CN212514866U - Quick detection device of anti water tree ability of crosslinked polyethylene cable - Google Patents
Quick detection device of anti water tree ability of crosslinked polyethylene cable Download PDFInfo
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- CN212514866U CN212514866U CN202021332973.2U CN202021332973U CN212514866U CN 212514866 U CN212514866 U CN 212514866U CN 202021332973 U CN202021332973 U CN 202021332973U CN 212514866 U CN212514866 U CN 212514866U
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Abstract
The utility model particularly relates to a quick detection device of anti water tree ability of crosslinked polyethylene cable belongs to the insulating detection technology field of power cable, and the problem that solve provides one kind and can carry out the detection device of short-term test and aassessment to the water tree ability of resistant water of crosslinked polyethylene cable, and the technical scheme of adoption is: an organic glass cylinder in the thermostat is arranged above the insulating base, NaCl solution is contained in the organic glass cylinder, an organic glass cover covers the upper port of the organic glass cylinder, a copper electrode penetrates through the organic glass cover, the upper end of the copper electrode is grounded, a plurality of cable samples penetrate through the cylinder wall of the organic glass cylinder, one end of each cable sample is connected with a high-voltage fuse through a wire, and the high-voltage fuses are all connected with a high-frequency high-voltage power supply through wires; the utility model discloses once can accomplish the water tree aging test of a plurality of cable samples, solve the unable technical problem appearance of accuse of the cable quality of going into the net.
Description
Technical Field
The utility model belongs to the technical field of the power cable insulation detects, concretely relates to anti water tree ability quick detection device of crosslinked polyethylene cable.
Background
In recent years, a power grid company has a plurality of large-area power failure accidents caused by cable breakdown, a plurality of cables often fail prematurely due to short design life, and premature breakdown accidents may occur due to the fact that the quality of the traditional network cables is uneven due to the lack of technical means for detecting the network access of the cables in an early stage. The water tree aging is the main reason of the insulation reduction of the cable, and the water tree resistance of the cable has important influence on the insulation life of the cable. Therefore, the water tree resistance of cable insulation is an important indicator of insulation life and long-term operational reliability. Different cable design life and water tree resistance can lead to the great difference of cable cost, and the producer can sacrifice life and water tree resistance to reduce cost, leads to the cable quality of netting to be difficult to guarantee, far away not reaching expected life. The low quality of the cable that enters the network has caused very big pressure for later stage operation maintenance, has increased huge fortune dimension cost input, and the operation risk in later stage is uncontrollable.
The existing cable networking detection project only relates to some basic performances of the cable, such as geometric parameters, crosslinking degree, flame retardance, basic electrical parameters and the like, and a corresponding quick detection method for the water tree resistance of the cable is not available. The water tree accelerated aging of a cable sample is required to be carried out in the detection of the water tree resistance of the cable, the existing water tree accelerated aging method generally takes more than 7 days, a few samples are obtained in one water tree aging test, the repeatability of the water tree aging process is poor, the effect cannot be guaranteed, and the existing water tree accelerated aging method is not suitable for carrying out the rapid detection work of the water tree resistance of the cable. Therefore, how to obtain considerable cable water tree samples in a short time and detect the cable water tree samples has important significance for rapidly evaluating the water tree resistance of the cable, helps to master the quality of the cable entering the network from the source, and improves the operation reliability of the power grid.
SUMMERY OF THE UTILITY MODEL
The utility model overcomes prior art exists not enough, provides a cross-linked polyethylene cable water-tree resistance ability short-term test device, can carry out short-term test and aassessment to cross-linked polyethylene cable's water-tree resistance ability, has solved the unable technical problem of accuse of the cable quality of going into the net.
In order to solve the technical problem, the utility model discloses a technical scheme be: a cross-linked polyethylene cable water tree resistance ability rapid detection device includes: the device comprises a high-frequency high-voltage power supply, a thermostat, a high-voltage fuse, cable samples, an organic glass cylinder, an organic glass cover, a copper electrode, an insulating base and a NaCl solution, wherein the organic glass cylinder is arranged above the insulating base, the organic glass cylinder and the insulating base are fixed in the thermostat, the NaCl solution is filled in the organic glass cylinder, an upper end cover of the organic glass cylinder is closed with the organic glass cover which can be opened, the copper electrode penetrates through the organic glass cover, the lower end of the copper electrode is submerged in the NaCl solution, the upper end of the copper electrode is grounded, the number of the cable samples is axially and horizontally arranged, the plurality of the cable samples penetrate through the cylinder walls on the two opposite sides of the organic glass cylinder, the cable samples are connected with the wall of the organic glass cylinder in a sealing manner, and the plurality of the cable samples are uniformly arranged on the same, the NaCl solution submerges and is located the inside cable sample of organic glass jar, each the one end and the high-voltage fuse of cable sample pass through the wire and are connected, and are a plurality of the high-voltage fuse all with be fixed in the thermostated container is outside the high frequency high voltage power passes through the wire and connects.
The cable sample is formed by stripping, and the cable sample comprises: the cable comprises an La section, an Lb section and an Lc section, wherein the Lb section and the Lc section are two sections, the La section is located in the middle of the cable sample, one end of the La section is sequentially provided with the Lb section and the Lc section, the other end of the La section is sequentially provided with the Lb section and the Lc section, the Lb section and the Lc section are symmetrically arranged, the Lc section is symmetrically arranged, the outermost layer of the La section is an outer semi-conducting layer, the outermost layer of the La section is an insulating layer, the outermost layer of the Lc section is a cable core, the La section is arranged inside the organic glass cylinder, two rows of needle holes are uniformly arranged on the La section, the deepest part of each needle hole is 2-2.5 mm away from the inner semi-conducting layer of the cable sample, and the two Lb sections penetrate through two opposite side cylinder walls of the organic glass cylinder and are. One Lc section of the cable sample is connected with the high-voltage fuse through a lead.
And the high-voltage fuses are connected with high-voltage sleeves on the wires connected with the high-frequency high-voltage power supply, and the high-voltage sleeves penetrate through the wall of the thermostat.
The length ratio of the La section to the Lb section to the Lc section is as follows: la section Lb section Lc section =20:14: 1.
Two rows of through holes are oppositely formed in the two opposite side cylinder walls of the organic glass cylinder, and the Lb section of the cable sample penetrates through the corresponding through holes and is connected in a sealing mode through glass cement. The diameter of the through holes is 2mm larger than the Lb section diameter of the cable sample, and the distance between every two adjacent through holes in the same row is more than or equal to 10 cm.
The organic glass cover is provided with a through hole through which the copper electrode penetrates.
The distance between every two adjacent pinholes on the La section of the cable sample is 1 cm.
A detection method of a device for rapidly detecting the water tree resistance of a crosslinked polyethylene cable comprises the following steps:
1) and preparing a cable sample:
removing the outer sheath, the steel armor, the filler and the copper strip of the cable, exposing the single-phase cable, cutting the single-phase cable into small cable sections, respectively stripping the outer semi-conducting layer from two ends of the cable to leak the insulating layer, stripping the insulating layer from the end parts to leak the cable core, and reserving two symmetrical rows of pin holes in the middle part of the cable sample, which is reserved with the outer conducting layer, by using a steel needle, wherein the pin hole distance is about 1 cm;
2) and installing a cable sample:
inserting the cable sample prepared in the step 1) into a through hole in the side surface of an organic glass cylinder, placing an outer semi-conductive layer part left in the middle of the cable sample in the organic glass cylinder, and filling a gap between the through hole and the cable sample by using glass cement to ensure that a solution in the cylinder does not leak;
3) and adding a NaCl solution:
injecting a NaCl solution with the mass fraction of 20% into the organic glass cylinder, submerging the cable sample by the NaCl solution, placing the copper electrode into the through hole on the organic glass cover and fixing, placing the organic glass cover on the organic glass cylinder, and immersing the lower end of the copper electrode into the NaCl solution;
4) and connecting the wires:
placing the organic glass cylinder and the sample manufactured in the step 3) on an insulating base of a thermostat, connecting a cable core at one end of the cable sample with a high-voltage fuse, a high-voltage sleeve and a high-frequency high-voltage power supply by using a lead, and grounding a copper electrode;
5) and accelerating aging of the water tree:
setting the temperature of a thermostat to be 60 ℃, starting a high-frequency high-voltage power supply, and keeping the voltage to be 5kV for 120 hours;
6) and analyzing results:
and after continuously pressurizing for 120 hours, taking out the cable sample, removing the cable core, cutting the cable sample into slices with the thickness of 0.1mm along the pinhole, observing and measuring the slice sample under a microscope, recording the water tree initiation condition at the tip of the pinhole and the length and width of the water tree, counting data of at least ten needle-point water trees of each cable sample, calculating the average values of the initiation rate, the length and the width of the water tree, comparing the initiation rate and the size of the water tree with standard values, and evaluating the water tree resistance of the cable.
Compared with the prior art, the utility model following beneficial effect has.
The utility model discloses a multiunit cable sample pressurization's method carries out the water tree ageing tests, once can accomplish the water tree ageing tests of a plurality of cable samples, and tens of water tree samples of every cable sample ageing, this kind of method can make cable sample water tree ageing time reduce at double, and efficiency improves at double. After a single cable sample is punctured, the high-voltage fuse of the sample branch is disconnected, the water branch aging of other cable samples cannot be influenced, and the reliability and the safety of the test are greatly improved.
Two, the utility model discloses the water tree to a plurality of samples causes and the method that the water tree size was averaged can assess the water tree resistance ability of cable sample more accurately.
Drawings
The present invention will be further described with reference to the accompanying drawings.
Fig. 1 is a front view of the device for rapidly detecting the water tree resistance of the cross-linked polyethylene cable.
Fig. 2 is the utility model discloses the quick detection device of water tree resistance ability of crosslinked polyethylene cable.
Fig. 3 is a schematic structural diagram of the cable sample of the present invention.
Fig. 4 is a left side view of the organic glass jar of the present invention.
In the figure: 1 is high frequency high voltage power supply, 2 is high-voltage bushing, 3 is the thermostated container, 4 is high-voltage fuse, 5 is the cable sample, 6 is the organic glass lid, 7 is the copper electrode, 8 is insulating base, 9 is the NaCl solution, 10 is the cable core, 11 is the insulating layer, 12 is outer semi-conducting layer, 13 is the pinhole, 14 is the through hole, 15 is the organic glass jar.
Detailed Description
The present invention will be further described with reference to the following specific examples.
A cross-linked polyethylene cable water tree resistance ability rapid detection device includes: the device comprises a high-frequency high-voltage power supply 1, a thermostat 3, a high-voltage fuse 4, cable samples 5, an organic glass cylinder 15, an organic glass cover 6, a copper electrode 7, an insulating base 8 and NaCl solution 9, wherein the organic glass cylinder 15 is arranged above the insulating base 8, the organic glass cylinder 15 and the insulating base 8 are fixed inside the thermostat 3, the NaCl solution 9 is filled inside the organic glass cylinder 15, the organic glass cover 6 capable of being opened is covered on the upper end of the organic glass cylinder 15, the copper electrode 7 penetrates through the organic glass cover 6, the lower end of the copper electrode 7 is submerged into the NaCl solution 9, the upper end of the copper electrode 7 is grounded, the cable samples 5 are horizontally arranged in the axial direction, the cable samples 5 penetrate through the cylinder walls on the two opposite sides of the organic glass cylinder 15, and the cable samples 5 are hermetically connected with the organic glass cylinder 15, a plurality of cable sample 5 is at same horizontal plane align to grid, NaCl solution 9 submergence is located the inside cable sample 5 of organic glass jar 15, each the one end and the high-voltage fuse 4 of cable sample 5 pass through the wire and are connected, and is a plurality of high-voltage fuse 4 with be fixed in 3 outsides of thermostated container the high frequency high voltage power supply 1 passes through the wire and connects.
The cable sample 5 is formed by peeling, and the cable sample 5 includes: the cable comprises an La section, an Lb section and an Lc section, wherein the Lb section and the Lc section are both two sections, the La section is located in the middle of the cable sample 5, one end of the La section is sequentially provided with the Lb section and the Lc section, the other end of the La section is sequentially provided with the Lb section and the Lc section, the Lb section and the Lc section are symmetrically arranged, the Lc section and the Lc section are symmetrically arranged, the outermost layer of the La section is an outer semi-conducting layer 12, the outermost layer of the Lb section is an insulating layer 11, the outermost layer of the Lc section is a cable core 10, the La section is arranged inside the organic glass cylinder 15, two rows of pin holes 13 are uniformly arranged on the La section, the deepest part of each pin hole 13 is 2-2.5 mm away from the inner semi-conducting layer of the cable sample, and the two Lb sections penetrate through the two opposite side cylinder walls of. One Lc section of the cable sample 5 is connected with the high-voltage fuse 4 through a wire.
The high-voltage fuses 4 are connected with a high-voltage bushing 2 on a lead connected with the high-frequency high-voltage power supply 1, and the high-voltage bushing 2 penetrates through the wall of the thermostat 3.
The length ratio of the La section to the Lb section to the Lc section is as follows: la section Lb section Lc section =20:14: 1. The total length of the cable sample 5 is 50cm, the length of the La section is 20cm, the length of the Lb section is 14cm, and the length of the Lc section is 1 cm.
Two rows of through holes 14 are oppositely arranged on two opposite side walls of the organic glass cylinder 15, and the Lb section of the cable sample 5 penetrates through the corresponding through holes 14 and is connected in a sealing mode through glass cement. The diameter of the through holes 14 is 2mm larger than the Lb section of the cable sample 5, and the distance between every two adjacent through holes 14 in the same row is greater than or equal to 10 cm.
And the organic glass cover 6 is provided with a through hole through which the copper electrode 7 penetrates.
The distance between every two adjacent pinholes 13 on the 5La section of the cable sample is 1 cm.
A detection method of a device for rapidly detecting the water tree resistance of a crosslinked polyethylene cable comprises the following steps:
1) and preparing a cable sample:
removing the outer sheath, the steel armor, the filler and the copper strip of the cable to expose the single-phase cable and cut the single-phase cable into small cable samples with the length of about 50cm, respectively stripping the outer semi-conducting layers from two ends of each cable sample to expose the insulating layers, stripping the insulating layers from the end parts to expose the cable cores, and reserving two symmetrical rows of pin holes in the middle part of the cable sample where the outer conducting layer is reserved by using a steel needle, wherein the pin holes are spaced by about 1 cm;
2) and installing a cable sample:
inserting the cable sample prepared in the step 1) into a through hole in the side surface of an organic glass cylinder, placing an outer semi-conductive layer part left in the middle of the cable sample in the organic glass cylinder, and filling a gap between the through hole and the cable sample by using glass cement to ensure that a solution in the cylinder does not leak;
3) and adding a NaCl solution:
injecting a NaCl solution with the mass fraction of 20% into an organic glass cylinder, wherein the liquid level of the NaCl solution is at least 1cm higher than that of a cable sample, placing a copper electrode into a through hole in an organic glass cover and fixing, placing the organic glass cover on the organic glass cylinder, and immersing the lower end of the copper electrode into the NaCl solution for at least 2 cm;
4) and connecting the wires:
placing the organic glass cylinder and the sample manufactured in the step 3) on an insulating base of a thermostat, connecting a cable core at one end of the cable sample with a high-voltage fuse, a high-voltage sleeve and a high-frequency high-voltage power supply by using a lead, and grounding a copper electrode;
5) and accelerating aging of the water tree:
setting the temperature of a thermostat to be 60 ℃, starting a high-frequency high-voltage power supply, and keeping the voltage to be 5kV for 120 hours;
6) and analyzing results:
and after continuously pressurizing for 120 hours, taking out the cable sample, removing the cable core, cutting the cable sample into slices with the thickness of 0.1mm along the pinhole, observing and measuring the slice sample under a microscope, recording the water tree initiation condition at the tip of the pinhole and the length and width of the water tree, counting data of at least ten needle-point water trees of each cable sample, calculating the average values of the initiation rate, the length and the width of the water tree, comparing the initiation rate and the size of the water tree with standard values, and evaluating the water tree resistance of the cable.
The experimental sample data is as follows:
and (4) conclusion: the water tree initiation rate of the sample was 100%, the average length of the water tree was 152.8 μm, and the average width of the water tree was 43.8. mu.m, respectively. A large number of experiments show that the standard value of the cable of the model is that the initiation rate of the water tree is less than 56%, the average length of the water tree is less than 53.3 mu m, and the average width of the water tree is less than 12.3 mu m. The water tree initiation rate, the water tree average length and the water tree average width of the sample are all larger than the standard values, so the sample is unqualified in the test.
The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. It will be apparent to those skilled in the art that modifications and improvements can be made to the above-described embodiments without departing from the spirit and scope of the invention. Accordingly, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to these embodiments without departing from the spirit and scope of the present invention as defined by the appended claims.
Claims (7)
1. The utility model provides a quick detection device of anti water tree ability of crosslinked polyethylene cable which characterized in that includes: the device comprises a high-frequency high-voltage power supply (1), a thermostat (3), a high-voltage fuse (4), a cable sample (5), an organic glass cylinder (15), an organic glass cover (6), a copper electrode (7), an insulating base (8) and NaCl solution (9), wherein the organic glass cylinder (15) is arranged above the insulating base (8), the organic glass cylinder (15) and the insulating base (8) are fixed inside the thermostat (3), the NaCl solution (9) is filled in the organic glass cylinder (15), the upper end cover cap of the organic glass cylinder (15) can be opened, the organic glass cover (6) is penetrated by the copper electrode (7), the lower end of the copper electrode (7) is submerged in the NaCl solution (9), the upper end of the copper electrode (7) is grounded, the axial direction is horizontally arranged, the number of the cable sample (5) is multiple, it is a plurality of cable sample (5) all run through the jar wall of the relative both sides of organic glass jar (15), just cable sample (5) with organic glass jar (15) jar wall sealing connection, NaCl solution (9) submerge and are located cable sample (5) inside organic glass jar (15), each the one end and a high-voltage fuse (4) of cable sample (5) pass through the wire and are connected, a plurality of high-voltage fuse (4) all with be fixed in thermostated container (3) are outside high frequency high voltage power supply (1) passes through the wire and connects.
2. The device for rapidly detecting the water tree resistance of the crosslinked polyethylene cable according to claim 1, wherein the cable sample (5) comprises: the cable comprises an La section, an Lb section and an Lc section, wherein the Lb section and the Lc section are both two sections, the La section is located in the middle of a cable sample (5), one end of the La section is sequentially the Lb section and the Lc section, the other end of the La section is sequentially the Lb section and the Lc section, the outermost layer of the La section is an outer semi-conducting layer (12), the outermost layer of the Lb section is an insulating layer (11), the outermost layer of the Lc section is a cable core (10), the La section is arranged in an organic glass cylinder (15), two rows of pin holes (13) are uniformly formed in the La section, and the two Lb sections penetrate through the two opposite side cylinder walls of the organic glass cylinder (15) and are in sealing connection with the cylinder walls of the organic glass cylinder (15).
3. The device for rapidly detecting the water tree resistance of the cross-linked polyethylene cable according to claim 1 or 2, wherein a high voltage bushing (2) is further connected to a lead connecting the high voltage fuses (4) and the high frequency high voltage power supply (1), and the high voltage bushing (2) penetrates through the wall of the thermostat (3).
4. The device of claim 2, wherein the length ratio of the La section to the Lb section to the Lc section is: la section Lb section Lc section =20:14: 1.
5. The device for rapidly detecting the water tree resistance of the crosslinked polyethylene cable according to claim 4, wherein two rows of through holes (14) are oppositely arranged on the two opposite side walls of the organic glass cylinder (15), and the Lb section of the cable sample (5) penetrates through the corresponding through hole (14) and is hermetically connected through glass cement.
6. The device for rapidly detecting the water tree resistance of the cross-linked polyethylene cable according to claim 5, wherein a through hole through which the copper electrode (7) penetrates is formed in the organic glass cover (6).
7. The device for rapidly detecting the water tree resistance of the crosslinked polyethylene cable according to claim 6, wherein the distance between every two adjacent pinholes (13) on the La section of the cable sample (5) is 1 cm.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111665426A (en) * | 2020-07-09 | 2020-09-15 | 国网山西省电力公司电力科学研究院 | Device and method for rapidly detecting water tree resistance of crosslinked polyethylene cable |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111665426A (en) * | 2020-07-09 | 2020-09-15 | 国网山西省电力公司电力科学研究院 | Device and method for rapidly detecting water tree resistance of crosslinked polyethylene cable |
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