Overhead conductor vibration fatigue test system and experimental method

Abstract

The application provides an overhead conductor vibration fatigue test system and a test method, the system comprising a tension driving system, a vibration loading system and a central control operation system; the tension driving system comprising a front end load loading system and a tail end tension adjusting system; the vibration loading system comprising a hydraulic exciting system and an exciting power source system. The overhead conductor vibration fatigue test system has the following advantages: the system reduces the bending moment of the loading end and the fixed end during operation, improves the safety margin of the test operation, reduces the operation difficulty of the test, facilitates the maintenance of the equipment, greatly improves the space utilization, effectively reduces the lateral force during the vibration process, relieves the influence of the vibration impact on the tension load of the sample, the front end driving system is equipped with a high sensitivity servo motor and a load sensor, and the load accuracy during long time experiment is improved. The sensitivity of the exciting system is further improved, and the anti-fatigue performance of the test system is enhanced.

Description

Technical Field

[0001] This invention specifically relates to a vibration fatigue testing system and method for overhead conductors. Background Technology

[0002] Steel-cored aluminum stranded wire is a crucial carrier for power transmission. With the construction of ultra-high voltage and extra-high voltage transmission lines, large-capacity, long-distance transmission lines are being put into operation one after another, leading to increasingly stringent requirements for line safety. However, overhead conductors operate in complex environments, often experiencing slight vibrations under light winds. These vibrations frequently cause fatigue damage to the conductors, directly impacting the safe operation of transmission lines. Therefore, testing the vibration fatigue performance of transmission conductors before line erection provides a strong guarantee for the continuous and stable operation of transmission lines. To further promote the construction and development of transmission lines in my country, the vibration fatigue performance of transmission conductors will receive high attention from production, design, and user units, as well as relevant government departments. Furthermore, the testing of this performance will become a key focus for various testing institutions.

[0003] The vibration fatigue performance testing of overhead conductors involves simulating high-frequency vibration tests under aerodynamic conditions. Domestically, most testing equipment is limited to miniature test systems (span not exceeding 10m) used for studying fretting wear and fretting fatigue theory; very few are specifically designed for testing the vibration fatigue performance of finished overhead conductors. Research indicates that only the Shanghai Cable Research Institute and the China Electric Power Research Institute have conducted this test in China. Domestic methods for testing the vibration fatigue performance of overhead conductors include Q / GDW 13236.1 "Conductor and Ground Wire Procurement Standard Part 1: General Technical Specifications" and Q / FSDYS007-2007 "Vibration Fatigue Test Method for Overhead Line Conductors and Ground Wires." These standards stipulate that each sample group must undergo 90 million vibrations under resonance conditions, with the vibration angle at the clamp exit maintained within 25°–30°, and the conductor tension consistently maintained at 25% RTS during the long-term test. Currently, there is no mature testing system for this experiment, and the numerous repeated long-term tests place higher demands on the fatigue resistance of the testing unit itself. Simultaneously, the test requires an effective span of at least 35m for the stranded wire, and with the tensioning devices at both ends, the testing machine occupies at least 40 meters of space, resulting in a large footprint. During long-term testing, the conductor tension must be maintained stably at 25% RTS. Under static conditions, the tensioning devices at both ends of the conductor will bear greater bending moment forces as the specimen height increases, especially under vibration. Therefore, there is an urgent need for a testing system with reasonable spatial dimensions, stable structure, high operability, and the ability to meet all the stringent requirements of the test. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing an overhead conductor vibration fatigue testing system that can effectively solve the aforementioned problems.

[0005] To achieve the above requirements, the technical solution adopted by the present invention is as follows: An overhead conductor vibration fatigue testing system is provided, comprising a tensioning drive system, a vibration loading system, and a central control operating system; the tensioning drive system includes a front-end load loading system and a rear-end tension adjustment system; the vibration loading system includes a hydraulic excitation system and an excitation power source system; the front-end load loading system includes a front-end connecting seat fixed on a foundation support; the top of the front-end connecting seat is provided with a front-end guide support and a front-end drive mechanism, and a front-end clamp sliding along the front-end guide support is provided above the front-end guide support; the front-end drive mechanism includes a front-end drive support, a servo motor, a front-end reduction device, and a front-end worm gear lifter; the bottom of the front-end drive support is fixedly connected to the top of the front-end connecting seat, and the servo motor is fixed to the front-end drive support. The system includes a front-end reduction gear, with the output end of the servo motor connected to a front-end worm gear jack. The other end of the front-end worm gear jack is connected to a load sensor, and the other end of the load sensor is connected to one end of the front-end clamp via an elastic connection device. The tail-end tension adjustment system includes a tail-end connecting seat fixed to a foundation support. A tail-end tension adjustment device and a tail-end fixing mechanism are fixed to the upper surface of the tail-end connecting seat. The tail-end tension adjustment device includes a tail-end drive support, a tail-end drive motor, a tail-end reduction gear, a tail-end lead screw, and a tail-end drive motor controller. The tail-end drive motor, tail-end reduction gear, and tail-end lead screw are connected to the tail end via the tail-end drive support. The tail-end lead screw passes through the center of the connecting plate of the tail-end drive support and connects to the tail-end clamp. The tail-end fixing mechanism includes a tail-end guide support and a tail-end clamp that slides along the tail-end guide support.

[0006] The advantages of this overhead conductor vibration fatigue testing system are as follows:

[0007] (1) The sunken design of the overall structure reduces the bending moment at the loading end and the fixed end during operation, while improving the safety margin of the test operation, reducing the difficulty of the test operation, facilitating the maintenance of the equipment, and greatly improving the space utilization.

[0008] (2) The tension drive system at both ends of the conductor is designed with an elastic device between the guide support and the load sensor and the elevator connecting rod, which effectively reduces the lateral force during the vibration process and alleviates the influence of the sample vibration on the sensor data during the test. The front drive system is equipped with a high-sensitivity servo motor and a load sensor, which improves the accuracy and stability of the load during long-term experiments.

[0009] (3) The sensitivity of the excitation system was further improved, and the fatigue resistance of the test system was enhanced. Attached Figure Description

[0010] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, use the same reference numerals to denote the same or similar parts. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0011] Figure 1 A schematic diagram of the structure of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0012] Figure 2 A schematic diagram of the structure of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0013] Figure 3 A schematic diagram of the front-end load loading system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0014] Figure 4 A schematic diagram of the front-end load loading system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0015] Figure 5 A schematic diagram of the tail end tensioning adjustment system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0016] Figure 6 A schematic diagram of the tail end tensioning adjustment system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0017] Figure 7 A schematic diagram of the traction and laying system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0018] Figure 8 A schematic diagram of the traction and laying system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0019] Figure 9 A schematic diagram of the traction and laying system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0020] Figure 10 A schematic diagram of the traction and laying system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0021] Figure 11A schematic diagram of the conductor clamp device of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0022] Figure 12 A schematic diagram of the conductor clamp device of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0023] Figure 13 A schematic diagram of the hydraulic excitation system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0024] Figure 14 A schematic diagram of the hydraulic excitation system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0025] Figure 15 A schematic diagram of the excitation force source system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0026] Figure 16 A schematic diagram of the excitation force source system of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0027] Figure 17 A schematic diagram of the conductor clamp device of an overhead conductor vibration fatigue testing system according to an embodiment of this application is shown.

[0028] The system includes: 1. Tensioning drive system; 2. Vibration loading system; 3. Central control operating system; 4. Front-end load loading system; 5. Tail-end tension adjustment system; 6. Traction and laying system; 7. Conductor clamp device; 8. Hydraulic vibration excitation system; 9. Vibration power source system; 10. Foundation support; 11. Front-end connecting seat; 12. Front-end drive mechanism; 13. Load sensor; 14. Elastic connection device; 15. Front-end fixing mechanism; 16. Front-end guide support; 17. Front-end clamp; 18. Front-end drive support; 19. Servo motor; 20. Front-end reduction device; 21. Front-end worm gear jack; 22. Tail-end connecting seat; 23. Tail-end tension adjustment device; 24. Tail-end fixing mechanism; 25. Tail-end guide support; 26. Tail-end clamp; 27. Tail-end drive support; 28. Tail-end... 29. End drive motor; 30. Tail-end reduction gear; 31. Tail-end lead screw; 32. Tail-end drive motor controller; 33. Wire feeding device; 34. Traction device; 35. Wire feeding frame fixed base; 36. Wire feeding frame; 37. Traction motor; 38. Traction line; 39. Connecting accessories; 40. Wire clamp device connecting seat; 41. Two-sided wire clamp support frame; 42. Wire clamp support beam; 43. Suspension wire clamp; 44. Pit; 45. Static pressure support actuator; 46. Oil suction pump; 47. Vibration connection assembly; 48. Vibration sensor; 49. Soundproof room; 50. Oil pump motor set; 51. Oil source cooling system; 52. Central operation control console; 53. Acceleration sensor; 54. Upper fixing block; 55. Fixed support foot; 56. Fixing plate; 57. Vertical adjustment rod; 58. Adjustment screw hole. Detailed Implementation

[0029] To make the objectives, technical solutions and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and specific embodiments.

[0030] In the following description, references to "an embodiment," "an embodiment," "an example," "example," etc., indicate that the described embodiment or example may include a particular feature, structure, characteristic, property, element, or limitation, but not every embodiment or example necessarily includes that particular feature, structure, characteristic, property, element, or limitation. Furthermore, the repeated use of the phrase "an embodiment according to this application," while possibly referring to the same embodiment, does not necessarily refer to the same embodiment.

[0031] For simplicity, certain technical features known to those skilled in the art are omitted in the following description.

[0032] According to one embodiment of this application, a vibration fatigue testing system for overhead conductors is provided, such as... Figure 1-7As shown, it includes a tension drive system 1, a vibration loading system 2, and a central control operating system 3; the tension drive system 1 includes a front-end load loading system 4 and a tail-end tension adjustment system 5; the vibration loading system 2 includes a hydraulic excitation system 8 and an excitation power source system 9.

[0033] According to one embodiment of this application, the front-end load loading system 4 of the overhead conductor vibration fatigue test system includes a front-end connecting seat fixed on a foundation support; the top of the front-end connecting seat is provided with a front-end guide support and a front-end drive mechanism, and a front-end clamp sliding along the front-end guide support is provided above the front-end guide support; the front-end drive mechanism includes a front-end drive support, a servo motor, a front-end reduction device, and a front-end worm gear jack; the bottom of the front-end drive support is fixedly connected to the top of the front-end connecting seat, the servo motor is fixed on the front-end drive support, the servo motor is provided with a front-end reduction device, the output end of the servo motor is connected to the front-end worm gear jack, the other end of the front-end worm gear jack is connected to a load sensor, and the other end of the load sensor is connected to one end of the front-end clamp through an elastic connection device.

[0034] According to one embodiment of this application, the tail end tension adjustment system 5 of the overhead conductor vibration fatigue test system includes a tail end connecting seat fixed on the foundation support; the upper end surface of the tail end connecting seat is fixed with a tail end tension adjustment device and a tail end fixing mechanism; the tail end tension adjustment device includes a tail end drive support, a tail end drive motor, a tail end reduction device, a tail end lead screw, and a tail end drive motor controller; the tail end drive motor, the tail end reduction device, and the tail end lead screw are connected to the tail end through the tail end drive support; the tail end lead screw passes through the center position of the connecting plate of the tail end drive support and is connected to the tail end clamp; the tail end fixing mechanism includes a tail end guide support and a tail end clamp that slides along the tail end guide support.

[0035] According to one embodiment of this application, the tensioning drive system 1 of the overhead conductor vibration fatigue test system further includes a traction and laying system 6 and a conductor clamp device 7.

[0036] According to one embodiment of this application, the traction and wire-laying system 6 of the overhead conductor vibration fatigue test system includes a wire-laying device 32 and a traction device 33. The wire-laying device 32 includes a wire-laying frame fixing base 34 and a wire-laying frame 35. The traction device 32 includes a traction motor 36, a traction line 37, and connecting accessories 38. The wire-laying device 32 is used to fix the sample 54 and is installed next to the tail end tension adjustment system 5. The traction device 33 is installed next to the front end load loading system 4 and pulls the sample 54 at the wire-laying device 32 to the front end load loading system 4 through the traction line 37.

[0037] According to one embodiment of this application, the conductor clamp device 7 of the overhead conductor vibration fatigue test system includes a clamp device connecting seat mounted on a foundation support; two clamp support frames are provided above the clamp device connecting seat, each clamp support frame including an upper fixing block, and three fixing feet connected to the bottom of the upper fixing block, the bottom of the fixing feet being connected to the clamp device connecting seat via a fixing plate; a vertical adjusting rod is provided at the bottom of each upper fixing block, and at least two adjusting screw holes are evenly provided on the vertical adjusting rod; a clamp support beam is also included, with both ends of the clamp support beam inserted into the two adjusting screw holes for fixation; a suspension clamp is connected to the center of the bottom of the clamp support beam.

[0038] According to one embodiment of this application, the hydraulic excitation system 8 of the overhead conductor vibration fatigue test system is used to provide excitation force to the specimen 54. The hydraulic excitation system 8 is installed in a 1.0m*1.5m*1.5m pit 43 that has been reinforced and waterproofed and is equipped with a cover plate. The hydraulic excitation system 8 includes a hydrostatic support actuator 44, an oil suction pump 45, an excitation connection assembly 46, and a vibration sensor 47.

[0039] According to one embodiment of this application, the excitation power source system 9 of the overhead conductor vibration fatigue test system includes an oil pump motor unit 49, an oil tank 50, and an oil source cooling system 51; the oil tank 50 is connected to the hydrostatic support actuator 44 and the oil source cooling system 51 through an oil pipe and is controlled by the pump motor unit 49, and the suction pump 45 draws excess hydraulic oil back to the oil tank 50.

[0040] According to one embodiment of this application, the overhead conductor vibration fatigue testing system includes a tensioning drive system fixed to a precisely positioned and pre-treated foundation support. The tensioning drive system includes a front-end load loading system, a rear-end tension adjustment system, a conductor clamp device, and a traction and release system, used for sample installation and tension load application. The upper surfaces of the foundation supports under the front-end load loading system, the rear-end tension adjustment system, and the suspension clamp device are on the same horizontal plane, and their central axes are aligned. The inner edges of the foundation supports at both ends under the front-end load loading system and the rear-end tension adjustment system are 40 meters apart, and the center of the foundation support under the suspension clamp device is 0.5 meters from the inner side of the foundation support under the front-end load loading system.

[0041] According to one embodiment of this application, the front-end connecting seat of the front-end load loading system of the overhead conductor vibration fatigue testing system is a 1m x 0.5m x 0.1m steel plate, connected to the foundation support by anchor bolts, with its upper surface flush with the ground. The end drive support is fixed to the front-end connecting seat, and the front-end servo motor and front-end reduction device are fixed to the front-end drive support. The lead screw of the front-end worm gear lift passes through the center of the front-end drive support connecting plate and is connected to the load sensor. The front-end guide support is fixed to the front-end connecting seat by corresponding connection assembly. The double-sided guide rails of the front-end guide support are 0.7m long, and the guide rails are equipped with connecting slots, allowing for smooth axial movement on the guide rails. Baffles are installed at both ends of the guide rails to prevent the slots from slipping out of the guide rails. The clamp is fixed to the connecting slots, so that during vibration, the clamp can only move back and forth along the guide rail axially through the connecting slots, reducing the influence of lateral forces on the clamp and load sensor. An elastic device is added between the load sensor and the lift connecting rod to mitigate the influence of sample vibration on sensor data during the test. The center axis of the fixture is aligned with the center axis of the lead screw and coincides with the center axis of the sample.

[0042] According to one embodiment of this application, the tail-end tension adjustment system of the overhead conductor vibration fatigue testing system is designed with an additional 1-meter adjustable space, allowing for sample installation with lengths ranging from 39 meters to 40 meters through the forward and backward movement of the lead screw. The tail-end connecting seat of the tail-end tension adjustment system is a 1.5-meter by 0.5-meter by 0.1-meter steel plate, connected to the foundation support by anchor bolts, with its upper surface at the same level as the upper surface of the front-end connecting seat. The tail-end drive support is fixed to the tail-end connecting seat, and the tail-end reduction device and tail-end drive motor are fixed to the tail-end drive device support frame. The tail-end lead screw passes through the center of the tail-end drive support connecting plate and connects to the clamp, and is aligned with the axis of the front-end lead screw. The tail-end guide support is fixed to the tail-end connecting seat through corresponding connections. The double-sided guide rails of the tail-end guide support are 1.2 meters long, and their axes are aligned with the corresponding double-sided guide rails at the front end. The clamp can only move forward and backward along the guide rail axis during vibration through the connecting slot.

[0043] According to one embodiment of this application, the traction and laying system of the overhead conductor vibration fatigue testing system includes a laying device and a traction device. The laying device is used to fix the sample reel and is installed on a foundation support near the tail end tension adjustment system. The traction device is installed on a foundation support near the front end load loading system and pulls the sample from the laying device to the vicinity of the front end load loading system via a traction line. This is used to straighten the sample and cut it to a suitable length for testing.

[0044] According to one embodiment of this application, the conductor clamp device connecting seat of the overhead conductor vibration fatigue testing system is a 0.6m x 1m x 0.1m steel plate, with its center 0.8m from the inner side of the front connecting seat. The two side clamp support frames are triangular steel structures connected to the conductor clamp device connecting seat by bolts. The apex of the two side clamp support frames is 0.8m from the upper surface of the conductor clamp device connecting seat, and the center is an I-beam with continuous screw holes. The height of the screw holes from the upper surface of the conductor clamp device connecting seat ranges from 0.4m to 0.5m. The clamp support beam can move up and down according to the change in the position of the conductor's central axis and is then fixed to the double-sided clamp support frame. Different specifications of suspension clamps are used for the conductor clamps. The clamps are connected to the support beam by U-shaped hanging rings and are connected to the clamp support beam. The axis of the suspension clamps coincides with the axis of the sample, the axis of the front clamp, and the axis of the rear clamp.

[0045] According to one embodiment of this application, the hydraulic excitation system of the overhead conductor vibration fatigue testing system is installed in a 1.0m*1.5m*1.5m pit with reinforced and waterproofed foundation and equipped with a cover plate. It includes a static pressure support actuator, an oil suction pump, an excitation connection assembly, and a vibration sensor. The hydraulic excitation system base plate is fixedly connected to the foundation support by anchor bolts and is waterproofed. The static pressure support actuator is fixedly connected to the hydraulic excitation system base plate, with its top end 0.1 meters above the ground. The oil suction pump is mounted on the hydraulic excitation system base plate via a bracket to draw the leaked hydraulic oil generated during the operation of the static pressure support actuator into the oil tank. The excitation connection assembly is available in several height-adjustable specifications according to the sample diameter. The sample is connected to the static pressure support actuator, and after adjusting the sample's central axis to coincide with the central axes of the front and rear clamps, it is fixed.

[0046] According to one embodiment of this application, the excitation power source system of the overhead conductor vibration fatigue testing system is installed in a well-ventilated and soundproofed room, including an oil pump motor unit, an oil tank, and an oil source cooling system. The oil pump motor unit inputs oil from the oil tank into the hydrostatic support actuator through the inlet pipe, and outputs oil from the hydrostatic support actuator to the oil pipe through the outlet pipe. The hydraulic oil in the oil tank is circulated and cooled by the oil source cooling system to ensure that the oil temperature of the hydraulic pump station is strictly controlled within a certain range, generally around 15–50°C.

[0047] According to one embodiment of this application, the overhead conductor vibration fatigue testing system disclosed in this invention includes a tensioning drive system, a vibration loading system, and a central control operating system. The tensioning drive system is used for the installation and fixation of the specimen and the loading of a specified load tension. It is fixed on a precisely positioned and pre-treated foundation support and includes a front-end load loading system, a tail-end tension adjustment system, a traction and laying system, and a conductor clamp device. The upper surfaces of the foundation supports under the front-end load loading system, the tail-end tension adjustment system, and the suspension clamp device are on the same horizontal plane, and the central axes of the foundation supports are on the same straight line. Specifically, the distance between the inner edges of the two foundation supports under the front-end load loading system and the tail-end tension adjustment system is 40 meters, and the center distance between the foundation support under the suspension clamp device and the inner side of the foundation support under the front-end load loading system is 0.5 meters. The system includes a central control operating system that establishes communication with the tension drive system and vibration loading system. It includes a central operation console and an acceleration sensor, which is installed on the test specimen. By analyzing the information fed back from the vibration acceleration sensor, load sensor, and vibration sensor, the system uses a servo motor, hydrostatic support actuator, and oil pump unit to precisely control the tension and vibration load of the specimen, ensuring the stability of the specimen tension and vibration angle during long-term vibration. At the same time, the system monitors the tensile load, vibration frequency, vibration force value, and antinode amplitude in real time during the experiment, so as to calculate the wavelength and vibration angle and plot the time curves of the corresponding parameters.

[0048] like Figures 3 to 4 As shown, the front-end load loading system's base plate is a 1m x 0.5m x 0.1m steel plate, connected to the foundation support via anchor bolts, with its upper surface flush with the ground. Furthermore, the front-end connecting seat is tightly connected to the front-end base plate via bolts, and the front-end drive device support frame is fixed to the front-end connecting seat. The lead screw of the front-end worm gear jack passes through the center of the front-end drive device support frame connecting plate and connects to the load sensor. Further, the device and the front-end servo motor are fixed to the front-end drive device support frame. The front-end guide support is fixed to the front-end connecting seat via corresponding connections. The front-end double-sided guide rails are 0.7m long and equipped with connecting slots, allowing for smooth axial movement along the guide rails. Baffles are installed at both ends of the guide rails to prevent the slots from slipping out. The clamp is fixed to the connecting slots, ensuring that during vibration, the clamp can only move axially back and forth along the guide rails via the connecting slots, reducing the impact of lateral forces on the clamp and load sensor. The load sensor is connected to the clamp flange via a flexible joint. An elastic device is added between the load sensor and the lifting platform connecting rod to mitigate the influence of sample vibration on the sensor data during the test. The central axis of the clamp is aligned with the central axis of the lead screw and coincides with the central axis of the sample.

[0049] like Figures 5 to 6As shown, the tail-end tension adjustment system is designed with an additional 1-meter adjustable space, allowing for sample installation with lengths ranging from 39 to 40 meters through the forward and backward movement of the lead screw. Specifically, the tail-end base plate of the tail-end tension adjustment system is a 1.5-meter by 0.5-meter by 0.1-meter steel plate, connected to the foundation support by anchor bolts, with its upper surface at the same level as the upper surface of the front-end base plate. The tail-end connecting seat is tightly connected to the tail-end base plate by bolts, and the tail-end drive device support frame is fixed to the tail-end connecting seat. The tail-end lead screw passes through the center of the tail-end drive device support frame connecting plate and connects to the clamp, and is aligned with the axis of the front-end lead screw. The tail-end lead screw has a self-locking function, eliminating the need for the drive motor to be constantly energized during the test, and without affecting the overall test force control of the testing machine. The tail-end reduction device and the tail-end drive motor are fixed to the tail-end drive device support frame. The tail end guide support is fixed to the tail end connecting seat via corresponding connections. The tail end double-sided guide rails are 1.2 meters long, and their axes are aligned with the front end double-sided guide rails. The clamp can only move back and forth along the guide rail axis during vibration via the connecting slots. If space adjustment is needed, the drive motor can be energized and the lead screw retracted. The lead screw has a self-locking function, so the drive motor does not need to be energized at all times during the test, and it will not affect the overall test force control of the testing machine.

[0050] like Figures 7 to 10 As shown, the traction and laying system includes a laying frame, a traction line, a traction motor, and connecting accessories. Specifically, the foundation supports under the laying frame and the traction motor are respectively located next to the foundation supports of the tail-end tension adjustment system and the front-end load loading system. The laying frame and the traction motor are fixedly installed on the foundation supports. The traction motor is connected to the sample through the traction line, pulling the sample from the tail-end tension adjustment system to the front-end load loading system. After straightening the sample, it is cut to a suitable length for testing.

[0051] like Figures 11 to 12 As shown, the conductor clamp device includes a clamp base plate, a clamp bracket, and a bracket suspension beam. Specifically, the base plate of the conductor clamp device is a steel plate measuring 0.6 meters by 1 meter by 0.1 meters. The double-sided brackets of the suspension clamp adopt a triangular steel structure and are connected to the base plate with bolts. The apex of the bracket is 0.8 meters from the base plate, and the center is an I-beam with continuous screw holes. The height of the screw holes from the base plate ranges from 0.4 meters to 0.5 meters. The middle bracket suspension beam can move up and down according to the position of the conductor's central axis. The conductor clamp uses a suspension clamp of model XG-XX, and the clamp is connected to the bracket suspension beam by a U-shaped hanging ring, which is connected to the center of the bracket suspension beam.

[0052] like Figures 1 to 2As shown, the hydraulic vibration system is used to load vibration onto the sample. It is installed in a 1.0m*1.5m*1.5m pit with a reinforced and waterproofed foundation and a cover plate. The system includes a hydrostatic support actuator, an oil pump, and a vibration connection assembly. Further, the base plate of the hydraulic vibration system is fixedly connected to the foundation support with anchor bolts and is waterproofed. The hydrostatic support actuator is fixedly connected to the base plate, with its top end 0.1 meters above the ground. The oil pump is mounted on the base plate via a bracket and draws leaked hydraulic oil generated during the operation of the hydrostatic support actuator into the oil tank. The vibration connection assembly is available in multiple specifications according to the sample diameter. It connects the sample to the hydrostatic support actuator, and after adjusting the height, the sample's central axis coincides with the fixture's central axis. Specifically, the hydrostatic servo actuator's journal liner uses a plastic coating and is equipped with a hydrostatic bearing oil pump to continuously maintain liquid oil lubrication between the piston rod and the cylinder wall, enabling perfectly frictionless linear motion under high loads. Each servo cylinder is equipped with an oil suction pump to draw hydraulic oil into the oil tank, ensuring leak-free operation. This actuator features frictionless operation, high-frequency response, and excellent resistance to lateral forces. Figures 13 to 14 As shown, the excitation connection assembly uses two central conical wheels to support the steel-cored aluminum stranded wire, which is fixed and locked with screws to eliminate the radial clearance of the steel-cored aluminum stranded wire, ensuring reliable transmission of excitation force. At the same time, it can move along the axis of the steel-cored aluminum stranded wire, eliminating the damage of lateral forces to the hydrostatic support actuator and improving the service life of the hydrostatic support cylinder.

[0053] like Figures 15-16 As shown, the excitation power source system is installed in a well-ventilated and soundproofed room, including an oil pump motor unit, an oil tank, and an oil source cooling system. The oil pump motor unit inputs oil from the oil tank into the hydrostatic support actuator through the inlet pipe, and outputs oil from the hydrostatic support actuator to the oil pipe through the outlet pipe. The hydraulic oil in the oil tank is circulated and cooled by the oil source cooling system to ensure that the oil temperature of the hydraulic pump station is strictly controlled within a certain range, generally around 15-50℃. Specifically, the oil tank adopts a fully enclosed structure with an internal baffle in the middle. The baffle divides the interior of the oil tank into a return oil zone and an oil suction zone, allowing the oil to circulate along the tank wall. The notch in the baffle has a sufficiently large flow area to ensure that the circulation velocity meets the supply of the oil suction zone. The circulation of oil in the oil tank promotes more oil to participate in the system circulation, which is beneficial for the separation and sedimentation of air bubbles and impurities in the oil, and also ensures uniform oil temperature and improves cooling efficiency.

[0054] This invention discloses a vibration fatigue testing system for overhead conductors, comprising a central control operating system. During long-term experiments, changes in specimen parameters due to creep and other factors cause variations in tension load and vibration parameters. The central control operating system communicates with the tension drive system and the vibration loading system to precisely monitor the loading and vibration, and control the operation of the excitation force source system to meet the requirements of tension load and vibration angle during long-term testing. The central control operating system communicates with the tension drive system to measure and control the applied tension load according to the prescribed test steps, calibrate the load sensor periodically, and correct the specimen loading load according to test requirements, while simultaneously plotting a real-time load-time curve. Specifically, the load sensor feeds back the real-time monitored tension load to the central control operating system. The central control operating system compares the data from the load sensor with the required experimental tension value. When the required tension threshold is exceeded, the system precisely controls the servo motor to adjust the front ball screw to move outward, thereby adjusting the tension load.

[0055] The central control operating system establishes communication with the vibration loading system, including the central operation console 52 and the acceleration sensor 53. Information from the vibration acceleration sensor 53, load sensor 13, and vibration sensor 47 is used to precisely control the tensile load and excitation angle. Simultaneously, the tensile load, vibration frequency, vibration force value, and antinode amplitude are monitored in real time during the experiment to calculate the wavelength and vibration angle, and to plot the corresponding time curves. The system measures and controls the amplitude and frequency of the excitation point, reads the values ​​from the vibration acceleration sensor, calculates the vibration angle, and corrects the vibration loading of the sample according to the experimental requirements to meet the vibration angle requirements. Real-time vibration time curves and vibration angle time curves are also plotted. Specifically, the vibration acceleration sensor, excitation point amplitude sensor, and excitation point frequency sensor feed back the real-time monitored vibration data to the central control operating system. The central control operating system calculates the vibration angle based on the feedback data and compares the calculated vibration angle with the required value. The servo valve controls the movement and force direction of the servo actuator according to the signal from the servo controller, adjusting the vibration frequency and amplitude of the excitation point and correcting the vibration angle.

[0056] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A vibration fatigue testing system for overhead conductors, characterized in that: It includes a tension drive system (1), a vibration loading system (2), and a central control operating system (3); The tension drive system (1) includes a front-end load loading system (4) and a tail-end tension adjustment system (5). The vibration loading system (2) includes a hydraulic excitation system (8) and an excitation power source system (9). The front-end load loading system (4) includes a front-end connecting seat fixed on the foundation support; the top of the front-end connecting seat is provided with a front-end guide support and a front-end drive mechanism, and a front-end clamp that slides along the front-end guide support is provided above the front-end guide support; the front-end drive mechanism includes a front-end drive support, a servo motor, a front-end reduction device and a front-end worm gear lifter; the bottom of the front-end drive support is fixedly connected to the top of the front-end connecting seat, the servo motor is fixed on the front-end drive support, the servo motor is provided with a front-end reduction device, the output end of the servo motor is connected to the front-end worm gear lifter, the other end of the front-end worm gear lifter is connected to a load sensor, and the other end of the load sensor is connected to one end of the front-end clamp through an elastic connection device; The tail end tension adjustment system (5) includes a tail end connecting seat fixed on the foundation support; the upper end surface of the tail end connecting seat is fixed with a tail end tension adjustment device and a tail end fixing mechanism; the tail end tension adjustment device includes a tail end drive support, a tail end drive motor, a tail end reduction device, a tail end lead screw and a tail end drive motor controller; the tail end drive motor, tail end reduction device and tail end lead screw are connected to the tail end through the tail end drive support; the tail end lead screw passes through the center position of the connecting plate of the tail end drive support and is connected to the tail end clamp; the tail end fixing mechanism includes a tail end guide support and a tail end clamp that slides along the tail end guide support.

2. The overhead conductor vibration fatigue testing system according to claim 1, characterized in that: The tensioning drive system (1) also includes a traction and wire laying system (6) and a wire clamp device (7).

3. The overhead conductor vibration fatigue testing system according to claim 2, characterized in that: The traction and wire-laying system (6) includes a wire-laying device (32) and a traction device (33). The wire-laying device (32) includes a wire-laying frame fixing base (34) and a wire-laying frame (35). The traction device (33) includes a traction motor (36), a traction line (37), and connecting accessories (38). The wire-laying device (32) is used to fix the sample (54) and is installed next to the tail end tension adjustment system (5). The traction device (33) is installed next to the front end load loading system (4) and the sample (54) at the wire-laying device (32) is pulled to the front end load loading system (4) by the traction line (37).

4. The overhead conductor vibration fatigue testing system according to claim 2, characterized in that: The wire clamp device (7) includes a wire clamp device connecting seat set on the foundation support; two wire clamp support frames are provided above the wire clamp device connecting seat, each wire clamp support frame includes an upper fixing block, and three fixing feet are connected to the bottom of the upper fixing block. The bottom of the fixing feet is connected to the wire clamp device connecting seat through a fixing plate; a vertical adjustment rod is provided at the bottom of the upper fixing block, and at least two adjustment screw holes are evenly provided on the vertical adjustment rod; it also includes a wire clamp support beam, and the two ends of the wire clamp support beam are respectively inserted into the two adjustment screw holes for fixation; a suspension wire clamp is connected to the center of the bottom of the wire clamp support beam.

5. The overhead conductor vibration fatigue testing system according to claim 1, characterized in that: The hydraulic vibration system (8) is used to provide vibration force to the sample (54). The hydraulic vibration system (8) is installed on a 1.0m high foundation that has been reinforced and waterproofed. 1.5m The hydraulic vibration system (8) is located in a 1.5m pit (43) and is covered with a cover plate. It includes a hydrostatic support actuator (44), an oil suction pump (45), a vibration connection assembly (46), and a vibration sensor (47).

6. The overhead conductor vibration fatigue testing system according to claim 5, characterized in that: The excitation power source system (9) includes an oil pump motor unit (49), an oil tank (50), and an oil source cooling system (51). The oil tank (50) is connected to the hydrostatic support actuator (44) and the oil source cooling system (51) via oil pipes and is controlled by the oil pump motor unit (49). The suction pump (45) pumps excess hydraulic oil back to the oil tank (50).

7. A method for vibration fatigue testing of overhead conductors, characterized in that: Fatigue tests were conducted using any one of the overhead conductor vibration fatigue testing systems as described in claims 1 to 6.

Images