CN100410675C - Power cable damage synchronous magnetic field directioning positioning method - Google Patents
Power cable damage synchronous magnetic field directioning positioning method Download PDFInfo
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- CN100410675C CN100410675C CNB2005100424550A CN200510042455A CN100410675C CN 100410675 C CN100410675 C CN 100410675C CN B2005100424550 A CNB2005100424550 A CN B2005100424550A CN 200510042455 A CN200510042455 A CN 200510042455A CN 100410675 C CN100410675 C CN 100410675C
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Abstract
The present invention relates to a synchronous magnetic field directional positioning method for an electric power cable fault, which belongs to the detection field of an electric fault. The present invention is characterized in that a voltage pulse generator is arranged between a fault core wire at any one end of a fault cable and a steel armour to periodically exert a voltage pulse signal, and the voltage pulse generator generates a magnetic field signal which regards a fault point as a center and orderly changes along a cable waling direction near the fault point of the fault cable. A magnetic field signal detection device is used for measuring a polarity and an amplitude value of the magnetic field signal along the fault cable. The direction and the specific position of the fault point can be confirmed by detecting the change of the polarity and the amplitude value of the magnetic field signal. The method of the present invention has high positioning precision, and can rapidly and exactly find the fault point. A measuring device which is used has the advantages of low cost, convenient and quick use, and simple and visual operation, and can carry out quick directional/exact pointing measurement to the fault of the fault cable. The present invention can be widely used for the grounding fault detection field of various cables which are directly embedded, laid in a pipe penetrated mode, or laid in a cable tunnel.
Description
Technical field
The invention belongs to the field of detecting of electric fault, relate in particular to a kind of orientation and detection and localization the armoured power cable earth fault.
Background technology
The cable that is used for electric power transfer and distribution is called power cable.
Along with the progress of society and the development of industrial and agricultural production, cable consumption shared ratio in whole power transmission lines improves day by day, and cable is compared with overhead transmission line, has following major advantage:
1. power supply quality is good, and the reliability height is not subject to the influence of surrounding environment and pollution;
2. insulation distance is little between line, takes up an area of to lack noiseless electric wave;
3. during underground laying, do not take up an area of face and space, both safe and reliable, be difficult for again giving away one's position.
For the consideration of construction cost and other various factorss, the underground system of laying of main system of laying multiselect that power cable is present.
Along with the quick growth of power cable consumption, the thing followed is increasing of various cable faults.
But, relatively difficulty, long deficiency of consumption time are sought and are keeped in repair in the survey that present prior art exists Method of Cable Trouble Point, especially the fast measuring of the earth fault of the cable that lays for poling and cable tunnel and accurately orientation problem are difficult problems that is perplexing power industry relevant technologies personnel and maintenance personal always.
At present, the localization of fault of power cable mainly contains following several method:
1. sound magnetic-synchro method: this method uses high-tension apparatus to make Method of Cable Trouble Point disruptive discharge, utilizes receiver record discharge sound, and with field signal it is carried out synchronously, by analysis sound waveform or earphone fault is found range and is fixed a point.But this method can only obtain the voice signal of about 2～3 meters distances of distance fault point, and field personnel's technical quality is had relatively high expectations, and for the low-resistance fault, the type cable failure positioning that poling, tunnel lay, the method can't solve.
2. frequency induction fix point method: this method adopts the sound signal that applies a characteristics frequency to failure cable, prolongs the change point that cable is sought sound signal along the line with an audio detector, with this failure judgement point particular location.But the method only is applicable to the low-resistance fault.
3. step voltage method: this method uses high-tension apparatus to make Method of Cable Trouble Point to the earth disruptive discharge, utilizes near the variation of the ground voltage of receiver record trouble point, and cable fault is fixed a point.But the trouble spot that this method can only the detection streamer sheath be damaged, for the type cable failure positioning that poling, tunnel lay, the method can't solve.
Summary of the invention
The earth fault that technical matters to be solved by this invention provides a kind of cable that can lay direct-burried, cable installation in pipe or cable tunnel is carried out the directed localization method of synchronous field of the power cable fault that slewing/pinpoint measures.
Technical scheme of the present invention is: the directed localization method of synchronous field that a kind of power cable fault is provided, comprise failure cable to be measured, it is characterized in that: between the fault heart yearn and steel armour of the arbitrary end of failure cable, one voltage pulse generation device is set, periodically apply voltage pulse signal, making it near the trouble spot of failure cable to produce one is center and the field signal that changes successively along cable louding with the trouble spot; With a field signal sniffer, failure cable is carried out the measurement of field signal polarity and signal amplitude along the line; By detecting the variation of field signal polarity and amplitude, the direction of the localization of faults and particular location.
Wherein, described field signal sniffer comprises that at least one surveys magnetic induction coil and the field signal processing that is attached thereto and judgement, display unit, described survey magnetic induction coil produces the simulating signal of a tested magnetic field intensity of representative, described field signal processing and judgement, display unit are handled this signal, and it is transformed to discernible sound, light, pointer, numeral or waveform signal output.
The coil spiral direction of winding of its described survey magnetic induction coil is parallel to cable steel armour lapping direction, is oriented on the strongest direction by the magnetic field that transient current produced on the wrapped steel armour of failure cable, and the field signal of failure cable is detected.
Further, the axial line of described survey magnetic induction coil is identical with the cable laying direction or parallel, is transversal position with the cable laying direction and puts, and places the top of cable or all around, and the field signal of failure cable is detected.
Above-mentioned survey magnetic induction coil is air core coil or ribbon core coil; Surveying magnetic induction coil can be made of single coil, also can be made of a plurality of coils from parallel connection of coils and/or series connection.
Its described voltage pulse generation device is the high direct voltage pulse generating unit.
Compared with the prior art, advantage of the present invention is:
1. adopt the method that detects field signal polarity and amplitude variation, the bearing accuracy height can reach almost zero error, according to the direction indication on the instrument, along cable detection, can find the trouble spot quickly and accurately;
2. employed measuring equipment is with low cost, easy to use, quick, simple to operate, directly perceived;
3. the earth fault of the cable that can be simultaneously direct burial, cable installation in pipe or cable tunnel be laid is carried out slewing/pinpoint and is measured.
Description of drawings
Directed and the localization method synoptic diagram of tested cable fault among Fig. 1 the present invention;
Transient current magnetic field in the steel armour among Fig. 2 the present invention before and after the tested Method of Cable Trouble Point and survey magnetic induction coil direction of current synoptic diagram;
Fig. 3 survey magnetic induction coil of the present invention position is apart from the relation of position of failure point and inductive coil size of current and direction;
Fig. 4 survey magnetic induction coil of the present invention position is apart from the another kind relation of position of failure point and inductive coil size of current and direction;
The actual test waveform of survey lines of magnetic induction loop current when Fig. 5 trouble spot is positioned at field signal sniffer the place ahead;
The actual test waveform of inductive coil electric current is surveyed in survey when Fig. 6 trouble spot is positioned at field signal sniffer rear.
Among the figure, 1 is the earth; 2 is tested cable; 3 is the trouble spot; 4 is the fault phase; 5 is tested cable steel armour; 6 is the high-voltage dc pulse generator; 6a is a pulse producer negative voltage output terminal; 6b is the pulse producer positive voltage output end; 7 is the field signal sniffer; 8 are field signal processing and judgement display unit; 9 for surveying magnetic induction coil; 10a is that the trouble spot is positioned at the inductive current direction when surveying magnetic induction coil the place ahead (right side); 10b is that the trouble spot is positioned at the inductive current direction when surveying magnetic induction coil rear (left side); 11a is the direction of current in the steel armour of left side, trouble spot; 11b is the direction of current in the steel armour of right side, trouble spot; 12a is trouble spot left side electric current formed Distribution of Magnetic Field of steel armour and direction; 12b is electric current formed Distribution of Magnetic Field of right side, trouble spot steel armour and direction; 13a is that the trouble spot is positioned at the induction current waveform when surveying magnetic induction coil the place ahead (right side); 13b is that the trouble spot is positioned at the induction current waveform when surveying magnetic induction coil rear (left side); When 13c was steel armour another kind winding, the trouble spot was positioned at the induction current waveform when surveying magnetic induction coil the place ahead (right side); When 13d was steel armour another kind winding, the trouble spot was positioned at the survey induced field current waveform when surveying magnetic induction coil rear (left side); 14a is that the trouble spot is positioned at when surveying magnetic induction coil the place ahead (right side), surveys first wave head peak envelope line of induced field current; 14b is trouble spot when being positioned at inductive coil rear (left side), surveys first wave head peak envelope line of induced field current; When 14c is steel armour another kind winding, first wave head peak envelope line of the survey induced field current the when trouble spot is positioned at inductive coil the place ahead (right side); When 14d is steel armour another kind winding, first wave head peak envelope line of the survey induced field current the when trouble spot is positioned at inductive coil rear (left side); 15 for surveying the axial line of magnetic induction coil; 16 is tested cable laying direction.
Embodiment
The present invention will be further described below in conjunction with drawings and Examples.
Among Fig. 1, the negative voltage output terminal 6a of high-voltage dc pulse voltage generator 6 connects on the fault phase 4 of tested cable 2, its positive voltage output end 6b connects on the tested cable steel armour 5, and the high-voltage dc pulse voltage generator periodically applies the negative high voltage dc pulse signal mutually and between the steel armour to fault.
Wherein, field signal sniffer 7 is made up of with survey magnetic induction coil 9 field signal processing and judgement display unit 8.
The hand-held field signal sniffer 7 of staff is surveyed along the direction of lay 16 of tested cable 2, and during detection, the axial line 15 of surveying magnetic induction coil 9 should be parallel with the direction of lay 16 of tested cable 2.
Field signal is handled and is judged that the magentic test coil sensor current signal of 8 pairs of detections of display unit handles, and judges the amplitude and the direction of first wave head of sensor current signal, according to the variation of the two can the accurate localization of faults direction and position.
Among Fig. 2, when the high-voltage pulse that applies produces discharge in the trouble spot 3 of tested cable 2, its direction of front and back of 3 is respectively 11a and 11b to the transient state capacitive discharge electric current that produces in the steel armour 5 in the trouble spot, according to the right-handed helix rule, magnetic field or magnetic line of force direction around the tested cable 2 are respectively 12a and 12b, in the time of around survey magnetic induction coil 9 is placed on tested cable 2, just can respond to the electric current in the tapping armour 5.
It is parallel with tested cable laying direction 16 all the time to survey magnetic induction coil axial line 15.
Equally according to the right-handed helix rule, can determine the inductive current direction of surveying when diverse location in the magnetic induction coil 9, as seen before and after the trouble spot, its inductive current direction 10a and 10b are just in time opposite, therefore can accurately judge to provide position of failure point according to these characteristics.
When Fig. 3 has provided survey magnetic induction coil 9 distance faults and puts 3 diverse locations, survey the variation tendency of size of current and direction in the magnetic induction coil.
When surveying magnetic induction coil 9 and be positioned at the same side of trouble spot and impulse voltage generator 6 (survey magnetic induction coil between trouble spot and impulse voltage generator time), it is constant substantially to survey magnetic induction coil current shape and direction, and amplitude has obvious variation trend.
When the survey magnetic induction coil is positioned at the opposite side of trouble spot and impulse voltage generator, to survey the magnetic induction coil direction of current and change, amplitude also has obvious variation trend.
Therefore can utilize these characteristics to carry out directed and location, trouble spot.
Survey magnetic induction coil size of current when Fig. 4 has provided the another kind of steel armour lapping direction of cable (opposite with the lapping direction of Fig. 3) and the variation tendency of direction.
As seen, except that current polarity was opposite, all the other characteristics were identical with Fig. 3.
Fig. 5 and Fig. 6 are the survey lines of magnetic induction loop current actual waveforms when being positioned at the front and back, trouble spot with the survey magnetic induction coil that oscillograph observes, and the longitudinal axis is the detected magnetic field intensity amplitude of magentic test coil among the figure, and transverse axis is the time.
The polarity changed features of electric current before and after the trouble spot that also can be observed Fig. 3, Fig. 4 from the figure and embodied.
Embodiment
For the single-phase of 10Kv armoured power cable earth fault is detected, between cable fault heart yearn and steel armour, apply the 15Kv dc pulse voltage, Method of Cable Trouble Point disruptive discharge, the staff is hand-held to be surveyed along the direction of lay of tested cable by surveying the field signal sniffer that magnetic induction coil and field signal are handled and the judgement display unit constitutes.
During 5 meters of distance fault points, can detect the field signal that strengthens successively, 0.5 meter in the distance trouble spot, signal intensity (amplitude) reaches the highest, goes ahead again, and signal intensity obviously reduces; To the trouble spot, signal intensity is zero; Continue to move ahead, detected signal polarity is reverse, and amplitude changes also 0.5 meter feature that reaches maximum, then progressively decays apart from the trouble spot, is zero place in aforesaid signal intensity, and the strip off cable sheath finds to have tangible breakdown point, and localization of fault finishes.
Employed high-voltage dc pulse voltage generator and field signal are handled and are judged display unit in above-mentioned testing process, are existing open in 200410035595.0 the Chinese patent application at the application number that the applicant applies for a few days ago, no longer narrate at this.
The high-voltage dc pulse voltage generator also can be selected suitable commercially available prod for use according to the voltage cable grade; Field signal is handled and is judged display unit, and also can select other for use can be the similar commercially available prod that various discernible sound, light, pointer, numeral or waveform signal are exported with electrical signal conversion, the simplyst can adopt portable oscilloscope; As for surveying magnetic induction coil, can adopt commercially available magnetic induction coil (as the pull-in winding of various commercially available relays or contactor) or own coiling all can, survey magnetic induction coil and adopt the air core coil structure not as adopting the highly sensitive of ribbon core loop construction form; Surveying magnetic induction coil can be made of single coil, also can be made of a plurality of coils from parallel connection of coils and/or series connection, its concrete type of attachment depends on that field signal is handled and the height of the sensitivity of judgement needed input signal strength of display unit and whole detection device (perhaps gain); Other no specific (special) requirements.
The present invention can be widely used in the Earth Fault Detection field of the cable that lays in various direct-burrieds, cable installation in pipe or cable tunnel.
Claims (5)
1. the directed localization method of the synchronous field of a power cable fault comprises failure cable to be measured, it is characterized in that:
Between the fault heart yearn and steel armour of the arbitrary end of failure cable, one voltage pulse generation device is set, periodically apply voltage pulse signal, making it near the trouble spot of failure cable to produce one is center and the field signal that changes successively along cable louding with the trouble spot;
With a field signal sniffer, failure cable is carried out the measurement of field signal polarity and signal amplitude along the line;
By detecting the variation of field signal polarity and amplitude, the direction of the localization of faults and particular location;
Described voltage pulse generation device is the high direct voltage pulse generating unit;
Described field signal sniffer comprises that at least one surveys magnetic induction coil and the field signal processing that is attached thereto and judgement, display unit;
Described survey magnetic induction coil produces the simulating signal of a tested magnetic field intensity of representative, and described field signal processing and judgement, display unit are handled this signal, and it is transformed to discernible sound, light, pointer, numeral or waveform signal output.
2. according to the directed localization method of the synchronous field of the described power cable fault of claim 1, the coil spiral direction of winding that it is characterized in that described survey magnetic induction coil is parallel to cable steel armour lapping direction, be oriented on the strongest direction by the magnetic field that transient current produced on the wrapped steel armour of failure cable, the field signal of failure cable is detected.
3. according to the directed localization method of the synchronous field of claim 1 or 2 described power cable faults, the axial line that it is characterized in that described survey magnetic induction coil is identical with the cable laying direction or parallel, being transversal position with the cable laying direction puts, place the top of cable or all around, the field signal of failure cable is detected.
4. according to the directed localization method of the synchronous field of the described power cable fault of claim 1, it is characterized in that described survey magnetic induction coil is air core coil or ribbon core coil.
5. according to the directed localization method of the synchronous field of the described power cable fault of claim 1, it is characterized in that described survey magnetic induction coil can be made of single coil, also can be made of a plurality of coils from parallel connection of coils and/or series connection.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100424550A CN100410675C (en) | 2005-02-03 | 2005-02-03 | Power cable damage synchronous magnetic field directioning positioning method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB2005100424550A CN100410675C (en) | 2005-02-03 | 2005-02-03 | Power cable damage synchronous magnetic field directioning positioning method |
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| CN1651926A CN1651926A (en) | 2005-08-10 |
| CN100410675C true CN100410675C (en) | 2008-08-13 |
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| Application Number | Title | Priority Date | Filing Date |
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| CNB2005100424550A Expired - Fee Related CN100410675C (en) | 2005-02-03 | 2005-02-03 | Power cable damage synchronous magnetic field directioning positioning method |
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| CN100456048C (en) * | 2005-11-08 | 2009-01-28 | 财团法人工业技术研究院 | Magnetism orientation apparatus of dynamic institution and measuring method for pipeline |
| CN101446616B (en) * | 2008-02-29 | 2012-07-04 | 田振国 | Method for finding fault point of cable or pipeline and device thereof |
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| CN112557821B (en) * | 2020-12-03 | 2022-09-06 | 广东电网有限责任公司江门供电局 | Low-voltage cable fault magnetic detection fixed point method and system |
| CN113514732A (en) * | 2021-07-30 | 2021-10-19 | 华能东营河口风力发电有限公司 | Long cable line fault point searching method |
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