CN110554295A - method for searching power cable insulation fault point by using high-precision multimeter - Google Patents
method for searching power cable insulation fault point by using high-precision multimeter Download PDFInfo
- Publication number
- CN110554295A CN110554295A CN201810561496.8A CN201810561496A CN110554295A CN 110554295 A CN110554295 A CN 110554295A CN 201810561496 A CN201810561496 A CN 201810561496A CN 110554295 A CN110554295 A CN 110554295A
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- Prior art keywords
- cable
- phase
- point
- fault point
- fault
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Classifications
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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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/1227—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials
- G01R31/1263—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation
- G01R31/1272—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing of components, parts or materials of solid or fluid materials, e.g. insulation films, bulk material; of semiconductors or LV electronic components or parts; of cable, line or wire insulation of cable, line or wire insulation, e.g. using partial discharge measurements
-
- 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
- G01R31/12—Testing dielectric strength or breakdown voltage ; Testing or monitoring effectiveness or level of insulation, e.g. of a cable or of an apparatus, for example using partial discharge measurements; Electrostatic testing
- G01R31/14—Circuits therefor, e.g. for generating test voltages, sensing circuits
Abstract
a method for searching an insulation fault point of a power cable by using a high-precision multimeter comprises the following steps: one end of a fault phase B is connected with the same end of a cable phase A, and the other end of the cable phase B and the other end of the cable phase A are connected with the output end of a current generator; connecting one end of the C phase of the cable with a steel belt of the cable, and connecting the other end of the C phase with the other end of the steel belt and connecting the other end of the C phase with the output end of the current generator; thirdly, selecting the gear of the voltmeter to be below 1 mV; fourthly, the test power supply is switched on, the switch is connected to a k1 position to read the voltmeter, and the value is the voltage V1 between the point a and the fault point; keeping the test current unchanged, connecting the switch to k2, and reading the value of a voltmeter, wherein the value is the voltage V2 between the point b and the fault point; setting the length of the cable as L and the length of the fault point and the power supply point a as Lx; seventhly, calculating the distance Lx between the fault point and the point a; adjusting the current, measuring for several times according to the step, and calculating an average value. The invention can quickly find the fault point and has extremely low cost.
Description
The technical field is as follows:
the invention belongs to a method suitable for searching fault points in installation engineering and operation of electrical equipment, and particularly relates to a method for searching an insulation fault point of a power cable by using a high-precision multimeter.
Background art:
In the power installation engineering and the operation of power equipment, main insulation breakdown faults caused by insulation reduction of cables or tearing and twisting of armored steel belts often occur. How to accurately and quickly locate the fault point after breakdown is a difficult point to solve. At present, cable fault tests have various modes, such as a pulse method, a flashover method, a bridge method, an audio method and the like, but the equipment investment cost is expensive and is not economical and reasonable.
the invention content is as follows:
The present invention is directed to overcome the above-mentioned shortcomings of the prior art, and provides a method for finding insulation fault point of power cable by using a high-precision multimeter, which can quickly find the fault point after insulation breakdown of the buried power cable in power installation engineering and power equipment operation, and has a very low cost.
As conceived above, the technical scheme of the invention is as follows: a method for searching an insulation fault point of a power cable by using a high-precision multimeter is characterized by comprising the following steps: the method comprises the following steps:
one end of a fault phase B is connected with the same end of a cable phase A, and the other end of the cable phase B and the other end of the cable phase A are connected with the output end of a current generator;
connecting one end of the C phase of the cable with a steel belt of the cable, and connecting the other end of the C phase with the other end of the steel belt and connecting the other end of the C phase with the output end of the current generator;
Thirdly, selecting the gear of the voltmeter to be below 1 mV;
Fourthly, the test power supply is switched on, the switch is connected to the position k1, the output current is regulated until the voltmeter has obvious reading, and the reading and the recording are carried out, wherein the value is the voltage V1 between the point a and the fault point;
Keeping the test current unchanged, connecting a switch to k2, reading and recording the value of a voltmeter, wherein the value is the voltage V2 between the point b and the fault point;
Setting the length of the cable as L and the length of the fault point and the power supply point a as Lx;
According to the formuladerived out ofThus calculating the distance Lx between the fault point and the point a;
And adjusting the current, measuring for 3-5 times according to the step, and calculating an average value, wherein the average value is the approximate position distance of the fault point.
The method is realized by utilizing the relationship between the resistivity of the cables at two sides of the fault point and the length of the cable core, and the fault point after insulation breakdown of the direct-buried power cable in the power installation engineering and the power equipment operation can be quickly found by only using a high-precision voltmeter (the gear is below 1 mV) and a current generator, and the cost is extremely low.
Description of the drawings:
FIG. 1 is a wiring diagram of the present invention;
fig. 2 is an equivalent circuit diagram of the test wiring of the present invention.
in the figure: a-cable phase A; b-cable phase B; c-cable C phase; i-a current generator; v-voltmeter; l-cable length; l isx-distance of the failure point to the test end.
the specific implementation mode is as follows:
as shown in the figure: a method for searching an insulation fault point of a power cable by using a high-precision multimeter takes B-phase insulation breakdown of an armored cable as an example, and comprises the following steps:
1. One end of the fault phase (phase B) is reliably connected with the same end of the cable phase A by a copper nose. The other end of the B-phase cable and the other end of the A-phase cable are connected with the output end of the current generator, as shown in the figure.
2. And one end of the cable C phase is reliably connected with the steel belt of the cable. And connecting the other end of the phase C with the other end of the steel strip and connecting the other end of the phase C with the output end of the current generator.
3. Since the resistance at the fault point cannot be determined, the voltmeter can obtain a clear reading when the current generator supplies a small current when the resistance is small. When the resistance of the fault point is large, large current is needed to obtain obvious voltage reading, so the gear of the voltmeter is selected to be below 1 mV.
4. The test power was turned on, the switch was connected to the k1 position, and the output current was regulated until the voltmeter had a clear reading, read and recorded. This value is the voltage at point a and the fault point V1.
5. the test current was held constant and the switch was connected to k2 and the voltmeter value was read and recorded. This value is the voltage at point b and the fault point V2.
6. the length of the cable is set to be L, and the length of the fault point and the power supply point a is set to be Lx.
7. according to the formuladerived out ofthus, the distance Lx between the fault point and the point a is calculated.
8. And adjusting the current, measuring for 3-5 times according to the step, and calculating an average value, wherein the average value is the approximate position distance of the fault point.
9. in order to ensure the precision of the measurement result, the accuracy of the total length of the cable and the stability of the test current should be ensured.
Claims (1)
1. A method for searching an insulation fault point of a power cable by using a high-precision multimeter is characterized by comprising the following steps: the method comprises the following steps:
Connecting one end of a fault phase B phase with the same end of a cable phase A, and connecting the other end of the cable phase B and the other end of the cable phase A with the output end of a current generator;
connecting one end of the C phase of the cable with a steel belt of the cable, and connecting the other end of the C phase with the other end of the steel belt and connecting the other end of the C phase with the output end of the current generator;
Thirdly, selecting the gear of the voltmeter to be below 1 mV;
Fourthly, the test power supply is switched on, the switch is connected to the position k1, the output current is regulated until the voltmeter has obvious reading, and the reading and the recording are carried out, wherein the value is the voltage V1 between the point a and the fault point;
Keeping the test current unchanged, connecting a switch to k2, reading and recording the value of a voltmeter, wherein the value is the voltage V2 between the point b and the fault point;
Setting the length of the cable as L and the length of the fault point and the power supply point a as Lx;
According to the formulaDerived out ofthus calculating the distance Lx between the fault point and the point a;
and adjusting the current, measuring for 3-5 times according to the step, and calculating an average value, wherein the average value is the approximate position distance of the fault point.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810561496.8A CN110554295A (en) | 2018-06-04 | 2018-06-04 | method for searching power cable insulation fault point by using high-precision multimeter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810561496.8A CN110554295A (en) | 2018-06-04 | 2018-06-04 | method for searching power cable insulation fault point by using high-precision multimeter |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN110554295A true CN110554295A (en) | 2019-12-10 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201810561496.8A Pending CN110554295A (en) | 2018-06-04 | 2018-06-04 | method for searching power cable insulation fault point by using high-precision multimeter |
Country Status (1)
| Country | Link |
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| CN (1) | CN110554295A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113804543A (en) * | 2021-09-14 | 2021-12-17 | 山东省医疗器械和药品包装检验研究院 | Artificial cochlea implant electrode lead stretchability evaluation method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54155082A (en) * | 1978-05-26 | 1979-12-06 | Hitachi Cable Ltd | Insulating faulty point location detecting circuit of wire and cable |
| CN101290339A (en) * | 2007-04-20 | 2008-10-22 | 宝山钢铁股份有限公司 | High-voltage cable trouble point checking method and its device |
| CN102298104A (en) * | 2010-06-25 | 2011-12-28 | 上海宝钢工业检测公司 | Method for detecting ground fault of bridge cable |
-
2018
- 2018-06-04 CN CN201810561496.8A patent/CN110554295A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54155082A (en) * | 1978-05-26 | 1979-12-06 | Hitachi Cable Ltd | Insulating faulty point location detecting circuit of wire and cable |
| CN101290339A (en) * | 2007-04-20 | 2008-10-22 | 宝山钢铁股份有限公司 | High-voltage cable trouble point checking method and its device |
| CN102298104A (en) * | 2010-06-25 | 2011-12-28 | 上海宝钢工业检测公司 | Method for detecting ground fault of bridge cable |
Non-Patent Citations (2)
| Title |
|---|
| 徐丙垠: ""高压电缆护层故障测距新方法"", 《山东工程学院学报》 * |
| 杨济溶: ""多芯电缆故障部位的快速查找方法"", 《中小企业管理与科技(上旬刊)》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113804543A (en) * | 2021-09-14 | 2021-12-17 | 山东省医疗器械和药品包装检验研究院 | Artificial cochlea implant electrode lead stretchability evaluation method |
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Application publication date: 20191210 |