and a drainage cable provided by an embodiment of the present invention is shown.

[0041] An embodiment of the present invention provides a method for connecting a grounding electrode diversion central terminal tower and a drainage cable, comprising:

[0042] Step S1, peeling off the outer protective layer 1 to the inner insulating layer 4 at one end of the main cable layer by layer to form a step-shaped cross section.

[0043] In one achievable manner, when peeling off the outer protective layer 1 to the inner insulating layer 4 at one end of the main cable layer by layer, the following steps may be specifically performed:

[0044] The outer protective layer 1, armor layer 2, inner shielding layer 3 and inner insulating layer 4 at one end of the main cable are peeled off layer by layer, and the length of the exposed armor layer 2, inner shielding layer 3, inner insulating layer 4 and / or conductor layer 5 is not less than 20 mm.

[0045] Preferably, when the outer protective layer 1, armor layer 2, inner shielding layer 3 and inner insulating layer 4 at one end of the main cable are peeled off layer by layer, the length of the exposed armor layer 2, inner shielding layer 3, inner insulating layer 4 and conductor layer 5 can all be 20 mm.

[0046] The embodiment of the present invention improves the surface insulation capability between the armor layer 2 and the main cable by stripping one end of the main cable into a step-shaped section, thereby effectively solving the circulation problem of the armor layer 2 of the grounding electrode main cable.

[0047] Step S2, connecting the conductor layer 5 exposed at the stepped section to the metal connecting plate connected to the drainage cable, and connecting the other end of the main cable to the drainage center terminal tower.

[0048] In one achievable manner, when the other end of the main cable is connected to the diversion center terminal tower, the armor layer 2 at the other end of the main cable is cut off, and then the exposed conductor layer 5 at the other end of the main cable is connected to the diversion center terminal tower through a cable connector. Specifically, when the armor layer 2 at the other end of the main cable is cut off, the armor layer 2 and the outer protective layer 1 at the other end of the main cable can be peeled off to expose the inner shielding layer 3 of the main cable. The cut length of the armor layer 2 at the other end of the main cable is not less than 300 mm.

[0049] It should be noted that the operation of connecting the exposed conductor layer 5 at the other end of the main cable to the diversion center terminal tower can be performed according to an existing operation method, and the embodiment of the present invention is not limited thereto.

[0050] By cutting off the armor layer 2 at the other end of the main cable, the armor layer 2 of the main cable can be prevented from being grounded at the terminal tower of the diversion center, thereby effectively avoiding the occurrence of circulating current in the armor layer 2 of the grounding electrode main cable.

[0051] The invention also provides a connection structure between a grounding electrode diversion center terminal tower and a diversion cable.

[0052] A connection structure between a grounding electrode diversion central terminal tower and a drainage cable provided by an embodiment of the present invention is:

[0053] The outer protective layer 1 to the inner insulating layer 4 at one end of the main cable are peeled off layer by layer to form a step-shaped section, and the conductor layer 5 exposed at the step-shaped section is connected to the metal connecting plate connected to the drainage cable; the other end of the main cable is connected to the diversion center terminal tower.

[0054] The schematic diagram of the main cable being stripped into a step-shaped section is shown in the figure. Figure 3 shown.

[0055] In one achievable manner, the length of the armor layer 2, the inner shielding layer 3, the inner insulating layer 4 and / or the conductor layer 5 exposed at the step-shaped section is not less than 20 mm.

[0056] In one achievable manner, the armor layer 2 at the other end of the main cable is cut off.

[0057] In one achievable manner, the armor layer 2 at the other end of the main cable is cut off by a length of not less than 300 mm.

[0058] In one achievable manner, the exposed conductor layer 5 at the other end of the main cable is connected to the diversion center terminal tower via a cable connector.

[0059] The above-mentioned embodiment of the present invention improves the connection structure between the grounding electrode diversion center terminal tower and the drainage cable, enhances the direct surface insulation capacity of the armor layer 2 and the main cable, and can effectively solve the circulation problem of the armor layer 2 of the grounding electrode main cable.

[0060] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for connecting a grounding electrode diversion center terminal tower and a drainage cable, wherein the grounding electrode is connected to the diversion center terminal tower and the drainage cable through a main cable, and the main cable is composed of an outer protective layer, an armor layer, an inner shielding layer, an inner insulating layer and a conductor layer from the outside to the inside, characterized in that: The connection method includes: Peel off the outer protective layer to the inner insulation layer at one end of the main cable layer by layer to form a step-shaped section; Connecting the conductor layer exposed at the stepped section to the metal connecting plate connected to the drainage cable, and connecting the other end of the main cable to the drainage center terminal tower; The method of connecting the other end of the main cable to the central terminal tower of the diversion center includes: Cutting off the armor layer at the other end of the main cable; The step of cutting off the armor layer at the other end of the main cable comprises: Make sure the cut-off length of the armor layer at the other end of the main cable is not less than 300mm; The step of stripping the outer protective layer to the inner insulating layer at one end of the main cable layer by layer comprises: The outer protective layer, armor layer, inner shielding layer and inner insulating layer of one end of the main cable are peeled off layer by layer, and the length of the exposed armor layer, inner shielding layer, inner insulating layer and / or conductor layer is not less than 20 mm.

2. The method for connecting the grounding electrode diversion center terminal tower and the drainage cable according to claim 1 is characterized in that: The method of connecting the other end of the main cable to the central terminal tower of the diversion center also includes: The exposed conductor layer at the other end of the main cable is connected to the diversion center terminal tower through a cable connector.

3. A connection structure between a grounding electrode diversion center terminal tower and a drainage cable, wherein the grounding electrode is connected to the diversion center terminal tower and the drainage cable through a main cable, and the main cable is composed of an outer protective layer, an armor layer, an inner shielding layer, an inner insulating layer and a conductor layer from the outside to the inside, characterized in that: The connection structure is: The outer protective layer to the inner insulating layer at one end of the main cable are peeled off layer by layer to form a step-shaped section, and the conductor layer exposed at the step-shaped section is connected to the metal connecting plate connected to the drainage cable; the other end of the main cable is connected to the drainage center terminal tower; The armor layer at the other end of the main cable is cut off; The length of the armor layer cut off at the other end of the main cable is not less than 300 mm; The length of the armor layer, inner shielding layer, inner insulation layer and / or conductor layer exposed at the step-shaped section is not less than 20 mm.

4. The connection structure between the grounding electrode diversion central terminal tower and the drainage cable according to claim 3 is characterized in that: The exposed conductor layer at the other end of the main cable is connected to the diversion center terminal tower through a cable connector.

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