CN104483571A - Cable insulation detection method - Google Patents
Cable insulation detection method Download PDFInfo
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- CN104483571A CN104483571A CN201410790700.5A CN201410790700A CN104483571A CN 104483571 A CN104483571 A CN 104483571A CN 201410790700 A CN201410790700 A CN 201410790700A CN 104483571 A CN104483571 A CN 104483571A
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Abstract
The invention discloses a cable insulation detection method. The cable insulation detection method is characterized by collecting cable load current Ia, cable voltage to ground Ua and current If of the grounded end of a cable metal protection layer, wherein the current If of the grounded end of the cable metal protection layer comprises cable capacitive current Ic to ground, single-point or multi-point grounded loop current Ih of the metal protection layer and main insulation discharge current Ix; the three types of current Ic, Ih and Ix of the collection current If of the grounded end of the cable metal protection layer are extracted by phase comparison, waveform capture and fourier expansion; a device is used for warning that one point or a plurality of points of the cable metal protection layer are grounded if the single-point or multi-point grounded loop current Ih of the metal protection layer reaches a set value; the device is used for warning that the cable main insulation is abnormal if the main insulation discharge current Ix reaches the set value.
Description
Technical field
The present invention relates to cable detecting device field, specifically a kind of cable insulation detection method.
Background technology
Current China's single core cable protective layer many employings one end ground connection, earth-free or the high resistance ground of the other end, for the major insulation of cable or protective layer insulation against ground mainly or detect by preventive trial, also ideal solution is not had at present under on-line operation state, indivedual producer adopts surface temperature measurement method, due to cable length and earth point ground connection situation difference, temperature profile really cannot can react cable insulation fault.Also have some to adopt voltage-current relationship to carry out triphase parameter control methods, could can only find during cable insulation very serious even fault, the initial stage cannot find, result of use is undesirable.
In prior art, general by gathering earth terminal to vagabond current, three-phase current compares, if certain phase current is variant with other two-phases, namely judge that this phase cable is abnormal, this measuring method Problems existing is as follows:
1, the electric current collected by earth terminal is actually the synthesis (circulation of capacitance current, some multipoint earthing alive of three electric currents, the leakage current of major insulation) and these three current phases and amplitude widely different, three electric currents reflect cable three kinds of operation characteristics respectively, only accurately cannot judge that cable is abnormal with the current characteristic after these three electric current synthesis;
2, capacitance current is owing to affecting by the Abnormal Insulation outside this cable of whole system, from resultant current, list accurately can not judge that cable insulation is abnormal.
summary of the inventionthe object of this invention is to provide a kind of cable insulation detection method, to solve prior art Problems existing.In order to achieve the above object, the technical solution adopted in the present invention is:
Cable insulation detection method, it is characterized in that: gather cable load current Ia, cable voltage-to-ground Ua, cable metal protective layer earth terminal electric current I f, wherein cable metal protective layer earth terminal electric current I f is by cable earth capacitance electric current I c, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix is formed, utilize 90 degree, cable earth capacitance electric current I c phase place advanced cable voltage-to-ground Ua phase place, metal protection layer single-point or 180 degree, multipoint earthing circulation Ih phase place advanced cable load current Ia phase place, the characteristic that major insulation discharge current Ix phase place is identical with cable voltage-to-ground Ua same-phase, analyzed by phase characteristic, carry out phase compare successively, waveform capture, Fourier expansion, cable metal protective layer earth terminal is gathered the cable earth capacitance electric current I c comprised in electric current I f, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix extracts, can judge that whether cable insulation is abnormal according to metal protection layer single-point or multipoint earthing circulation Ih and major insulation discharge current Ix.
The present invention accurately can calculate the feature of each electric current of resultant current, accurately judges that cable is abnormal according to the size of each electric current.By detection load electric current, system voltage, earth point electric current, adopts Waveform forecast and synthesis phase relative method, by three kinds of size of current and characteristic parameter extraction out, according to system voltage and load current comprehensive descision cable insulation abnormal.
The present invention normally runs timer can Real-Time Monitoring major insulation leakage current, capacitance current, one or more grounding circulations, according to Parameters variation Real-time Alarm, parameter are uploaded dispatching terminal or Surveillance center, and planned enforcement has a power failure process.
Accompanying drawing explanation
Fig. 1 is the present invention program's schematic diagram.
Fig. 2 is wave form analysis figure.
Embodiment
Cable insulation detection method, gather cable load current Ia, cable voltage-to-ground Ua, cable metal protective layer earth terminal electric current I f, wherein cable metal protective layer earth terminal electric current I f is by cable earth capacitance electric current I c, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix is formed, utilize 90 degree, cable earth capacitance electric current I c phase place advanced cable voltage-to-ground Ua phase place, metal protection layer single-point or 180 degree, multipoint earthing circulation Ih phase place advanced cable load current Ia phase place, the characteristic that major insulation discharge current Ix phase place is identical with cable voltage-to-ground Ua same-phase, analyzed by phase characteristic, carry out phase compare successively, waveform capture, Fourier expansion, cable metal protective layer earth terminal is gathered the cable earth capacitance electric current I c comprised in electric current I f, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix extracts, can judge that whether cable insulation is abnormal according to metal protection layer single-point or multipoint earthing circulation Ih and major insulation discharge current Ix.
As shown in Figure 1, Fig. 1 is A phase cable insulation on-line monitoring schematic diagram, and figure is identical for B phase, C facies principle, and three-phase concentrates on a signal analysis and processing unit and processes.Held with device Ia* by the KI of Current Transmit 1 end and be connected, the K2 end of Current Transmit 1 is held with device Ia and is connected; The Ua of voltage transformer pt end is held with the Ua of device and is connected, the Un of voltage transformer pt end is held with the Un of device and is connected; Ground connection resultant current is introduced signal acquisition module ground connection recombination current terminal by precision current sensor CT2 by earth terminal electric current, and polarity connects on request.
As shown in Figure 2, by to cable load current Ia waveform, cable voltage-to-ground Ua waveform, cable metal protective layer earth terminal electric current I f waveform, cable earth capacitance electric current I c waveform, metal protection layer single-point or multipoint earthing circulation Ih waveform, major insulation discharge current Ix wave form analysis, metal protection layer single-point or multipoint earthing circulation Ih waveform, major insulation discharge current Ix waveform phase feature accurately can be captured.From wave form analysis, 90 degree, cable earth capacitance electric current I c phase place advanced cable voltage-to-ground Ua phase place, metal protection layer single-point or 180 degree, multipoint earthing circulation Ih phase place advanced cable load current Ia phase place, major insulation discharge current Ix phase place is identical with cable voltage-to-ground Ua same-phase.By above-mentioned phase characteristic, pass through phase compare, waveform capture, and Fourier expansion, cable metal protective layer earth terminal is gathered the three kinds of electric currents (Ic, Ih, Ix) comprised in electric current I f extract, if metal protection layer single-point or multipoint earthing circulation Ih reach one or more ground connection of setting value device alarm cable metal protection layer, if major insulation discharge current Ix reaches setting value device alarm cable major insulation extremely.
Claims (1)
1. cable insulation detection method, it is characterized in that: gather cable load current Ia, cable voltage-to-ground Ua, cable metal protective layer earth terminal electric current I f, wherein cable metal protective layer earth terminal electric current I f is by cable earth capacitance electric current I c, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix is formed, utilize 90 degree, cable earth capacitance electric current I c phase place advanced cable voltage-to-ground Ua phase place, metal protection layer single-point or 180 degree, multipoint earthing circulation Ih phase place advanced cable load current Ia phase place, the characteristic that major insulation discharge current Ix phase place is identical with cable voltage-to-ground Ua same-phase, analyzed by phase characteristic, carry out phase compare successively, waveform capture, Fourier expansion, cable metal protective layer earth terminal is gathered the cable earth capacitance electric current I c comprised in electric current I f, metal protection layer single-point or multipoint earthing circulation Ih, major insulation discharge current Ix extracts, can judge that whether cable insulation is abnormal according to metal protection layer single-point or multipoint earthing circulation Ih and major insulation discharge current Ix.
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| CN201410790700.5A CN104483571B (en) | 2014-12-17 | 2014-12-17 | Cable insulation detection method |
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| CN201410790700.5A CN104483571B (en) | 2014-12-17 | 2014-12-17 | Cable insulation detection method |
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| CN104483571A true CN104483571A (en) | 2015-04-01 |
| CN104483571B CN104483571B (en) | 2017-11-10 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108710016A (en) * | 2018-03-01 | 2018-10-26 | 华南理工大学 | A kind of computational methods of the single-core cable distributed electrical capacitance current of the golden cloth containing insulation |
| CN110412418A (en) * | 2019-07-22 | 2019-11-05 | 国网湖北省电力有限公司电力科学研究院 | Insulating tube type busbar insulation diagnosis and localization method based on earth current measurement |
| CN113295977A (en) * | 2021-06-03 | 2021-08-24 | 长沙理工大学 | Cable insulation state and fault monitoring method |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201229389Y (en) * | 2008-07-24 | 2009-04-29 | 福建省泉州电业局 | Cable sheath insulation on-line monitoring device |
| CN101825657A (en) * | 2010-05-12 | 2010-09-08 | 国网电力科学研究院 | Medium-high voltage single-core crosslinked cable induction voltage and circular-current online detection method and device |
| CN103336230A (en) * | 2013-06-21 | 2013-10-02 | 国家电网公司 | Device and method for predicting cable insulation failure rate in power distribution network |
| CN103630814A (en) * | 2013-12-11 | 2014-03-12 | 国家电网公司 | Insulating dielectric loss angle tendency online monitoring method of high-voltage cables under cross interconnection |
| CN103941161A (en) * | 2014-05-12 | 2014-07-23 | 国家电网公司 | On-line monitoring system for current and carrying capacity of cable sheath |
-
2014
- 2014-12-17 CN CN201410790700.5A patent/CN104483571B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201229389Y (en) * | 2008-07-24 | 2009-04-29 | 福建省泉州电业局 | Cable sheath insulation on-line monitoring device |
| CN101825657A (en) * | 2010-05-12 | 2010-09-08 | 国网电力科学研究院 | Medium-high voltage single-core crosslinked cable induction voltage and circular-current online detection method and device |
| CN103336230A (en) * | 2013-06-21 | 2013-10-02 | 国家电网公司 | Device and method for predicting cable insulation failure rate in power distribution network |
| CN103630814A (en) * | 2013-12-11 | 2014-03-12 | 国家电网公司 | Insulating dielectric loss angle tendency online monitoring method of high-voltage cables under cross interconnection |
| CN103941161A (en) * | 2014-05-12 | 2014-07-23 | 国家电网公司 | On-line monitoring system for current and carrying capacity of cable sheath |
Non-Patent Citations (1)
| Title |
|---|
| 柴旭峥等: "交联聚乙烯电力电缆的绝缘在线监测技术", 《电线电缆》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108710016A (en) * | 2018-03-01 | 2018-10-26 | 华南理工大学 | A kind of computational methods of the single-core cable distributed electrical capacitance current of the golden cloth containing insulation |
| CN108710016B (en) * | 2018-03-01 | 2019-10-18 | 华南理工大学 | A kind of calculation method of the single-core cable distributed electrical capacitance current containing the golden cloth that insulate |
| CN110412418A (en) * | 2019-07-22 | 2019-11-05 | 国网湖北省电力有限公司电力科学研究院 | Insulating tube type busbar insulation diagnosis and localization method based on earth current measurement |
| CN113295977A (en) * | 2021-06-03 | 2021-08-24 | 长沙理工大学 | Cable insulation state and fault monitoring method |
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| CN104483571B (en) | 2017-11-10 |
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Effective date of registration: 20171102 Address after: 230088 building, B6 building, 168 science and Technology Industrial Park, 2 camphor Road, hi tech Zone, Hefei, Anhui Patentee after: Hefei Ruida Software Technology Co., Ltd. Address before: 230022 Hefei, Anhui, South Road, cooperative building, No. 28, 11F Patentee before: ANHUI TARY TONGDA MECHANICAL & ELECTRICAL CO., LTD. |
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