CN112557821B - Low-voltage cable fault magnetic detection fixed point method and system - Google Patents

Low-voltage cable fault magnetic detection fixed point method and system Download PDF

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CN112557821B
CN112557821B CN202011401290.2A CN202011401290A CN112557821B CN 112557821 B CN112557821 B CN 112557821B CN 202011401290 A CN202011401290 A CN 202011401290A CN 112557821 B CN112557821 B CN 112557821B
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cable
voltage
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receiving coil
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CN112557821A (en
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苏珏
廖卫平
何俊廷
冯佳伟
黄练栋
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Jiangmen Power Supply Bureau of Guangdong Power Grid Co Ltd
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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
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00—Systems supporting electrical power generation, transmission or distribution
    • Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
    • Y04S10/52—Outage or fault management, e.g. fault detection or location

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Abstract

The invention relates to the technical field of cable fault detection, in particular to a magnetic detection and point fixing method and a magnetic detection and point fixing system for low-voltage cable faults, which comprise the following steps: s1, adopting a variable-frequency low-voltage signal generator to access a fault phase on one side of a fault cable;s2, applying a voltage with constant voltage amplitude and adjustable frequency to the fault cable through the variable-frequency low-voltage signal generator, automatically adjusting the frequency, searching the active output power of the variable-frequency low-voltage signal generator, and ensuring that the active output power reaches a minimum threshold value P MIN And locking the frequency of the variable-frequency low-voltage signal generator; s3, adjusting the frequency of the fault signal receiver to the frequency corresponding to the variable-frequency low-voltage signal generator; and S4, searching along the direction of the cable path, recording the magnetic induction intensity of each point of the fault signal receiver, and judging the fault point of the low-voltage cable according to the magnetic induction intensity. The method is suitable for finding the fault of the low-voltage cable with any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable, and has better applicability and practicability.

Description

Low-voltage cable fault magnetic detection fixed point method and system
Technical Field
The invention relates to the technical field of cable fault detection, in particular to a magnetic detection fixed-point method and system for low-voltage cable faults.
Background
The method for positioning the fault of the high-voltage power cable mainly comprises two parts of pre-positioning and accurate positioning. Pre-positioning is cable fault coarse ranging, namely measuring the distance from a fault point to a cable head. And the accurate positioning means accurately determining the position of the fault point. The mainstream methods in the pre-positioning method include: bridge method, low-voltage pulse reflection method, pulse voltage method, pulse current method, secondary pulse method, and the like. The method for accurately locating the fault mainly comprises the following steps: the fault finding method mainly aims at high-voltage cable faults, is low in effectiveness when applied to low-voltage cables, and even breaks through other insulation weak positions of the low-voltage cables in the fault finding process.
Chinese patent CN1651926 discloses a synchronous magnetic field orientation positioning method for power cable fault, a voltage pulse generating device is arranged between a fault core wire and a steel armor at any end of a fault cable, and a voltage pulse signal is periodically applied to generate a magnetic field signal which takes the fault point as a center and sequentially changes along the cable direction near the fault point of the fault cable; measuring the polarity and the amplitude of the magnetic field signal along the fault cable by using a magnetic field signal detection device; the direction and the specific position of the fault point can be determined by detecting the change of the polarity and the amplitude of the magnetic field signal. Although the scheme can realize quick orientation and fixed point of cable faults, the scheme adopts the voltage pulse generating device to transmit signals, and is difficult to be suitable for fault query of low-voltage cables.
Disclosure of Invention
The invention aims to overcome the defects in the prior art, and provides a low-voltage cable fault magnetic detection fixed-point method and a low-voltage cable fault magnetic detection fixed-point system, which are suitable for fault finding of a low-voltage cable and cannot damage the insulation level of the normal part of the low-voltage cable.
In order to solve the technical problems, the invention adopts the technical scheme that:
the magnetic detection and positioning method for the low-voltage cable fault comprises the following steps:
s1, a frequency conversion low-voltage signal generator is adopted to access a fault phase on one side of a fault cable, and the opposite side end of the fault cable is suspended;
s2, applying a voltage with constant voltage amplitude and adjustable frequency to the fault cable through the variable-frequency low-voltage signal generator, automatically adjusting the frequency, searching the active output power of the variable-frequency low-voltage signal generator, and ensuring that the active output power reaches a minimum threshold value P MIN To ensure the current intensity flowing through the fault point and lock the frequency of the variable frequency low voltage signal generator;
s3, adjusting the frequency of the fault signal receiver to the frequency corresponding to the variable-frequency low-voltage signal generator;
and S4, searching along the direction of the cable path, recording the magnetic induction intensity of each point of the fault signal receiver, and judging the fault point of the low-voltage cable according to the detected magnetic induction intensity.
The invention relates to a magnetic detection and fixed-point method for low-voltage cable faults, which applies a voltage signal with adjustable frequency to one end of a cable and then searches an electromagnetic field signal generated by a scattered flow field at a fault point on the ground surface through a fault signal receiver to search for the fault fixed-point. Compared with a low-voltage pulse method, a high-voltage flashover method and an acousto-magnetic detection method, the method provided by the invention is suitable for low-voltage cable fault finding of any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable, and has better applicability and practicability.
Preferably, in step S2, a voltage signal with variable frequency is applied to one end of the fault cable, and a current flows into the ground through the inductance of the cable, the inductance of the cable to the ground and the transition resistance of the fault point, so as to establish a cable-to-ground fault cable model.
Preferably, the cable earth fault cable model comprises a variable-frequency low-voltage signal generator S and a cable earth capacitance C before a fault point 1 Rear section cable earth capacitance C of fault point 2 And the front section cable inductance L of the fault point 1 And the inductance L of the cable at the rear section of the fault point 2 And one end of the grounding resistor R and one end of the grounding resistor S of the fault point are respectively connected with the capacitor C 1 、L 1 And the other end of S is respectively connected to C 1 、R、C 2 Another end of (1), L 1 Are respectively connected to R, L at the other ends 2 One end of R and L 2 Is connected at one end to L 2 The other end is connected to C 2 One end of (A) C 1 、C 2 And the other end of the R is connected and grounded.
Preferably, in step S2, the current at the fault point of the fault cable is calculated according to the following formula:
Figure BDA0002817035260000021
in the formula, C 1 The cable is the ground capacitance of the front-section cable of the fault point; c2 is the cable earth capacitance of the rear section of the fault point; l1 is the inductance of the cable at the front section of the fault point; l is a radical of an alcohol 2 The inductance of the cable at the rear section of the fault point; r is the grounding resistance of a fault point; u is the output voltage of the variable-frequency low-voltage generator.
Preferably, in step S2, the current flowing through the fault point forms a dispersion field around the fault point, and the dispersion field forms a circular alternating magnetic field on the ground with the fault point as the center.
Preferably, in step S3, the fault signal receiver includes a first receiving coil, a second receiving coil, a third receiving coil and a fourth receiving coil located on the same horizontal plane, the first receiving coil and the second receiving coil are perpendicular to the cable direction, the third receiving coil and the fourth receiving coil are parallel to the cable direction, and the third receiving coil and the fourth receiving coil are symmetrically located on two sides of the cable respectively.
Preferably, in step S4, when the induced voltages of the first receiving coil, the second receiving coil, the third receiving coil and the fourth receiving coil are equal and the sum is maximum, it is determined that the fault point of the low-voltage cable is directly below the fault signal receiver.
Preferably, before step S1, the insulation megohmmeter is used to measure the resistance of the faulty cable, and the fault type of the faulty low-voltage cable is determined: if the fault is judged to be a low-resistance fault, the step S1 is switched to; if the fault is judged to be a high-resistance fault or a flashover fault, the breakdown of the fault is converted into a low-resistance fault by adopting a burnthrough instrument, and then the step S1 is executed.
The invention also provides a magnetic detection fixed point system for the fault of the low-voltage cable, which comprises a variable-frequency low-voltage generator and a fault signal receiver, wherein the variable-frequency low-voltage generator is connected to a fault phase on one side of the fault cable, and the opposite side end of the fault cable is suspended; the frequency conversion low-voltage generator applies voltage to form a magnetic field around a fault point, and the fault signal receiver receives the magnetic induction intensity of the magnetic field.
The low-voltage cable fault magnetic detection measuring point system applies a voltage signal with adjustable frequency to one end of a cable, and then searches an electromagnetic field signal generated by a dispersion field at a fault point on the ground surface through a fault signal receiver to search for a fault at a fixed point; compared with a low-voltage pulse method, a high-voltage flashover method and an acoustic-magnetic detection method, the method is applicable to fault finding of low-voltage cables with any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable, and has better applicability and practicability.
Furthermore, the fault signal receiver comprises a first receiving coil, a second receiving coil, a third receiving coil and a fourth receiving coil which are located on the same horizontal plane, the first receiving coil and the second receiving coil are perpendicular to the direction of the cable, the third receiving coil and the fourth receiving coil are parallel to the direction of the cable, and the third receiving coil and the fourth receiving coil are respectively and symmetrically located on two sides of the cable.
Compared with the prior art, the invention has the beneficial effects that:
according to the low-voltage cable fault magnetic detection fixed-point method and system, a voltage signal with adjustable frequency is applied to one end of a cable, and then an electromagnetic field signal generated by a scattered flow field at a fault point on the ground surface is searched through a fault signal receiver to carry out fault fixed-point search; compared with a low-voltage pulse method, a high-voltage flashover method and an acoustic-magnetic detection method, the method is applicable to fault finding of low-voltage cables with any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable, and has better applicability and practicability.
Drawings
FIG. 1 is a schematic diagram of a low voltage cable fault magnetic detection point system;
FIG. 2 is a schematic diagram of a cable ground fault cable model;
FIG. 3 is a schematic view of a fault point dissipation field;
FIG. 4 is a schematic diagram of an alternating magnetic field formed by a diffusion field on the ground;
FIG. 5 is a block diagram of a fault signal receiver induction coil;
in the drawings: 1-a cable; 2-fault point; 3-frequency conversion low-voltage signal generator; 4-a fault signal receiver; 41-a first receiving coil; 42-a second receive coil; 43-a third receive coil; 44-fourth receive coil.
Detailed Description
The present invention will be further described with reference to the following embodiments. Wherein the showings are for the purpose of illustration only and are shown by way of illustration only and not in actual form, and are not to be construed as limiting the present patent; to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
Example one
Fig. 2 to 5 show an embodiment of the magnetic fault detection and location method for a low voltage cable 1 according to the present invention, which includes the following steps:
s1, a frequency conversion low-voltage signal generator 3 is connected into a fault phase on one side of a fault cable 1, and the opposite side end of the fault cable 1 is suspended;
s2, applying a voltage with constant voltage amplitude and adjustable frequency to the fault cable 1 through the variable-frequency low-voltage signal generator 3, automatically adjusting the frequency, searching the active output power of the variable-frequency low-voltage signal generator 3, and ensuring that the active output power reaches a minimum threshold value P MIN To ensure the current intensity flowing through the fault point 2 and lock the frequency of the variable frequency low voltage signal generator 3;
s3, adjusting the frequency of the fault signal receiver 4 to the frequency corresponding to the variable-frequency low-voltage signal generator 3;
and S4, searching along the path direction of the cable 1, recording the magnetic induction intensity of each point of the fault signal receiver 4, and judging the fault point 2 of the low-voltage cable 1 according to the detected magnetic induction intensity.
The invention relates to a fault magnetic detection fixed point method of a low-voltage cable 1, which comprises the steps of applying a voltage signal with adjustable frequency to one end of the cable 1, and searching an electromagnetic field signal generated by a free flow field at a fault point 2 on the ground surface through a fault signal receiver 4 to search for a fault fixed point; compared with a low-voltage pulse method, a high-voltage flashover method and an acoustic-magnetic detection method, the method is suitable for fault finding of the low-voltage cable 1 with any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable 1, and has good applicability and practicability.
In step S2, a voltage signal with variable frequency is applied to one end of the fault cable 1, and a current flows into the ground through the inductance of the cable 1, the ground inductance of the cable 1 and the transition resistance of the fault point 2, so as to establish a cable-to-ground fault cable model.
As shown in FIG. 2, the cable model for ground fault comprises a variable frequency low voltage signal generator 3S, a fault point 2 and a front cable 1 with a capacitance to ground C 1 And a rear section cable 1 of a fault point 2 is grounded by a capacitor C 2 And 2 front section cable 1 inductance L of fault point 1 And the inductance L of the rear section cable 1 of the fault point 2 2 And one end of the grounding resistor R and one end of the grounding resistor S of the fault point 2 are respectively connected with the resistor C 1 、L 1 And the other end of S is respectively connected to C 1 、R、C 2 Another end of (1), L 1 Are respectively connected to R, L at the other ends 2 One end of R and L 2 Is connected at one end to L 2 The other end is connected to C 2 One end of (A), C 1 、C 2 And the other end of the R is connected and grounded.
In step S2, the current at fault point 2 of fault cable 1 is calculated according to the following formula:
Figure BDA0002817035260000051
in the formula, C 1 The front-section cable 1 of the fault point 2 is capacitance to ground; c2 is the capacitance to ground of the rear cable 1 of the fault point 2; l1 is the inductance of the cable 1 at the front section of the fault point 2; l is 2 The inductance of the cable 1 at the rear section of the fault point 2; r is the grounding resistance of the fault point 2; u is the output voltage of the variable-frequency low-voltage generator.
In step S2, the current flowing through the failure point 2 forms a radiation field around the failure point 2, as shown in fig. 3; each differential current in the dispersive field will produce a magnetic induction at the surface above the fault point 2. For convenient calculation, influence of the cable 1 on a dispersion field in soil is ignored, and the resistivity and the permeability of the soil around the fault point 2 are the same, so that points with the same distance from the fault point 2 have the same current density rho R Current density ρ at point Q R Will generate a magnetic induction B at the ground point P P According to the biot-savart law, there are:
Figure BDA0002817035260000052
in the formula: mu.s 0 Vacuum magnetic conductivity; a is the distance from the point P to any point Q in the astigmatism field.
According to the symmetry analysis, the magnetic field intensity B generated by the whole stray field at the point P can be judged P The direction is vertical to the connecting line of the point P and the point O right above the fault point 2 and is parallel to the ground. Therefore, it can be judged that the free flow field formed by the fault point 2 forms a circular alternating magnetic field on the ground with the point O as the center, as shown in fig. 4.
In step S3, the fault signal receiver 4 includes a first receiving coil 41, a second receiving coil 42, a third receiving coil 43, and a fourth receiving coil 44 located on the same horizontal plane, where the first receiving coil 41 and the second receiving coil 42 are perpendicular to the cable 1 direction, the third receiving coil 43 and the fourth receiving coil 44 are parallel to the cable 1 direction, and the third receiving coil 43 and the fourth receiving coil 44 are symmetrically located on both sides of the cable 1, respectively, as shown in fig. 5.
In step S4, when the induced voltages of the first receiving coil 41, the second receiving coil 42, the third receiving coil 43, and the fourth receiving coil 44 are equal to each other and the sum is maximum, it is determined that the failure point 2 of the low-voltage cable 1 is located directly below the failure signal receiver 4.
Before step S1, the insulation megohmmeter is used to measure the resistance value of the fault cable 1, and the fault type of the fault low-voltage cable 1 is determined: if judging that the fault is a low-resistance fault, turning to step S1; if the fault is judged to be a high-resistance fault or a flashover fault, the breakdown of the fault is converted into a low-resistance fault by adopting a burnthrough instrument, and then the step S1 is executed.
Example two
The embodiment is an embodiment of a fault magnetic detection measuring point system of a variable-frequency low-voltage cable 1, and comprises a variable-frequency low-voltage generator and a fault signal receiver 4, wherein the variable-frequency low-voltage generator is connected to a fault phase on one side of the fault cable 1, and the opposite side end of the fault cable 1 is suspended; the variable frequency low voltage generator applies a voltage to form a magnetic field around the fault point 2 and the fault signal receiver 4 receives the magnetic induction of the magnetic field as shown in fig. 1.
According to the frequency conversion low-voltage cable 1 fault magnetic detection measuring point system, a voltage signal with adjustable frequency is applied to one end of a cable 1, and then an electromagnetic field signal generated by a free flow field at a fault point 2 on the ground surface is searched through a fault signal receiver 4 to carry out fault fixed point search; compared with a low-voltage pulse method, a high-voltage flashover method and an acoustic-magnetic detection method, the method is suitable for fault finding of the low-voltage cable 1 with any wire diameter, does not damage the insulation level of the normal part of the low-voltage cable 1, and has good applicability and practicability.
The fault signal receiver 4 includes a first receiving coil 41, a second receiving coil 42, a third receiving coil 43, and a fourth receiving coil 44 located on the same horizontal plane, the first receiving coil 41 and the second receiving coil 42 are perpendicular to the cable 1 direction, the third receiving coil 43 and the fourth receiving coil 44 are parallel to the cable 1 direction, and the third receiving coil 43 and the fourth receiving coil 44 are respectively located on two sides of the cable 1 symmetrically.
It should be understood that the above-described embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. This need not be, nor should it be exhaustive of all embodiments. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention should be included in the protection scope of the claims of the present invention.

Claims (7)

1. A magnetic detection and point fixing method for low-voltage cable faults is characterized by comprising the following steps:
s1, a frequency conversion low-voltage signal generator (3) is connected into a fault phase on one side of a fault cable (1), and the opposite side end of the fault cable is suspended;
s2, applying a voltage with constant voltage amplitude and adjustable frequency to the fault cable through the variable-frequency low-voltage signal generator (3), automatically adjusting the frequency, searching the active output power of the variable-frequency low-voltage signal generator (3), and ensuring that the active output power reaches a minimum threshold value P MIN To ensure the current intensity flowing through the fault point (2) and lock the frequency of the variable-frequency low-voltage signal generator (3);
s3, adjusting the frequency of the fault signal receiver (4) to the frequency corresponding to the variable-frequency low-voltage signal generator (3);
s4, searching along the direction of a cable path, recording the magnetic induction intensity of each point of the fault signal receiver (4), and judging the low-voltage cable fault point (2) according to the detected magnetic induction intensity;
in step S2, applying a voltage signal with variable frequency to one end of a fault cable, and establishing a cable ground fault cable model by enabling current to flow into the ground through the inductance of the cable, the ground inductance of the cable and the transition resistance of a fault point (2);
the cable model for the ground fault comprises a variable-frequency low-voltage signal generator S and a cable ground capacitor C at the front section of a fault point 1 Rear section cable earth capacitance C of fault point 2 Front section cable inductor L of fault point 1 And the inductance L of the cable at the rear section of the fault point 2 And one end of the grounding resistor R and one end of the grounding resistor S of the fault point are respectively connected with the capacitor C 1 、L 1 And the other end of S is respectively connected to C 1 、R、C 2 Another end of (1), L 1 Are respectively connected to R, L at the other ends 2 One end of R and L 2 Is connected at one end to L 2 The other end is connected to C 2 One end of (A), C 1 、C 2 The other end of the R is connected and grounded;
in step S2, the current at the fault point (2) of the faulty cable is calculated according to the following formula:
Figure FDA0003736430510000011
in the formula, C 1 The cable is the ground capacitance of the front-section cable of the fault point; c2 is the cable earth capacitance of the rear section of the fault point; l1 is the inductance of the cable at the front section of the fault point; l is a radical of an alcohol 2 The inductance of the cable at the rear section of the fault point; r is the grounding resistance of a fault point; u is the output voltage of the variable frequency low voltage generator.
2. The low voltage cable fault magnetic detection pointing method according to claim 1, wherein in step S2, the current flowing through the fault point (2) forms a dispersion field around the fault point (2), and the dispersion field forms a circular alternating magnetic field on the ground centered around the fault point (2).
3. The low voltage cable fault magnetic detection pointing method according to claim 1, wherein in step S3, the fault signal receiver (4) includes a first receiving coil (41), a second receiving coil (42), a third receiving coil (43), and a fourth receiving coil (44) located at the same horizontal plane, the first receiving coil (41) and the second receiving coil (42) are perpendicular to the cable direction, the third receiving coil (43) and the fourth receiving coil (44) are parallel to the cable direction, and the third receiving coil (43) and the fourth receiving coil (44) are respectively located at two sides of the cable symmetrically.
4. The low-voltage cable fault magnetic detection locating method according to claim 3, characterized in that in step S4, when the induced voltages of the first receiving coil (41), the second receiving coil (42), the third receiving coil (43) and the fourth receiving coil (44) are equal and the sum is maximum, it is determined that the fault signal receiver (4) is a low-voltage cable fault point (2) directly below.
5. The magnetic detection and pointing method for low-voltage cable faults according to claim 1, wherein before step S1, an insulation megohmmeter is used to measure the fault cable resistance value to determine the fault type of the fault low-voltage cable: if judging that the fault is a low-resistance fault, turning to step S1; if the fault is judged to be a high-resistance fault or a flashover fault, the breakdown of the fault is converted into a low-resistance fault by adopting a burn-through instrument, and then the step S1 is executed.
6. A magnetic detection and pointing system for faults of low-voltage cables, characterized in that it is used to implement the method of claim 1, said system comprises a variable frequency low-voltage generator and a fault signal receiver (4), the variable frequency low-voltage generator is connected to the fault phase on one side of the fault cable, and the opposite side end of the fault cable is suspended; the variable-frequency low-voltage generator applies voltage to form a magnetic field around the fault point (2), and the fault signal receiver (4) receives the magnetic induction intensity of the magnetic field.
7. The low-voltage cable fault magnetic detection pointing system according to claim 6, characterized in that the fault signal receiver (4) comprises a first receiving coil (41), a second receiving coil (42), a third receiving coil (43) and a fourth receiving coil (44) which are located at the same horizontal plane, the first receiving coil (41) and the second receiving coil (42) are perpendicular to the cable direction, the third receiving coil (43) and the fourth receiving coil (44) are parallel to the cable direction, and the third receiving coil (43) and the fourth receiving coil (44) are symmetrically located at two sides of the cable respectively.
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Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6263047B1 (en) * 1999-09-07 2001-07-17 Tempo Research Corporation Apparatus and method for characterizing the loading pattern of a telecommunications transmission line
CN100410675C (en) * 2005-02-03 2008-08-13 淄博博鸿电气有限公司 Power cable damage synchronous magnetic field directioning positioning method
CN201789474U (en) * 2010-08-19 2011-04-06 河南省电力公司郑州供电公司 Low-voltage pulse generator based on single chip microcomputer
CN102540008A (en) * 2010-12-17 2012-07-04 中冶宝钢技术服务有限公司 Cable fault detection instrument
TWI580992B (en) * 2011-11-18 2017-05-01 富克有限公司 System, method and test instrument for determining location and orientation of wire
CN102759686B (en) * 2012-07-26 2015-04-01 山东科汇电力自动化股份有限公司 Method for locating power cable faults
CN203798967U (en) * 2014-04-08 2014-08-27 国家电网公司 Detection impedance unit of long-distance high-voltage cable partial discharging and fault positioning
CN105388392B (en) * 2015-10-20 2018-04-03 北京交通大学 The single-ended online Fault Locating Method of DC distribution cable based on apparent impedance identification
KR102268079B1 (en) * 2017-11-21 2021-06-23 주식회사 엘지화학 Positive electrode active material for secondary battery, method for preparing the same and lithium secondary battery comprising the same
CN110350969B (en) * 2019-07-29 2021-04-27 浙江大学 Submarine observation network and submarine cable short-circuit fault positioning method based on optical fiber energy transmission

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