CN113514732A - Long cable line fault point searching method - Google Patents
Long cable line fault point searching method Download PDFInfo
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- CN113514732A CN113514732A CN202110868662.0A CN202110868662A CN113514732A CN 113514732 A CN113514732 A CN 113514732A CN 202110868662 A CN202110868662 A CN 202110868662A CN 113514732 A CN113514732 A CN 113514732A
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- 238000000034 method Methods 0.000 title claims abstract description 49
- 230000005236 sound signal Effects 0.000 claims abstract description 40
- 238000005259 measurement Methods 0.000 claims description 8
- 239000000203 mixture Substances 0.000 claims 1
- 239000002994 raw material Substances 0.000 claims 1
- 230000005674 electromagnetic induction Effects 0.000 description 9
- 230000006698 induction Effects 0.000 description 7
- 230000005389 magnetism Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 230000005684 electric field Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 230000000149 penetrating effect Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
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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
- G01R31/088—Aspects of digital computing
Abstract
The invention discloses a method for searching fault points of a long cable line, which comprises the steps of setting the output of a path signal generator to be discontinuous or continuous according to the surrounding environment; the path signal generator outputs a first signal with fixed frequency and applies the first signal to one item of the tested cable to generate a second signal; converting the second signal into a third signal by using a magneto-electric device; amplifying the third signal with a signal processor; the amplified third signal is converted into a sound signal through audio output equipment; the variation of the sound signal is used for further determining the trend and the depth of the cable. The method for searching for the fault point of the long cable line has good guiding function and strong field operability on the fault point searching of the cable, particularly the long cable line.
Description
Technical Field
The invention relates to the technical field of cable fault finding, in particular to a method for finding a fault point of a long cable line.
Background
With the development of new energy industry, the demand of wind power plants/photovoltaic power stations on power cables is increasing. Current collecting lines of coastal wind power plants which are put into production earlier are laid by cables. Due to the fact that the wind power plant fan layout has the advantages of being large in dispersity and large in span, cable lines are long, and the number of cable middle heads is large. Once a cable line breaks down, the exact position of a fault point is difficult to find quickly, faults cannot be eliminated in time, power transmission can be recovered, long-time shutdown of the line is caused, and great economic loss is caused to an electric field. In a power system, the finding and the detection of cable faults are very troublesome problems, and particularly for a new energy wind power plant, the long-term outage of a line causes great economic loss. Thus, the cable fault point is located as soon as possible, and power restoration is often a very urgent task.
Disclosure of Invention
This section is for the purpose of summarizing some aspects of embodiments of the invention and to briefly introduce some preferred embodiments. In this section, as well as in the abstract and the title of the invention of this application, simplifications or omissions may be made to avoid obscuring the purpose of the section, the abstract and the title, and such simplifications or omissions are not intended to limit the scope of the invention.
The present invention has been made in view of the above and/or problems occurring in the existing cable line fault point finding method.
Therefore, the problem to be solved by the present invention is to provide a method for finding a fault point of a long cable line.
In order to solve the technical problems, the invention provides the following technical scheme: a method for searching for a fault point of a long cable line comprises the steps of setting the output of a path signal generator to be discontinuous or continuous according to the surrounding environment; the path signal generator outputs a first signal with fixed frequency and applies the first signal to one item of the tested cable to generate a second signal; converting the second signal into a third signal by using a magneto-electric device; amplifying the third signal with a signal processor; the amplified third signal is converted into a sound signal through audio output equipment; the variation of the sound signal is used for further determining the trend and the depth of the cable.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the first signal is a sinusoidal alternating current signal.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the first signal is a cosine alternating current signal.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the second signal is a magnetic signal.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the third signal is an electrical signal.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the magneto-electric equipment reaches a point H, the loudness of a sound signal converted by the audio output equipment is minimum, and the right lower part of the point H is the correct direction of the cable.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the magneto-electric equipment moves from the point H to the point S, the sound signal converted by the audio output equipment is minimum, and moves left and right by taking the point S as a center, the loudness of the sound signal is increased, and the embedding depth of the tested cable at the position is the distance of the line segment HS.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: the magnetoelectric device and the tested cable move to the vertical direction and move to one side at an angle of alpha with the horizontal direction, the sound signal converted by the audio output device has the process of changing from big to small and then from small to big, and the distance between the point where the minimum sound signal is located and the tested cable multiplied by tan alpha is the burying depth of the tested cable at the position.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: under the condition that the cable to be measured is known to have a cable middle head, firstly, the accuracy of rough measurement is confirmed, the fixed point range is expanded, the fault point deviation possibly caused by inaccurate measurement is eliminated, and then the fault point is searched.
As a preferred scheme of the method for finding the fault point of the long cable line, the method comprises the following steps: under the condition that the cable middle head of the tested cable is unknown, the possibility that fault points exist in other areas is eliminated, and then the fault points are searched.
The invention has the beneficial effects that: the method for searching for the fault point of the long cable line has good guiding function and strong field operability on the cable, particularly on the fault point of the long cable line.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise. Wherein:
fig. 1 is a signal connection B-phase wiring diagram of a long cable line fault point searching method.
Fig. 2 is a schematic diagram of cable path search in a method for searching for a fault point of a long cable line.
Fig. 3 is a path search sound law diagram of the long cable line fault point search method.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described and will be readily apparent to those of ordinary skill in the art without departing from the spirit of the present invention, and therefore the present invention is not limited to the specific embodiments disclosed below.
Furthermore, reference herein to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one implementation of the invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.
Example 1
Referring to fig. 1, a first embodiment of the present invention provides a long cable run fault point finding method including setting a path signal generator output to be intermittent or continuous according to a surrounding environment; the path signal generator outputs a first signal with fixed frequency and applies the first signal to one item of the tested cable to generate a second signal; converting the second signal into a third signal by using a magneto-electric device; amplifying the third signal with a signal processor; the amplified third signal is converted into a sound signal through audio output equipment; the variation of the sound signal is used for further determining the trend and the depth of the cable.
In the cable fault fine detection process, firstly, it is necessary and necessary to find the correct direction of the cable. Usually, testers are confused to different degrees about unclear cable trend due to personnel change or loss of drawings, and the only way is to use an instrument to make correct judgment.
In use, the output of the path signal generator (using an existing signal generator such as a path meter) is set to be continuous according to the surrounding environment; as shown in fig. 1, a path signal generator continuously outputs a first signal with a fixed frequency, the first signal is an ac signal, such as a sine ac signal or a cosine ac signal, and the like, and is applied to a certain item of a cable to be tested, the path signal generator outputs the first signal with the fixed frequency and is applied to a certain item of the cable to be tested to generate a second signal, according to the electromagnetic induction principle, an electromagnetic wave is inevitably generated around the cable to be tested, and the second signal may be an electromagnetic wave or a magnetic signal; be provided with closed coil on the magnetoelectric equipment (adopting current magnetoelectric sensor, like the probe), utilize magnetism to generate electricity, will the second signal turns into the third signal, the third signal is induced-current, and will through signal processor again after the third signal enlargies the third signal will through audio output equipment (like earphone, stereo set etc.) the third signal turns into sound signal, utilizes the trend and the degree of depth of sound signal's further definite cable.
Example 2
Referring to fig. 1 to 3, a second embodiment of the present invention is based on the first embodiment.
Specifically, the first signal is a sinusoidal alternating current signal, a changing electric field generates a magnetic field according to Maxwell's equation, and the direction of the sinusoidal alternating current signal changes repeatedly, so that electromagnetic generation can be realized.
Further, the second signal is a magnetic signal, and the magnetic signal is inevitably generated around the cable to be detected according to the electromagnetic induction principle.
Preferably, the third signal is an electrical signal, and the magnetoelectric device is provided with a closed coil and generates electricity by using magnetism.
Preferably, the magnetoelectric device reaches a point H, the loudness of the sound signal converted by the audio output device is minimum, and the right lower side of the point H is the correct direction of the cable; when the magnetoelectric device moves left and right along the direction perpendicular to the ground (namely the normal direction of the induction coil forms an included angle of 90 degrees with the ground), the theory of electromagnetic induction considers that: the coil is bound to have magnetic lines of force passing through it. When the magnetoelectric device reaches the point H, the normal direction of the magnetoelectric device is vertical to the field intensity direction of the point, and the magnetic force line passing through the coil is zero, so that the loudness of the sound signal converted by the audio output device is minimum.
Furthermore, the magneto-electric device moves from the point H to the point S, the sound signal converted by the audio output device is minimum, the magnetic line of force passing through the coil is 0, and the magnetic line of force moves left and right by taking the point S as the center, the loudness of the sound signal is increased, and the embedding depth of the tested cable at the point H is the distance of the line segment HS.
Specifically, the magnetoelectric device and the tested cable move vertically and move to one side at an angle of alpha with the horizontal direction, the sound signal converted by the audio output device has a process of changing from large to small and then from small to large, and the distance between the point where the minimum sound signal is located and the tested cable multiplied by tan alpha is the embedding depth of the tested cable at the measuring point; according to the trigonometric function formula, the burying depth of the measured cable at the measuring point can be calculated.
Preferably, under the condition that the cable to be detected has a cable middle head, firstly, the accuracy of rough measurement is confirmed, the fixed point range is expanded, the fault point deviation possibly caused by inaccurate measurement is eliminated, and then the fault point is searched.
In conclusion, when the device is used, under the condition that the cable to be measured is known to have a cable middle head, the accuracy of rough measurement is firstly confirmed, the fixed point range is expanded, the fault point deviation possibly caused by inaccurate measurement is eliminated, and then the fault point is searched; setting the path signal generator output to continuous according to the surrounding environment; the path signal generator continuously outputs sinusoidal alternating current signals with fixed frequency, according to the electromagnetic induction law and the right-hand spiral law, magnetic lines around the cable are concentric circles taking the cable as the center of a circle, and the tangential direction of any point on the magnetic lines is the magnetic field direction of the point; a sinusoidal alternating current signal is added to a certain item of a cable to be detected, electromagnetic waves are inevitably generated around the cable to be detected according to the electromagnetic induction principle, a closed coil is arranged on the magnetoelectric device, induction current is generated by utilizing magnetism, the induction current is amplified by a signal processor, an electric signal is converted into a sound signal through audio output equipment (such as earphones, sound equipment and the like), and the trend and the depth of the cable are further determined by utilizing the change of the sound signal; when the magnetoelectric device moves left and right along the direction perpendicular to the ground (namely the normal direction of the induction coil forms an included angle of 90 degrees with the ground), the theory of electromagnetic induction considers that: the coil is bound to have magnetic lines of force passing through it. When the magnetoelectric device reaches a point H, the normal direction of the magnetoelectric device is vertical to the field intensity direction of the point, and the magnetic force line passing through the coil is zero, so that the loudness of the sound signal converted by the audio output device is minimum; the method comprises the steps that a magneto-electric device is perpendicular to a tested cable and moves to one side at an angle alpha with the horizontal direction, a sound signal converted by an audio output device has a process of changing from large to small and then changing from small to large, the distance between a point where the minimum sound signal is located and the tested cable is multiplied by tan alpha to be the buried depth of the tested cable at the measuring point, the buried depth of the tested cable at the measuring point is set to be H, alpha is 45 degrees and tan45 degrees is 1, as shown in fig. 2, the magneto-electric device moves from the point H to the point S, the sound signal converted by the audio output device is minimum, the magnetic force line penetrating through a coil is 0, the magneto-electric device moves left and right around the point S, the loudness of the sound signal is changed to large, and the buried depth H, HS, tan45 degrees, namely the distance of a line segment HS, of the tested cable at the point H is formed.
Example 3
Referring to fig. 2 and 3, a third embodiment of the present invention is shown, which differs from the first two embodiments.
Specifically, the first signal is a cosine alternating current signal, a changing electric field generates a magnetic field according to Maxwell's equation, and the direction of the cosine alternating current signal changes repeatedly, so that electromagnetic generation can be realized.
Furthermore, under the condition that the cable middle head of the tested cable is unknown, the possibility that fault points exist in other areas is eliminated, and then the fault points are searched.
In summary, under the condition that the cable middle head of the tested cable is unknown, the possibility that fault points exist in other areas is eliminated, then fault point searching is carried out on the cable middle head, and the output of the path signal generator is set to be continuous according to the surrounding environment; the path signal generator continuously outputs cosine alternating current signals with fixed frequency, according to the electromagnetic induction law and the right-hand spiral law, magnetic lines of force around the cable are concentric circles taking the cable as the center of a circle, and the tangential direction of any point on the magnetic lines of force is the magnetic field direction of the point; a sinusoidal alternating current signal is added to a certain item of a cable to be detected, electromagnetic waves are inevitably generated around the cable to be detected according to the electromagnetic induction principle, a closed coil is arranged on the magnetoelectric device, induction current is generated by utilizing magnetism, the induction current is amplified by a signal processor, an electric signal is converted into a sound signal through audio output equipment (such as earphones, sound equipment and the like), and the trend and the depth of the cable are further determined by utilizing the change of the sound signal; when the magnetoelectric device moves left and right along the direction perpendicular to the ground (namely the normal direction of the induction coil forms an included angle of 90 degrees with the ground), the theory of electromagnetic induction considers that: the coil is bound to have magnetic lines of force passing through it. When the magnetoelectric device reaches a point H, the normal direction of the magnetoelectric device is vertical to the field intensity direction of the point, and the magnetic force line passing through the coil is zero, so that the loudness of the sound signal converted by the audio output device is minimum; the method comprises the steps that a magneto-electric device is perpendicular to a tested cable and moves to one side at an angle alpha with the horizontal direction, a sound signal converted by an audio output device has a process of changing from large to small and then changing from small to large, the distance between a point where the minimum sound signal is located and the tested cable is multiplied by tan alpha to be the buried depth of the tested cable at the measuring point, the buried depth of the tested cable at the measuring point is set to be H, alpha is 45 degrees and tan45 degrees is 1, as shown in fig. 2, the magneto-electric device moves from the point H to the point S, the sound signal converted by the audio output device is minimum, the magnetic force line penetrating through a coil is 0, the magneto-electric device moves left and right around the point S, the loudness of the sound signal is changed to large, and the buried depth H, HS, tan45 degrees, namely the distance of a line segment HS, of the tested cable at the point H is formed.
It should be noted that the above-mentioned embodiments are only for illustrating the technical solutions of the present invention and not for limiting, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions may be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, which should be covered by the claims of the present invention.
Claims (10)
1. A method for searching fault points of long cable lines is characterized by comprising the following steps: comprises the steps of (a) preparing a mixture of a plurality of raw materials,
setting the path signal generator output to be intermittent or continuous according to the surrounding environment;
the path signal generator outputs a first signal with fixed frequency and applies the first signal to one item of the tested cable to generate a second signal;
converting the second signal into a third signal by using a magneto-electric device;
amplifying the third signal with a signal processor;
the amplified third signal is converted into a sound signal through audio output equipment;
the variation of the sound signal is used for further determining the trend and the depth of the cable.
2. The method for finding a fault point of a long cable line according to claim 1, wherein: the first signal is a sinusoidal alternating current signal.
3. The method for finding a fault point of a long cable line according to claim 1, wherein: the first signal is a cosine alternating current signal.
4. A method for finding a fault point of a long cable run according to claim 2 or 3, characterized in that: the second signal is a magnetic signal.
5. The method for finding a fault point of a long cable run according to claim 4, wherein: the third signal is an electrical signal.
6. The method for finding a fault point of a long cable run according to claim 5, wherein: the magneto-electric equipment reaches a point H, the loudness of a sound signal converted by the audio output equipment is minimum, and the right lower part of the point H is the correct direction of the cable.
7. The method for finding a fault point on a long cable run according to claim 6, wherein: the magneto-electric equipment moves from the point H to the point S, the sound signal converted by the audio output equipment is minimum, and moves left and right by taking the point S as a center, the loudness of the sound signal is increased, and the embedding depth of the tested cable at the point H is the distance of the line segment HS.
8. The method for finding the fault point of the long cable line according to any one of claims 1 to 3 and 5 to 7, wherein: the magnetoelectric device and the tested cable move to the vertical direction and move to one side at an angle of alpha with the horizontal direction, the sound signal converted by the audio output device has the process of changing from big to small and then changing from small to big, and the distance between the point where the minimum sound signal is located and the tested cable multiplied by tan alpha is the burying depth of the tested cable at the measuring point.
9. The method for finding a fault point on a long cable run according to claim 8, wherein: under the condition that the cable to be measured is known to have a cable middle head, firstly, the accuracy of rough measurement is confirmed, the fixed point range is expanded, the fault point deviation possibly caused by inaccurate measurement is eliminated, and then the fault point is searched.
10. The method for finding a fault point on a long cable run according to claim 8, wherein: under the condition that the cable middle head of the tested cable is unknown, the possibility that fault points exist in other areas is eliminated, and then the fault points are searched.
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| CN202110868662.0A CN113514732A (en) | 2021-07-30 | 2021-07-30 | Long cable line fault point searching method |
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| CN202110868662.0A CN113514732A (en) | 2021-07-30 | 2021-07-30 | Long cable line fault point searching method |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1651926A (en) * | 2005-02-03 | 2005-08-10 | 淄博博鸿电气有限公司 | Power cable damage synchronous magnetic field directioning positioning method |
| CN2872385Y (en) * | 2006-03-02 | 2007-02-21 | 西安四方机电有限责任公司 | Identifier of underground cable path |
| CN101881799A (en) * | 2010-06-23 | 2010-11-10 | 河南送变电建设公司 | Grounding net distribution detector |
| CN102520453A (en) * | 2011-12-15 | 2012-06-27 | 西安四方机电有限责任公司 | Method used for searching path of live power cable |
| CN102680857A (en) * | 2012-05-25 | 2012-09-19 | 河南省电力公司漯河供电公司 | Power cable fault locator |
| CN110031724A (en) * | 2019-04-30 | 2019-07-19 | 广州供电局有限公司 | Distribution cable medial head monitoring device |
-
2021
- 2021-07-30 CN CN202110868662.0A patent/CN113514732A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1651926A (en) * | 2005-02-03 | 2005-08-10 | 淄博博鸿电气有限公司 | Power cable damage synchronous magnetic field directioning positioning method |
| CN2872385Y (en) * | 2006-03-02 | 2007-02-21 | 西安四方机电有限责任公司 | Identifier of underground cable path |
| CN101881799A (en) * | 2010-06-23 | 2010-11-10 | 河南送变电建设公司 | Grounding net distribution detector |
| CN102520453A (en) * | 2011-12-15 | 2012-06-27 | 西安四方机电有限责任公司 | Method used for searching path of live power cable |
| CN102680857A (en) * | 2012-05-25 | 2012-09-19 | 河南省电力公司漯河供电公司 | Power cable fault locator |
| CN110031724A (en) * | 2019-04-30 | 2019-07-19 | 广州供电局有限公司 | Distribution cable medial head monitoring device |
Non-Patent Citations (1)
| Title |
|---|
| 裴继红 等: "10kV电缆主绝缘故障查找应用实例", 山西电力, no. 06, 31 December 2010 (2010-12-31), pages 26 - 27 * |
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