Test device for the pollution level of high voltage external insulation equipment

Abstract

The invention belongs to the technical field of anti-pollution flashover of high-voltage external insulation equipment, and specifically relates to a testing device for the pollution level of high-voltage external insulation equipment; the adopted technical scheme is: a test strip is arranged on an insulator component, and an insulation resistance tester is connected to the test strip through a plurality of wires; the test strip comprises an upper sealing strip and a lower sealing strip, an absorbent cotton wet wipe and an insulating polyvinyl chloride layer are arranged between the upper sealing strip and the lower sealing strip, the insulating polyvinyl chloride layer is arranged on the lower surface of the absorbent cotton wet wipe, and the insulating polyvinyl chloride layer is a mesh-shaped protective layer woven from cross-linked polyvinyl chloride; the test strip is attached to the insulator component to make the insulator component uniformly moistened, and the insulation resistance tester measures the resistance value of the dirty layer on the surface of the insulator through the wire, and records the resistance measurement value, which effectively solves the problem that the surface pollution of the insulator component cannot be fully and uniformly moistened, thereby causing the measurement of different pollution levels of the external insulation to be unable to be characterized by the insulation resistance value.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-pollution flashover of high-voltage external insulation equipment, and in particular relates to a testing device for the pollution level of high-voltage external insulation equipment. Background Art

[0002] The pollution level of the external insulation surface is closely related to the external insulation configuration of the power transmission and transformation equipment of the power grid. Affected by the power grid operating environment (industrial waste gas, traffic exhaust, saline-alkali land, etc.), after a certain number of years of operation of the external insulation equipment, dirt will accumulate on its surface. Under atmospheric conditions such as rain, snow, and fog, the surface of the external insulation equipment will be wet or damp, and the accumulated dirt layer will form a conductive layer on the surface of the external insulation, reducing the insulation performance of the external insulation. In severe cases, "surface flashover" will occur, causing the power transmission and transformation equipment to trip, which is the so-called pollution flashover trip. Therefore, the dirtier the power grid operating environment, the higher the pollution level of the external insulation surface, and the larger the insulation configuration of the power transmission and transformation (the number of insulators or the creepage distance). According to the power grid operation and maintenance regulations, the pollution level test of the external insulation equipment is carried out every 3 to 5 years to ensure that the external insulation is "configured in place and with margin". The existing pollution level test method is based on GB / T 26218.1-2010 "Selection and sizing of high-voltage insulators used under dirty conditions Part 1", that is, the equivalent salt-ash density method. The main testing process of this method is: remove the porcelain insulator for pollution test from the gantry of the power plant (substation) or the transmission line tower, and determine the amount of deionized water used to scrub the insulator according to the upper and lower surface areas of the insulator porcelain medium; use a certain amount of deionized water to clean the dirt on the surface of the insulator, minimize the loss of ionized water, collect the sewage after wiping, and use a conductivity tester to test the conductivity of the sewage; filter the sewage, retain the insoluble dirt, dry and weigh; calculate and determine the salt ash density on the surface of the insulator according to the conductivity of the sewage and the weight of the insoluble dirt, combined with the insulator area and the amount of ionized water, so as to obtain the pollution level of the insulator surface. The existing pollution level test method has the following disadvantages: First, all operation processes cannot be completed at the equipment operation site or in the field, and most of the links need to be completed in a test room far away from the test site; second, the measurement and calculation process is cumbersome and requires certain training to complete the relevant work.

[0003] One of the important reasons why the pollution level of the outer insulation surface is measured using the method specified in GB / T 26218.1-2010 is that it is a technical problem to make the pollution layer on the surface of the insulator uniform and fully wet. Therefore, the existing method uses deionized water to wipe the surface of the insulator for measurement. If there is a technical device that can make the pollution layer on the surface of the insulator uniform and fully wet, the resistance of the insulator pollution layer can be directly measured using an insulation resistance tester, and the resistivity of the pollution layer can be calculated to determine the pollution level of the insulator surface. If a new test method is used, the test process will be greatly reduced, and on-site and field tests can be realized, greatly improving the detection efficiency. Summary of the invention

[0004] The invention overcomes the shortcomings of the prior art and provides a device for testing the pollution level of high-voltage external insulation equipment.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a test device for the pollution level of high-voltage external insulation equipment, including a test strip, an insulator component and an insulation resistance tester, wherein the test strip is arranged on the insulator component, and the insulation resistance tester is connected to the test strip through two measuring wires; the test strip is attached to the insulator component to make the insulator component evenly wet, and the insulation resistance tester measures the resistance value of the dirt layer on the surface of the insulator through the wire and records the resistance measurement value, which effectively solves the problem that the surface dirt of the insulator component cannot be fully and evenly wetted, resulting in the inability to use the insulation resistance value to characterize the measurement of different pollution levels of the external insulation;

[0006] The test strip comprises an upper sealing strip and a lower sealing strip, between which an absorbent cotton wet wipe and an insulating polyvinyl chloride layer are arranged, the insulating polyvinyl chloride layer is arranged on the lower surface of the absorbent cotton wet wipe, and the insulating polyvinyl chloride layer is a protective layer woven into a mesh by cross-linked polyvinyl chloride.

[0007] Preferably, the insulating polyvinyl chloride layer comprises a grid line layer and a plurality of mesh grids evenly arranged at the lower end of the grid line layer, and the area of ​​a single grid of the grid line layer is 1 mm 2 The spacing between two adjacent grids is 0.5 mm.

[0008] Preferably, the upper surface and the lower surface on both sides of the edge of the insulating polyvinyl chloride layer are provided with adhesive strips A, and the upper sealing strip and the lower sealing strip are sealed by adhesive strips B; the lower sealing strip is torn off, the insulating polyvinyl chloride layer is attached to the insulator component, and the deionized water is passed through the grid line layer and evenly placed in the grid by pressing the absorbent cotton wipes, which can make the water film uniform without affecting the insulation resistance test path.

[0009] Preferably, the absorbent cotton wipes have deionized water adsorbed inside and are used to moisten the surface of the insulator component.

[0010] Preferably, the insulator component includes an insulator iron cap, a porcelain insulator body and an insulator steel leg, the porcelain insulator body is arranged between the insulator iron cap and the insulator steel leg, the surface length of the cross-section of the porcelain insulator body is the insulator creepage distance, and the test strip is arranged to fit the insulator creepage distance.

[0011] Preferably, one end of the test strip is attached to one side of the insulator iron cap, and the other end of the test strip is attached to one side of the insulator steel foot.

[0012] Preferably, the insulation resistance tester is provided with two measuring terminals, and the two measuring terminals are respectively connected to two end points of the test strip through test lines.

[0013] Preferably, the two measuring terminals include a high voltage terminal "L" and a ground terminal "E".

[0014] Preferably, the measuring line is connected to a test electrode clamp, and the test electrode clamp can clamp the test strip.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. The present invention adopts a test strip, which changes the previous situation of needing to scrub and collect stains on the surface of the running insulator. The test strip can evenly wet all the surface dirt of the insulator components, and measure and calculate the dirt level through the insulation resistance, which greatly simplifies the test process and improves the detection efficiency.

[0017] 2. The present invention adopts an insulating polyvinyl chloride layer composed of a grid line layer and a mesh grid, and the area of ​​a single grid in the grid line layer is set to 1mm 2 , so that the spacing between two adjacent grids is 0.5mm, and the grid is set on the lower surface of the grid line layer to ensure the fineness of the insulating polyvinyl chloride layer, so that the deionized water forms a uniform water film without affecting the insulation resistance test path.

[0018] 3. The device used in the present invention can realize rapid measurement of the contamination level of the external insulation surface, and reduces the measurement time and the workload of the inspectors without reducing the measurement accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] Figure 1 It is a structural schematic diagram of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the test strip of the present invention;

[0022] Figure 3A top view of the insulating polyvinyl chloride layer of the present invention;

[0023] Figure 4 is a side view of the insulating polyvinyl chloride layer of the present invention;

[0024] Figure 5 A top view of an insulator component of the present invention;

[0025] Figure 6 It is a bottom view of the insulator component of the present invention.

[0026] In the figure: 1 is the upper sealing strip, 2 is the absorbent cotton wipes, 3 is the insulating polyvinyl chloride layer, 4 is the lower sealing strip, 5 is the adhesive strip, 6 is the grid line layer, 7 is the mesh grid, 8 is the insulator iron cap, 9 is the insulator steel foot, 10 is the upper surface of the insulator, 11 is the lower surface of the insulator, 12 is the porcelain insulator body, 13 is the insulator creepage distance, 14 is the test strip, 15 is the high voltage terminal "L", 16 is the ground terminal "E", 17 is the insulation resistance tester, 18 is the measuring line, and 19 is the test electrode clamp. DETAILED DESCRIPTION

[0027] As shown in the figure, in the first embodiment, the first step is the specific use method of the wet test strip on the surface of the insulator, the lower sealing strip 4 in the test strip 14 is torn off to expose the adhesive strip 5 on the lower surface of the insulating polyvinyl chloride layer 3, one end of the test strip 14 is attached to one side of the insulator iron cap 8 and the upper surface 10 of the insulator, the test strip 14 is straightened, the lower sealing strip 4 is slowly torn off completely, and the test strip 14 is attached to the upper surface 10 and the lower surface 11 of the insulator along the creepage distance 13 of the insulator, so that the test strip 14 is evenly attached to the porcelain insulator body 12, and the other end of the test strip 14 stops at one side of the bottom of the insulator steel foot 9, and the length of the test strip 14 is equal to the creepage distance 13 of the insulator;

[0028] Then, the upper sealing strip 1 is evenly squeezed with fingers to squeeze out the deionized water in the absorbent cotton wipes 2, and the deionized water is squeezed into the grid of the insulating polyvinyl chloride layer 3. The grid of the insulating polyvinyl chloride layer 3 is in close contact with the upper surface 10 of the insulator and the lower surface 11 of the insulator (the mesh grid 7 is in close contact with the insulator component), and the deionized water in the grid is absorbed by the upper surface 7 of the insulator and the lower surface 8 of the insulator, while the excess deionized water is gathered in the grid line layer 6. Since the absorbent cotton wipes 2 are in close contact with the insulating polyvinyl chloride fine mesh layer 3, the excess deionized water is sucked back by the absorbent cotton wipes 2; thus, the upper surface 10 of the insulator and the lower surface 11 of the insulator are evenly moistened with the deionized water.

[0029] Step 2: Take out the insulation resistance tester 17 for wiring; connect the two measuring wires 18 to the two test electrode clamps 19 respectively; one measuring wire 18 is connected to the high voltage terminal "L" 15 of the insulation resistance tester 17, and the other measuring wire 18 is connected to the ground terminal "E" 16 of the insulation resistance tester 17; the two test electrode clamps 19 clamp the two ends of the test strip 14 respectively.

[0030] Step 3: Tear off the upper sealing strip 1 and absorbent cotton wipes 2, leaving only the insulating polyvinyl chloride fine mesh layer 3; two test electrode clamps 19 are tightly attached to the upper surface 10 of the insulator and the lower surface 11 of the insulator that have been evenly moistened with deionized water; use an insulation resistance tester 17 to measure the resistance value of the dirty layer on the surface of the insulator, and record the resistance measurement value.

[0031] Step 4: Calculate the "ρ / h" value, ρ / h = (R×w) / L; L is a known parameter of the measured creepage distance 13 of the insulator, in millimeters (mm); w is the width of the absorbent cotton wipes 2 and the insulating polyvinyl chloride fine mesh layer 3, 10 millimeters (mm); R is the recorded resistance measurement value.

[0032] Step 5: According to Table 2 "Correspondence between different pollution levels and calculated indications of resistivity 'ρ / h' values", the pollution level of the insulator operating environment is obtained.

[0033] Step 6: Since the dirt layer on the surface of the insulator is somewhat uneven, multiple measurements can be performed at different locations on the insulator.

[0034] Embodiment 2:

[0035] According to the basic circuit theory, use an insulation resistance tester to test the insulation resistance of porcelain insulators. The resistance value is the parallel resistance value of the insulator porcelain dielectric resistance and the insulator surface pollution layer resistance.

[0036] When the surface of the insulator is dry, the surface dirt layer of the insulator is very thin and has low conductivity, so its resistance value is extremely large (but less than air insulation). Therefore, the resistance value of the surface dirt layer of the insulator is much greater than the resistance of the insulator porcelain dielectric. According to the parallel resistance calculation formula, the resistance tested by the insulation resistance tester is the resistance of the insulator porcelain dielectric.

[0037] When the surface of the insulator is wet, the dirt layer on the insulator surface absorbs moisture, the conductivity of the dirt layer is greatly improved, and its resistance becomes smaller, while the resistance of the insulator porcelain dielectric remains unchanged, and the resistance of the insulator porcelain dielectric is much larger than the resistance of the dirt layer on the insulator surface. Similarly, the resistance tested by the insulation resistance tester is the resistance of the dirt layer on the insulator surface. It can be seen that when the surface of the insulator is wet, the resistance of the dirt layer on the insulator surface can be directly measured using an insulation resistance tester.

[0038] From the resistance formula, we know that: R = (ρL) / S → R = (ρL) / (wh), where: R represents the resistance of the dirt layer on the surface of the insulator, S is the cross-sectional area of ​​the wet dirt layer, L is the length of the dirt layer (L is equal to the creepage distance of the insulator), h is the water film height of the wet dirt layer, w is the water film width of the wet dirt layer, and S = wh.

[0039] During the measurement process, if the height of the water film h is a constant, then the volume of water adsorbed per unit area of ​​the insulator surface is also a constant; if the weight of the dirt layer per unit area of ​​the insulator surface is known to be a constant, then the dirt concentration of the dirt layer per unit area of ​​the insulator surface dissolved under unit volume of water is a constant, and the dirt conductivity ρ is a constant; therefore, the ρ value is related to the weight of the dirt per unit area of ​​the insulator surface and the height of the water film h.

[0040] Therefore, the size of ρ does not change with the change of the width of the water film of the wetted pollution layer w; when the creepage distance of the L insulator is a known value, the change of w only affects the change of the test resistance R; expressed by the formula: ρ / h=(R 1 × 1 ) / L=(R 2 × 2 ) / L. It can be seen that the width of the water film in the wetted pollution layer does not affect the size of "ρ / h", which means that "ρ / h" can be measured and calculated by only partially wetting the surface of the insulator.

[0041] According to the solid layer method in Section 4 of GB / T 4585-2004 "Artificial pollution test for high-voltage insulators for AC systems", the test obtained the corresponding relationship between the "ρ / h" value measured by the test strip and the pollution level (see Table 1).

[0042] Table 1 Correspondence between different pollution levels and the calculated indication value of resistivity "ρ / h"

[0043]

[0044] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Those familiar with the technology may modify or improve the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A test device for the pollution level of high voltage external insulation equipment, characterized in that: It comprises a test strip (14), an insulator component and an insulation resistance tester (17), wherein the test strip (14) is arranged on the insulator component, and the insulation resistance tester (17) is connected to the test strip (14) via two measuring lines (18); The test strip (14) comprises an upper sealing strip (1) and a lower sealing strip (4); an absorbent cotton wet wipe (2) and an insulating polyvinyl chloride layer (3) are arranged between the upper sealing strip (1) and the lower sealing strip (4); the insulating polyvinyl chloride layer (3) is arranged on the lower surface of the absorbent cotton wet wipe (2); the insulating polyvinyl chloride layer (3) is a protective layer woven into a mesh of cross-linked polyvinyl chloride; the insulating polyvinyl chloride layer (3) comprises a grid line layer (6) and a plurality of mesh grids (7) evenly arranged at the lower end of the grid line layer (6); the area of ​​a single grid of the grid line layer (6) is 1 mm 2 , the spacing between two adjacent mesh grids (7) is 0.5 mm; Adhesive strips (5) are provided on the upper surface and the lower surface of both sides of the edge of the insulating polyvinyl chloride layer (3), and the upper sealing strip and the lower sealing strip are sealed by the adhesive strips (5); One end of the test strip (14) is attached to one side of the insulator iron cap (8), and the other end of the test strip (14) is attached to one side of the insulator steel foot (9).

2. The device for testing the pollution level of high voltage external insulation equipment according to claim 1, characterized in that: The absorbent cotton wet wipes (2) have deionized water adsorbed inside and are used to moisten the surface of the insulator component.

3. The device for testing the pollution level of high voltage external insulation equipment according to claim 1, characterized in that: The insulator component comprises an insulator iron cap (8), a porcelain insulator body (12) and an insulator steel leg (9); the porcelain insulator body (12) is arranged between the insulator iron cap (8) and the insulator steel leg (9); the surface length of the cross section of the porcelain insulator body (12) is the insulator creepage distance (13); and the test strip (14) is arranged in close contact with the insulator creepage distance (13).

4. The device for testing the pollution level of high voltage external insulation equipment according to claim 1, characterized in that: The insulation resistance tester (17) is provided with two measuring ends, and the two measuring ends are respectively connected to two end points of the test strip (14) through test wires (18).

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