CN109596952A - A kind of cable partial discharge source localization method and system based on active synchronization - Google Patents
A kind of cable partial discharge source localization method and system based on active synchronization Download PDFInfo
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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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
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- Locating Faults (AREA)
- Testing Relating To Insulation (AREA)
Abstract
The invention discloses a kind of cable partial discharge source localization method and system based on active synchronization, this method following steps: endless metal pole plate tectonic coupling capacitor is wrapped up on cable jacket, and distinguishes housing shielding magnet ring at the both ends of cable range to be detected to construct traveling wave boundary；High-frequency impulse is injected as synchronization signal to cable shield by coupled capacitor in one end of cable range to be detected；Partial discharge pulse signal and synchronization signal are extracted respectively at the both ends of cable range to be detected；And the both ends based on cable range to be detected partial discharge pulse and the lock-out pulse time difference to cable partial discharge source carry out location Calculation.The present invention constructs coupled capacitor using external ring-shaped metal polar plate, solve the problems, such as that synchronization pulse injects, partial discharge source is completed using the time difference of synchronization signal and cable partial discharge pulse to position, with traditional satellite time transfer compared with synchronous, the optical fiber method of synchronization, implementation is upper more convenient at the scene, essentially eliminates time synchronization bring extra error.
Description
Technical field
The present invention relates to cable local discharge detection field more particularly to a kind of cable partial discharge source based on active synchronization are fixed
Position each cable partial discharge source positioning system of method.
Background technique
Cable is influenced in longtime running by electricity, heat, stress, and the improper operation in construction, installation process, is had
It may cause cable body, the insulation defect of part occurs in attachment, generation shelf depreciation (referred to as partial discharge).With cable part
Electric discharge continues, and local defect eventually develops as the whole breakdown of insulation.
Currently, research unit has carried out a large amount of cable local discharge detection/study on monitoring both at home and abroad, and achieve more
Achievement.The authoritative institutions such as IEEE all think that partial discharge measurement is to assess the effective means of cable insulation status, can more comprehensive
Reflect cable insulation status.Opposite partial discharge detection/the study of the monitoring method, the research of partial discharge source positioning is still in its infancy.?
In actual production, after detecting that cable local discharge is out-of-limit, needs to find partial discharge source and rechecked, taken a long time, scene
Person works' amount is big.Site workload can be reduced by the positioning of partial discharge source, reduces external influences.Existing partial discharge source positioning side
Method includes:
(1) single-ended method: by calculating partial discharge pulse first arrival time and cable opposite end reflection wave signal reaching time-difference,
It is positioned in conjunction with velocity of wave is propagated, this is the localization method being most widely used at present.Single-ended method main problem is to be difficult to answer
For long distance line, and due to the decaying and wave distortion during high frequency signal transmission, reflected wave identification difficulty is big, reliably
Property is relatively low.
(2) both-end method: reaching the time difference of cable ends by calculating partial discharge pulse signal, in conjunction with cable length, propagates
Velocity of wave etc. is positioned.Both-end method only needs identification inceptive impulse signal, and principle is simple and reliable, but both-end method needs the height of cable ends
The time synchronization of precision determines that partial discharge pulse reaches the absolute time of cable ends.
(3) it amplitude-frequency method: is declined by information, the amplitudes for analyzing signal such as amplitude, the frequency bands of comparison cable ends partial discharge pulse
Subtract and judges partial discharge source position.The calculating of amplitude-frequency method is not influenced by time synchronization, velocity of wave, but amplitude-frequency method can only calculate rough partial discharge source
Position, precision are not able to satisfy field demand, use generally as supplementary means cooperation both-end method.
Develop in terms of angle from technology, both-end method is the trend of technology development since positioning accuracy is high, principle is reliable.But often
Following problems are faced in being applied at the scene with method for synchronizing time:
(1) satellite (GPS/BD) time service is synchronous, and satellite time transfer needs external antenna, for being frequently mounted on tunnel/cable
For cable partial discharge monitoring device in ditch, antenna is laid with more difficult.In addition, existing GPS/BD time service precision generally exists
10ns rank cannot fully meet cable partial discharge source positioning requirements.
(2) optical fiber synchronization accuracy is higher, can achieve 1ns rank, but optical fiber synchronizes and needs long range optical cable, field conduct
It is more difficult, and price is more expensive.
Summary of the invention
For the above problem existing for both-end method, the purpose of the present invention is to provide a kind of cable office based on active synchronization
Source localization method is put, based on the method for synchronization of active Injection Signal, for solving the problems, such as the time service in the positioning of cable partial discharge source.
The object of the invention is also to provide a kind of cable partial discharge source localization method based on active synchronization, based on actively infusing
The method of synchronization for entering signal, for solving the problems, such as the time service in the positioning of cable partial discharge source.
For this purpose, one aspect of the present invention provides a kind of cable partial discharge source localization method based on active synchronization, including following
Step: S10: endless metal pole plate tectonic coupling capacitor is wrapped up on cable jacket, and the two of cable range to be detected
Housing shields magnet ring to construct traveling wave boundary respectively at end；S20: one end of cable range to be detected by the coupled capacitor to
Cable shield injects high-frequency impulse as synchronization signal；S30: partial discharge pulse is extracted respectively at the both ends of cable range to be detected
Signal and synchronization signal；And S40, the partial discharge pulse at both ends based on cable range to be detected and lock-out pulse time difference are to electricity
Cable partial discharge source carries out location Calculation.
According to another aspect of the present invention, a kind of cable partial discharge source positioning system based on active synchronization is provided, comprising:
Magnet ring is shielded, for constructing traveling wave boundary at the both ends of cable range to be detected；Endless metal pole plate, in detection cable range
One end and cable shield tectonic coupling capacitor；High frequency pulse generator, for by the coupled capacitor to the cable screens
Layer injection high-frequency impulse is covered as synchronization signal；The both ends of cable range to be detected are arranged in partial discharge sensor, are used for detection office
Put pulse signal and synchronization signal；And partial discharge detection device, the partial discharge at the both ends for extracting cable range to be detected respectively
Pulse signal and synchronization signal, and the both ends based on cable range to be detected partial discharge pulse and the lock-out pulse time difference to electricity
Cable partial discharge source carries out location Calculation.
Cable partial discharge source localization method according to the present invention based on active synchronization utilizes external ring-shaped metal polar plate structure
Coupled capacitor is built, solves the problems, such as that synchronization pulse injects, utilizes the time difference completion office of synchronization signal and cable partial discharge pulse
Put source positioning.The more traditional satellite time transfer synchronization of the method for the invention, the optical fiber method of synchronization, it is more square in implementation at the scene
Just, time synchronization bring extra error is essentially eliminated.
Other than objects, features and advantages described above, there are also other objects, features and advantages by the present invention.
Below with reference to figure, the present invention is described in further detail.
Detailed description of the invention
The accompanying drawings constituting a part of this application is used to provide further understanding of the present invention, and of the invention shows
Examples and descriptions thereof are used to explain the present invention for meaning property, does not constitute improper limitations of the present invention.In the accompanying drawings:
Fig. 1 is coupled capacitor and traveling wave Boundary Principle figure in the localization method of cable partial discharge source according to the present invention；
Fig. 2 is the active synchronization method schematic diagram in the localization method of cable partial discharge source according to the present invention, wherein (a)；
Fig. 3 a and Fig. 3 b are the partial discharge source positioning schematics in the localization method of cable partial discharge source according to the present invention, wherein
Fig. 3 a is the schematic diagram for injecting end signal, and Fig. 3 b is schematic diagram of the route to end signal；
Fig. 4 is the flow chart of cable partial discharge source according to an embodiment of the invention localization method；And
Fig. 5 is the flow chart of cable partial discharge source according to another embodiment of the present invention localization method.
Specific embodiment
It should be noted that in the absence of conflict, the features in the embodiments and the embodiments of the present application can phase
Mutually combination.The present invention will be described in detail below with reference to the accompanying drawings and embodiments.
Two end device synchronous method in the positioning of existing cable partial discharge source are: satellite synchronization is synchronous with optical fiber, both sides
Formula field conduct difficulty is big, and the cost is relatively high.In view of the above-mentioned problems, the invention proposes the synchronization signals of tectonic coupling capacitor
Injection mode, compared with inductive coupling mode.Synchronization signal is injected by coupled capacitor mode, signal decaying is small, is suitable for
Partial Discharge Detection based on capacitance type transducers/monitoring system.
The cable partial discharge source positioning system based on active synchronization that the invention proposes a kind of, as shown in Figure 1, by with lower module
Constitute: coupled capacitor 60, shielding magnet ring 20, partial discharge sensor 30 and partial discharge detection/monitoring device 40, high-frequency impulse occur
Device 50.
In Fig. 1, the construction of cable is as follows, from the inside to the outside successively are as follows: cable core 11, cable major insulation 12, cable screens
Cover layer 13 and cable jacket 14.
Shielding magnet ring 20 is used to form traveling wave boundary, and high frequency pulse generator 50 is used to generate high-frequency pulse signal, and
Cable shield 13 is injected by coupled capacitor.
The invention proposes a kind of cable partial discharge source localization method based on active synchronization method, as shown in figure 4, including following
Step:
Step S10: tectonic coupling capacitor and traveling wave boundary.
Reference carrier communication, high frequency electrocardiography mode have: inductive coupling and capacitive coupling.Inductive coupling passes through coil
Electromagnetic induction effect needs primary and secondary coil magnetic conductivity higher, and cable shield is difficult to meet above-mentioned want as secondary coil
It asks, Injection Signal decaying is more serious, is not also suitable for the partial discharge monitoring system based on capacitance sensor.Therefore, institute of the present invention
Method is stated using capacitive coupling injection high-frequency signal as synchronization signal.
Step S10 specifically includes two links:
1) endless metal pole plate (copper or aluminium) is wrapped up on cable jacket, to increase coupling capacitance, metal polar plate is answered
It is tightly attached on oversheath；To avoid metal polar plate damp failure, waterproof layer is covered with outside metal polar plate.As shown in Figure 1, annular
Metal polar plate 61, cable jacket 14, cable shield 13 constitute a coupled capacitor, the coupling capacitance and cable
Diameter, pole plate length are related.By taking typical XLPE single-core cable as an example, when outside diameter of cable 50mm, metal polar plate length 1m, coupled capacitor
Value is about 20pF.
2) traveling wave boundary is constructed in cable two sides housing shielding magnet ring.As shown in Figure 1, for high-frequency signal (traveling wave), by
A traveling wave boundary is formed compared with higher position in ring inductance value.The voltage traveling wave signal boundary of high frequency can be totally reflected, enhancing
Synchronization signal and partial discharge pulse's signal amplitude improve the sensitivity of partial discharge pulse detection；Meanwhile the synchronization signal of injection
It is enclosed in cable range to be detected.
Step S20: injection high-frequency impulse is as synchronization signal.
High-frequency pulse signal is generated using impulse generator, which injects cable shield, and edge by coupled capacitor
Cable shield is transferred to cable opposite end.Comprehensive coupling capacitance, partial discharge pulse signal width, sensor bandwidth, and it is synchronous
Attenuation characteristic of the signal in cable shield, Injection Signal have the following characteristics that
1) signal frequency should be between 10MHz~20MHz, i.e. rising edge 0.1us~0.05us, and pulse signal pulsewidth should not be big
In 0.2us；
2) signal amplitude is about in 20V or so, slightly larger than the amplitude of typical local discharge signal；
3) signal injected frequency answers 10ms primary, and the Injection Signal moment should control near 90 ° of positions of power-frequency voltage.
Step S30: partial discharge pulse signal and synchronization signal are extracted.
The present invention extracts partial discharge pulse signal and synchronization signal using common time frequency analysis means-multi-scale wavelet transformation.
Since multiple partial discharge pulse can be generated in a frequency cycle.To guarantee in the positioning of partial discharge source, cable two
End is to reduce influence of the multiple partial discharge pulse signal to positioning based on same pulse signal.When location Calculation, partial discharge pulse signal
Only extract the partial discharge pulse signal of amplitude maximum in the 10us of synchronization signal front and back.
Step S40: based on partial discharge pulse and lock-out pulse time difference to cable partial discharge source location Calculation.
The absolute moment that traditional both-end method is authorized using satellite or optical fiber is as time tag.The method of the invention principle
As shown in Fig. 2, the synchronization signal of injection can synchronize two end devices as time tag.
Partial discharge pulse collected for cable ends, lock-out pulse, as shown in Fig. 3 (a)/(b).Assuming that Injection Signal
End, synchronization signal and partial discharge time pulse signal difference are Δ t1, and cable opposite end synchronization signal is with partial discharge time pulse signal difference
Δ t2, then partial discharge source ranging formula is as follows:
L1=(Δ t2-Δ t1) × v/2-------------------------- (1)
Wherein, L1 is the distance of partial discharge source distance signal injection end, and v is partial discharge pulse, the biography of synchronization signal in the cable
Broadcast speed.
Wherein, the L1 repeatedly obtained after measurement can average.
As shown in figure 5, in an alternative embodiment of the invention, the cable partial discharge source localization method based on active synchronization further includes
Step S50: cluster operation improves positioning accuracy and reliability.
Since cable partial discharge can occur repeatedly in a power frequency period, by repeatedly measuring using clustering method
The precision and reliability of positioning can be improved.
Compared with the localization method of existing partial discharge source, localization method proposed by the invention is had the advantage that
(1) field application limitation is few.The method of the invention utilizes cable shield without installing antenna or being laid with optical fiber
Synchronization signal is injected as transmission medium, field application limitation is few.
(2) time service precision is high.Relative to satellite time transfer, optical fiber time service mode, methods described herein only need to utilize cable two
The positioning of partial discharge source can be completed in end synchronization signal and partial discharge pulse arrival time difference, will not theoretically cause because of time service precision problem
Additional position error.
The foregoing is only a preferred embodiment of the present invention, is not intended to restrict the invention, for the skill of this field
For art personnel, the invention may be variously modified and varied.All within the spirits and principles of the present invention, made any to repair
Change, equivalent replacement, improvement etc., should all be included in the protection scope of the present invention.
Claims (6)
1. a kind of cable partial discharge source localization method based on active synchronization, which comprises the following steps:
S10: endless metal pole plate tectonic coupling capacitor is wrapped up on cable jacket, and at the both ends of cable range to be detected
Housing shields magnet ring to construct traveling wave boundary respectively；
S20: high-frequency impulse is injected as same to cable shield by the coupled capacitor in one end of cable range to be detected
Walk signal；
S30: partial discharge pulse signal and synchronization signal are extracted respectively at the both ends of cable range to be detected；And
S40, the partial discharge pulse at both ends based on cable range to be detected and lock-out pulse time difference determine cable partial discharge source
Position calculates.
2. the cable partial discharge source localization method according to claim 1 based on active synchronization, which is characterized in that pass through,
In, the endless metal pole plate should be tightly attached on oversheath, to avoid metal polar plate damp failure, be covered with outside metal polar plate
Waterproof layer.
3. the cable partial discharge source localization method according to claim 1 based on active synchronization, which is characterized in that be detected
High-frequency impulse is injected by the coupled capacitor by high frequency pulse generator, as synchronization signal in one end of cable range.
4. the cable partial discharge source localization method according to claim 1 based on active synchronization, which is characterized in that pass through more rulers
It spends wavelet transformation and extracts partial discharge pulse signal and synchronization signal.
5. the cable partial discharge source localization method according to claim 1 based on active synchronization, which is characterized in that cable partial discharge
The location Calculation formula in source is as follows:
L1=(Δ t2-Δ t1) × v/2-------------------------- (1)
Wherein, L1 is the distance of partial discharge source distance signal injection end, and v is the propagation speed of partial discharge pulse, synchronization signal in the cable
Degree, Δ t1 is poor for the synchronization signal and partial discharge time pulse signal at Injection Signal end, and Δ t2 is cable opposite end synchronization signal and office
It is poor to put time pulse signal.
6. a kind of cable partial discharge source positioning system based on active synchronization characterized by comprising
Magnet ring is shielded, for constructing traveling wave boundary at the both ends of cable range to be detected；
Endless metal pole plate, one end and cable shield tectonic coupling capacitor in detection cable range；
High frequency pulse generator, for injecting high-frequency impulse as synchronous letter to the cable shield by the coupled capacitor
Number；
The both ends of cable range to be detected are arranged in partial discharge sensor, for detecting partial discharge pulse signal and synchronization signal；And
Partial discharge detection device, for extracting the partial discharge pulse signal and synchronization signal at the both ends of cable range to be detected respectively, and
And the both ends based on cable range to be detected partial discharge pulse and the lock-out pulse time difference to cable partial discharge source carry out location Calculation.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110456166A (en) * | 2019-08-22 | 2019-11-15 | 北京大泽科技有限公司 | A method of measurement inhibits the rejection characteristic of network |
| CN110726906A (en) * | 2019-10-15 | 2020-01-24 | 武汉三相电力科技有限公司 | Method and system for detecting cable length |
| CN114814492A (en) * | 2022-04-22 | 2022-07-29 | 华北电力大学 | Cable partial discharge source double-end positioning method based on relation between signal pulse width and propagation distance |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002048836A (en) * | 2000-08-04 | 2002-02-15 | Hitachi Cable Ltd | Method of detecting partial discharge in power cable |
| CN103558514A (en) * | 2013-10-10 | 2014-02-05 | 广东电网公司惠州供电局 | Double-end cable oscillatory wave partial discharge locating system and method based on pulse injection |
| CN105004973A (en) * | 2015-07-10 | 2015-10-28 | 陕西省地方电力（集团）有限公司 | Dual-end measured overhead insulating wire local discharge positioning system and method |
| CN105988066A (en) * | 2015-02-09 | 2016-10-05 | 华北电力大学（保定） | Double-end partial discharging positioning method of long-distance cable based on correction pulses |
| CN106556782A (en) * | 2016-11-17 | 2017-04-05 | 中国电力科学研究院 | A kind of Partial Discharge Sources location determining method and system |
-
2018
- 2018-12-19 CN CN201811557067.XA patent/CN109596952A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002048836A (en) * | 2000-08-04 | 2002-02-15 | Hitachi Cable Ltd | Method of detecting partial discharge in power cable |
| CN103558514A (en) * | 2013-10-10 | 2014-02-05 | 广东电网公司惠州供电局 | Double-end cable oscillatory wave partial discharge locating system and method based on pulse injection |
| CN105988066A (en) * | 2015-02-09 | 2016-10-05 | 华北电力大学（保定） | Double-end partial discharging positioning method of long-distance cable based on correction pulses |
| CN105004973A (en) * | 2015-07-10 | 2015-10-28 | 陕西省地方电力（集团）有限公司 | Dual-end measured overhead insulating wire local discharge positioning system and method |
| CN106556782A (en) * | 2016-11-17 | 2017-04-05 | 中国电力科学研究院 | A kind of Partial Discharge Sources location determining method and system |
Non-Patent Citations (3)
| Title |
|---|
| 杜言: "交联聚乙烯电缆局部放电在线监测及定位研究", 《中国优秀博硕士学位论文全文数据库（硕士）工程科技II辑》 * |
| 沙占友等: "《特种集成电源设计与应用》", 31 January 2007 * |
| 谭志良等: "《电磁脉冲防护理论与技术》", 31 May 2013 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110456166A (en) * | 2019-08-22 | 2019-11-15 | 北京大泽科技有限公司 | A method of measurement inhibits the rejection characteristic of network |
| CN110456166B (en) * | 2019-08-22 | 2021-08-24 | 北京大泽科技有限公司 | Method for measuring inhibition characteristic of inhibition network |
| CN110726906A (en) * | 2019-10-15 | 2020-01-24 | 武汉三相电力科技有限公司 | Method and system for detecting cable length |
| CN110726906B (en) * | 2019-10-15 | 2022-03-15 | 武汉三相电力科技有限公司 | Method and system for detecting cable length |
| CN114814492A (en) * | 2022-04-22 | 2022-07-29 | 华北电力大学 | Cable partial discharge source double-end positioning method based on relation between signal pulse width and propagation distance |
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Application publication date: 20190409 |