CN101645548A - Method for grounding single-core high-voltage cable metal sheath - Google Patents
Method for grounding single-core high-voltage cable metal sheath Download PDFInfo
- Publication number
- CN101645548A CN101645548A CN200910017744A CN200910017744A CN101645548A CN 101645548 A CN101645548 A CN 101645548A CN 200910017744 A CN200910017744 A CN 200910017744A CN 200910017744 A CN200910017744 A CN 200910017744A CN 101645548 A CN101645548 A CN 101645548A
- Authority
- CN
- China
- Prior art keywords
- grounding
- earth
- cable
- metal sheath
- ground connection
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Cable Accessories (AREA)
Abstract
The invention discloses a method for grounding a single-core high-voltage cable metal sheath, which comprises the following steps: the cable metal sheath is led to the line inlet end of a grounding box by a coaxial cable; then the grounding end of the grounding box is connected with a grounding belt by a grounding wire; a parallel connection grounding line is also arranged between the grounding box and the grounding belt; one end of the parallel connection grounding line is connected with the original grounding line by a grounding wire clamp, and the other end is connected with the grounding belt by a grounding bolt; and both the grounding wire clamp and the grounding bolt are carried out seal processing by a waterproof adhesive tape. The invention effectively solves the problems of leakage current increase, grounding point heating and power failure overhauling processing on a high-voltage cable, which are caused by grounding point resistance increase because of oxidation and corrosiondue to the damp of the grounding end of the cable line metal sheath erected on a channel, and can be widely applied to the running and the overhauling maintenance of a high-voltage power transmissionline.
Description
Technical field
The present invention relates to transmission line high-tension cable ground protection field, be specifically related to a kind of metallic sheath earthing protecting method of single-core high-voltage cable.
Background technology
Along with the develop rapidly of national economy and the quick propelling of urbanization, urban construction high voltage appearance, long-distance cable circuit increase rapidly, and direct-burried and tunnel cable erection mode become main direction, and the high pressure single-core power cables is generally used.
For ensureing the safety and the efficiency of transmission of electric power networks, the high pressure single-core power cables must carry out reliable ground.Reason is when cable line generation overvoltage and short trouble; on metallic sheath or metal sheath, can form very high induced voltage; the cable jacket insulation is punctured; so should adopt special connected mode and earthing mode at the certain position of metallic sheath; sheath protector is installed simultaneously; induced voltage and circulation with rational earthing mode restriction cable cover(ing) ensure the safe operation of cable line.
According to country's " Code for design of cables of electric works " (GB50217-94), exchange the necessary directly ground connection of metal sheath of Monophase electric power cable, and the normal induction voltage at the non-ground connection of any point place must not be greater than 50V on metal sheath, when having taked arbitrarily the safety measure of contacting metal sheath, must not be greater than 100V.The earthing mode that exchanges Monophase electric power cable metal sheath is selected, according to the difference of line length, and circuit selectable metal sheath one end ground connection, neutral earthing or two ends direct grounding way.For long cable line, should divide suitable unit insulating joint is set, make the separation of cable metal sheath at three sections with cross interconnected ground connection, thereby effectively reduce metallic sheath induced voltage and circulation.
The single-core high-voltage cable metal sheath earthing method of prior art; cable metal sheath is to the ground connection case; usually adopt coaxial cable to connect between cross interconnected case or the sheath protector; and the ground connection case; the earth terminal of cross interconnected case or sheath protector adopts the ground connection mode; its existing problems mainly are: owing to adopt single ground connection mode; adopt cable connecting terminal to be connected between earth connection and earth strip or the return wire with bolt crimping mode; earth point is exposed under ground elevation zero the rice following subterranean tunnel and direct-burried environment for a long time; be subjected to underground infiltration water and seasonal rainwater; the moisture influence; oxidation and corrosion can take place in connecting bolt for a long time; earth point resistance increases; cause leakage current to increase; the earth point heating; need when serious the high-tension cable interruption maintenance is handled; operation and the hypervisor of having a power failure during maintenance is loaded down with trivial details, and the work personnel labor intensity is big.
March 19 2008 Granted publication day; notification number is that the Chinese patent of CN 201038515Y discloses a kind of " the cross interconnected case of high pressure single-core power cables "; comprise casing and sheath protector; the inlet wire cable adopts the plug-in wiring construction by a connect-disconnect plug and plug seat thereof with described sheath protector; has simple installation; waterproof and dampproof characteristics; be used for the cross interconnected of high pressure single-core power cables metallic sheath; solved the waterproof connectivity problem of insulating joint two ends metallic sheath well, but do not solved cross interconnected case and earth strip coupling part corrosion problem through coaxial cable and cross interconnected case and sheath protector.
March 19 2008 Granted publication day; the patent No. is that the Chinese patent of ZL200720062875.X also discloses " a kind of high pressure single-core power cables earthing device "; comprise casing; binding post; the ground connection piece; described binding post adopts pluggable mode to be connected with the inlet wire cable; be connected with connector between binding post and the ground connection piece or directly be connected; when can be used as the ground protection case during for sheath protector, uses connector; binding post is that direct ground connection case uses when directly linking to each other with the ground connection piece; though solved the convenience of inlet wire coaxial cable; fast; the waterproof connectivity problem, how its ground connection piece is connected with earth strip and the moistureproof corrosion problem of earth point but still do not solve.
Summary of the invention
The technical problem to be solved in the present invention is: what the tunnel set up cable line cable secondary earth terminal earth connection and earth strip is connected moisture-sensitive generation oxidation and corrosion, earth point resistance increases, cause leakage current to increase, the earth point heating problem, and need overhaul processing to the high-tension cable power failure, maintenance power failure operation and hypervisor are loaded down with trivial details, the big problem of work personnel labor intensity.
Technical scheme of the present invention is: a kind of method for grounding single-core high-voltage cable metal sheath, comprise the end of incoming cables that earlier cable metal sheath is led to the ground connection case with coaxial cable, then ground connection case earth terminal is connected with earth strip with earth connection, it is characterized in that, between described ground connection case and earth strip, increase and connect ground wire in the lump.
Further, described earth connection one end in parallel adopts earthing clamp to be connected with former earth connection, and the employing earth stud is connected between the other end and the earth strip; Described earthing clamp and earth stud all adopt the adhesive waterproof tape encapsulation process.
The present invention has following advantage compared with the prior art:
1, the present invention has been owing to adopted cable secondary earth terminal earthing method in parallel, reduced half leakage current numerical value and grounding resistance of existing earth terminal, guaranteed the safe operation of cable line.
2, transmission line cable grounding point heating problem need not the high-tension cable power failure and gets final product emergency processing, has reduced loaded down with trivial details power failure operation and hypervisor.
3, the present invention is simple, the operating personnel of transmission of electricity Voltage Cable Lines Construction ground connection maintenance construction can reduce half, and can accomplish optimization in the place adjustment that needs are handled, realize laborsaving, save time, reduce to cause various as need handle first kind of power failure working bill, tunnel ventilation, bustling residential block hoistway mouth guard etc. because of operation distance is excessive, the operating personnel grasps construction easily, has accomplished safety, reliable operation.
4, compare with traditional ground connection maintenance construction, operation easier of the present invention reduces greatly, has also reduced staff's labour intensity, and the processing time shortens, and has guaranteed safety in production indirectly, has improved efficiency.
Description of drawings
Fig. 1 is a ground connection case earth terminal ground connection principle schematic of the present invention;
Among the figure: 1-coaxial cable, 2-ground connection case, 3-earth connection, 4-earth strip, 5-earth connection in parallel, 6-earthing clamp, 7-earth stud.
Embodiment
The invention will be further described below in conjunction with accompanying drawing.
In Fig. 1 ground connection case of the present invention earth terminal ground connection principle schematic, the metallic sheath of three-phase electrical cable (not drawing among the figure) leads to the end of incoming cables of ground connection case 2 respectively with coaxial cable 1, the interconnected earth terminal of ground connection case 2 or transposition bus are connected with earth strip 4 by earth connection 3.
The Voltage Cable Lines Construction of setting up for the tunnel; owing to set up the length difference; earthing mode is also different; thereby the type of ground connection case 2 is also different; can be directly ground connection case, cross interconnected ground connection case or ground protection case (being provided with cable protective layer protector in the case), the mutual contact mode of the metallic sheath of three-phase electrical cable after respectively in coaxial cable causes the ground connection case is also different.
When cable line shorter, length 500 meters and when following metallic sheath adopt the direct ground connection of an end, the other end connected mode usually through protector ground connection, make metallic sheath not constitute the loop, eliminate the ring current on the metallic sheath.
When cable line longer; in the time of in 1000 meters; if cable line adopts an end ground connection; its metallic sheath induced voltage will not satisfy the design specification requirement; the metallic sheath of cable of can taking to name a person for a particular job in cable line carries out the interconnected ground connection of single-point; and two terminals of cable metal sheath are by protective earthing, and guarantee that the cable metal sheath induced voltage is no more than 50 volts.
As when cable length surpasses 1000 meters; usually adopt the cross interconnected earthing mode of cable metal sheath; need on the three-phase high-voltage transmission line, divide a plurality of cellular systems; use the cut section that insulating joint is divided into three equal in length in each cellular system; the three-phase metallic sheath at each insulating joint place drawn with coaxial cable and through cross interconnected case carry out cross interconnected after by cable protective layer protector ground connection, the metallic sheath of the three-phase single-core high-voltage cable at each cellular system two ends is by the interconnected back of direct ground connection case ground connection simultaneously.
Usually, adopt bolts to be connected with earth strip 4 after earth connection 3 is drawn from the interconnected earth terminal of ground connection case 2.If earth connection 3 adopts earth cables, can be at first at the termination of earth cable crimping binding post, compress by earth stud with earth electrode or earth strip support then and be connected.But because of earth point and connecting bolt after the cable line long-time running are exposed under subterranean tunnel and the direct-burried environment for a long time, influenced by underground infiltration water and seasonal rainwater, moisture, oxidation and corrosion can take place in connecting bolt for a long time, earth point resistance increases, cause leakage current to increase, the earth point heating needs high-tension cable to have a power failure and overhauls processing when serious, maintenance power failure operation and hypervisor are loaded down with trivial details, and the work personnel labor intensity is big.
The present invention increases between described ground connection case 2 and earth strip 4 and connects ground wire 5 in the lump, and an end of earth connection 5 in parallel is connected with former earth connection 3 outside the ground connection case, and the other end is connected with earth strip 4.When concrete line maintenance is installed, judge, articulate temporary ground wire according to the advanced line position of electric power overhaul rules, and then along former earth connection 3 parallel installations earth connection 5 in parallel.Earth connection 5 in parallel can adopt material and sectional area to satisfy the earth cable of the band oversheath of design ground short circuit capacity, the one end adopts earthing clamp 6 to be connected with former earth connection 3, the junction need break the earth cable oversheath, twine encapsulation process with adhesive waterproof tape again after the installation, carry out the water-proofing treatment work of tie point; Coat conductive paste after adopting the crimping binding post also to be connected and fixed between the other end and the earth strip 4, use the adhesive waterproof tape encapsulation process equally with earth stud 7.Receive and send messages after the maintenance installment work finishes, remove the temporary grounding device, earth connection in parallel comes into operation.
Cable secondary earth terminal of the present invention adopts the method for ground protection earth connection in parallel; reduced half leakage current numerical value and grounding resistance of existing earth terminal; earth point adopts the adhesive waterproof tape encapsulation process; after can effectively solving the cable line long-time running; the earth point connecting bolt is subjected to the influence of underground infiltration water and seasonal rainwater, moisture and oxidation and corrosion takes place; cause leakage current to increase, the problem of earth point heating.Adopt this method in the cable line maintenance, do not need high-tension cable to have a power failure and can operate enforcement, safe and reliable, simple and practical, raise the efficiency.Simultaneously because the enforcement of earth connection in parallel, guaranteed the reliability of cable grounding, avoided wrong construction or maintainer to walk the incidental danger of wrong position in the line process hangingly, improve the fail safe of high voltage power cable operation and personnel's maintenance, can be widely used in the operation and the repair and maintenance of ultra-high-tension power transmission line.
Claims (3)
1, a kind of method for grounding single-core high-voltage cable metal sheath, comprise the end of incoming cables that earlier cable metal sheath is led to the ground connection case with coaxial cable, then ground connection case earth terminal is connected with earth strip with earth connection, it is characterized in that, increase connects ground wire in the lump between described ground connection case and earth strip.
2, method for grounding single-core high-voltage cable metal sheath according to claim 1 is characterized in that: described earth connection one end in parallel adopts earthing clamp to be connected with former earth connection, and the employing earth stud is connected between the other end and the earth strip.
3, method for grounding single-core high-voltage cable metal sheath according to claim 2 is characterized in that: described earthing clamp and earth stud all adopt the adhesive waterproof tape encapsulation process.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910017744A CN101645548A (en) | 2009-08-25 | 2009-08-25 | Method for grounding single-core high-voltage cable metal sheath |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN200910017744A CN101645548A (en) | 2009-08-25 | 2009-08-25 | Method for grounding single-core high-voltage cable metal sheath |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101645548A true CN101645548A (en) | 2010-02-10 |
Family
ID=41657311
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910017744A Pending CN101645548A (en) | 2009-08-25 | 2009-08-25 | Method for grounding single-core high-voltage cable metal sheath |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101645548A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103346509A (en) * | 2013-07-23 | 2013-10-09 | 国家电网公司 | Improved coaxial cable connector hot-line mounting technology |
| CN103579949A (en) * | 2013-11-11 | 2014-02-12 | 国家电网公司 | Method for maintaining high-voltage transformer substation distribution box cable shielded wire |
| CN104113004A (en) * | 2014-06-18 | 2014-10-22 | 国家电网公司 | High-voltage cable protection grounding system transfer device |
| CN108519537A (en) * | 2018-03-01 | 2018-09-11 | 华南理工大学 | Leak electricity greatly flow calculation methodologies under a kind of cable metal sheath multipoint earthing |
| CN112117719A (en) * | 2020-08-27 | 2020-12-22 | 上海外高桥造船有限公司 | IP44 and novel electrical equipment inlet wire construction equipment of following grade |
-
2009
- 2009-08-25 CN CN200910017744A patent/CN101645548A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103346509A (en) * | 2013-07-23 | 2013-10-09 | 国家电网公司 | Improved coaxial cable connector hot-line mounting technology |
| CN103346509B (en) * | 2013-07-23 | 2016-05-04 | 国家电网公司 | The charged mounting process of a kind of coaxial fitting |
| CN103579949A (en) * | 2013-11-11 | 2014-02-12 | 国家电网公司 | Method for maintaining high-voltage transformer substation distribution box cable shielded wire |
| CN104113004A (en) * | 2014-06-18 | 2014-10-22 | 国家电网公司 | High-voltage cable protection grounding system transfer device |
| CN104113004B (en) * | 2014-06-18 | 2016-08-24 | 国家电网公司 | A kind of high tension cable protective grounding system switching device |
| CN108519537A (en) * | 2018-03-01 | 2018-09-11 | 华南理工大学 | Leak electricity greatly flow calculation methodologies under a kind of cable metal sheath multipoint earthing |
| CN108519537B (en) * | 2018-03-01 | 2019-10-18 | 华南理工大学 | Leak electricity greatly flow calculation methodologies under a kind of cable metal sheath multipoint earthing |
| CN112117719A (en) * | 2020-08-27 | 2020-12-22 | 上海外高桥造船有限公司 | IP44 and novel electrical equipment inlet wire construction equipment of following grade |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN203734209U (en) | Live working device for cable bypass | |
| CN202978174U (en) | Windage yaw flashover preventing device of transmission lines | |
| CN102255274A (en) | Direct-current de-icing method of overhead ground wire and composite optical fibre ground wire | |
| CN101645548A (en) | Method for grounding single-core high-voltage cable metal sheath | |
| CN201490354U (en) | Grounding system of metal sheath of single-core high-voltage cable | |
| CN104113002B (en) | A kind of high tension cable cross connection grounding system switching device | |
| CN204964657U (en) | Test device suitable for research 10kV line gap ground connection form | |
| CN201430401Y (en) | Position-changing and connection system for tower and ground wires | |
| CN205212399U (en) | Safe pressure release formula cross -bonding grounding test case | |
| CN103840276A (en) | Connecting device of insulating buses | |
| CN204190345U (en) | 110kV and the cross interconnected protective earthing case of above band detection of electrical leakage type | |
| CN210779513U (en) | Power distribution device of transformer substation | |
| CN202602234U (en) | Medium-pressure cross-linked polyethylene cable terminal with insulation stress cone | |
| CN108683082B (en) | Power station at dam toe's outlet method for arranging | |
| CN208337122U (en) | A kind of 10kV suspended insulated guide wire with the anti-lightning strike broken string of shielded layer | |
| CN107863746A (en) | A kind of 0.4KV power cables underground termination | |
| CN106169729A (en) | A kind of transmission line of electricity roundabout series connection ground wire de-icing method | |
| CN201430402Y (en) | Connection system for tower and ground wires | |
| CN106159798A (en) | A kind of transmission line of electricity connection in series-parallel mixing ground wire de-icing method | |
| CN202737115U (en) | Grounding structure of high voltage single core cable metal outer sheath | |
| CN207732407U (en) | A kind of 0.4kV power cables underground termination | |
| CN107332149B (en) | Transformer substation main transformer low-voltage side field and arrangement method thereof | |
| CN104393426A (en) | Method and apparatus for reducing potential difference between grounding conductors | |
| CN202443903U (en) | Non-conductor maintenance cover for outdoor high-voltage vacuum circuit breaker | |
| CN203632182U (en) | Lightning protection device of 20kV overhead line |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20100210 |