Test fixture and test method for equalizing shield ring

Abstract

The embodiment of the application provides a test tool and a test method for a voltage-sharing shielding ring, and belongs to the technical field of electrical component testing. The test tool for the voltage-sharing shielding ring comprises a base, a vibration platform is arranged on the base, and the vibration platform is configured to reciprocally displace along a first direction relative to the base. One end of a first supporting arm is rotationally connected to the vibration platform, and the other end of the first supporting arm is rotationally connected to a second supporting arm. The first supporting arm is configured to reciprocally rotate about a second direction, and the second supporting arm is configured to reciprocally rotate about a third direction. The first direction, the second direction and the third direction are perpendicular to each other in pairs. An installation platform is connected to one end of the second supporting arm away from the first supporting arm, and the installation platform is used for fixing the voltage-sharing shielding ring. A stress detection piece is arranged on the installation platform, and the stress detection piece is used for detecting stress applied by the voltage-sharing shielding ring to the installation platform. The test tool for the voltage-sharing shielding ring provided by the embodiment of the application realizes vibration simulation in multiple degrees of freedom directions of the voltage-sharing shielding ring, and improves test accuracy.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical component testing, in particular to a test tool and test method for a grading ring. BACKGROUND

[0002] The grading ring is an electrical component in a high-voltage transmission line, which is generally arranged at an insulator string or a cable terminal of the high-voltage transmission line, and is used to balance the electric field distribution of the high-voltage transmission line and reduce corona loss.

[0003] Due to wind, conductor dancing, mechanical vibration and other factors, the grading ring will bear complex vibration and dancing loads during operation, which may cause material fatigue, connection loosening or even breakage of the grading ring, and affect the safe and stable operation of the high-voltage transmission line.

[0004] In the related art, a vibration platform is used to simulate the working scene of the grading ring to test the fatigue life of the grading ring. However, the existing vibration platform cannot accurately simulate the vibration and dancing working conditions of the grading ring in actual operation, and the test result has low accuracy. SUMMARY

[0005] The present application provides a test tool and test method for a grading ring to solve the technical problem of low simulation accuracy of the grading ring in the related art.

[0006] In one aspect, the present application provides a test tool for a grading ring, comprising:

[0007] a base;

[0008] a vibration platform arranged on the base, the vibration platform being configured to reciprocally displace relative to the base along a first direction;

[0009] a first arm and a second arm, one end of the first arm being rotatably connected to the vibration platform, the other end of the first arm being rotatably connected to the second arm, the first arm being configured to reciprocally rotate about a second direction, the second arm being configured to reciprocally rotate about a third direction, the first direction, the second direction and the third direction being perpendicular to each other in pairs;

[0010] a mounting platform connected to one end of the second arm away from the first arm, the mounting platform being used to fix the grading ring, the mounting platform being provided with a stress detection member, the stress detection member being used to detect the stress applied by the grading ring to the mounting platform.

[0011] In some possible implementations, there are at least two of both the first arm and the second arm, the first arm and the second arm are connected in a one-to-one correspondence, the at least two first arms are spaced apart and arranged symmetrically, and the at least two second arms are connected to the mounting platform.

[0012] In some possible implementations, the base is provided with a vibration excitation assembly having a drive end extending out of the base, the drive end being connected to the vibration platform to drive the vibration platform to reciprocate relative to the base in the first direction.

[0013] In some possible implementations, the base is further provided with a guide post extending along the first direction, the guide post being inserted into the vibration platform to guide the vibration platform to move back and forth along the first direction.

[0014] In some possible implementations, it also includes:

[0015] A first rotary drive component is connected to the first support arm and is used to drive the first support arm to rotate relative to the base within a first preset angle range around the second direction.

[0016] The second rotary drive component is connected to the second arm and is used to drive the second arm to rotate relative to the first arm within a second preset angle range around the third direction.

[0017] Wherein, at least one of the first preset angle range and the second preset angle range is greater than or equal to 45° and less than or equal to 135°.

[0018] In some possible implementations, the mounting platform is provided with a connecting part for connecting to the mounting end of the equalizing shield ring by fasteners that pass through both; the stress detection element is located in the connection and fastening point area between the mounting end and the connecting part.

[0019] On the other hand, this application provides a test method applicable to the test fixture of the equalizing shield ring described in any of the above claims, the test method comprising:

[0020] The equalizing shielding ring is fixed on the mounting platform of the test fixture of the equalizing shielding ring;

[0021] The simulated motion parameters of the test fixture are determined, including the frequency of the reciprocating motion of the vibration platform of the test fixture, and the rotation angles of the first arm and the second arm.

[0022] Based on the simulated motion parameters, the operating conditions of the equalizing shield ring are simulated using the test fixture;

[0023] The stress applied to the mounting platform by the equalizing shield ring is obtained through the stress detection device, and the actual simulated cycle number of the equalizing shield ring is obtained; the actual simulated cycle number is the number of reciprocating displacements or reciprocating rotations of at least one of the vibration platform, the first support arm, and the second support arm when the equalizing shield ring fails due to fatigue.

[0024] The fatigue life of the equalizing shield ring is determined based on the stress and the actual number of simulated cycles.

[0025] In some possible implementations, determining the fatigue life of the equalizing shield ring based on the stress and the actual number of simulated cycles includes:

[0026] The theoretical simulation cycle number of the equalizing shield ring is obtained through the stress calculation.

[0027] The cumulative damage degree of the equalizing shielding ring is determined based on the actual number of simulation cycles and the theoretical number of simulation cycles.

[0028] The fatigue life of the equalizing shield ring is determined based on the cumulative damage.

[0029] In some possible implementations, the theoretical simulation cycle number is calculated using formula (1):

[0030] ; Formula (1)

[0031] Where N is the theoretical simulation cycle number of the equalizing shielding ring, and C is the vibration resistance coefficient of the equalizing shielding ring. The stress is denoted as , and m is the fatigue sensitivity coefficient of the equalizing shield ring.

[0032] In some possible implementations, the cumulative damage is calculated using formula (2):

[0033] ; Formula (2)

[0034] in, The actual simulated cycle number of the equalizing shielding ring under the i-th operating condition is given. The theoretical simulation cycle number is the number of cycles for the equalizing shielding ring under the i-th operating condition.

[0035] In some possible implementations, the rotation angle of the first arm and / or the second arm is obtained by formula (3):

[0036] ; Formula (3)

[0037] Where A is the rotation amplitude of the first arm and / or the second arm, V is the wind speed under simulated operating conditions of the equalizing shield ring, and K is the conductor characteristic coefficient of the conductor used to connect with the equalizing shield ring.

[0038] The test fixture and test method for the equalizing shield ring provided in this application, in the test fixture for the equalizing shield ring, the vibration platform reciprocates relative to the base along a first direction, the first support arm is configured to reciprocate about a second direction, the second support arm is configured to reciprocate about a third direction, and the first direction, the second direction and the third direction are mutually perpendicular.

[0039] This increases the simulation degree of freedom of the equalizing shield ring. The first and second arms are connected, and the double-arm rotating structure allows the equalizing shield ring to bear multi-directional loads in the spatial direction, realistically reproducing the centrifugal force of wind galloping, the inertial impact of conductor swinging, and other transmitted loads. This is beneficial for reproducing the working conditions of the equalizing shield ring under different working conditions such as wind, conductor galloping, or mechanical vibration, and facilitates the improvement of the testing accuracy of the equalizing shield ring. Attached Figure Description

[0040] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0041] Figure 1 This is a schematic diagram of the test fixture for the equalizing shielding ring in the embodiments of this application;

[0042] Figure 2 This is a schematic diagram showing the connection of some components of the test fixture for the equalizing shielding ring in the embodiments of this application;

[0043] Figure 3 This is a schematic diagram of the steps of the test method in the embodiments of this application.

[0044] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments.

[0045] Explanation of reference numerals in the attached figures

[0046] 100 - Base; 101 - Guide post;

[0047] 200 - Vibration platform; 210 - Vibration excitation assembly;

[0048] 300 - First arm; 310 - First rotary drive component;

[0049] 400 - Second support arm; 410 - Second rotary drive component;

[0050] 500 - Installation platform; 510 - Connection part; 520 - Stress testing component;

[0051] 600-Driver. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0053] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0054] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0055] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0056] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0057] As mentioned in the background section, due to factors such as wind, conductor galloping, and mechanical vibration, the equalizing shield ring will be subjected to complex vibration and galloping loads during operation, which may lead to material fatigue, loosening of connections, or even breakage of the equalizing shield ring, affecting the safe and stable operation of high-voltage transmission lines.

[0058] In related technologies, vibration platforms are used to simulate the working scenario of equalizing shielding rings in order to test their fatigue life. However, existing vibration platforms are difficult to accurately simulate the vibration and galloping conditions of equalizing shielding rings in actual operation, resulting in low accuracy of test results.

[0059] Based on the above description of the relevant technology, one or more embodiments of this application provide a test fixture and test method for an equalizing shield ring. In the test fixture for the equalizing shield ring, the vibration platform reciprocates relative to the base along a first direction, the first arm is configured to reciprocate about a second direction, and the second arm is configured to reciprocate about a third direction, wherein the first direction, the second direction, and the third direction are mutually perpendicular.

[0060] This increases the simulation degree of freedom of the equalizing shield ring. The first and second arms are connected, and the double-arm rotating structure allows the equalizing shield ring to bear multi-directional loads in the spatial direction, realistically reproducing the centrifugal force of wind galloping, the inertial impact of conductor swinging, and other transmitted loads. This is beneficial for reproducing the working conditions of the equalizing shield ring under different working conditions such as wind, conductor galloping, or mechanical vibration, and facilitates the improvement of the testing accuracy of the equalizing shield ring.

[0061] The following description, in conjunction with the accompanying drawings, illustrates the solutions of the embodiments of this application.

[0062] like Figure 1 As shown, the test fixture for the equalizing shielding ring in this embodiment of the application includes a base 100, a vibration platform 200, a first support arm 300 and a second support arm 400, and a mounting platform 500.

[0063] A vibration platform 200 is mounted on a base 100 and is configured to reciprocate relative to the base 100 in a first direction. One end of a first support arm 300 is rotatably connected to the vibration platform 200, and the other end of the first support arm 300 is rotatably connected to a second support arm 400. The first support arm 300 is configured to reciprocate about a second direction, and the second support arm 400 is configured to reciprocate about a third direction. The first direction, the second direction, and the third direction are mutually perpendicular. A mounting platform 500 is connected to the end of the second support arm 400 away from the first support arm 300. The mounting platform 500 is used to fix the equalizing shielding ring. A stress detection element 520 is provided on the mounting platform 500 to detect the stress applied by the equalizing shielding ring to the mounting platform 500.

[0064] As can be seen from the above description, the test fixture for the equalizing shield ring provided in this application embodiment, with the vibration platform 200, the first arm 300 and the second arm 400 combined, can simulate the vibration and oscillation of the equalizing shield ring in multiple directions, realistically reproducing the centrifugal force of wind galloping, the inertial impact of conductor oscillation and other transmitted loads, which is beneficial to reproducing the working conditions of the equalizing shield ring under different working conditions such as wind, conductor galloping or mechanical vibration, and facilitates the improvement of the test accuracy of the equalizing shield ring.

[0065] In this embodiment, the equalizing shielding ring can be an electrical component in a high-voltage transmission line. The equalizing shielding ring is generally a metal cylindrical tube forming a ring, with a mounting end in the middle for fixed connection to the end of an insulating string or cable. Here, this embodiment conducts vibration simulation tests on the equalizing shielding ring, without making absolute limitations on the specific type or shape of the equalizing shielding ring.

[0066] In some embodiments, there are at least two first arms 300 and at least two second arms 400, the first arms 300 and the second arms 400 are connected in a one-to-one correspondence, the at least two first arms 300 are spaced apart and arranged symmetrically, and the at least two second arms 400 are connected to the mounting platform 500.

[0067] like Figure 1 As shown, Figure 1 There are two of each of the first arm 300 and the second arm 400. The two first arms 300 are spaced apart, and the two second arms 400 are connected to the two first arms 300 in a one-to-one correspondence.

[0068] Here, when the two first arms 300 rotate and swing in the same direction and move synchronously, the uniform wind sway of the equalizing shielding ring in the second direction can be simulated. When the two first arms 300 rotate differently, the non-uniform wind sway of the equalizing shielding ring in the second direction can be simulated. Similarly, when the two second arms 400 rotate and swing in the same direction and move synchronously, the uniform wind sway of the equalizing shielding ring in the third direction can be simulated. When the two second arms 400 rotate differently, the non-uniform wind sway of the equalizing shielding ring in the third direction can be simulated.

[0069] For example, displacement sensors and acceleration sensors are provided on both the first arm 300 and the second arm 400 to detect the swing amplitude and angle. The displacement sensors and acceleration sensors can be installed on the main body of the first arm 300 and swing synchronously with the first arm 300 and the second arm 400 to more accurately simulate wind swing conditions.

[0070] Setting up two first arms 300 can avoid motion distortion caused by the torsion of a single-arm structure. The two arms transmit vibration energy synchronously, which makes it easier to realistically reproduce the dancing state of the equalizing shield ring.

[0071] For example, Figure 1 In the diagram, the Y direction is the first direction of vibration of the vibration platform 200, the Z direction is the second direction of the first arm 300, and the X direction is the third direction of the second arm 400. It can be seen that the design of the vibration platform 200, the first arm 300, and the second arm 400 makes the simulation direction of the equalizing shield ring more diversified, which is convenient for reproducing the complex operating conditions of the equalizing shield ring.

[0072] like Figure 2 As shown, in some embodiments, the test fixture for the equalizing shield ring further includes a first rotation drive 310 and a second rotation drive 410. The first rotation drive 310 is connected to the first support arm 300 and is used to drive the first support arm 300 to rotate relative to the base 100 within a first preset angle range around a second direction. The second rotation drive 410 is connected to the second support arm 400 and is used to drive the second support arm 400 to rotate relative to the first support arm 300 within a second preset angle range around a third direction.

[0073] Wherein, at least one of the first preset angle range and the second preset angle range is greater than or equal to 45° and less than or equal to 135°.

[0074] The aforementioned first rotary drive component 310 and second rotary drive component 410 can adopt a structural design of linkage between a rotary servo motor and a harmonic reducer. This structural design can refer to the rotary drive linkage structure used on the test platform in related technologies. Taking the first arm 300 as an example, the fixed end of the rotary servo motor is mounted on the base 100, and the drive rotation end is connected to the first arm 300 to drive the first arm 300 to rotate. For the second arm 400, since the first arm 300 itself is rotating, the fixed end of the second rotary drive component 410 on the second arm 400 can be mounted on the first arm 300, and the rotary drive end 600 is connected to the second arm 400 to drive the second arm 400 to rotate.

[0075] For example, the first preset angle range and the second preset angle range are the same, both greater than or equal to 45° and less than or equal to 135°. In the initial state, the first arm 300 is vertically positioned at 90° to the ground. This design can simulate the actual installation posture of the equalizing shielding ring at the end of the insulator string or cable. The first and second preset angle ranges are illustrated with reference to the ground being a horizontal plane and the angle formed by the ground and the two arms. During the rotation and swinging process, the first arm 300's clockwise and counterclockwise rotation range along the second direction does not exceed 45°. The ±45° swing range can completely cover the maximum wind deflection angle of the conductor under strong winds. Simultaneously, the forward and reverse rotations facilitate the reproduction of the conductor's figure-eight-shaped oscillation, improving the simulation accuracy of the equalizing screen.

[0076] The second arm 400 can be set with reference to the rotation drive form of the first arm 300, or it can be adjusted according to other needs and scenarios.

[0077] like Figure 2 As shown, in some embodiments, the base 100 is provided with a vibration excitation component 210, which has a drive end 600 extending out of the base 100. The drive end 600 is connected to the vibration platform 200 to drive the vibration platform 200 to move back and forth relative to the base 100 in a first direction.

[0078] The aforementioned vibration excitation component 210 can employ electromagnetic exciters, hydraulic servo actuators, or linear motors, as exemplarily, when using a linear motor. The stator segment bolt press base 100 of the linear motor is rigidly locked to the vibration platform 200, thereby accurately simulating waveform reproduction and achieving random vibration effects. The vibration excitation component 210 needs to cover vibration frequencies of 0.1-20Hz, with low frequencies of 0.1-5Hz simulating gentle breezes and high frequencies of 5-20Hz simulating conductor vibration.

[0079] Furthermore, the base 100 is also provided with a guide post 101 extending along the first direction. The guide post 101 is inserted into the vibration platform 200 to guide the vibration platform 200 to move back and forth along the first direction.

[0080] The guide post 101 is threaded or welded to the base 100. The vibration platform 200 has a through hole for the guide post 101 to pass through. The guide post 101 passes through the through hole of the vibration platform 200 without affecting the normal reciprocating movement of the vibration platform 200. The guide post 101 enables precise control of the movement trajectory of the vibration platform 200, eliminating lateral drift and deflection during vibration and ensuring linear guidance of the vibration platform 200. Preferably, an oil groove can be provided on the surface of the guide post 101, with solid lubricant embedded in the groove to reduce wear between the guide post 101 and the vibration platform 200.

[0081] In some embodiments, the mounting platform 500 is provided with a connecting part 510, which is used to connect with the mounting end of the equalizing shield ring by fasteners that pass through both; the stress detection element 520 is located in the connection and fastening point area between the mounting end and the connecting part 510.

[0082] The aforementioned mounting platform 500 can be a plate-shaped platform. The connecting part 510 consists of multiple mounting holes provided on the mounting platform 500. For example, the connecting part 510 consists of four mounting holes evenly spaced apart. The mounting end of the shielding ring and the mounting holes are connected by fasteners that pass through both of them. The fasteners are bolts.

[0083] In actual installation, the equalizing shielding ring is also fixed to the insulation string or cable end with bolts. Therefore, the equalizing shielding ring is directly fixed to the mounting platform 500 with fasteners, directly replicating the on-site installation method of the equalizing shielding ring. The pressure distribution of the contact surface between the equalizing shielding ring and the mounting platform 500 is equivalent to the actual operating load borne by the equalizing shielding ring. Therefore, by setting stress detection elements 520 on the mounting platform 500, the stress changes of the equalizing shielding ring can be effectively monitored, which is beneficial for calculating the expected fatigue life of the equalizing shielding ring later.

[0084] Here, the stress detection element 520 may be a strain gauge that is connected to an external device, or other relevant components that can detect stress.

[0085] like Figure 3 As shown, another embodiment of this application also provides a test method applicable to the test fixture of the equalizing shield ring in any of the above embodiments. The test method includes the following steps:

[0086] Step 100: Fix the equalizing shielding ring on the mounting platform 500 of the test fixture for the equalizing shielding ring;

[0087] Step 200: Determine the simulated motion parameters of the test fixture. The simulated motion parameters include the reciprocating frequency of the vibration platform 200 of the test fixture, and the rotation angle of the first arm 300 and the second arm 400.

[0088] Step 300: Based on the simulated motion parameters, simulate the operating conditions of the equalizing shield ring using test fixtures;

[0089] Step 400: The stress applied to the mounting platform 500 by the stress detection device 520 is obtained, and the actual simulated cycle number of the equalizing shield ring is obtained; the actual simulated cycle number is the number of reciprocating displacements or reciprocating rotations of at least one of the vibration platform 200, the first arm 300, and the second arm 400 when the equalizing shield ring fails due to fatigue.

[0090] Step 500: Determine the fatigue life of the equalizing shield ring based on the stress and the actual number of simulated cycles.

[0091] As can be seen from the above description, the test method provided in this application embodiment simulates the wind vibration factor of the conductor by superimposing the linear motion of the vibration platform 200, and simulates the galloping factor of the large-amplitude conductor by using the rotational motion of the first arm 300 and the second arm 400. Thus, the multi-directional composite load of the equalizing shield ring is reproduced by using the test fixture of the equalizing shield ring, and the fatigue life is determined according to the actual number of simulation cycles and stress, so that the calculated fatigue life is closer to the actual installation environment and working conditions of the equalizing shield ring, and the accuracy is higher.

[0092] For example, in step 100, the mounting end of the equalizing shield ring and the mounting platform 500 are connected by fasteners that pass through both of them. The mounting end of the equalizing shield ring is located at its center. Therefore, the mounting end is fixedly connected to the mounting platform 500, which can also realistically simulate the actual installation scenario of the equalizing shield ring.

[0093] In step 200, determining the simulated motion parameters of the test fixture refers to converting the actual working conditions of the equalizing shield ring into test parameters that can be executed in the laboratory. The vibration and wind swaying that the equalizing shield ring actually experiences on-site are not independent but coupled. Therefore, for example, by detecting the actual vibration and wind swaying at the end of the equalizing shield ring connecting cable on-site, the dominant frequency of the vibration is extracted and equivalent to the vibration frequency of the vibration platform 200, and the swing rotation amplitude of the first arm 300 and the second arm 400 is modified accordingly as the simulated motion parameters of the test fixture.

[0094] Of course, in some embodiments, the first arm 300 and the second arm 400 can move simultaneously or separately during the actual test, depending on factors such as the working environment of the equalizing shielding ring and the long-term influence of wind direction.

[0095] For example, a typical operating condition for the equalizing shielding ring is a winter windy scenario, in which the equalizing shielding ring is prone to ring fatigue. The first arm 300 reciprocates within an angle range of 55°-145° to simulate the vertical swaying of the conductor supported by the equalizing shielding ring, and the second arm 400 reciprocates within an angle range of 70°-160° to simulate the horizontal displacement of the conductor supported by the equalizing shielding ring due to wind sway. Based on this, the vibration platform 200 applies a high-frequency vibration of 20Hz to simulate the vibration of the conductor where the equalizing shielding ring is located. Here, the angles of the first arm 300 and the second arm 400 are both set with the ground as the horizontal plane.

[0096] In step 400, the actual number of simulated cycles refers to the number of reciprocating movements or rotations of at least one of the vibration platform 200, the first arm 300, and the second arm 400. For example, the upward and downward movement of the vibration platform 200 constitutes one complete cycle. Similarly, the first arm 300 rotating from an initial position of 55° forward and then in the opposite direction to return to a position of 55° constitutes one complete cycle. Likewise, the second arm 400 rotating from an initial position of 70° forward and then in the opposite direction to return to a position of 70° constitutes one complete cycle. Of course, the actual number of simulated cycles can be flexibly selected according to the actual simulation scenario; this embodiment is merely an example.

[0097] In step 500, the fatigue life of the equalizing shield ring is determined based on the stress and the actual number of simulated cycles, including:

[0098] Step 501: The theoretical simulation cycle number of the equalizing shield ring is obtained through stress calculation;

[0099] Step 502: Determine the cumulative damage degree of the equalizing shielding ring based on the actual number of simulation cycles and the theoretical number of simulation cycles;

[0100] Step 503: Determine the fatigue life of the equalizing shielding ring based on the cumulative damage.

[0101] In step 501 above, the theoretical simulation cycle number is calculated using formula (1):

[0102] ; Formula (1)

[0103] Where N is the theoretical simulation cycle number of the equalizing shielding ring, and C is the vibration resistance coefficient of the equalizing shielding ring. Let be the stress, and m be the fatigue sensitivity coefficient of the equalizing shielding ring.

[0104] Here, the vibration resistance coefficient and fatigue sensitivity coefficient of the equalizing shielding ring are determined by its own material, which can be obtained by consulting relevant data.

[0105] Due to the different experimental materials, the fatigue sensitivity coefficient and vibration resistance coefficient of the equalizing shield ring will also vary. Therefore, in some embodiments, before the actual test of the equalizing shield ring, the same material as the equalizing shield ring can be selected as the experimental object to pre-test and calculate the vibration resistance coefficient and fatigue sensitivity coefficient of the material.

[0106] This application provides an example to illustrate this. For instance, the vibration resistance coefficient C of cast aluminum alloy materials is a comprehensive indicator for evaluating the material's resistance to vibration fatigue. It is generally characterized by a combination of damping characteristics (the ability to dissipate vibration energy) and fatigue strength (the ability to resist cyclic loads). Here, in this application embodiment, the damping ratio is used. and fatigue limit The calculated vibration resistance coefficient is expressed as follows.

[0107] Among them, damping ratio The measurement can be performed as follows: Tap the equalizing shielding ring with a sample of the same material, record the amplitude decay curve of the sample material over time, and calculate the damping ratio using formula (1-1):

[0108] ; (Formula 1-1)

[0109] Where ς is the damping ratio. and These are two adjacent amplitude peaks.

[0110] For example, the damping ratio ς of the cast aluminum alloy calculated by the above method (1-1) is 0.001, 0.003 or 0.005.

[0111] Fatigue Limit Through SN curve tests using the same sample material as the equalizing shielding ring, with the number of cycles N=10... 7 The corresponding stress amplitude is used as value.

[0112] Therefore, the vibration resistance coefficient C of the equalizing shield ring is the product of the damping ratio and the fatigue limit value. The larger the vibration resistance coefficient, the longer the service life of the equalizing shield ring in the vibration environment.

[0113] The vibration resistance coefficient of an aluminum alloy cast equalizing shield is generally 1×10¹² (unit (MPa)ᵐ·cycle, m is a constant). The fatigue sensitivity coefficient of an aluminum alloy cast equalizing shield is 8-12. Therefore, the actual theoretical simulation cycle number obtained by formula (1) is a constant value.

[0114] In step 502, the cumulative damage is calculated using formula (2):

[0115] ; Formula (2)

[0116] in, The actual simulated cycle number of the equalizing shielding ring under the i-th operating condition is given. The theoretical simulation cycle number is denoted as _i_th.

[0117] In the above formula, the equalizing shield ring actually withstands multiple different operating conditions, including operating conditions with only light wind conductor vibration, and operating conditions with both conductor micro-vibration and wind sway in strong wind weather. Therefore, by integrating and superimposing data from multiple different operating conditions, the cumulative damage of the equalizing shield ring can be simulated more accurately, and the fatigue life prediction can be more precise.

[0118] In addition, the frequency of encounters between light wind vibration and strong wind vibration in actual working scenarios is different. Therefore, when setting different operating conditions, a weighted average method can be used to balance the test results of the equalizing shielding ring.

[0119] For example, the equalizing shielding ring operates mostly under light wind vibration conditions and less frequently under strong wind-induced swaying conditions. Light wind vibration conditions can be simulated using the vibration platform 200, while strong wind-induced swaying conditions can be simulated using the first arm 300 and the second arm 400. In the calculation, the weight of the light wind vibration condition is set to 0.7, and the weight of the strong wind-induced swaying condition is set to 0.3. Finally, the weighted average of the two different operating conditions is calculated. Of course, the equalizing shielding ring may have multiple operating conditions, and the actual weights for these different operating conditions can be flexibly determined according to the design scenario. This embodiment is only an example for illustration.

[0120] For example, , The theoretical simulation cycle count for the equalizing shielding ring under this operating condition is calculated to be 1000 cycles; when , The theoretical simulation cycle count for the equalizing shielding ring under this operating condition is calculated to be 2000 cycles; cumulative damage degree When D≥1, the equalizing ring reaches its fatigue limit.

[0121] It should be noted that the stress in the above formula (1) may not be the same in the actual measured value of each cycle of vibration. Just take the average value of the stress values ​​of multiple cycles of vibration under the same operating condition.

[0122] In some embodiments, the rotation angle of the first arm and / or the second arm is obtained by formula (3):

[0123] ; Formula (3)

[0124] Where A is the rotation amplitude of the first arm and / or the second arm, V is the wind speed under the simulated operating conditions of the equalizing shield ring, and K is the conductor characteristic coefficient of the conductor used to connect with the equalizing shield ring.

[0125] In the above embodiments, the conductor characteristic coefficient of the conductor connected to the equalizing shielding ring can be obtained from relevant data, and this embodiment does not impose an absolute limitation on it.

[0126] For example, the conductor characteristic coefficient K represents the sensitivity of the conductor to wind. The larger K is, the more violent the conductor gallops in the wind. It is mainly affected by the conductor diameter, mass per unit length, conductor tension, surface roughness, and icing conditions.

[0127] In some embodiments, the conductor characteristic coefficient K can be obtained through field measurement data. Taking a 500kV transmission line conductor as an example, the conductor diameter is 30 mm, the mass per unit length is 1.5 kg / m, the static tension is 20 kN, and the surface is free of ice. Through field testing, its conductor characteristic coefficient K is calibrated to be 0.6.

[0128] When the equalizing shield ring is simulated to swing under wind on the test fixture, the rotation amplitude is 34.8° when the simulated wind speed is 15 m / s, according to formula (3), which is consistent with the amplitude of conductor galloping of the transmission line observed on site.

[0129] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0130] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A test fixture for an equalizing shielding ring, characterized in that, include: Base (100); A vibration platform (200) is disposed on the base (100), and the vibration platform (200) is configured to reciprocate relative to the base (100) in a first direction; A first arm (300) and a second arm (400), one end of the first arm (300) being rotatably connected to the vibration platform (200), and the other end of the first arm (300) being rotatably connected to the second arm (400), the first arm (300) being configured to reciprocate about a second direction, and the second arm (400) being configured to reciprocate about a third direction, wherein the first direction, the second direction, and the third direction are mutually perpendicular; The mounting platform (500) is connected to the end of the second support arm (400) away from the first support arm (300). The mounting platform (500) is used to fix the equalizing shielding ring. The mounting platform (500) is provided with a stress detection element (520). The stress detection element (520) is used to detect the stress applied by the equalizing shielding ring to the mounting platform (500).

2. The test fixture for the equalizing shielding ring according to claim 1, characterized in that, There are at least two of the first support arm (300) and the second support arm (400), and the first support arm (300) and the second support arm (400) are connected in a one-to-one correspondence. At least two of the first support arms (300) are spaced apart and arranged symmetrically, and at least two of the second support arms (400) are connected to the mounting platform (500).

3. The test fixture for the equalizing shielding ring according to claim 1, characterized in that, The base (100) is provided with a vibration excitation component (210), which has a drive end (600) extending out of the base (100). The drive end (600) is connected to the vibration platform (200) to drive the vibration platform (200) to reciprocate relative to the base (100) in the first direction.

4. The test fixture for the equalizing shielding ring according to claim 3, characterized in that, The base (100) is also provided with a guide post (101) extending along the first direction. The guide post (101) is inserted into the vibration platform (200) to guide the vibration platform (200) to move back and forth along the first direction.

5. The test fixture for the equalizing shielding ring according to claim 1, characterized in that, Also includes: The first rotary drive (310) is connected to the first support arm (300) and is used to drive the first support arm (300) to rotate relative to the base (100) around the second direction within a first preset angle range; The second rotary drive (410) is connected to the second support arm (400) and is used to drive the second support arm (400) to rotate relative to the first support arm (300) around the third direction within a second preset angle range; Wherein, at least one of the first preset angle range and the second preset angle range is greater than or equal to 45° and less than or equal to 135°.

6. The test fixture for the equalizing shielding ring according to claim 5, characterized in that, The mounting platform (500) is provided with a connecting part (510), which is used to connect with the mounting end of the equalizing shield ring by fasteners that pass through both; the stress detection element (520) is located in the connection and fastening point area of ​​the mounting end and the connecting part (510).

7. A test method, characterized in that, The test fixture applicable to the equalizing shielding ring according to any one of claims 1 to 6, the test method comprising: The equalizing shielding ring is fixed on the mounting platform (500) of the test fixture of the equalizing shielding ring; Determine the simulated motion parameters of the test fixture, including the reciprocating frequency of the vibration platform (200) of the test fixture, and the rotation angles of the first arm (300) and the second arm (400); Based on the simulated motion parameters, the operating conditions of the equalizing shield ring are simulated using the test fixture; The stress applied to the mounting platform (500) by the stress detection device (520) is obtained, and the actual simulated cycle number of the equalizing shield ring is obtained; the actual simulated cycle number is the number of reciprocating displacements or reciprocating rotations of at least one of the vibration platform (200), the first support arm (300) and the second support arm (400) when the equalizing shield ring fails due to fatigue. The fatigue life of the equalizing shield ring is determined based on the stress and the actual number of simulated cycles.

8. The test method according to claim 7, characterized in that, Determining the fatigue life of the equalizing shielding ring based on the stress and the actual simulated cycle number includes: The theoretical simulation cycle number of the equalizing shield ring is obtained through the stress calculation. The cumulative damage degree of the equalizing shielding ring is determined based on the actual number of simulation cycles and the theoretical number of simulation cycles. The fatigue life of the equalizing shield ring is determined based on the cumulative damage.

9. The test method according to claim 8, characterized in that, The theoretical simulation cycle number is calculated using formula (1): ; Formula (1) Where N is the theoretical simulation cycle number of the equalizing shielding ring, and C is the vibration resistance coefficient of the equalizing shielding ring. The stress is denoted as , and m is the fatigue sensitivity coefficient of the equalizing shield ring.

10. The test method according to claim 8, characterized in that, The cumulative damage degree is calculated using formula (2): ; Formula (2) in, The actual simulated cycle number of the equalizing shielding ring under the i-th operating condition is given. The theoretical simulation cycle number is the number of cycles for the equalizing shielding ring under the i-th operating condition.

11. The test method according to claim 7, characterized in that, The rotation angles of the first arm (300) and / or the second arm (400) are obtained by formula (3): ; Formula (3) Wherein, A is the rotation amplitude of the first arm (300) and / or the second arm (400), V is the wind speed under simulated operating conditions of the equalizing shield ring, and K is the conductor characteristic coefficient of the conductor used to connect with the equalizing shield ring.

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