CN112599287A - Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method - Google Patents
Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method Download PDFInfo
- Publication number
- CN112599287A CN112599287A CN202011331101.9A CN202011331101A CN112599287A CN 112599287 A CN112599287 A CN 112599287A CN 202011331101 A CN202011331101 A CN 202011331101A CN 112599287 A CN112599287 A CN 112599287A
- Authority
- CN
- China
- Prior art keywords
- phase line
- insulation resistance
- steel armor
- copper
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B9/00—Power cables
- H01B9/02—Power cables with screens or conductive layers, e.g. for avoiding large potential gradients
- H01B9/028—Power cables with screens or conductive layers, e.g. for avoiding large potential gradients with screen grounding means, e.g. drain wires
-
- G—PHYSICS
- G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
- G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
- G09B19/00—Teaching not covered by other main groups of this subclass
- G09B19/0069—Engineering, e.g. mechanical, electrical design
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/02—Disposition of insulation
- H01B7/0208—Cables with several layers of insulating material
- H01B7/0225—Three or more layers
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/36—Insulated conductors or cables characterised by their form with distinguishing or length marks
- H01B7/365—Insulated conductors or cables characterised by their form with distinguishing or length marks being indicia imposed on the insulation or conductor
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B7/00—Insulated conductors or cables characterised by their form
- H01B7/38—Insulated conductors or cables characterised by their form with arrangements for facilitating removal of insulation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B9/00—Power cables
- H01B9/02—Power cables with screens or conductive layers, e.g. for avoiding large potential gradients
- H01B9/021—Features relating to screening tape per se
Landscapes
- Engineering & Computer Science (AREA)
- Business, Economics & Management (AREA)
- Computer Hardware Design (AREA)
- General Engineering & Computer Science (AREA)
- Entrepreneurship & Innovation (AREA)
- Physics & Mathematics (AREA)
- Educational Administration (AREA)
- Educational Technology (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Testing Of Short-Circuits, Discontinuities, Leakage, Or Incorrect Line Connections (AREA)
Abstract
The invention discloses a teaching power cable, a fault judgment method thereof and a manufacturing method of an intermediate joint, wherein the teaching power cable comprises an A phase line, a B phase line and a C phase line, the A phase line, the B phase line and the C phase line are extruded together through an inner sheath, an outer sheath and a steel armor layer to form a power cable, the inner sheath is arranged at one side close to the A phase line, the B phase line and the C phase line, the outer sheath is arranged at one side far away from the A phase line, the B phase line and the C phase line, fillers are arranged between the inner sheath and the A phase line, the B phase line and the C phase line, the steel armor layer is arranged between the inner sheath and the outer sheath, the A phase line, the B phase line and the C phase line at the left end of the cable are cable terminal-shaped parts, the A phase line, the B phase line and the C phase line at the right end of the cable are cable capable of showing internal structure parts, the intermediate joint is, so as to facilitate the teaching of cable fault property judgment. The invention is convenient for teaching, can be repeatedly used and does not waste resources.
Description
Technical Field
The invention belongs to the field of power cables, and particularly relates to a teaching power cable, a fault judgment method thereof and a middle joint manufacturing method.
Background
The power cable is used for transmitting and distributing electric energy, the power cable is commonly used for urban underground power grids, power station leading-out lines, power supply inside industrial and mining enterprises and power transmission lines under river-crossing seawater, in the power line, the proportion of the cable is gradually increased, the power cable is a cable product used for transmitting and distributing high-power electric energy in a main line of the power system, the power cable is known and how to judge that the fault of the power cable is an indispensable course in practical teaching, the power cable used for physical connection operation and judgment is usually made of national standard cables, however, in the teaching, if the national standard cable is directly used, the cost is very high, the waste phenomenon is serious, and in the teaching of judging the fault property of the cable, various faults are not easy to set vividly, and the teaching effect is influenced.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: the teaching power cable and the fault judgment method thereof and the intermediate joint manufacturing method can vividly demonstrate fault judgment of the power cable.
The technical scheme adopted by the invention for solving the technical problem is as follows:
the power cable for teaching comprises an A phase line, a B phase line and a C phase line, wherein the A phase line, the B phase line and the C phase line form a power cable through extrusion molding of an inner sheath, an outer sheath and a steel armor layer, the inner sheath is arranged on one side close to the A phase line, the B phase line and the C phase line, the outer sheath is arranged on one side far away from the A phase line, the B phase line and the C phase line, fillers are arranged between the inner sheath and the A phase line, the B phase line and the C phase line, the steel armor layer is arranged between the inner sheath and the outer sheath, the A phase line, the B phase line and the C phase line at the left end of the cable are cable terminal-shaped parts, the A phase line, the B phase line and the C phase line at the right end of the cable are stripped and cut parts capable of displaying internal structure of the cable, an intermediate joint is arranged at the intermediate part of, The B phase line and the C phase line are respectively set to be fault structures so as to facilitate the teaching of cable fault property judgment, and the power cable is provided with a cable model so as to facilitate the teaching of the cable model and technical parameters.
The structure that sets up respectively and each other of the internal A phase line, B phase line and C phase line of intermediate head is: the phase line A is conducted, the phase line B and the phase line C are disconnected, the phase line A is connected with the steel armor layer through a conducting wire and then is connected with a capacitor, the left end of the disconnected phase line B is directly connected with the steel armor layer through the conducting wire and is equivalent to direct grounding, and the right end of the disconnected phase line B is connected with a first resistor through the conducting wire and then is connected with the steel armor layer and is equivalent to grounding through a resistor; the left end of the disconnected phase line C is connected with the second resistor through a wire and then is connected with the steel armor layer, namely the phase line C is grounded through the resistor, and the right end of the disconnected phase line C is connected with the phase line B through a wire and then is connected with the third resistor, namely the phase-to-phase short circuit; the first resistor, the second resistor and the third resistor are low-resistance resistors or high-resistance resistors.
The phase line A, the phase line B and the phase line C all include sinle silk, interior semi-conducting layer, main insulating layer, outer semi-conducting layer and copper shield layer, the sinle silk by first the interior semi-conducting layer wraps up, interior semi-conducting layer with set gradually between the copper shield layer main insulating layer and outer semi-conducting layer, phase line A, phase line B and phase line C with be connected between the steel armoring layer and the connection that phase line A, phase line B and phase line C are each other all sinle silk with be connected of steel armoring layer or be connected between sinle silk and the sinle silk.
The disconnection part of the phase line B and the phase line C adopts a non-crimping connecting pipe, a certain gap is kept, copper-plastic wires are welded on two sides of the disconnection part of the phase line B and the phase line C, the copper-plastic wires welded on the phase line B on the left side of the disconnection part of the phase line B extend out of the outer layer of the inner sheath and then are welded on the steel armor layer, and the copper-plastic wires welded on the phase line B on the right side extend out of the outer layer of the inner sheath and then are connected with the first resistor in series and then are welded on the steel armor layer; the copper-plastic wire welded on the C wire on the left side of the C-phase wire disconnection position extends out of the outer layer of the inner sheath and then is connected with the second resistor in series and then is welded to the steel armor layer, and the copper-plastic wire welded on the C wire on the right side extends out of the main insulating layer and then is connected with the third resistor in series and then is welded to the copper-plastic wire extending out of the B-phase wire on the right end of the disconnection position; and a copper-plastic wire is led out of the phase line A, extends out of the outer layer of the inner sheath, is connected with the capacitor in series and is welded to the steel armor layer, and all the structures are connected in the outer sheath.
A power cable fault judging method comprises the following steps,
1) respectively leading out a copper-plastic wire from both ends of the phase line A, the phase line B and the phase line C on the power cable and both ends of the steel armor layer;
2) respectively carrying out short circuit on the phase line A, the phase line B, the phase line C and the steel armor layer at one end of the power cable in pairs by using the led-out copper-plastic wires, measuring the insulation resistance of the two short-circuited wires at the other end of the power cable by using an insulation meter, recording the insulation resistance value, and judging whether the phase line A, the phase line B and the phase line C are broken or not according to the recorded combined insulation resistance value;
3) removing the lead wires of the A phase wire, the B phase wire, the C phase wire and the steel armor layer at one end of the power cable in a manner of being respectively short-circuited two by utilizing the led-out copper-plastic wires, then measuring the insulation resistance value between the A phase wire and the B phase wire, the insulation resistance value between the A phase wire and the C phase wire and the insulation resistance value between the B phase wire and the C phase wire at two ends of the power cable by using an insulation resistance meter respectively, recording the insulation resistance values, and judging the interphase short circuit or the interphase insulation resistance value reduction through the recorded combined insulation resistance values;
4) respectively measuring the insulation resistance value between the phase line A and the copper-plastic wire led out from the steel armor layer, the insulation resistance value between the phase line B and the copper-plastic wire led out from the steel armor layer and the insulation resistance value between the phase line C and the copper-plastic wire led out from the steel armor layer by using an insulation resistance meter at two ends of the power cable, recording the insulation resistance values, and judging whether the insulation is good, high-resistance grounding, low-resistance grounding or direct grounding according to the recorded combined insulation resistance value;
in step 2), the recorded insulation resistance values are respectively the insulation resistance value between the phase line A and the phase line B, the insulation resistance value between the phase line A and the phase line C, the insulation resistance value between the phase line B and the phase line C, the insulation resistance value between the phase line A and the steel armor layer, the insulation resistance value between the phase line B and the steel armor layer and the insulation resistance value between the phase line C and the steel armor layer, and the recording result shows, the insulation resistance value between the phase line A and the phase line B, the insulation resistance value between the phase line A and the phase line C, the insulation resistance value between the phase line B and the steel armor layer and the insulation resistance value between the phase line C and the steel armor layer are infinite, the insulation resistance value between the phase line A and the steel armor layer is very small and close to zero, it can be known that the phase line A and the steel armor layer are conducted, and the phase line B and the phase line C are disconnected.
In step 3), among the recorded insulation resistance values, the insulation resistance values between the phase lines a and B at both ends of the power cable are both large, the insulation resistance values between the phase lines a and C at both ends of the power cable are also large, the insulation resistance value between the phase lines B and C at one end of the power cable is large, the insulation resistance value between the phase lines B and C at the other end of the power cable is reduced, and then it is determined that an inter-phase short circuit occurs between the phase lines B and C at the end where the insulation resistance value is reduced.
In the step 4), in the recorded insulation resistance values, the insulation resistance values between the two ends of the phase line A and the copper-plastic wires led out from the steel armor layer are all changed all the time, which indicates that the insulation between the two ends of the phase line A and the steel armor layer is good, and a capacitor is arranged between the phase line A and the steel armor layer, which is equivalent to a grounding capacitor, and can calculate an absorption ratio, wherein the common absorption ratio is the insulation resistance value of one minute divided by the insulation resistance value of fifteen seconds; the insulation resistance value between the left end of the phase line B and the steel armor layer is very small and is close to zero, the condition that the left end of the phase line B is directly connected with the steel armor layer is equivalent to direct grounding, the insulation resistance value between the right end of the phase line B and the steel armor layer is reduced, and the condition that the right end of the phase line B is connected with the steel armor layer through a resistor is indicated; the insulation resistance value between the left end of the C-phase line and the steel armor layer is reduced, the fact that the left end of the C-phase line is connected with the steel armor layer through a resistor is shown, the insulation resistance value between the right end of the C-phase line and the steel armor layer is infinite, and the fact that the insulation between the right end of the C-phase line and the steel armor layer is good is shown.
A manufacturing method of an intermediate joint of a power cable comprises the following steps:
1) stripping the power cable at the position where the middle joint is arranged, exposing the phase line A, the phase line B and the phase line C inside, cutting off the phase line B and the phase line C from the middle, and cutting off a section;
2) the method comprises the following steps that non-crimping connecting pipes are adopted at the disconnected positions of the phase line B and the phase line C, a certain gap is kept, lead-out copper-plastic wires are welded at two sides of the disconnected positions of the phase line B and the phase line C, a main insulating layer is contracted after the copper-plastic wires are led out, and a copper-plastic wire is also led out from the phase line A without cutting off the phase line A;
3) welding the copper-plastic wires welded on the B phase line on the left side of the disconnected position of the B phase line to the steel armor layer after extending out of the outer layer of the inner sheath, and welding the copper-plastic wires welded on the B phase line on the right side to the steel armor layer after extending out of the outer layer of the inner sheath and being connected with the first resistor in series;
4) extending the copper-plastic wire welded on the C wire on the left side of the C-phase wire disconnection position out of the outer layer of the inner sheath, connecting the copper-plastic wire with the second resistor in series, welding the copper-plastic wire on the steel armor layer, extending the copper-plastic wire welded on the C wire on the right side out of the main insulating layer, connecting the copper-plastic wire with the third resistor in series, and welding the copper-plastic wire extended on the B wire on the right end of the disconnection position;
5) the copper-plastic wire led out from the phase line A extends out of the outer layer of the inner sheath, is connected with the capacitor in series and is welded to the steel armor layer;
6) after the components are welded, the steel armor layer is connected, and finally the outer sheath is shrunk.
In step 2), a copper-plastic wire is also led out from the phase a wire, which means that a core is stripped and cut from the phase a wire by adopting a stripping and cutting method, a copper-plastic wire is welded and led out of the phase a wire, and then an inner semi-conducting layer, a main insulating layer, an outer semi-conducting layer and a copper shielding layer on the phase a wire are respectively connected and restored.
The invention has the following positive beneficial effects:
the left end of the cable is set to be the cable terminal shape part, so that the teaching of the cable terminal can be facilitated; phase lines A, B and C at the right end of the cable are stripped and cut to show the internal structure of the cable, so that the teaching of the structural composition and composition function of the cable can be conveniently carried out; the middle part of the cable is provided with an intermediate joint, and phase lines A, B and C in the intermediate joint are respectively arranged into fault structures so as to facilitate the teaching of judging the fault property of the cable; the absorption ratio can be measured, and the cable model is arranged on the power cable, so that the teaching of the cable model and the technical parameters is facilitated; all the teaching can be explained on the same power cable, so that the teaching device is convenient and practical, can be repeatedly utilized, and does not waste resources; in addition, because various faults are arranged in the intermediate joint, various judgment results can be taught aiming at the various faults when the faults are judged, and the teaching effect is greatly improved.
Drawings
FIG. 1 is a schematic view of the overall construction of a teaching power cable according to the present invention;
FIG. 2 is a schematic structural view of the intermediate joint section of FIG. 1;
FIG. 3 is a view of the left end power cable connection of the center connector portion;
fig. 4 is a diagram of a power cable connection structure at the right end of the intermediate joint part.
Detailed Description
The invention will be further explained and explained with reference to the drawings and the specific embodiments:
referring to fig. 1, 2, 3 and 4, in which: 1-phase line A, 2-phase line B, 3-phase line C, 4-inner sheath, 5-outer sheath, 6-power cable, 7-filler, 8-steel armor layer, 9-cable terminal shape part, 10-cable internal structure part, 11-middle part, 12-middle joint, 13-first resistor, 14-second resistor, 15-third resistor, 16-cable model, 17-wire core, 18-inner semi-conductive layer, 19-main insulating layer, 20-outer semi-conductive layer, 21-copper shielding layer and 22-capacitor.
Example (b): a power cable 6 for teaching comprises an A phase line 1, a B phase line 2 and a C phase line 3, wherein the A phase line 1, the B phase line 2 and the C phase line 3 are extruded together through an inner sheath 4, an outer sheath 5 and a steel armor layer 8 to form the power cable 6, the inner sheath 4 is arranged on one side close to the A phase line 1, the B phase line 2 and the C phase line 3, the outer sheath 5 is arranged on one side far away from the A phase line 1, the B phase line 2 and the C phase line 3, a filler 7 is arranged between the inner sheath 4 and the A phase line 1, the B phase line 2 and the C phase line 3, the steel armor layer 8 is arranged between the inner sheath 4 and the outer sheath 5, the A phase line 1, the B phase line 2 and the C phase line 3 at the left end of the cable are cable terminal-shaped parts 9, the A phase line 1, the B phase line 2 and the C phase line 3 at the right end of the cable are, phase lines A1, B2 and C3 in the middle joint 12 are respectively set to be fault structures to facilitate the teaching of cable fault property judgment, and a cable model 16 is arranged on the power cable 6 to facilitate the teaching of the cable model 16 and technical parameters.
The structure that phase line 1, phase line 2 and C3 of A in the internal part of intermediate head 12 set up respectively and each other is: the phase line A1 is conducted, the phase line B2 and the phase line C3 are disconnected, the phase line A1 is connected with the steel armor layer 8 after being connected with the capacitor 22 through a lead, the left end of the disconnected phase line B2 is directly connected with the steel armor layer 8 through a lead, namely, the disconnected phase line B is directly grounded, and the right end of the disconnected phase line B is connected with the first resistor; the left end of the disconnected C phase line 3 is connected with a second resistor 14 through a wire and then connected with a steel armor layer 8, namely, the disconnected C phase line is grounded through a resistor, and the right end of the disconnected C phase line is connected with a B phase line 2 through a third resistor 15 through a wire and then connected with an interphase short circuit; the first resistor 13, the second resistor 14, and the third resistor 15 are low resistance resistors or high resistance resistors.
The phase lines A1, B2 and C3 respectively comprise a wire core 17, an inner semi-conducting layer 18, a main insulating layer 19, an outer semi-conducting layer 20 and a copper shielding layer 21, the wire core 17 is wrapped by the inner semi-conducting layer 18, the main insulating layer 19 and the outer semi-conducting layer 20 are sequentially arranged between the inner semi-conducting layer 18 and the copper shielding layer 21, and the connection between the phase lines A1, B2 and C3 and the steel armor layer 8 and the connection between the phase lines A1, B2 and C3 are the connection between the wire core 17 and the steel armor layer 8 or the connection between the wire core 17 and the wire core 17.
The disconnection part of the phase line B2 and the phase line C3 adopts a non-crimping connecting pipe, a certain gap is kept, copper-plastic wires are welded on two sides of the disconnection part of the phase line B2 and the phase line C3, the copper-plastic wires welded on the phase line B2 on the left side of the disconnection part of the phase line B2 extend out of the outer layer of the inner sheath 4 and then are welded on the steel armor layer 8, and the copper-plastic wires welded on the phase line B2 on the right side extend out of the outer layer of the inner sheath 4 and then are connected with the first resistor 13 in series and then are welded on the; the copper-plastic wire welded on the left C wire at the disconnection position of the C phase wire 3 extends out of the outer layer of the inner sheath 4, then is connected with the second resistor 14 in series and then is welded on the steel armor layer 8, and the copper-plastic wire welded on the right C phase wire 3 extends out of the main insulating layer 19, then is connected with the third resistor 15 in series and then is welded on the copper-plastic wire extending out of the B phase wire 2 at the right end of the disconnection position; a copper-plastic wire is led out of the phase line A1, extends out of the outer layer of the inner sheath 4, is connected with a capacitor 22 in series and then is welded to the steel armor layer 8, and all the structures are connected in the outer sheath 5.
A power cable fault judging method comprises the following steps,
1) respectively leading out a copper-plastic wire from both ends of a phase line A1, a phase line B2 and a phase line C3 on the power cable 6 and both ends of the steel armor layer 8;
2) respectively carrying out short circuit on the phase line A1, the phase line B2 and the phase line C3 at one end of the power cable 6 and the steel armor layer 8 in pairs by using the led-out copper-plastic wires, measuring the insulation resistance of the two short-circuited wires at the other end of the power cable 6 by using an insulation meter, recording the insulation resistance value, and judging whether the phase line A1, the phase line B2 and the phase line C3 are broken or not according to the recorded combined insulation resistance value;
3) respectively removing the lead wires of the A phase wire 1, the B phase wire 2, the C phase wire 3 and the steel armor layer 8 at one end of the power cable 6 in a two-to-two short circuit mode by utilizing the led-out copper-plastic wires, then respectively measuring the insulation resistance value between the A phase wire 1 and the B phase wire 2, the insulation resistance value between the A phase wire 1 and the C phase wire 3 and the insulation resistance value between the B phase wire 2 and the C phase wire 3 at two ends of the power cable 6 by using an insulation resistance meter, recording the insulation resistance values, and judging the interphase short circuit or the interphase insulation resistance value reduction according to the recorded combined insulation resistance values;
4) respectively measuring the insulation resistance value between the phase line A1 and the copper-plastic wire led out from the steel armor layer 8, the insulation resistance value between the phase line B2 and the copper-plastic wire led out from the steel armor layer 8 and the insulation resistance value between the phase line C3 and the copper-plastic wire led out from the steel armor layer 8 by using an insulation resistance meter at two ends of the power cable 6, recording the insulation resistance values, and judging whether the insulation is good, high-resistance grounding, low-resistance grounding or direct grounding according to the recorded combined insulation resistance value;
in step 2), the recorded insulation resistance values are respectively the insulation resistance value between the phase line a 1 and the phase line B2, the insulation resistance value between the phase line a 1 and the phase line C3, the insulation resistance value between the phase line B2 and the phase line C3, the insulation resistance value between the phase line a 1 and the steel armor layer 8, the insulation resistance value between the phase line B2 and the steel armor layer 8, and the insulation resistance value between the phase line C3 and the steel armor layer 8, and the recorded results show that the insulation resistance value between the phase line a 1 and the phase line B2, the insulation resistance value between the phase line a 1 and the phase line C3, the insulation resistance value between the phase line B2 and the steel armor layer 8, and the insulation resistance value between the phase line a 1 and the steel armor layer 8 are all infinite, and the insulation resistance value between the phase line a 1 and the steel armor layer 8 is small and close to zero, so that, the phase line A1 and the steel armor layer 8 are conducted, and the phase line B2 and the phase line C3 are disconnected.
In step 3), among the recorded insulation resistance values, the insulation resistance values between the phase lines a 1 and B2 at the two ends of the power cable 6 are both large, the insulation resistance values between the phase lines a 1 and C3 at the two ends of the power cable 6 are also large, the insulation resistance value between the phase line B2 and C3 at one end of the power cable 6 is large, the insulation resistance value between the phase line B2 and C3 at the other end of the power cable is reduced, and then it is determined that the phase lines B2 and C3 at the end with the reduced insulation resistance values are short-circuited alternately.
In step 4), the insulation resistance values between the two ends of the phase line a 1 and the copper-plastic wires led out from the steel armor layer 8 in the recorded insulation resistance values all change all the time, which means that the insulation between the two ends of the phase line a 1 and the steel armor layer 8 is good, and a capacitor 22 is arranged between the phase line a 1 and the steel armor layer 8, which is equivalent to a grounded capacitor 22, and the absorption ratio can be calculated, and is generally the insulation resistance value of one minute divided by the insulation resistance value of fifteen seconds.
The insulation resistance value between the left end of the phase line B2 and the steel armor layer 8 is very small and is close to zero, which indicates that the left end of the phase line B2 is directly connected with the steel armor layer 8, namely directly grounded, the insulation resistance value between the right end of the phase line B2 and the steel armor layer 8 is reduced, and indicates that the right end of the phase line B2 is connected with the steel armor layer 8 through a resistor; the insulation resistance value between the left end of the C phase line 3 and the steel armor layer 8 is reduced, which shows that the left end of the C phase line 3 is connected with the steel armor layer 8 through a resistor, and the insulation resistance value between the right end of the C phase line 3 and the steel armor layer 8 is infinite, which shows that the insulation between the right end of the C phase line 3 and the steel armor layer 8 is good.
Whether the resistor is a high resistance value resistor or a low resistance value resistor is judged, and the measured resistance value is higher than 100 megaohms, is a high resistance value resistor, is lower than 100 megaohms and is a low resistance value resistor according to the numerical representation measured by the insulation resistance meter.
A manufacturing method of an intermediate joint of a power cable comprises the following steps:
1) stripping off the power cable 6 at the position where the middle joint 12 is arranged, exposing the phase lines A1, B2 and C3 inside, cutting off the phase lines B2 and C3 from the middle, and cutting off a section;
2) non-crimping connecting pipes are adopted at the disconnected positions of the phase lines 2 and 3, a certain gap is kept, the two sides of the disconnected positions of the phase lines 2 and 3 are welded with led-out copper-plastic wires, the main insulating layer 19 is contracted after the copper-plastic wires are led out, and one copper-plastic wire is also led out from the phase line A1, but the phase line A1 is not cut off;
3) welding the copper-plastic wires welded on the left phase line 2 at the position where the phase line B2 is disconnected to the steel armor layer 8 after extending out of the outer layer of the inner sheath 4, and welding the copper-plastic wires welded on the right phase line B2 to the steel armor layer 8 after extending out of the outer layer of the inner sheath 4 and being connected with a first resistor 13 in series;
4) extending the copper-plastic wires welded on the left C wire at the disconnection position of the C phase wire 3 out of the outer layer of the inner sheath 4, connecting the copper-plastic wires in series with a second resistor 14, welding the copper-plastic wires on the right C phase wire 3 on the steel armor layer 8, extending the copper-plastic wires on the right C phase wire 3 out of the main insulating layer 19, connecting the copper-plastic wires in series with a third resistor 15, and welding the copper-plastic wires extending out of the B phase wire 2 at the right end of the disconnection position;
5) the copper-plastic wires led out from the phase line A1 extend out of the outer layer of the inner sheath 4, are connected with the capacitor 22 in series and then are welded on the steel armor layer 8;
6) after the components are welded, the steel armor layer 8 is connected, and finally the outer sheath 5 is shrunk.
In step 2), a copper-plastic wire is also led out from the a-phase line 1, which means that the a-phase line 1 is stripped and cut to the wire core 17 by adopting a stripping and cutting method, a copper-plastic wire is welded and led out of the a-phase line 1, and then the inner semi-conducting layer 18, the main insulating layer 19, the outer semi-conducting layer 20 and the copper shielding layer 21 on the recovered a-phase line 1 are respectively connected.
In operation, teaching of the cable termination is performed using the cable termination shape portion 9 of the left end of the power cable 6; the method comprises the following steps of (1) utilizing a phase line A1, a phase line B2 and a phase line C3 which are stripped and cut at the right end of a power cable 6 to carry out teaching on cable structure composition and composition functions; the teaching of judging the fault property of the power cable is carried out by utilizing a fault structure in the middle joint 12 of the power cable 6, wherein the teaching comprises cable disconnection, high-resistance grounding, low-resistance grounding, direct grounding and interphase short circuit; the teaching of the cable model 16 and the technical parameters is performed by using the cable model 16 arranged on the power cable 6.
The invention is not limited to the above embodiments, and those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of the invention, and such equivalent modifications or substitutions are included in the scope defined by the claims of the present application.
Claims (10)
1. The utility model provides a teaching power cable, includes A phase line, B phase line and C phase line, A phase line, B phase line and C phase line form a power cable through inner sheath, oversheath and steel armor extrusion molding together, the inner sheath sets up and is being close to one side of A phase line, B phase line and C phase line, the oversheath sets up and is keeping away from one side of A phase line, B phase line and C phase line, the inner sheath with be provided with the filler between A phase line, B phase line and the C phase line, the inner sheath with be provided with steel armor between the oversheath, its characterized in that: cable left end A phase line, B phase line and C phase line are cable terminal shape part, cable right-hand member A phase line, B phase line and C phase line can demonstrate the cable inner structure part for peeling open, the mid portion of cable is provided with intermediate head, trouble structure is set to respectively to the inside A phase line of intermediate head, B phase line and C phase line to make things convenient for the teaching of cable fault nature judgement, be provided with the cable model on the power cable, in order to conveniently develop the teaching of cable model and technical parameter.
2. The teaching power cable of claim 1, wherein: the structure that sets up respectively and each other of the internal A phase line, B phase line and C phase line of intermediate head is: the phase line A is conducted, the phase line B and the phase line C are disconnected, the phase line A is connected with the steel armor layer through a conducting wire and then is connected with a capacitor, the left end of the disconnected phase line B is directly connected with the steel armor layer through the conducting wire and is equivalent to direct grounding, and the right end of the disconnected phase line B is connected with a first resistor through the conducting wire and then is connected with the steel armor layer and is equivalent to grounding through a resistor; the left end of the disconnected phase line C is connected with the second resistor through a wire and then is connected with the steel armor layer, namely the phase line C is grounded through the resistor, and the right end of the disconnected phase line C is connected with the phase line B through a wire and then is connected with the third resistor, namely the phase-to-phase short circuit; the first resistor, the second resistor and the third resistor are low-resistance resistors or high-resistance resistors.
3. The teaching power cable of claim 2, wherein: the phase line A, the phase line B and the phase line C all include sinle silk, interior semi-conducting layer, main insulating layer, outer semi-conducting layer and copper shield layer, the sinle silk by first the interior semi-conducting layer wraps up, interior semi-conducting layer with set gradually between the copper shield layer main insulating layer and outer semi-conducting layer, phase line A, phase line B and phase line C with be connected between the steel armoring layer and the connection that phase line A, phase line B and phase line C are each other all sinle silk with be connected of steel armoring layer or be connected between sinle silk and the sinle silk.
4. The teaching power cable of claim 3, wherein: the disconnection part of the phase line B and the phase line C adopts a non-crimping connecting pipe, a certain gap is kept, copper-plastic wires are welded on two sides of the disconnection part of the phase line B and the phase line C, the copper-plastic wires welded on the phase line B on the left side of the disconnection part of the phase line B extend out of the outer layer of the inner sheath and then are welded on the steel armor layer, and the copper-plastic wires welded on the phase line B on the right side extend out of the outer layer of the inner sheath and then are connected with the first resistor in series and then are welded on the steel armor layer; the copper-plastic wire welded on the C wire on the left side of the C-phase wire disconnection position extends out of the outer layer of the inner sheath and then is connected with the second resistor in series and then is welded to the steel armor layer, and the copper-plastic wire welded on the C wire on the right side extends out of the main insulating layer and then is connected with the third resistor in series and then is welded to the copper-plastic wire extending out of the B-phase wire on the right end of the disconnection position; and a copper-plastic wire is led out of the phase line A, extends out of the outer layer of the inner sheath, is connected with the capacitor in series and is welded to the steel armor layer, and all the structures are connected in the outer sheath.
5. A power cable failure judgment method using the teaching power cable of claim 4, comprising the steps of:
1) leading out one copper-plastic wire from two ends of the phase line A, the phase line B and the phase line C on the power cable and two ends of the steel armor layer respectively;
2) respectively short-circuiting the phase line A, the phase line B, the phase line C and the steel armor layer at one end of the power cable in pairs by using the led-out copper-plastic wires, measuring the insulation resistance of the two short-circuited wires at the other end of the power cable by using the insulation meter, recording the insulation resistance value, and judging whether the phase line A, the phase line B and the phase line C are broken or not according to the recorded combined insulation resistance value;
3) removing the lead wires of the phase line A, the phase line B, the phase line C and the steel armor layer at one end of the power cable in a short circuit mode in pairs by using the led-out copper-plastic wires, measuring the insulation resistance value between the phase line A and the phase line B, the insulation resistance value between the phase line A and the phase line C and the insulation resistance value between the phase line B and the phase line C at two ends of the power cable by using the insulation resistance meter, recording the insulation resistance values, and judging the interphase short circuit or the interphase insulation resistance value reduction through the recorded combined insulation resistance values;
4) and respectively measuring the insulation resistance value between the phase line A and the copper-plastic wire led out from the steel armor layer, the insulation resistance value between the phase line B and the copper-plastic wire led out from the steel armor layer and the insulation resistance value between the phase line C and the copper-plastic wire led out from the steel armor layer by using the insulation resistance meters at two ends of the power cable, recording the insulation resistance values, and judging whether the power cable is good in insulation, high-resistance grounding, low-resistance grounding or direct grounding according to the recorded combined insulation resistance value.
6. The power cable fault diagnosis method according to claim 5, wherein: in step 2), the recorded insulation resistance values are insulation resistance values between the a-phase line and the B-phase line, insulation resistance values between the a-phase line and the C-phase line, insulation resistance values between the B-phase line and the C-phase line, insulation resistance values between the a-phase line and the steel armor layer, insulation resistance values between the B-phase line and the steel armor layer, and insulation resistance values between the C-phase line and the steel armor layer, respectively, and the recorded results show that the insulation resistance values between the a-phase line and the B-phase line, the insulation resistance values between the a-phase line and the C-phase line, the insulation resistance values between the B-phase line and the steel armor layer, and the insulation resistance values between the C-phase line and the steel armor layer are infinite, and the insulation resistance values between the a-phase line and the steel armor layer are small, close to zero, it can be known that the phase line a and the steel armor are conductive, and the phase line B and the phase line C are disconnected.
7. The power cable fault diagnosis method according to claim 5, wherein: in step 3), among the insulation resistance value of record, the power cable both ends the a phase line with insulation resistance value between the B phase line is all very big, the power cable both ends the a phase line with insulation resistance value between the C phase line is also all very big, power cable one end the B phase line with insulation resistance value between the C phase line is very big, the other end the B phase line with insulation resistance value between the C phase line reduces, then judges this end that insulation resistance value reduces the B phase line with alternate short circuit between the C phase line.
8. The power cable fault diagnosis method according to claim 5, wherein: in the step 4), in the recorded insulation resistance values, the insulation resistance values between the two ends of the phase line A and the copper-plastic wires led out from the steel armor layer are all changed all the time, which indicates that the insulation between the two ends of the phase line A and the steel armor layer is good, and a capacitor is arranged between the phase line A and the steel armor layer, which is equivalent to a grounding capacitor, and can calculate an absorption ratio, wherein the common absorption ratio is the insulation resistance value of one minute divided by the insulation resistance value of fifteen seconds; the insulation resistance value between the left end of the phase line B and the steel armor layer is very small and is close to zero, the left end of the phase line B is directly connected with the steel armor layer and is equivalent to direct grounding, the insulation resistance value between the right end of the phase line B and the steel armor layer is reduced, and the right end of the phase line B is connected with the steel armor layer through a resistor; the insulation resistance value between the left end of the C-phase line and the steel armor layer is reduced, the left end of the C-phase line is connected with the steel armor layer through a resistor, and the insulation resistance value between the right end of the C-phase line and the steel armor layer is infinite, so that the right end of the C-phase line and the steel armor layer are well insulated.
9. A method for manufacturing an intermediate joint for teaching power cables according to claim 4, comprising the steps of:
1) stripping the power cable at the position where the middle joint is arranged, exposing the phase line A, the phase line B and the phase line C in the power cable, cutting off the phase line B and the phase line C from the middle, and cutting off a section;
2) the method comprises the following steps that non-crimping connecting pipes are adopted at the disconnected positions of the phase line B and the phase line C, a certain gap is kept, lead-out copper-plastic wires are welded at two sides of the disconnected positions of the phase line B and the phase line C, a main insulating layer is contracted after the copper-plastic wires are led out, and a copper-plastic wire is also led out from the phase line A without cutting off the phase line A;
3) welding the copper-plastic wires welded on the B phase line on the left side of the disconnected position of the B phase line to the steel armor layer after extending out of the outer layer of the inner sheath, and welding the copper-plastic wires welded on the B phase line on the right side to the steel armor layer after extending out of the outer layer of the inner sheath and being connected with the first resistor in series;
4) extending the copper-plastic wire welded on the C wire on the left side of the C-phase wire disconnection position out of the outer layer of the inner sheath, connecting the copper-plastic wire with the second resistor in series, welding the copper-plastic wire on the steel armor layer, extending the copper-plastic wire welded on the C wire on the right side out of the main insulating layer, connecting the copper-plastic wire with the third resistor in series, and welding the copper-plastic wire extended on the B wire on the right end of the disconnection position;
5) the copper-plastic wire led out from the phase line A extends out of the outer layer of the inner sheath, is connected with the capacitor in series and is welded to the steel armor layer;
6) and after the components are welded, connecting the steel armor layer, and finally contracting the outer sheath.
10. The method according to claim 9, wherein in step 2), a copper-plastic wire is led out from the phase a wire, that is, the phase a wire is stripped and cut to form a wire core, a copper-plastic wire is welded and led out of the phase a wire, and then the inner semi-conducting layer, the main insulating layer, the outer semi-conducting layer and the copper shielding layer on the phase a wire are respectively connected and restored.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011331101.9A CN112599287A (en) | 2020-11-24 | 2020-11-24 | Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011331101.9A CN112599287A (en) | 2020-11-24 | 2020-11-24 | Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112599287A true CN112599287A (en) | 2021-04-02 |
Family
ID=75184067
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011331101.9A Pending CN112599287A (en) | 2020-11-24 | 2020-11-24 | Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112599287A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115102132A (en) * | 2022-05-26 | 2022-09-23 | 汤国军 | Novel railway signal cable terminating method and terminating box |
-
2020
- 2020-11-24 CN CN202011331101.9A patent/CN112599287A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115102132A (en) * | 2022-05-26 | 2022-09-23 | 汤国军 | Novel railway signal cable terminating method and terminating box |
| CN115102132B (en) * | 2022-05-26 | 2024-02-13 | 中铁电气化局集团第三工程有限公司 | Novel railway signal cable end forming method and end forming box |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9960530B2 (en) | Terminal connection device for a power cable | |
| CN103308832B (en) | A kind of high-voltage cable insulating transition joint local discharge test device and using method | |
| CN103323751B (en) | A kind of high pressure stub cable insulation terminal local discharge test device and using method | |
| CN207651690U (en) | Coaxial fitting | |
| CN112599287A (en) | Power cable for teaching, fault judgment method thereof and intermediate joint manufacturing method | |
| CN110763957A (en) | Novel method for monitoring insulation fault of medium-voltage cable on line | |
| CN110244181B (en) | Method and device for positioning electrical fault of submarine cable of current collecting line of offshore wind farm | |
| CN214068369U (en) | Power cable for teaching | |
| CN205429680U (en) | Cable cross -bonding case | |
| CN109920601B (en) | Power cable suitable for partial discharge detection positioning | |
| CN202602234U (en) | Medium-pressure cross-linked polyethylene cable terminal with insulation stress cone | |
| CN202949202U (en) | Main body of intermediate connector of cross-linked cable and novel intermediate connector formed by same | |
| CN102254615A (en) | Cross-connect grounding coaxial cable for extra-high tension cable circuit | |
| CN203299317U (en) | Online test device for 2M wire joint welding | |
| CN105958459A (en) | Railway signal cable grounding system | |
| CN108344926B (en) | Power cable partial discharge online monitoring device and method | |
| CN219086278U (en) | Medium-voltage cable joint capable of continuously adding wire cores and achieving different-diameter butt joint | |
| CN211859571U (en) | Cable intermediate joint | |
| CN209929940U (en) | High-voltage crosslinked polyethylene insulated cable molding type insulated joint | |
| CN213151040U (en) | Lightning wire providing additional grounding mode | |
| CN113593764B (en) | Communication cable with built-in fault removal function and use method thereof | |
| CN202997066U (en) | Electrical junction box | |
| CN220020639U (en) | Three-core medium-voltage power cable with grounded copper conductor | |
| CN212875273U (en) | Take earth connection carbon fiber water joint and system of generating heat | |
| EP2710683B1 (en) | Dead front cable terminal with isolated shield |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |