A 500kV wind-proof jumper insulator bending fatigue test method

Abstract

The invention relates to a bending fatigue test method for a 500kV windproof jumper insulator. The 500kV windproof jumper insulator comprises a core body and a core rod, and also comprises a frame and a supporting frame. A lifting mechanism is arranged on the frame. The method comprises the following steps in sequence: step one, testing a bending deflection value y1; step two, performing a swing fatigue test to detect whether there are visually visible cracks at a connection position between the core rod and the core body; and step three, testing a bending deflection value y2. The invention has the advantages that the amplitude of the swing fatigue test in step two is set by the bending deflection value y1, so that the safety performance of the swing fatigue test can be improved, the influence on the 500kV windproof jumper insulator due to excessive amplitude can be prevented, and the reliability of the swing fatigue test can be improved. By comparing the values ​​of the bending deflection value y2 and the bending deflection value y1, and judging whether the 500kV windproof jumper insulator is a qualified product by the ratio of the bending deflection value y2 to the bending deflection value y1, the inspection personnel can obtain the test results quickly and accurately, and the test accuracy rate can be improved.

Description

Technical Field

[0001] The invention relates to a method for testing the bending fatigue resistance of a 500kV wind-proof jumper insulator. Background Art

[0002] In recent years, the frequency of tripping accidents caused by flashovers caused by diversion jumpers on 500kV transmission lines in many regions across the country has exceeded the acceptable limit for safe operation of the power system, which has brought great harm to the safe operation of power lines. According to statistics, in 2018, there were more than 100 wind-induced trippings on 500kV and above lines under the jurisdiction of State Grid Corporation, covering Jiangsu, Zhejiang, Anhui, Hubei, Henan, Shandong, Shanxi, Beijing, Hebei, Northeast China and other places. Wind-induced discharges have a wide range, many times, and great impacts, especially in typhoon-prone areas in coastal areas. Unlike lightning flashovers and operating impulse flashovers, most wind-induced flashovers occur under working voltage and generally cannot be successfully reclosed, resulting in line shutdowns and causing significant losses to the national economy. According to the analysis of wind-induced tripping accidents that have occurred in recent years, the main causes of wind-induced flashovers of jumpers are as follows.

[0003] Strong wind is the most direct cause of wind deflection flashover of jumper. Traditional jumper string insulators are made of conventional porcelain and glass. When the wind speed exceeds the design, the insulator string tilts toward the pole tower, reducing the air gap distance between the conductor and the tower. When the air gap distance cannot meet the minimum voltage requirement for discharge, flashover occurs. After the line adjustment adopts composite insulators, wind deflection calibration is not carried out. Because the composite insulator has a light weight, even with a heavy hammer, the large swing amplitude during wind deflection will cause discharge.

[0004] The main solutions at present are: 1. Strengthen the windproof guy wire, fix the wire to the line hardware to fix the conductor, which can effectively suppress the wind deviation of the line. However, due to the inflexible rotation of wind deviation and long-term stress, the line hardware is susceptible to fatigue damage. Therefore, the installation of windproof guy wires poses a safety hazard to line operation; 2. Install a heavy hammer, but the effect of installing a heavy hammer is limited, and it is not the main measure to fundamentally solve the problem of wind deviation flashover of suspended strings; 3. Use wind-proof insulators: The insulator has a small swing amplitude due to wind deviation, which increases the electrical clearance between the conductor and the pole tower; the installation is reliable, but for 500kV and above lines, the wind dance of the conductor is more serious due to the large outer dimensions of the insulation.

[0005] 500kV lines still use conventional jumper strings due to the limitation of the bending resistance of the synthetic insulator core rod. At home and abroad, the 500kV transmission line jumper strings are generally assembled by vertical suspension or with a heavy hammer. This assembly method cannot fundamentally solve the problem of wind deflection and flashover of jumpers. In coastal areas with strong winds, V-type jumper string assembly may be used. Since it requires an additional insulator and the jumper cross arm needs to be lengthened, it will cause a large increase in investment. Since the jumper string of 500kV lines is long, the wind load is large, and the conductor is in a four-split form, the use of vertical fixed wind-proof jumper insulator strings will form a large bending moment at the tower fixing point.

[0006] 500kV windproof jumper insulator is a product suitable for 500kV lines, and 500kV windproof jumper insulator needs to undergo bending fatigue test. However, compared with 220kV windproof jumper insulator, 500kV windproof jumper insulator is much longer and heavier than 220kV windproof jumper insulator. Therefore, the original 220kv test method cannot be used to test 500kV windproof jumper insulator, resulting in reduced safety performance during the test and the test results are easily affected. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a 500kV windproof jumper insulator bending fatigue test method to solve the technical problem that there is no existing 500kV windproof jumper insulator bending fatigue test method, which leads to certain risks.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions: a 500kV wind-proof jumper insulator bending fatigue test method, the 500kV wind-proof jumper insulator includes a core body and core rods arranged at both ends of the core body, and also includes a device for installing the wind-proof jumper insulator, the device includes a frame and a support frame, the frame is provided with a lifting mechanism, the lifting mechanism is provided with a tension sensor, and the method includes the following steps in sequence:

[0009] Step 1: Fix one end of the 500kV windproof jumper insulator to the frame, and then apply the rated bending load to the other end of the 500kV windproof jumper insulator. After holding for 1 minute, test the bending deflection value y1 of the 500kV windproof jumper insulator. The rated bending load is 2.5kN.

[0010] Step 2: Install and fix the 500kV wind-proof jumper insulator after the test in step 1 on the lifting mechanism, and conduct a swing fatigue test on the 500kV wind-proof jumper insulator through the lifting mechanism. The test amplitude is +y1 / 2, -y1 / 4, the vibration frequency is 0.65Hz, and the number of vibrations is 5×104 Then observe the connection between the core rod and the core body, and make sure there are no visible cracks at the connection between the core rod and the core body;

[0011] Step 3: Repeat step 1 to test the bending deflection value y2 of the 500kV windproof jumper insulator after the fatigue test in step 2. If y2 is less than or equal to 1.2y1, the 500kV windproof jumper insulator is judged to be qualified. If y2 is greater than 1.2y1, the 500kV windproof jumper insulator is judged to be unqualified.

[0012] Preferably, the frame includes a horizontal part and a vertical part, the horizontal part is arranged at the top of the vertical part, the frame is installed on the ground relying on the vertical part, the support frame is arranged on the ground below the horizontal part, the lifting mechanism is arranged on the horizontal part, the vertical part includes a vertical frame and a horizontal cross bar arranged on the frame, and a connecting part is provided on the horizontal cross bar.

[0013] Preferably, the connecting portion comprises a column and a fixing plate arranged on the column, and one end of the windproof jumper insulator is mounted on the fixing plate through a bolt assembly.

[0014] Preferably, the vertical portion further comprises a mounting plate and anchor bolts, the mounting plate is arranged at the bottom end of the vertical frame, and the anchor bolts are arranged on the mounting plate.

[0015] Preferably, the horizontal part includes a horizontal frame and a horizontal slide rail, the lifting mechanism is arranged on the horizontal slide rail, and a limit switch is provided on the horizontal slide rail.

[0016] Preferably, the lifting mechanism comprises an electric hoist and a connecting rope, and the connecting rope is provided with a lifting ring connected to the electric hoist.

[0017] Preferably, the support frame includes a base and a support seat, the base is provided with a jack connected to the support seat, and the support seat is provided with a placement groove.

[0018] Preferably, a protective pad is provided in the placement groove.

[0019] In summary, the advantages of the present invention are: 1. By testing the bending deflection value y1 in step one, testing whether there are visually visible cracks at the connection between the core rod and the core body by a swing fatigue test in step two, and testing the bending deflection value y2 in step three, the amplitude of the swing fatigue test in step two is set by the bending deflection value y1, which can improve the safety performance of the swing fatigue test, prevent the influence of the 500kV windproof jumper insulator due to excessive amplitude, and improve the reliability of the swing fatigue test; by comparing the values ​​of the bending deflection value y2 and the bending deflection value y1, and judging whether the 500kV windproof jumper insulator is a qualified product by the ratio of the bending deflection value y2 to the bending deflection value y1, the inspection personnel can quickly and accurately obtain the test results, improve the accuracy of the test, and reduce the human error of the test; the whole test process is simple, and the device can simultaneously detect the bending resistance and fatigue performance of the 500kV windproof jumper insulator, and the lifting mechanism can ensure the reliability of the swing fatigue test, and the tension sensor can ensure the stability of the rated bending load during the test;

[0020] 2. One end of the windproof jumper insulator is fixedly installed on the horizontal part, and the other end of the windproof jumper insulator is connected to the lifting mechanism, and the tensile load of the lifting mechanism on the windproof jumper insulator during the test is collected in real time through the tension sensor, thereby ensuring the stability of the load during the test. During the test, the windproof jumper insulator only needs to be raised and lowered by the lifting mechanism, and the swing fatigue test of the windproof jumper insulator is realized by the rising and falling of the windproof jumper insulator. The overall test effect is good, which is conducive to the rapid installation of the windproof jumper insulator. The setting of the support frame can support the windproof jumper insulator and reduce the contact between the windproof jumper insulator and the ground during the descent process, thereby avoiding damage to the windproof jumper insulator during the test. The vertical part is set as a vertical frame and a horizontal cross bar. The horizontal cross bar can not only realize the installation of the windproof jumper insulator, but also improve the strength of the entire vertical part.

[0021] 3. The connection part is set as a structure of a column and a fixing plate, and one end of the wind-proof jumper insulator is installed on the fixing plate through a bolt assembly, which can improve the fixing quality of the wind-proof jumper insulator and facilitate installation and disassembly;

[0022] 4. Through the setting of the mounting plate and the anchor bolts, the mounting plate can increase the contact area between the vertical frame and the ground, ensuring that the vertical frame can be stably fixed on the ground;

[0023] 5. The horizontal part is set as a horizontal frame and a horizontal slide rail to ensure the straightness of the lifting mechanism sliding on the horizontal part, and the limit switch is used to limit the sliding displacement of the lifting mechanism on the horizontal slide rail to test the safety performance of the wind-proof jumper insulator during the test;

[0024] 6. The lifting mechanism is set to an electric hoist and a connecting rope, which is connected to the electric hoist through the lifting ring on the connecting rope, thereby improving the overall installation efficiency. The connecting rope can realize the stable fixation of the wind-proof jumper insulator, improve the fixing quality, and ensure the fixing quality of the wind-proof jumper insulator during the test;

[0025] 7. The support frame is set as a structure of a base and a support seat, which can not only support one end of the wind-proof jumper insulator, but also adjust the height of the support seat on the base through the jack provided on the base, thereby realizing the up and down shaking test of the wind-proof jumper insulator, and can be effectively adjusted according to different models of wind-proof jumper insulators;

[0026] 8. The setting of the protection pad can protect the windproof jumper insulator when the lifting mechanism is descending, greatly reducing the contact force between the windproof jumper insulator and the placement groove, thereby preventing damage to the windproof jumper insulator. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the accompanying drawings:

[0028] Figure 1 It is a structural schematic diagram of the device in the present invention;

[0029] Figure 2 It is a structural schematic diagram of the support frame in the present invention.

[0030] Reference numerals:

[0031] 1 rack, 2 horizontal part, 21 horizontal frame, 22 horizontal slide rail, 23 limit switch, 3 vertical part, 31 vertical frame, 32 horizontal cross bar, 33 connecting part, 34 column, 35 fixing plate, 36 bolt assembly, 37 mounting plate, 38 anchor bolt, 4 support frame, 41 base, 42 support seat, 43 jack, 44 placement slot, 45 protection pad, 5 lifting mechanism, 51 electric hoist, 52 connecting rope, 53 lifting ring, 6 tension sensor. DETAILED DESCRIPTION

[0032] A method for testing the bending fatigue resistance of a 500kV wind-proof jumper insulator, wherein the 500kV wind-proof jumper insulator comprises a core body and core rods arranged at both ends of the core body, and also comprises a device for installing the wind-proof jumper insulator, wherein the device comprises a frame 1 and a support frame 4, wherein a lifting mechanism 5 is arranged on the frame 1, and a tension sensor 6 is arranged on the lifting mechanism 5, wherein the method comprises the following steps in sequence:

[0033] Step 1: Fix one end of the 500kV windproof jumper insulator to the frame, and then apply the rated bending load to the other end of the 500kV windproof jumper insulator. After holding for 1 minute, test the bending deflection value y1 of the 500kV windproof jumper insulator. The rated bending load is 2.5kN.

[0034] Step 2: Install and fix the 500kV wind-proof jumper insulator after the test in step 1 on the lifting mechanism, and conduct a swing fatigue test on the 500kV wind-proof jumper insulator through the lifting mechanism. The test amplitude is +y1 / 2, -y1 / 4, the vibration frequency is 0.65Hz, and the number of vibrations is 5×10 4 Then observe the connection between the core rod and the core body, and make sure there are no visible cracks at the connection between the core rod and the core body;

[0035] Step 3: Repeat step 1 to test the bending deflection value y2 of the 500kV windproof jumper insulator after the fatigue test in step 2. If y2 is less than or equal to 1.2y1, the 500kV windproof jumper insulator is judged to be qualified. If y2 is greater than 1.2y1, the 500kV windproof jumper insulator is judged to be unqualified.

[0036] Through step one, the bending deflection value y1 is tested, and through step two, the swing fatigue test is performed to detect whether there are visually visible cracks at the connection between the core rod and the core body, and through step three, the bending deflection value y2 is tested. The amplitude of the swing fatigue test in step two is set by the bending deflection value y1, which can improve the safety performance of the swing fatigue test, prevent the influence of excessive amplitude on the 500kV windproof jumper insulator, and improve the reliability of the swing fatigue test. By comparing the values ​​of the bending deflection value y2 and the bending deflection value y1, and judging whether the 500kV windproof jumper insulator is a qualified product by the ratio of the bending deflection value y2 to the bending deflection value y1, the inspection personnel can quickly and accurately obtain the test results, improve the accuracy of the test, and reduce the human error of the test. The whole test process is simple, and the device can simultaneously detect the bending resistance and fatigue performance of the 500kV windproof jumper insulator. The reliability of the swing fatigue test can be ensured by the lifting mechanism, and the tension sensor can ensure the stability of the rated bending load during the test.

[0037] like Figure 1 , Figure 2As shown, the frame 1 includes a horizontal part 2 and a vertical part 3, the horizontal part 2 is arranged at the top of the vertical part 3, the frame 1 is installed on the ground relying on the vertical part 3, the support frame 4 is arranged on the ground below the horizontal part 2, the lifting mechanism 5 is arranged on the horizontal part 2, the vertical part 3 includes a vertical frame 31 and a horizontal cross bar 32 arranged on the frame, and the horizontal cross bar 32 is provided with a connecting part 33, one end of the windproof jumper insulator is fixedly installed on the horizontal part 2, and the other end of the windproof jumper insulator is connected to the lifting mechanism 5, and the tensile load of the lifting mechanism 5 on the windproof jumper insulator during the test is collected in real time through a tensile sensor, thereby ensuring the load during the test. Stability. During the test, the windproof jumper insulator only needs to be raised and lowered back and forth by the lifting mechanism 5. The swing fatigue test of the windproof jumper insulator is realized by the rising and falling of the windproof jumper insulator. The overall test effect is good, which is conducive to the rapid installation of the windproof jumper insulator. The setting of the support frame 4 can support the windproof jumper insulator and reduce the contact between the windproof jumper insulator and the ground during the descent process, thereby avoiding damage to the windproof jumper insulator during the test. The vertical part 3 is arranged into a vertical frame 31 and a horizontal cross bar 32. The horizontal cross bar 32 can not only realize the installation of the windproof jumper insulator, but also improve the strength of the entire vertical part 3.

[0038] The connecting portion 33 includes a column 34 and a fixing plate 35 arranged on the column 34, one end of the windproof jumper insulator is installed on the fixing plate 35 through a bolt assembly 36, and the connecting portion 33 is arranged as a structure of the column 34 and the fixing plate 35, and one end of the windproof jumper insulator is installed on the fixing plate 35 through the bolt assembly 36, which can improve the fixing quality of the windproof jumper insulator and facilitate installation and disassembly. The vertical portion 3 also includes a mounting plate 37 and an anchor bolt 38, and the mounting plate 37 is arranged at the bottom end of the vertical frame 31, and the anchor bolt 38 is arranged on the mounting plate 37. Through the arrangement of the mounting plate 37 and the anchor bolt 38, the mounting plate 37 can increase the contact area between the vertical frame 31 and the ground, ensuring that the vertical frame 31 can be stably fixed on the ground.

[0039] The horizontal part 2 includes a horizontal frame 21 and a horizontal slide rail 22, the lifting mechanism 5 is arranged on the horizontal slide rail 22, and a limit switch 23 is provided on the horizontal slide rail 22. The horizontal part 2 is set as the horizontal frame 21 and the horizontal slide rail 22, which can ensure the straightness of the lifting mechanism 5 sliding on the horizontal part 2, and limit the sliding displacement of the lifting mechanism 5 on the horizontal slide rail 22 by the limit switch 23, and the safety performance of the wind-proof jumper insulator during the test. The lifting mechanism 5 includes an electric hoist 51 and a connecting rope 52, and the connecting rope 52 is provided with a lifting ring 53 connected to the electric hoist 51. The lifting mechanism 5 is set as the electric hoist 51 and the connecting rope 52, and is connected to the electric hoist 51 through the lifting ring 53 on the connecting rope 52, which improves the overall installation efficiency. The connecting rope 52 can realize the smooth fixation of the wind-proof jumper insulator, improves the fixing quality, and ensures the fixing quality of the wind-proof jumper insulator during the test.

[0040] The support frame 4 includes a base 41 and a support seat 42. The base 41 is provided with a jack 43 connected to the support seat 42. The support seat 42 is provided with a placement groove 44. The support frame 4 is arranged into a structure of the base 41 and the support seat 42, which can not only support one end of the wind-proof jumper insulator, but also adjust the height of the support seat 42 on the base 41 through the jack 43 provided on the base 41, thereby realizing the up and down shaking test of the wind-proof jumper insulator, and can effectively adjust according to different models of wind-proof jumper insulators. A protective pad 45 is provided in the placement groove 44. The setting of the protective pad 45 can protect the wind-proof jumper insulator when the lifting mechanism 5 is descending, greatly reducing the contact force between the wind-proof jumper insulator and the placement groove 44, thereby preventing damage to the wind-proof jumper insulator.

[0041] In addition to the above preferred embodiments, the present invention has other implementation modes. Those skilled in the art may make various changes and modifications based on the present invention. As long as they do not depart from the spirit of the present invention, they should all fall within the scope defined by the claims attached to the present invention.

Claims

1. A method for testing the bending fatigue resistance of a 500kV windproof jumper insulator, wherein the 500kV windproof jumper insulator comprises a core body and core rods arranged at both ends of the core body, and is characterized in that: It also includes a device for installing a wind-proof jumper insulator, the device includes a frame and a support frame, the frame is provided with a lifting mechanism, the lifting mechanism is provided with a tension sensor, and the method includes the following steps in sequence: Step 1: Fix one end of the 500kV windproof jumper insulator to the frame, and then apply the rated bending load to the other end of the 500kV windproof jumper insulator. After holding for 1 minute, test the bending deflection value y1 of the 500kV windproof jumper insulator. The rated bending load is 2.5 kN. Step 2: Install and fix the 500kV wind-proof jumper insulator after the test in step 1 on the lifting mechanism, and conduct a swing fatigue test on the 500kV wind-proof jumper insulator through the lifting mechanism. The test amplitude is +y1 / 2, -y1 / 4, the vibration frequency is 0.65Hz, and the number of vibrations is 5×10 4 Then observe the connection between the core rod and the core body. There should be no visible cracks at the connection between the core rod and the core body. Step 3: Repeat step 1 to test the bending deflection value y2 of the 500kV windproof jumper insulator after the fatigue test in step 2. If y2 is less than or equal to 1.2 y1, the 500kV windproof jumper insulator is judged to be a qualified product. If y2 is greater than 1.2 y1, the 500kV windproof jumper insulator is judged to be an unqualified product. The frame includes a horizontal part and a vertical part, the horizontal part is arranged at the top of the vertical part, the frame is installed on the ground by relying on the vertical part, the support frame is arranged on the ground below the horizontal part, the lifting mechanism is arranged on the horizontal part, the vertical part includes a vertical frame and a horizontal cross bar arranged on the frame, and the horizontal cross bar is provided with a connecting part; The connecting part comprises a column and a fixing plate arranged on the column, and one end of the windproof jumper insulator is mounted on the fixing plate through a bolt assembly; The horizontal part includes a horizontal frame and a horizontal slide rail, the lifting mechanism is arranged on the horizontal slide rail, and a limit switch is arranged on the horizontal slide rail; The lifting mechanism comprises an electric hoist and a connecting rope, wherein the connecting rope is provided with a lifting ring connected to the electric hoist; The support frame comprises a base and a support seat, the base is provided with a jack connected to the support seat, and the support seat is provided with a placement groove.

2. A 500kV wind-proof jumper insulator bending fatigue test method according to claim 1, characterized in that: The vertical part further comprises a mounting plate and anchor bolts, wherein the mounting plate is arranged at the bottom end of the vertical frame, and the anchor bolts are arranged on the mounting plate.

3. A 500kV wind-proof jumper insulator bending fatigue test method according to claim 1, characterized in that: A protection pad is arranged in the placement groove.

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