CN106771843A - A kind of fault travelling wave ranging method of single-core power cables - Google Patents
A kind of fault travelling wave ranging method of single-core power cables Download PDFInfo
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- CN106771843A CN106771843A CN201510808586.9A CN201510808586A CN106771843A CN 106771843 A CN106771843 A CN 106771843A CN 201510808586 A CN201510808586 A CN 201510808586A CN 106771843 A CN106771843 A CN 106771843A
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- core power
- power cables
- travelling wave
- fault
- transition joint
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/083—Locating faults in cables, transmission lines, or networks according to type of conductors in cables, e.g. underground
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
- G01R31/08—Locating faults in cables, transmission lines, or networks
- G01R31/081—Locating faults in cables, transmission lines, or networks according to type of conductors
- G01R31/085—Locating faults in cables, transmission lines, or networks according to type of conductors in power transmission or distribution lines, e.g. overhead
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Locating Faults (AREA)
Abstract
The present invention relates to a kind of fault travelling wave ranging method of single-core power cables, including：Traveling wave ranging device is linked into the single-core power cables；Eliminate the wave impedance change of the cross interconnected generation of the transition joint of the single-core power cables；Fault localization is carried out to the single-core power cables by the traveling wave ranging device.The metal sheath at the cross interconnected place of single-core power cables transition joint is accessed capacitor or is directly grounded by the present invention, the change of wave impedance herein can be substantially eliminated, travelling wave signal is eliminated in catadioptric herein, so that when fault travelling wave ranging is carried out, fault traveling wave signal can be transmitted completely, realize all fronts fault travelling wave ranging of single-core power cables.
Description
Technical field
The present invention relates to electric device maintenance technical field, more particularly, to a kind of single electric power electricity
The fault travelling wave ranging method of cable.
Background technology
With technological progress and the raising of power supply quality requirement, power cable is shared in power network
Ratio is increasing, and overhead transmission line is progressively replaced in the urban district in some cities, and to electricity high
Pressure grade development.With number of cables increase and run time extension, the hair of cable fault
Life is further frequent.How accurate, the rapid position of failure point for judging power cable is to repair in time
Power cable, the premise for improving power supply reliability.
The localization of fault of power cable, generally requiring carries out fault diagnosis, fault localization and essence
It is determined that three steps of point.Wherein, fault diagnosis can be carried out by high-potting；Pinpoint
It is general to use audio frequency or other frequency induction technologies.Fault localization is also named failure bigness scale, refer to
The one or both ends of cable use appropriate instrument, and test signal is applied to failure cable core,
Or on-line measurement, analysis fault message, trouble point to the distance of certain one end is primarily determined that, be
Pinpoint provides range information.The fault distance-finding method of power cable is a lot, can generally divide
It is traveling wave method and the class of impedance method two, according to cable running status, offline range finding and online is divided into again
Range finding.In order to correctly find power cable fault point as early as possible, the quantities such as ground excavation are reduced
And power off time, fault travelling wave ranging technology is widely applied.
Traveling wave method carries out electrical breakdown, disruptive discharge at measurement failure to cable fault using high voltage
Time of the electric pulse from trouble point to test point can calculate trouble point distance.Fault traveling wave is surveyed
Away from not influenceed by factors such as trouble point transition resistance, line constructions, and range accuracy is high, because
This has obtained more being widely applied.
Usual 35kV and following power cable and control communication cable use three cores or multicore (low
Piezoelectric forces cable increases the neutral conductor, protective wire etc. as four cores, five-core cable) structure, electricity
Core outside resultant magnetic field is weaker, can use magnetic protection material.Cable intermediate joint screen
Cover protective layer to be typically directly connected and earth-free, transition joint wave impedance is varied less, therefore,
Cable total length wave impedance is basically unchanged, and transition joint is non-to the catadioptric of fault localization travelling wave signal
It is often weak, the identification and judgement of signal are not influenceed.Travelling wave ranging method in three core above power cables and
It is widely used in control communication cable, and the cable that will damage of utilization is when running
Weak discharge signal, develop online range finding or cable early warning technology.
35kV and above power cable are general to use single electric power due to manufacture and construction reason
The power cable of cable, especially more than 110kV.For single-core power cables more long, it is
Insulation outer jacket is avoided to puncture, related regulatory requirements power cable lines more long, cable should
Be divided into 3 multiple section, metal sheath carried out in each transition joint it is cross interconnected, by protect
Shield device ground connection, to ensure metal sheath induced voltage no more than 50V, and reduces overvoltage injury.
According to analysis, after metal sheath is cross interconnected at single-core power cables transition joint, phase in theory
When the insulating barrier electric field in cable is connected with extraneous air electric field, cable wave impedance is in transition joint
It is very big that place becomes.Therefore, travelling wave signal is in the cross interconnected place's meeting of single-core power cables transition joint
The serious catadioptric of generation so that traditional travelling wave ranging technology occur serious erroneous judgement, cannot be smooth
Realize.Live practical experience shows, as viewed from test point, with cross interconnected transition joint
First transition joint of single-core power cables after trouble point, travelling wave ranging instrument can be judged as therefore
Barrier point position is first transition joint, and travelling wave ranging method is directed to single-core power cables actually
It is to be difficult practical application, including online and offline method.
The content of the invention
Based on above mentioned problem, the present invention provides a kind of fault travelling wave ranging side of single-core power cables
Method, capacitor or straight is accessed by the metal sheath at the cross interconnected place of single-core power cables transition joint
Ground connection, can substantially eliminate the change of wave impedance herein, eliminate travelling wave signal in folding herein
Reflection, so that when fault travelling wave ranging is carried out, fault traveling wave signal can be transmitted completely,
Realize all fronts fault travelling wave ranging of single-core power cables.
For achieving the above object, the present invention provides a kind of failed row of single-core power cables
Ripple distance-finding method, it is characterised in that including：
Traveling wave ranging device is linked into the single-core power cables；
Eliminate the wave impedance of the cross interconnected generation of the transition joint of the single-core power cables
Change；
Fault localization is carried out to the single-core power cables by the traveling wave ranging device.
Wherein, the cross interconnected generation of the transition joint for eliminating the single-core power cables
Wave impedance change, specifically include：
The metal sheath of the single-core power cables transition joint is directly grounded, by the list
Metal sheath at core power cable transition joint is by the first capacitor grounding or in the list
Connected between two sections of metal sheaths of the same phase of core power cable transition joint the second capacitor.
Wherein, the metal sheath of the single-core power cables transition joint is directly grounded, specifically
Including：
By the sheath protector short circuit grounding, the gold of the single-core power cables transition joint
Category sheath is directly grounded.
Wherein, by the metal sheath at the single-core power cables transition joint by the first electricity
Receptacle ground, specifically includes：The metal sheath of the single-core power cables transition joint and ground
Between connect first capacitor, by first capacitor with the sheath protector simultaneously
Connection ground.
Wherein, it is described the single-core power cables are carried out by the traveling wave ranging device
Fault detect, specifically includes：
Trouble point is carried out to the single-core power cables under high pressure to puncture；
The single-core power cables produce failure high-frequency impulse travelling wave signal；
Gather the high-frequency impulse travelling wave signal；
The positional information of the trouble point is detected according to the high-frequency impulse travelling wave signal.
The fault travelling wave ranging method of single-core power cables of the invention, based on travelling wave ranging
Principle, capacitor is accessed by the metal sheath at the cross interconnected place of single-core power cables transition joint
Or be directly grounded, the cross interconnected metal sheath for causing and the ground of short-circuit cable intermediate joint
Between electric field, can substantially eliminate the change of wave impedance herein, eliminate travelling wave signal herein
Catadioptric so that when fault travelling wave ranging is carried out, fault traveling wave signal can be complete
Line is transmitted, and realizes all fronts fault travelling wave ranging of single-core power cables.
Brief description of the drawings
The features and advantages of the present invention can be more clearly understood from by reference to accompanying drawing, accompanying drawing is to show
Meaning property and should not be construed as carrying out the present invention any limitation, in the accompanying drawings：
Fig. 1 shows the flow of the fault travelling wave ranging method of single-core power cables of the invention
Figure.
Fig. 2 shows the capacitor of the first embodiment of fault travelling wave ranging method of the invention
Connection diagram.
Fig. 3 shows the capacitor of the second embodiment of fault travelling wave ranging method of the invention
Connection diagram.
Specific embodiment
To make the purpose, technical scheme and advantage of the embodiment of the present invention clearer, below will knot
Close the embodiment of the present invention in accompanying drawing, the technical scheme in the embodiment of the present invention is carried out it is clear,
It is fully described by, it is clear that described embodiment is a part of embodiment of the invention, rather than
Whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not having
The every other embodiment obtained under the premise of creative work is made, protection of the present invention is belonged to
Scope.
Fig. 1 shows the flow of the fault travelling wave ranging method of single-core power cables of the invention
Figure.
Reference picture 1, a kind of fault travelling wave ranging method of single-core power cables of the invention, tool
Body includes step：
S1, traveling wave ranging device is linked into the single-core power cables；
S2, the ripple of the cross interconnected generation of the transition joint of the elimination single-core power cables
Impedance variations；
S3, failure survey is carried out to the single-core power cables by the traveling wave ranging device
Away from.
In embodiments of the invention, traveling wave ranging device can be using single-ended or both-end, online
Or offline, one or many pulse, DC pulse or AC sine wave or hybrid waveform voltage,
It is not particularly limited herein.
In addition, step S2, eliminate the single-core power cables transition joint it is cross interconnected
The wave impedance change of generation, specifically includes：
The metal sheath of the single-core power cables transition joint is directly grounded, by the list
Metal sheath at core power cable transition joint is by the first capacitor grounding or in the list
Connected between two sections of metal sheaths of the same phase of core power cable transition joint the second capacitor.
In the above method, by the metal sheath of the transition joint of single-core power cables directly or
Ground connection, can be with the cross interconnected metal sheath for causing of short-circuit cable intermediate joint and ground
Between electric field, can substantially eliminate the change of wave impedance herein, eliminate travelling wave signal herein
Catadioptric so that when fault travelling wave ranging is carried out, fault traveling wave signal can be complete
Line is transmitted.
Fault travelling wave ranging method of the invention is described in detail below by way of specific embodiment.
Fig. 2 shows the capacitor of the first embodiment of fault travelling wave ranging method of the invention
Connection diagram.
In one embodiment, as shown in Fig. 2 the metal of the transition joint of single-core power cables
Sheath is connected respectively to one end of sheath protector 20 by cross interconnected connecting line 10, and sheath is protected
The other end ground connection of device 20 is protected, and capacitor 30 is parallel-connected to sheath protector 20.
In above-described embodiment, the Capacity Selection of capacitor 30 is caused for travelling wave signal, impedance
Close to 0；For line-frequency induction voltage or test frequency voltage, such as wave of oscillation or frequency conversion is tested
Power supply, impedance is relatively large, to avoid influence cable normally operation or trystate.
Specifically, in cable wave impedance Zc=50 Ω, power frequency f0=50Hz and traveling wave lowest frequency
fwUnder the conditions of=10kHz, condenser capacity selection：
To traveling wave frequency impedance very little, i.e.,Such as take 0.05ZcThat is 2.5 Ω, then
Capacitor
For power frequency impedance, condenser impedance
Maximum capacitor electric current, calculates according to maximum induced voltage 50V
Capacitor for cable fault travelling wave signal impedance very little, and for power frequency component
Impedance is very big so that the wave impedance air part of transition joint is shorted, and wave impedance changes very
Small, hardly there is catadioptric and pass through in fault traveling wave signal.
Fig. 3 shows the capacitor of the second embodiment of fault travelling wave ranging method of the invention
Connection diagram.
In another embodiment, as shown in figure 3, the metal of single-core power cables transition joint
By being connected in series to capacitor 40 after cross interconnected connecting line 10, then capacitor 40 is connected to sheath
One end of sheath protector 20, the other end ground connection of sheath protector 20.
In above-described embodiment, similarly in cable wave impedance Zc=50 Ω, power frequency f0=50Hz and
Traveling wave lowest frequency fwUnder the conditions of=10kHz, condenser capacity selection：
To traveling wave frequency impedance very little, i.e.,Such as take 0.1ZcThat is 5 Ω, then electric capacity
Device
For power frequency impedance, condenser impedance
Maximum capacitor electric current, calculates according to maximum induced voltage 50V
Based on above-mentioned, capacitor in this implementation for cable fault travelling wave signal impedance very
It is small, and it is very big for the impedance of power frequency component so that the cross interconnected wave resistance of transition joint
Anti- to be shorted, wave impedance is varied less, and fault traveling wave signal can be passed through.
In yet another embodiment of the present invention, in step S2, single-core power cables are eliminated
The wave impedance change of the cross interconnected generation of transition joint, or：By single electricity
The metal sheath of the transition joint of power cable is directly grounded.
In the present embodiment, metal sheath is directly grounded equivalent to physically by metal sheath split-phase
Direct connection is grounded, and this kind of mode is more beneficial for traveling wave, but metal sheath is directly grounded in electricity
Cable can influence to be grounded the electric current of return wire when normally running, therefore the scheme of the present embodiment is applicable
Fault travelling wave ranging is carried out when having a power failure and testing.
In addition, step S3 of the invention can be in one embodiment：
Trouble point is carried out to the single-core power cables under high pressure to puncture；
The single-core power cables produce failure high-frequency impulse travelling wave signal；
Gather the high-frequency impulse travelling wave signal；
The positional information of the trouble point is detected according to the high-frequency impulse travelling wave signal.
But the travelling wave ranging method of step S3 of the invention is not limited to above-described embodiment,
Any suitable detailed process in travelling wave ranging method of the invention is applied to the present invention.
Fault travelling wave ranging method of the invention, the principle based on travelling wave ranging, by single electricity
The cross interconnected place's ground connection of metal sheath of power cable accesses capacitor, short-circuit cable intermediate joint
The cross interconnected metal sheath for causing and ground between electric field, substantially eliminate cable herein
Wave impedance changes, it is to avoid the catadioptric of fault traveling wave signal so that cable fault travelling wave signal
Transition joint can be passed through, such that it is able to realize the offline of single-core power cables failure or
Line travelling wave ranging.
Above specific embodiment be only used to illustrate specific implementation technical scheme of the invention rather than
Limitation, although being described in detail to the present invention with reference to example, those skilled in the art should
Work as understanding, technical scheme can be modified or equivalent, without deviating from
The spirit and scope of technical solution of the present invention, it all should cover in scope of the presently claimed invention
It is central.
Claims (5)
1. a kind of fault travelling wave ranging method of single-core power cables, it is characterised in that including：
Traveling wave ranging device is linked into the single-core power cables；
Eliminate the wave impedance of the cross interconnected generation of the transition joint of the single-core power cables
Change；
Fault localization is carried out to the single-core power cables by the traveling wave ranging device.
2. fault travelling wave ranging method according to claim 1, it is characterised in that institute
State the wave resistance resistance of the cross interconnected generation of the transition joint for eliminating the single-core power cables
Change, specifically include：
The metal sheath of the single-core power cables transition joint is directly grounded, by the list
Metal sheath at core power cable transition joint is by the first capacitor grounding or in the electricity
Connected between two sections of metal sheaths of the same phase of core power cable transition joint the second capacitor.
3. fault travelling wave ranging method according to claim 2, it is characterised in that institute
The metal sheath for stating single-core power cables transition joint is directly grounded, and specifically includes：
By the sheath protector short circuit grounding, the gold of the single-core power cables transition joint
Category sheath is directly grounded.
4. fault travelling wave ranging method according to claim 2, it is characterised in that will
Metal sheath at the single-core power cables transition joint is by the first capacitor grounding, tool
Body includes：Connected between the metal sheath and ground of the single-core power cables transition joint described
First capacitor, by first capacitor and the sheath protector earth.
5. the fault travelling wave ranging method according to claim any one of 1-4, its feature
It is, it is described that failure is carried out to the single-core power cables by the traveling wave ranging device
Detection, specifically includes：
Trouble point is carried out to the single-core power cables under high pressure to puncture；
The single-core power cables produce failure high-frequency impulse travelling wave signal；
Gather the high-frequency impulse travelling wave signal；
The positional information of the trouble point is detected according to the high-frequency impulse travelling wave signal.
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| CN201510808586.9A CN106771843B (en) | 2015-11-19 | 2015-11-19 | Fault traveling wave distance measurement method for single-core power cable |
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| CN201510808586.9A CN106771843B (en) | 2015-11-19 | 2015-11-19 | Fault traveling wave distance measurement method for single-core power cable |
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Cited By (4)
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| CN108896874A (en) * | 2018-07-10 | 2018-11-27 | 中国矿业大学 | A kind of fault positioning method for transmission line of end connection short-term road |
| CN110275125A (en) * | 2019-06-18 | 2019-09-24 | 中国电力科学研究院有限公司 | A kind of system and method for calibrating impact current for measuring device dynamic characteristic |
| CN110895299A (en) * | 2018-09-12 | 2020-03-20 | 中国石油化工股份有限公司 | Power cable ranging identification method |
| CN112363008A (en) * | 2020-09-17 | 2021-02-12 | 广州长川科技有限公司 | Cable fault and running state comprehensive monitoring method and system |
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| CN110895299A (en) * | 2018-09-12 | 2020-03-20 | 中国石油化工股份有限公司 | Power cable ranging identification method |
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| CN112363008A (en) * | 2020-09-17 | 2021-02-12 | 广州长川科技有限公司 | Cable fault and running state comprehensive monitoring method and system |
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| Publication number | Publication date |
|---|---|
| CN106771843B (en) | 2020-02-14 |
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