CN212301751U - Quick detection device of anti electrical tree ability of crosslinked polyethylene cable - Google Patents
Quick detection device of anti electrical tree ability of crosslinked polyethylene cable Download PDFInfo
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- CN212301751U CN212301751U CN202021333016.1U CN202021333016U CN212301751U CN 212301751 U CN212301751 U CN 212301751U CN 202021333016 U CN202021333016 U CN 202021333016U CN 212301751 U CN212301751 U CN 212301751U
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Abstract
The utility model particularly relates to a device for rapidly detecting the tree resistance of a crosslinked polyethylene cable, which belongs to the technical field of power cable insulation detection, and aims to solve the technical problem of providing a detection device capable of rapidly detecting and evaluating the electrical properties of the crosslinked polyethylene cable, such as the tree resistance, and the like; the adopted scheme is as follows: an organic glass base is fixed inside the organic glass cylinder filled with the silicone oil, a sample grounding electrode which is grounded is arranged on the organic glass base, a plurality of cable samples are uniformly fixed on the sample grounding electrode, steel needles are respectively connected on the cable samples, and the steel needles are connected with a high-voltage fuse outside the organic glass cylinder through leads; CCD cameras electrically connected with the PC are fixed above the cable samples, and adjustable light sources are arranged below the cable samples; the utility model discloses make cable sample observation time reduce at double, efficiency improves at double.
Description
Technical Field
The utility model belongs to the technical field of the insulating detection of power cable, concretely relates to quick detection device of the anti-electricity tree ability 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 tree aging is a direct cause of cable insulation breakdown, and the tree resistance of the cable directly affects the service life of the cable. Therefore, the electrical tree resistance of cable insulation is an important indicator of insulation life and long-term operational reliability. The current 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, a corresponding rapid detection method for the electrical tree resistance of the cable is not available, different cable design life and treeing resistance can cause great difference of cable cost, a manufacturer may sacrifice life and electrical tree resistance to reduce cost, the networking cable quality is difficult to guarantee, and the expected service life is far from being achieved. 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 electrical tree resistance test needs to generate electrical tree branches rapidly in the cable insulation layer and observe and record the growth process of the electrical tree branches, but in the existing research results, only one cable sample can be observed at a time, the observation time is long, and the observation efficiency is low. Therefore, how to master the quality of the network cable from the source, especially to detect the electrical tree resistance and the service life of the network cable, is one of effective ways to solve the long-term operation reliability of the cable and save a large amount of operation and maintenance investment.
SUMMERY OF THE UTILITY MODEL
The utility model overcomes prior art exists not enough, provides an anti electrical tree ability quick detection device of crosslinked polyethylene cable, can carry out short-term test and aassessment to the anti electrical tree ability of crosslinked polyethylene cable, has solved the unable technical problem of controlling of cable quality of going into the net.
In order to solve the technical problem, the utility model discloses a technical scheme be: a quick detection device of anti electrical tree ability of crosslinked polyethylene cable includes: adjustable transformer, high-voltage fuse, organic glass jar, cable sample, CCD camera, silicon oil, PC, sample earthing pole, adjustable light source, organic glass base and steel needle, the inside of organic glass jar is fixed with the organic glass base, be provided with the sample earthing pole on the organic glass base, sample earthing pole ground connection, evenly be fixed with a plurality of semicircular on the sample earthing pole the cable sample, the number of cable sample is confirmed according to the actual demand, generally is not more than ten, each all be connected with a steel needle on the cable sample, the needle point end of steel needle inserts the inside of cable sample, what the other end homogeneous phase of steel needle corresponds is connected with a high-voltage fuse through the wire, and a plurality of high-voltage fuse all is fixed in the outside of organic glass jar, a plurality of high-voltage fuse with adjustable transformer passes through the wire and is connected, the high-voltage fuse is connected with the high-voltage output end of the adjustable transformer, silicone oil is filled in the organic glass cylinder, and the silicone oil submerges the cable sample and the steel needle;
the utility model discloses a cable test piece, including PC, cable sample's top all is fixed with the CCD camera, and is a plurality of the CCD camera with the PC passes through the data line connection, the PC is personal computer, the below of cable sample all is provided with adjustable light source, adjustable light source is fixed in the outside below of organic glass jar. The corresponding cable sample, the CCD camera and the adjustable light source are linearly arranged in the vertical direction, and the CCD camera has a larger multiplying power and can be used in combination with a microscope when necessary.
The cable sample is semi-circular slice shape, the cable sample forms through peeling off, and the cable sample after peeling off includes the three-layer, does in proper order: the insulation layer is penetrated through to the needle point of steel needle the interior semi-conducting layer of cable sample and pierce the insulation layer, the most advanced distance of needle of steel needle the outer semi-conducting layer distance of cable sample is 2 ~ 2.5mm, just the extension line of steel needle passes through the centre of a circle of insulation layer. The steel needle is perpendicular to the tangent of the insulating layer at the intersection of the insulating layer.
A grounding sleeve which is axially and horizontally arranged is fixed on one side of the organic glass cylinder, the grounding sleeve penetrates through the side wall of the organic glass cylinder, the sample grounding electrode is connected with the grounding sleeve through a lead, and the grounding sleeve is grounded; the steel needle with all be connected with high-voltage bushing on the circuit that high-voltage fuse connects, high-voltage bushing axial level sets up, and is a plurality of high-voltage bushing horizontal direction sets up side by side, high-voltage bushing runs through the lateral wall of organic glass jar opposite side, silicon oil submerges ground connection sleeve with high-voltage bushing.
A plurality of groove openings facing the horizontal concave grooves are uniformly formed in the sample grounding electrode along the horizontal direction, the concave grooves are matched with the semicircular cable samples, and the cable samples are fixed with the concave grooves through plastic insulating ropes. The number and the interval of the high-voltage sleeves are consistent with those of the concave grooves.
The sample grounding electrode is a strip copper electrode with the thickness of 6-8 mm.
The diameter of the steel needle is 1 mm.
The adjustable transformer is fixed outside the organic glass cylinder. And the low-voltage side of the adjustable transformer is electrically connected with an overcurrent protection relay, and the setting value converted from the high-voltage fuse to the low-voltage side is lower than the setting value of the overcurrent protection relay at the low-voltage side of the adjustable transformer.
A detection method of a device for rapidly detecting the tree resistance of a crosslinked polyethylene cable comprises the following steps:
1) and preparing a cable sample:
cutting the cable into a semicircular slice sample, and penetrating a steel needle into an inner semi-conducting layer and an insulating layer of the slice sample and into an outer semi-conducting layer;
2) fixing a cable sample:
putting the cable sample prepared in the step 1 into a concave groove of a sample grounding electrode, attaching an outer semi-conducting layer of the cable sample to the bottom of the concave groove, fixing the cable sample and the sample grounding electrode by using a plastic insulating rope, and placing the fixed cable sample and the sample grounding electrode above an organic glass base;
3) and connecting the wires:
connecting the steel needle, the high-voltage bushing, the high-voltage fuse, the high-voltage side output end of the adjustable transformer, the sample grounding electrode and the grounding bushing together by using a wire, and grounding the grounding bushing;
4) adding silicone oil:
injecting silicon oil into the organic glass cylinder, wherein the surface of the silicon oil submerges the high-voltage sleeve, the grounding sleeve, the steel needle and the cable sample;
5) the configuration of the adjustable light source and the CCD camera comprises the following steps:
a plurality of adjustable light sources and CCD cameras are arranged according to the number of samples, the adjustable light sources, the PC and the CCD cameras are turned on, and the CCD cameras and the light sources are adjusted, so that a PC display picture can be clearly focused at the point of the steel needle, and the same PC can be communicated with all the CCD cameras at the same time;
6) and detecting:
slowly adjusting the adjustable transformer to enable the initial voltage of the adjustable transformer to be increased to 10kV, adjusting the adjustable transformer according to the rule that the voltage is increased by 2kV every 5min until all cable samples are broken down and the high-voltage fuse is fused, reducing the voltage of the adjustable transformer to 0, disconnecting the low-voltage side power supply of the adjustable transformer, and recording the voltage and the time in the voltage adjusting process;
7) and data analysis:
after the low-voltage side power supply of the adjustable transformer is disconnected, stopping recording the images by the CCD camera, comparing the image time of the CCD camera recorded by the PC end with the voltage adjusting time, and recording the electric tree initiation time and the voltage amplitude of each cable sample, the sample breakdown time and the voltage amplitude; and respectively calculating the average values of the time for triggering and breaking down the electric tree and the voltage amplitude value of the cable sample according to statistical requirements, and comparing the average values with a standard value to evaluate the electric tree resistance of the cable sample.
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 ageing experiment of power tree, and single cable sample punctures the back, and the high-voltage fuse disconnection of this sample branch road can not influence the power tree of other cable samples ageing and survey, and this kind of method can make cable sample observation time reduce at double, and efficiency improves at double.
Two, the utility model discloses can cause and sample breakdown voltage to the electricity tree of a plurality of samples and ask the average value, can assess the anti electricity tree 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 structure diagram of the rapid detection device for the electrical tree resistance of the cross-linked polyethylene cable.
Fig. 2 is a schematic view of the overlooking structure of the organic glass cylinder of the present invention.
Fig. 3 is a schematic view of the structure of the sample grounding electrode in a top view.
Fig. 4 is an enlarged view of the position a of the present invention.
In the figure: the device comprises an adjustable transformer 1, a high-voltage fuse 2, a high-voltage bushing 3, an organic glass cylinder 4, a cable sample 5, a CCD (charge coupled device) camera 6, silicone oil 7, a grounding bushing 8, a PC9, a sample grounding electrode 10, an adjustable light source 11, an organic glass base 12, a steel needle 13, a concave groove 14, an inner semi-conducting layer 15, an insulating layer 16 and an outer semi-conducting layer 17.
Detailed Description
The present invention will be further described with reference to the following specific examples.
A quick detection device of anti electrical tree ability of crosslinked polyethylene cable includes: adjustable transformer 1, high-voltage fuse 2, organic glass jar 4, cable sample 5, CCD camera 6, silicon oil 7, PC9, sample earthing pole 10, adjustable light source 11, organic glass base 12 and steel needle 13, the inside of organic glass jar 4 is fixed with organic glass base 12, the thickness of organic glass base 12 is about 5cm, be provided with on the organic glass base 12 sample earthing pole 10, sample earthing pole 10 ground connection, evenly be fixed with a plurality of semicircular on the sample earthing pole 10 cable sample 5, be connected with steel needle 13 on the cable sample 5 respectively, the needle point end of steel needle 13 inserts the inside of cable sample 5, the other end of steel needle 13 all is connected with high-voltage fuse 2 through the wire, and is a plurality of high-voltage fuse 2 all is fixed in the outside of organic glass jar 4, a plurality of high-voltage fuse 2 with adjustable transformer 1 passes through the wire and is connected, the high-voltage fuse 2 is connected with the high-voltage output end of the adjustable transformer 1, silicone oil 7 is filled in the organic glass cylinder 4, and the silicone oil 7 submerges the cable sample 5 and the steel needle 13;
The cable sample 5 is in a semicircular sheet shape, the cable sample 5 is formed by stripping, and the stripped cable sample 5 comprises three layers which are sequentially as follows: the cable test piece comprises an inner semi-conducting layer 15, an insulating layer 16 and an outer semi-conducting layer 17, wherein the thickness of the cable test piece 5 is 5mm, the needle point of a steel needle 13 penetrates through the inner semi-conducting layer 15 of the cable test piece 5 and penetrates into the insulating layer 16, the distance from the needle point end of the steel needle 13 to the outer semi-conducting layer 17 of the cable test piece 5 is 2-2.5 mm, and the extension line of the steel needle 13 passes through the circle center of the insulating layer 16. The tangent of the insulating layer 16 at the intersection of the steel needle 13 and the insulating layer 16 is vertical.
A grounding sleeve 8 which is axially and horizontally arranged is fixed on one side of the organic glass cylinder 4, the grounding sleeve 8 penetrates through the side wall of the organic glass cylinder 4, the sample grounding electrode 10 is connected with the grounding sleeve 8 through a lead, and the grounding sleeve 8 is grounded; the steel needle 13 with all be connected with high-voltage bushing 3 on the circuit that high-voltage fuse 2 connects, 3 axial levels of high-voltage bushing set up, and are a plurality of 3 horizontal directions of high-voltage bushing set up side by side, high-voltage bushing 3 runs through the lateral wall of 4 opposite sides of organic glass jar, silicon oil 7 submerges ground sleeve 8 with high-voltage bushing 3. The vertical height between the central axes of the grounding sleeve 8 and the high-voltage sleeve 3 and the inner bottom surface of the organic glass cylinder 4 is 6 cm.
A plurality of notch orientation horizontally concave groove 14 have evenly been seted up along the horizontal direction on the sample earthing pole 10, concave groove 14 and semicircular 5 looks adaptations of cable sample, cable sample 5 with concave groove 14 passes through the insulating rope of plastics and fixes. The number and spacing of the high voltage bushings 3 are the same as the number and spacing of the recessed grooves 14.
The sample grounding electrode 10 is a strip copper electrode with the thickness of 6-8 mm.
The diameter of the steel needle 13 is 1 mm.
The adjustable transformer 1 is fixed outside the organic glass cylinder 4. The low-voltage side of the adjustable transformer 1 is electrically connected with an overcurrent protection relay, and the setting value converted from the high-voltage fuse 2 to the low-voltage side is lower than the setting value of the overcurrent protection relay at the low-voltage side of the adjustable transformer 1.
A detection method of a device for rapidly detecting the tree resistance of a crosslinked polyethylene cable comprises the following steps:
1) and preparing a cable sample:
cutting the cable into a semicircular slice sample with the thickness of about 5mm, penetrating a steel needle with the diameter of about 1mm through an inner semi-conducting layer of the slice sample and penetrating into an insulating layer, wherein the distance between the tip of the steel needle and the insulating layer is 2-2.5 mm close to the boundary of the outer semi-conducting layer; (ii) a
2) Fixing a cable sample:
putting the cable sample prepared in the step 1 into a concave groove of a sample grounding electrode, attaching an outer semi-conducting layer of the cable sample to the bottom of the concave groove, fixing the cable sample and the sample grounding electrode by using a plastic insulating rope, and placing the fixed cable sample and the sample grounding electrode above an organic glass base;
3) and connecting the wires:
connecting the steel needle, the high-voltage bushing, the high-voltage fuse, the high-voltage side output end of the adjustable transformer, the sample grounding electrode and the grounding bushing together by using a wire, and grounding the grounding bushing;
4) adding silicone oil:
injecting silicon oil into the organic glass cylinder, wherein the height of a silicon oil surface is about 7cm, and the silicon oil surface submerges the high-voltage bushing, the grounding bushing, the steel needle and the cable sample;
5) the configuration of the adjustable light source and the CCD camera comprises the following steps:
a plurality of adjustable light sources and CCD cameras are arranged according to the number of samples, the adjustable light sources, the PC and the CCD cameras are turned on, and the CCD cameras and the light sources are adjusted, so that a PC display picture can be clearly focused at the point of the steel needle, and the same PC can be communicated with all the CCD cameras at the same time;
6) and detecting:
slowly adjusting the adjustable transformer to enable the initial voltage of the adjustable transformer to be increased to 10kV, adjusting the adjustable transformer according to the rule that the voltage is increased by 2kV every 5min until all cable samples are broken down and the high-voltage fuse is fused, reducing the voltage of the adjustable transformer to 0, disconnecting the low-voltage side power supply of the adjustable transformer, and recording the voltage and the time in the voltage adjusting process;
7) and data analysis:
after the low-voltage side power supply of the adjustable transformer is disconnected, stopping recording the images by the CCD camera, comparing the image time of the CCD camera recorded by the PC end with the voltage adjusting time, and recording the electric tree initiation time and the voltage amplitude of each cable sample, the sample breakdown time and the voltage amplitude; and respectively calculating the average values of the time for triggering and breaking down the electric tree and the voltage amplitude value of the cable sample according to statistical requirements, and comparing the average values with a standard value to evaluate the electric tree resistance of the cable sample.
8) And data analysis results:
and (4) conclusion: the average tree initiation time of the sample is 17.6min, the average tree initiation voltage amplitude is 16.3kV, the average breakdown time is 27.4min, and the average breakdown voltage amplitude is 20.0 kV. A large number of experiments show that the standard values of the cable of the type are that the initiation time of an electric tree is 15.5min, the initiation voltage amplitude of the electric tree is 14.6kV, the breakdown time is 21min and the breakdown voltage amplitude is 17.8 kV. 4 indexes of the electrical tree initiation time, the electrical tree initiation voltage amplitude, the breakdown time and the breakdown voltage amplitude of the sample are all higher than standard values, so that the sample meets the requirements.
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 (6)
1. The utility model provides an anti electric tree ability quick detection device of crosslinked polyethylene cable which characterized in that includes: adjustable transformer (1), high-voltage fuse (2), organic glass jar (4), cable specimen (5), CCD camera (6), silicon oil (7), PC (9), sample earthing pole (10), adjustable light source (11), organic glass base (12) and steel needle (13), the inside of organic glass jar (4) is fixed with organic glass base (12), be provided with on organic glass base (12) sample earthing pole (10), sample earthing pole (10) ground connection, evenly be fixed with a plurality of semicircular on sample earthing pole (10) cable specimen (5), be connected with steel needle (13) on cable specimen (5) respectively, the needle point end of steel needle (13) inserts the inside of cable specimen (5), the other end of steel needle (13) all is connected with high-voltage fuse (2) through the wire, the high-voltage fuses (2) are all fixed outside the organic glass cylinder (4), the high-voltage fuses (2) are connected with the adjustable transformer (1) through a lead, silicone oil (7) is filled inside the organic glass cylinder (4), and the cable test sample (5) and the steel needle (13) are submerged by the silicone oil (7);
the top of cable sample (5) all is fixed with CCD camera (6), and is a plurality of CCD camera (6) with PC (9) pass through the data line and connect, the below of cable sample (5) all is provided with adjustable light source (11), adjustable light source (11) are fixed in the outside below of organic glass jar (4).
2. The device for rapidly detecting the electrical tree resistance of the cross-linked polyethylene cable according to claim 1, wherein the cable sample (5) is in a shape of a semicircular slice, the needle point of the steel needle (13) penetrates through the inner semi-conducting layer (15) of the cable sample (5) and penetrates into the insulating layer (16), the distance from the needle point end of the steel needle (13) to the outer semi-conducting layer (17) of the cable sample (5) is 2-2.5 mm, and the extension line of the steel needle (13) passes through the center of the insulating layer (16).
3. The device for rapidly detecting the electrical tree resistance of the cross-linked polyethylene cable according to claim 1 or 2, wherein an axial and horizontally arranged grounding sleeve (8) is fixed on one side of the organic glass cylinder (4), the grounding sleeve (8) penetrates through the side wall of the organic glass cylinder (4), the sample grounding electrode (10) is connected with the grounding sleeve (8) through a lead, and the grounding sleeve (8) is grounded; steel needle (13) with all be connected with high-voltage bushing (3) on the circuit that high-voltage fuse (2) are connected, high-voltage bushing (3) axial level sets up, and is a plurality of high-voltage bushing (3) horizontal direction sets up side by side, high-voltage bushing (3) run through the lateral wall of organic glass jar (4) opposite side, silicon oil (7) are drowned ground connection sleeve (8) with high-voltage bushing (3).
4. The device for rapidly detecting the electrical tree resistance of the cross-linked polyethylene cable according to claim 3, wherein a plurality of concave grooves (14) with notches facing horizontally are uniformly formed in the sample grounding electrode (10) along the horizontal direction, the concave grooves (14) are matched with the semicircular cable sample (5), and the cable sample (5) and the concave grooves (14) are fixed through a plastic insulating rope.
5. The device for rapidly detecting the tree resistance of the crosslinked polyethylene cable according to claim 4, wherein the sample grounding electrode (10) is an elongated copper electrode with a thickness of 6-8 mm.
6. The device for rapidly detecting the electrical tree resistance of the crosslinked polyethylene cable according to claim 5, wherein the diameter of the steel needle (13) is 1 mm.
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| CN202021333016.1U CN212301751U (en) | 2020-07-09 | 2020-07-09 | Quick detection device of anti electrical tree ability of crosslinked polyethylene cable |
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| CN202021333016.1U CN212301751U (en) | 2020-07-09 | 2020-07-09 | Quick detection device of anti electrical tree ability of crosslinked polyethylene cable |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111665425A (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 tree resistance of crosslinked polyethylene cable |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111665425A (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 tree resistance of crosslinked polyethylene cable |
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