CN104459486A - Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current - Google Patents
Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current Download PDFInfo
- Publication number
- CN104459486A CN104459486A CN201410691172.8A CN201410691172A CN104459486A CN 104459486 A CN104459486 A CN 104459486A CN 201410691172 A CN201410691172 A CN 201410691172A CN 104459486 A CN104459486 A CN 104459486A
- Authority
- CN
- China
- Prior art keywords
- cable
- polarization current
- voltage
- crosslinked polyethylene
- sample
- 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
Abstract
A method for evaluating insulation of a crosslinked polyethylene medium-voltage cable through polarization current includes the following steps that S1, a high-voltage end and a low-voltage end of a direct current high voltage power source (10) are directly connected with a cable core and a metal shielding layer of a crosslinked polyethylene medium-voltage cable sample (11) respectively, voltage -1kV is output, and cable polarization current is generated, wherein the sample comprises a new product and various cables at different aging degrees; S2, a weak current detection meter (12) is connected with a loop voltage end to detect the polarization current of the cable sample, the polarization current is transmitted, and polarization current data are stored through a computer (13) in real time; S3, fitting is carried out on the polarization current through an expansion Debye model to obtain model parameters, dielectric loss spectrums at the lower frequency of 0.001-0.05 Hz are obtained through Fourier transform, and the relative aging degree is evaluated by comparing the dielectric loss spectrums of the different cables. The method for evaluating insulation of the crosslinked polyethylene medium-voltage cable through the polarization current is simple and convenient in test process, free of damage and sensitive in response to partial serious defects, the overall aging degree of the XLPE cable is evaluated on the basis of the ageing mechanism, and the result is more persuasive.
Description
Technical field
The present invention relates to a kind of method assessing the insulation of crosslinked polyethylene midium voltage cable, especially relate to a kind of method utilizing polarization current to assess the insulation of crosslinked polyethylene midium voltage cable.
Background technology
The structure of crosslinked polyethylene (XLPE) power cable from inner be outwards core, inner semiconductor layer, XLPE insulation course, outer semiconductor layer, metal screen layer and oversheath, the advantages such as this kind of cable relies on the thermal conductance of its excellence, machinery and electric property and easy installation and maintenance, dielectric loss low, are widely used in urban power distribution network.In cable operational process, can form water tree under the acting in conjunction of moisture and electric field, water tree can further develop becomes electric branch, and this can make insulating performance of cable decline, and makes insulation breakdown sometimes, causes cable fault.Therefore need to find the on-site diagnosis method of cable insulation, the insulation status of assessment cable.
For cable insulation degradation detecting method, off-line checking method, live detection method and online test method can be divided into according to the running status residing for cable during test.The method of on-line checkingi is comparatively ripe, but owing to being subject to the interference of on-the-spot rugged surroundings and working voltage, making monitoring result accuracy not enough, be difficult to promote in electric system; Live detection method is the measurement carried out under the state do not had a power failure in system, more effectively can get rid of the interference of environment, but live detection method only rests on the stage of " pinpointing the problems ", cannot carry out quantification judge cable degree of aging.
Summary of the invention
Technical matters to be solved by this invention, is just to provide a kind of method utilizing polarization current to assess the insulation of crosslinked polyethylene midium voltage cable, and its accuracy in detection is high and can carry out quantifications judgement to cable degree of aging.
Solve the problems of the technologies described above, the technical solution used in the present invention is as follows:
Utilize polarization current to assess a method for crosslinked polyethylene midium voltage cable insulation, it is characterized in that comprising the following steps:
S1, by the high-pressure side of a DC high-voltage power supply 10 and low pressure end, is directly connected with metal screen layer with the core of described crosslinked polyethylene midium voltage cable sample 11 respectively, output voltage-1kV, produces cable polarization current;
Described sample comprises new product cable and various different degree of aging cable;
S2, utilizes weak current meter 12 to be connected to the polarization current of detection streamer sample 11 on loop voltage end, is sent to and preserves polarization current data in real time by computer 13;
S3, utilize expansion Debye model to carry out matching to polarization current and obtain model parameter, dielectric loss spectrum under utilizing Fourier transform to obtain 0.001 ~ 0.5Hz low frequency, by contrasting the dielectric loss spectrum of different cable, assesses the relative degree of aging of different cable.(this step is prior art)
This appraisal procedure, just for distinguishing the relative degree of aging between cable, still can not carry out residual life evaluation.
Beneficial effect: polarization current method of the present invention is a kind of XLPE cable insulation ag(e)ing appraisal procedure of off-line, concrete testing process applies DC voltage between cable core and metal screen layer, measure the polarization current of crosslinked polyethylene midium voltage cable in pressure process, theoretical according to cable extension Debye model, by analyzing the polarization current of the crosslinking polyethylene-insulated cable insulation of different digestion time, under being converted to low frequency, dielectric dissipation factor is composed, the insulation water-treeing state of assessment crosslinked polyethylene midium voltage cable.This law testing process is easy, and without destructive, sensitive to the reflection of local major defect, assess the overall degree of aging of XLPE cable agine mechaism, result has more cogency.
Accompanying drawing explanation
Fig. 1 is the method wiring schematic diagram utilizing polarization current to assess the insulation of crosslinked polyethylene midium voltage cable of the present invention;
Fig. 2 is the circuit diagram of the cable extension Debye model that the embodiment of the present invention provides;
Fig. 3 is the dielectric loss frequency spectrum of the aging front and back twisted polyethylene cable sample that the embodiment of the present invention provides.
Embodiment
Below in conjunction with drawings and Examples, the present invention is further elaborated.
The embodiment of the method utilizing polarization current method to assess the insulation of crosslinked polyethylene midium voltage cable of the present invention, comprises the following steps:
S1, by the high-pressure side of a DC high-voltage power supply 10 (being more than or equal to 1000V) and low pressure end, is directly connected with metal screen layer with the core of described crosslinked polyethylene midium voltage cable sample 11 respectively, produces cable polarization current;
Described sample comprises new product cable and various different degree of aging cable; S2, on the low pressure end utilizing weak current meter 12 to be connected to loop, the polarization current of detection streamer sample 11, is sent to and preserves polarization current data in real time by computer 13;
S3, utilizes expansion Debye model to carry out matching to polarization current and obtains model parameter, and the dielectric loss spectrum under utilizing Fourier transform to obtain low frequency, by contrasting the dielectric loss spectrum of different cable, assesses its ageing state.
In embodiments of the present invention, as Fig. 1 carries out polarization current measurement to new cable and aging cable sample.
The high-voltage output end of DC high-voltage power supply 10 is used for being connected with the core of cable sample 11, output voltage is-1kV, for generation of cable polarization current, low pressure end is directly connected with the metal screen layer of cable sample 11, simultaneously, utilize the polarization current of weak current meter 12 detection streamer sample 11, and preserve polarization current data in real time by computer 13.
In embodiments of the present invention, cable extension Debye model as shown in Figure 2, carries out matching to polarization current and obtains the resistance (R expanded in Debye model
i) and electric capacity (C
i) parameter, utilize Fourier transform calculate obtain different digestion time cable sample at low frequency (0.001 ~ 0.5Hz) loss factor spectrum, as shown in formula (1).
In formula: tan δ is loss factor; ω is angular frequency; R
0it is the bulk resistor of cable insulation; C
0it is the body capacitance of cable insulation; Different R
i-C
i(i=1,2,3 ..., be n) parameter that represent not same polarization branch road, characterize different aging mechanism.The aging meeting of cable causes the change of partial branch parameter, affects tested polarization current, causes the change of loss factor under different frequency.
Fig. 3 is that the Frequency Power Loss factor of new cable sample and aging cable sample is composed, as can be seen from the figure, along with the increase of digestion time, the integrated curved of loss factor spectrum obviously rises, and the loss factor spectrum therefore under low frequency can be used for the degree of aging characterizing twisted polyethylene cable.
Claims (1)
1. utilize polarization current to assess a method for crosslinked polyethylene midium voltage cable insulation, it is characterized in that comprising the following steps:
S1, by the high-pressure side of a DC high-voltage power supply (10) and low pressure end, is directly connected with metal screen layer with the core of described crosslinked polyethylene midium voltage cable sample (11) respectively, output voltage-1kV, produces cable polarization current;
Described sample comprises new product cable and various different degree of aging cable;
S2, utilizes weak current meter (12) to be connected to the polarization current of detection streamer sample (11) on loop voltage end, is sent to and preserves polarization current data in real time by computer (13);
S3, utilizes expansion Debye model to carry out matching to polarization current and obtains model parameter, and the dielectric loss spectrum under utilizing Fourier transform to obtain 0.001 ~ 0.5Hz low frequency, by contrasting the dielectric loss spectrum of different cable, assesses relative degree of aging.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410691172.8A CN104459486A (en) | 2014-11-25 | 2014-11-25 | Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201410691172.8A CN104459486A (en) | 2014-11-25 | 2014-11-25 | Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN104459486A true CN104459486A (en) | 2015-03-25 |
Family
ID=52905848
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201410691172.8A Pending CN104459486A (en) | 2014-11-25 | 2014-11-25 | Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN104459486A (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104865500A (en) * | 2015-05-22 | 2015-08-26 | 华南理工大学 | High voltage cable outer sheath differentiation insulation defect evaluation method |
| CN105467190A (en) * | 2015-11-13 | 2016-04-06 | 华中科技大学 | Measuring method of XLPE cable polarized-depolarized currents |
| CN106324454A (en) * | 2016-08-17 | 2017-01-11 | 华中科技大学 | XLPE cable insulation detection device and anti-electromagnetic interference method thereof |
| CN106841935A (en) * | 2015-12-04 | 2017-06-13 | 核动力运行研究所 | For the Time-Domain Measuring System and appraisal procedure of the assessment of dielectric ageing state |
| CN108627747A (en) * | 2018-08-23 | 2018-10-09 | 武汉脉源电气有限公司 | A kind of diagnostic model and its diagnostic method of the XLPE cable insulated water tree aging based on PDC methods |
| CN111736043A (en) * | 2020-06-19 | 2020-10-02 | 西安交通大学 | XLPE cable degassing state evaluation method based on low-frequency dielectric spectrum |
| WO2021098611A1 (en) * | 2019-11-19 | 2021-05-27 | 云南电网有限责任公司临沧供电局 | Platform for testing leakage current difference factor of aged xlpe cable, and method |
| CN113138325A (en) * | 2021-04-14 | 2021-07-20 | 长江大学 | Rapid diagnosis method for decoupling insulation low-frequency dielectric loss of crosslinked polyethylene cable |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277496A (en) * | 2001-03-16 | 2002-09-25 | Showa Electric Wire & Cable Co Ltd | Measuring method for dielectric loss tangent of cable |
| CN101738554A (en) * | 2009-12-30 | 2010-06-16 | 天津塑力线缆集团有限公司 | Cross-linked polyethylene insulated cable and method for testing cable insulation and sheath aging |
| CN103197171A (en) * | 2013-03-01 | 2013-07-10 | 中国南方电网有限责任公司超高压输电公司贵阳局 | Evaluation method for paper oil insulation aging state through characteristic parameters based on time domain dielectric response |
| CN103278756A (en) * | 2013-05-29 | 2013-09-04 | 国家电网公司 | Method for assessing transformer oil-paper insulation aging state |
| CN103558533A (en) * | 2013-11-20 | 2014-02-05 | 国家电网公司 | Insulation aging diagnostic system and method based on 10kV XLPE cable |
-
2014
- 2014-11-25 CN CN201410691172.8A patent/CN104459486A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277496A (en) * | 2001-03-16 | 2002-09-25 | Showa Electric Wire & Cable Co Ltd | Measuring method for dielectric loss tangent of cable |
| CN101738554A (en) * | 2009-12-30 | 2010-06-16 | 天津塑力线缆集团有限公司 | Cross-linked polyethylene insulated cable and method for testing cable insulation and sheath aging |
| CN103197171A (en) * | 2013-03-01 | 2013-07-10 | 中国南方电网有限责任公司超高压输电公司贵阳局 | Evaluation method for paper oil insulation aging state through characteristic parameters based on time domain dielectric response |
| CN103278756A (en) * | 2013-05-29 | 2013-09-04 | 国家电网公司 | Method for assessing transformer oil-paper insulation aging state |
| CN103558533A (en) * | 2013-11-20 | 2014-02-05 | 国家电网公司 | Insulation aging diagnostic system and method based on 10kV XLPE cable |
Non-Patent Citations (1)
| Title |
|---|
| 纪哲强 等: "基于等温松弛方法的发电机定子线棒绝缘检测方法研究", 《大电机技术》 * |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104865500A (en) * | 2015-05-22 | 2015-08-26 | 华南理工大学 | High voltage cable outer sheath differentiation insulation defect evaluation method |
| CN105467190A (en) * | 2015-11-13 | 2016-04-06 | 华中科技大学 | Measuring method of XLPE cable polarized-depolarized currents |
| CN106841935A (en) * | 2015-12-04 | 2017-06-13 | 核动力运行研究所 | For the Time-Domain Measuring System and appraisal procedure of the assessment of dielectric ageing state |
| CN106324454A (en) * | 2016-08-17 | 2017-01-11 | 华中科技大学 | XLPE cable insulation detection device and anti-electromagnetic interference method thereof |
| CN106324454B (en) * | 2016-08-17 | 2019-05-03 | 华中科技大学 | A kind of XLPE cable insulation detection device and its electromagnetism interference method |
| CN108627747A (en) * | 2018-08-23 | 2018-10-09 | 武汉脉源电气有限公司 | A kind of diagnostic model and its diagnostic method of the XLPE cable insulated water tree aging based on PDC methods |
| WO2021098611A1 (en) * | 2019-11-19 | 2021-05-27 | 云南电网有限责任公司临沧供电局 | Platform for testing leakage current difference factor of aged xlpe cable, and method |
| CN111736043A (en) * | 2020-06-19 | 2020-10-02 | 西安交通大学 | XLPE cable degassing state evaluation method based on low-frequency dielectric spectrum |
| CN113138325A (en) * | 2021-04-14 | 2021-07-20 | 长江大学 | Rapid diagnosis method for decoupling insulation low-frequency dielectric loss of crosslinked polyethylene cable |
| CN113138325B (en) * | 2021-04-14 | 2022-08-19 | 长江大学 | Rapid diagnosis method for loss decoupling of insulating low-frequency medium of crosslinked polyethylene cable |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104459486A (en) | Method for evaluating insulation of crosslinked polyethylene medium-voltage cable through polarization current | |
| CN104090214B (en) | A kind of Cable fault examination and aging analysis method | |
| US7966137B2 (en) | Line resonance analysis system | |
| CN203881897U (en) | Device for measuring insulating state of capacitive current transformer | |
| CN109342883A (en) | A kind of local ageing fault detecting and positioning method for cable | |
| CN103513132B (en) | Power transmission and transformation system equipment state simulator | |
| Jabha et al. | A new approach for the failure prediction in XLPE power cables using acoustic emission technique | |
| CN113740661A (en) | Cable defect positioning method and device, computer equipment and storage medium | |
| Govindarajan et al. | A review on partial discharge diagnosis in cables: Theory, techniques, and trends | |
| Ushakov et al. | Diagnostics of High-Voltage Cable Lines | |
| CN203502513U (en) | Power transmission and transformation system equipment state simulation apparatus | |
| KR20140033979A (en) | Apparatus for diagnosing a power transformer | |
| Li et al. | Location of cable joints with moisture in medium voltage distribution grid based on frequency domain reflection method | |
| KR20160131516A (en) | Outlet cable integrity assessment apparatus and method thereof | |
| Seifi et al. | A feasibility study on estimating induced charge of partial discharges in transformer windings adjacent to its origin | |
| CN110632481B (en) | Medium-voltage cable body insulation defect degree identification method | |
| Huang et al. | Detection of different cable defects simulated by impedance box based on FDR | |
| Yang et al. | Research on the diagnosis of MV power cable insulation based on PD and VLF-Tanδ | |
| Zhu et al. | Improvement of cable defect identification for power distribution networks | |
| Sumereder | A comparison of partial discharge detection with 50 Hz and 0, 1 Hz at XLPE Cables | |
| Ahmed et al. | Partial discharge measurements in distribution class extruded cables | |
| Jaroslaw et al. | Diagnostic and acceptance tests of AC long lengths high voltage power cables | |
| KR102313542B1 (en) | PD Measurement and Location Estimation of High Voltage Cables | |
| Liu et al. | The propagation of partial discharge pulses in a high voltage cable | |
| Cselkó et al. | Comparison of failure detection capability of available low-voltage cable diagnostic methods |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20150325 |
|
| WD01 | Invention patent application deemed withdrawn after publication |