CN2777820Y - Overvoltage compensation protector for cable protecting layer - Google Patents
Overvoltage compensation protector for cable protecting layer Download PDFInfo
- Publication number
- CN2777820Y CN2777820Y CN 200420054395 CN200420054395U CN2777820Y CN 2777820 Y CN2777820 Y CN 2777820Y CN 200420054395 CN200420054395 CN 200420054395 CN 200420054395 U CN200420054395 U CN 200420054395U CN 2777820 Y CN2777820 Y CN 2777820Y
- Authority
- CN
- China
- Prior art keywords
- cable
- sheath
- phase
- protector
- utility
- 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.)
- Expired - Fee Related
Links
Images
Landscapes
- Cable Accessories (AREA)
Abstract
The utility model relates to an over-voltage compensation protector for protecting layers of cables, which belongs to the technical field of power supplying electric power facilities. The protector comprises a three-phase cable, wherein a protecting layer at one end of the three-phase cable is grounded in the mode of three-phase interconnection. The utility model is characterized in that a protecting layer at the other end of the three-phase cable is grounded through a compensation inductor. Thus, so long as the appropriate compensation inductor is selected according to the factors of laying form and length difference, etc., the inductance of the cable can be made to be identical as much as possible; the three-phase voltage is balanced as much as possible. As a result, circulating current in the protecting layers of the cable is decreased. Because the manufacturing cost of the inductor is much cheaper than that of the cable and is not limited by laying conditions, the utility model has the advantage of economic cost and is feasible.
Description
Technical field
The utility model relates to a kind of protective device of cable sheath, and especially a kind of overvoltage compensation protective device of cable sheath belongs to power supply electric power facility technical field.
Background technology
As everyone knows, supply line generally adopts power cable as electric power transmission network.Because the demand difference of transmission capacity, the design of cable also is not quite similar.Circuit for carrying than low capacity generally adopts three-core cable; And require bigger circuit for transmission capacity, generally adopt single-core cable.In the use, the public same metal sheath of three cores of three-core cable, when three-phase current was in a basic balance, the three-phase resultant current approached zero, and resultant flux also approaches zero, so does not have the induced voltage generation on the metal sheath.Only when asymmetric short circuit, destroyed the symmetry of three-phase current, resultant flux no longer equals zero, and just has uneven induced voltage to produce on the metal sheath.
For single-core cable, the induced voltage of metal sheath is different fully with three-core cable.The lead of single-core cable and the relation of metal sheath can be regarded the elementary winding and the secondary winding of a transformer as.When cable conductor when the electric current, around it, produce magnetic flux, magnetic flux not only with core loop chain mutually, simultaneously also with the metal sheath of cable chain mutually, on core and metal sheath, produce induced voltage respectively.Because every special-purpose metal sheath of core, the magnetic flux that load current or short circuit current produced with the metal sheath interlinkage, so has induced voltage to exist all the time on the metal sheath.Distance is relevant with cable length with size of current between the value of this induced voltage and core cross section, cable.Especially when cable was very long, the induced voltage on the sheath can reach higher numerical value.
At present, new cable line adopts measure such as metal sheath transposition to solve the induced voltage problem (referring to Fig. 1) of metal sheaths usually.But along with the development of power construction, the transformation of cable line is increasing, improved cable line, and its length often can not satisfy three sections original transposition requirements, thereby causes the metal sheath Voltage unbalance.
The metal sheath Voltage unbalance not only can cause cable line sheath circulation, and the numerical value of sheath circulation can reach the order of magnitude identical with the core electric current under the situation about having, and causes the lot of energy loss, and might cause the cable heating, influences cable life.Therefore, must take measures to reduce or eliminate the influence of this sheath voltage.
At present, the method that generally adopts is that compensating cable (promptly increasing the length of cable) makes the cable of its length and former three sections conversion methods isometric both at home and abroad, and the cable hank that will put is placed in the cable trough more.This method obviously has its weak point, increase cable length and promptly increase cost, and many payouts often is subjected to the restriction of space and laid condition.
Retrieval is found; the applying date is that 1997.12.19, application number are that 97251313.2 Chinese patent discloses a kind of cable protective layer protector; it is made up of motor, contact chip, zinc oxide valve plate, adhesive glue, silicone rubber sleeve; described zinc oxide valve plate two sides contact by the end of contact chip with two electrodes; and by adhesive glue it is linked as an integral body, outside adhesive glue, is arranged with a silicone rubber sleeve.It is introduced that this protector structure is simple, processing and manufacturing is easy, and volume is little, and moulding process is good, and sealing, insulation property are good, and are reliable to the protective value of cable outer layer induction overvoltage, are suitable for using cable protective layer protector in power cable.But; from principle; this protector mainly is to carry out overvoltage protection by release current; and whether reduce circulating current; and it is in service at present high-tension cable; when this protector puts into operation at the 220KV cable, can not well play the sheath protective effect, still can cause metal sheath discharge over the ground (voltage even up to tens thousand of volts).
Summary of the invention
The technical problem that will solve of the present utility model is: at the shortcoming of above prior art existence; a kind of cable sheath overvoltage compensation protective device of cost economy is proposed; this device should compensate the not cable sheath overvoltage of isometric generation of three sections cables; thereby reduce sheath induced voltage and circulation greatly; improve the ampacity of cable, prolong the useful life of cable.
Theory analysis shows that induced voltage is directly proportional with the product of cable length and core electric current in the cable metal sheath.Under the bigger situation in the length of cable and core cross section, especially when system is short-circuited accident, induced voltage will reach the numerical value of harm personal safety, even cause the interruption of service of cable.Safety when contacting in order to ensure on duty and maintainer, regulation in " GB50217-94 ", induced voltage must not surpass 50V on the metal sheath.
In order to solve above technical problem; cable sheath overvoltage compensation protective device of the present utility model comprises threephase cable; the interconnected ground connection of sheath three-phase of described threephase cable one end is characterized in that: the sheath of the described threephase cable other end is by compensating inductance ground connection.
Like this, as long as according to factors such as the form of laying of threephase cable and differences in length, choose suitable compensating inductance, can make the inductance of cable identical as far as possible, three-phase voltage is balance as far as possible also.As a result, the circulation in the cable sheath will reduce greatly.Because the relative cable of cost of inductance is wanted considerably cheaper, nor is subjected to the restriction of laid condition, therefore adopt the utility model cost economy, practical.
Description of drawings
Below in conjunction with accompanying drawing the utility model is further described.
Fig. 1 is existing cable sheath transposition syndeton schematic diagram.
Fig. 2 is the structural representation of the utility model embodiment one.
Embodiment
Embodiment one
The cable sheath overvoltage of present embodiment compensates protective device as shown in Figure 2, and A, B, C threephase cable are divided into three sections of I, II, III.The sheath of threephase cable initiating terminal is the interconnected ground connection of plain edition jointing box 1 place's three-phase, and the metal sheath of each section cable connects by insulation joint box 2,3 difference coordinated transpositions at two exchange point places afterwards.If three sections cables are isometric, after the employing coordinated transposition, no matter adopt which kind of system of laying, the induced voltage on the three-phase sheath all equates.If three sections cables are not isometric, the numerical value of induced voltage has reduced after the coordinated transposition though adopt, and the induced voltage of three-phase is unequal, then can cause electric current and produce loss in sheath, reduces the transmission capacity of cable.For this reason, the 3rd section cable sheath passes through compensating inductance ground connection respectively at plain edition jointing box 4 places of terminal.
Like this, even when renovation of power lines exploitation, the 3rd segment length during less than raw footage, compensate as long as connect suitable inductance on the 3rd section cable sheath, just can make the inductance of three sections cables identical as far as possible, three-phase voltage is balance as far as possible also.As a result, the circulation in the cable sheath will reduce greatly.Because cheap many of the relative cable of cost of inductance, nor be subjected to the restriction of laid condition, therefore than employing compensating cable or protector economy, make things convenient for manyly.
In addition to the implementation, the utility model can also have other execution modes.All employings are equal to the technical scheme of replacement or equivalent transformation formation, all drop on the protection range of the utility model requirement.
Claims (4)
1. a cable sheath overvoltage compensation protective device comprises threephase cable, and the interconnected ground connection of sheath three-phase of described threephase cable one end is characterized in that: the sheath of the described threephase cable other end is by compensating inductance ground connection.
2. according to the described cable sheath overvoltage compensation of claim 1 protective device, it is characterized in that: described threephase cable is divided into three sections, and the metal sheath of described each section cable is in the coordinated transposition connection respectively of the two exchange point places at middle part.
3. according to the described cable sheath overvoltage compensation of claim 2 protective device, it is characterized in that: the metal sheath of described each section cable connects by the insulation joint box coordinated transposition at the exchange point place.
4. according to claim 2 or 3 described cable sheath overvoltage compensation protective devices, it is characterized in that: the 3rd section cable sheath passes through compensating inductance ground connection respectively at terminal fitting box place.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420054395 CN2777820Y (en) | 2004-12-15 | 2004-12-15 | Overvoltage compensation protector for cable protecting layer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200420054395 CN2777820Y (en) | 2004-12-15 | 2004-12-15 | Overvoltage compensation protector for cable protecting layer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2777820Y true CN2777820Y (en) | 2006-05-03 |
Family
ID=36745194
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200420054395 Expired - Fee Related CN2777820Y (en) | 2004-12-15 | 2004-12-15 | Overvoltage compensation protector for cable protecting layer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2777820Y (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103698653A (en) * | 2013-12-30 | 2014-04-02 | 国家电网公司 | System and method for detecting earth fault of sheath of single-core power cable on basis of circulation measurement |
| CN103971859A (en) * | 2014-05-26 | 2014-08-06 | 国家电网公司 | Design method for cable sheath circulating-current compensation device |
| CN109449862A (en) * | 2018-12-03 | 2019-03-08 | 江苏神马电力股份有限公司 | Transmission line of electricity pipeline and gas-insulated lines |
| CN109449861A (en) * | 2018-12-03 | 2019-03-08 | 江苏神马电力股份有限公司 | Transmission line of electricity pipeline and gas-insulated lines |
-
2004
- 2004-12-15 CN CN 200420054395 patent/CN2777820Y/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103698653A (en) * | 2013-12-30 | 2014-04-02 | 国家电网公司 | System and method for detecting earth fault of sheath of single-core power cable on basis of circulation measurement |
| CN103698653B (en) * | 2013-12-30 | 2016-05-04 | 国家电网公司 | Single-core power cables sheath ground-fault detection system and the method measured based on circulation |
| CN103971859A (en) * | 2014-05-26 | 2014-08-06 | 国家电网公司 | Design method for cable sheath circulating-current compensation device |
| CN109449862A (en) * | 2018-12-03 | 2019-03-08 | 江苏神马电力股份有限公司 | Transmission line of electricity pipeline and gas-insulated lines |
| CN109449861A (en) * | 2018-12-03 | 2019-03-08 | 江苏神马电力股份有限公司 | Transmission line of electricity pipeline and gas-insulated lines |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8410883B2 (en) | High voltage dry-type reactor for a voltage source converter | |
| JP2001509958A (en) | Power transformer / inductor | |
| CN202221672U (en) | DC 110 kV cross-linked polyethylene insulation single-core overland cable | |
| CN102437544B (en) | Prefabricated connector of high-voltage direct-current cross-linked polyethylene cable | |
| EP1320859B1 (en) | Electric device | |
| CN102361322A (en) | Technology determination method for changing crosslinked polyethylene cable alternating current line into direct current operation | |
| Kottonau et al. | Opportunities for high-voltage AC superconducting cables as part of new long-distance transmission lines | |
| CN1279830A (en) | Power flow control | |
| CN2777820Y (en) | Overvoltage compensation protector for cable protecting layer | |
| CN202996412U (en) | Ultrahigh-voltage crosslinking polyethylene insulated flexible direct-current fiber composite submarine cable | |
| CN207124443U (en) | A kind of new energy taking device of transmission line of electricity | |
| CN201430401Y (en) | Position-changing and connection system for tower and ground wires | |
| CN1635585A (en) | Method for inhibiting induced current of power cable sheath | |
| CN102522831A (en) | Non-contact electric field type induction power access method and power access apparatus thereof | |
| CN201904597U (en) | Precast connector of high-voltage direct-current cross-linked polyethylene cable | |
| CN106026119B (en) | Over long distances, the reactive-load compensation method of more load bus wire electric power systems | |
| CN201430402Y (en) | Connection system for tower and ground wires | |
| CN101206934A (en) | Direct current high voltage cable special for dust filter | |
| CN206311655U (en) | A kind of high-tension cable shield circulating current monitoring and compensating device | |
| Huang et al. | A dynamic-inductive-compensation-based method for improving tap-off power from insulated ground wires of overhead high voltage transmission lines | |
| CN110310816A (en) | Single-phase series transformer and power flow control system | |
| CN2805030Y (en) | Concentric conductor type electric power cable | |
| CN218897086U (en) | 330KV long-distance line-changing quick power-transferring electric main wiring structure | |
| CN209929042U (en) | Waterproof and anti-corrosion medium-voltage power cable | |
| CN213752302U (en) | Low-voltage coil copper bar outgoing line structure of dry-type transformer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |