A wind power aluminum alloy cable bending test method

Abstract

The present application relates to cable performance detection technical field, especially a kind of wind power aluminum alloy cable bending test method, the precision of calibration height adjustable optical ranging probe is used before test, the height of height adjustable optical ranging probe is adjusted;The 1m midpoint of sample is aligned with the top of supporting cylinder and is gently placed, and the counterweight is hung by synchronous weight device and is placed for ≥30s to stable;The outer arc length of 1m midpoint after 30s, 30min, 1h, 2h of automatic acquisition of intelligent data acquisition terminal after loading;After test, the sheath microcrack is detected by nondestructive testing instrument.The environmental control of the present application is more accurate: through the double parameter limitation of temperature and humidity, the interference of environmental factors on the deformation of cable material is eliminated, and the test consistency and repeatability are significantly improved;New stress-free pretreatment step is added, and the residual stress of cable winding is eliminated, and the test result accurately reflects the inherent flexibility of cable, and the sample state is more real.

Description

Technical Field

[0001] This invention relates to the field of cable performance testing technology, and in particular to a bending test method for wind power aluminum alloy cables. Background Technology

[0002] The interior space of wind turbine generator nacelles is small and the wiring is dense. Traditional copper core cables are expensive and heavy. The industry generally uses aluminum alloy cables with a Class II soft aluminum conductor and rubber insulation / sheath structure to achieve a 4D bending radius to adapt to compact laying requirements.

[0003] Existing cable bending test methods are mostly designed for conventional copper or hard aluminum cables and have not been deeply optimized for wind power scenarios. In addition to the original defects, the following new shortcomings also exist: 1) Only ambient temperature was controlled, but humidity was not. Fluctuations in temperature and humidity caused deviations in cable material deformation, resulting in poor test consistency. 2) The lack of stress-free straightening pretreatment of the specimens and the residual stress from winding affect the bending measurement results; 3) The support cylinder only requires a smooth surface, without any roughness measurement indicators, which can easily scratch the sheath or change the friction force; 4) Manually hanging the counterweights at both ends results in poor synchronization and uneven force distribution, leading to distortion of bending deformation; 5) Without a calibration mechanism for measuring tools, the error of the flexible ruler directly affects the judgment result; 6) Only covers 1×500mm 2 1×630mm 2 Specifications, 1×400mm not included 2 Commonly used large cross-section specifications; 7) Without dynamic deformation monitoring, it is impossible to record the deformation pattern throughout the bending process; 8) Damage to the sheath can only be observed with the naked eye, which cannot detect microcracks and poses a potential risk for future operation; 9) The test bench lacks vibration damping design, and environmental vibrations interfere with measurement accuracy; 10) Relying on manual data recording is inefficient and prone to errors, and there is no end-to-end data traceability.

[0004] Therefore, there is an urgent need for a high-precision, full-specification, automated, and non-destructive special wind power aluminum alloy cable bending test method to overcome the shortcomings of existing technologies and improve the reliability of testing. Summary of the Invention

[0005] The technical problem to be solved by this invention is to overcome the problems of lack of environmental control, insufficient operational accuracy, single detection dimension and untraceable data in existing wind power cable bending test methods, and to provide a wind power aluminum alloy cable bending test method that is adapted to 4D bending conditions, covers all specifications, synchronously loads, accurately measures, performs non-destructive testing, and automatically records data, thereby improving the reproducibility of the test and the accuracy of the judgment.

[0006] The technical solution adopted by this invention to solve its technical problem is: a bending test method for wind power aluminum alloy cables, applicable to rated voltage 1.8 / 3kV and specifications 1×400mm. 2 1×500mm 2 1×630mm 2 Category II soft aluminum conductor, rubber insulation / sheath, wind turbine nacelle aluminum alloy cable that meets 4D bending requirements, including: Test conditions and sample preparation: Ambient temperature 20℃±2℃, relative humidity 45%~65%, cable reel pretreatment and static treatment ≥24h, sample horizontal straightening stress-free treatment ≥4h; 2m samples from the first and last ends of every 500m / reel; effective sample length 2.0m, with 20cm reserved at each end for hanging weight; sample kept straight, without twisting or sheath damage; Test setup: A rigid fixed support cylinder with a diameter of 18cm is used, and a shock-absorbing base is set at the bottom of the support cylinder. The surface roughness Ra≤0.8μm; a counterweight of 20kg is loaded at both ends of the cable through a synchronous hanging device; a height-adjustable optical ranging probe, a non-destructive testing instrument and an intelligent data acquisition terminal are configured. Test Procedure: Before the test, calibrate the accuracy of the height-adjustable optical rangefinder and adjust its height; gently place the 1m midpoint of the sample at the top of the supporting cylinder, suspend the counterweight using the synchronous weight-hanging device, and let it stand still for ≥30s until stable; the intelligent data acquisition terminal automatically collects the arc length of the outer arc at the 1m midpoint at 30s, 30min, 1h, and 2h after loading; after the test, use a non-destructive testing instrument to detect microcracks in the sheath. Acceptance criteria: Based on 1 hour measurement, 1×400mm 2 ≤54cm, 1×500mm 2 ≤57cm, 1×630mm 2 ≤61cm is acceptable, and the sheath must be free of cracks; if it exceeds the tolerance or has cracks, it is considered unacceptable. Two more sections from the same reel will be taken for retesting. If they are still unacceptable, the entire reel will be rejected. Recording and Safety: The intelligent data acquisition terminal automatically and completely records the test data; counterweights prevent falls, supporting columns are fixed, the shock-absorbing base is locked, there is no forced bending, and the test area is dry and free from strong vibration.

[0007] The synchronous weight-bearing device ensures that the counterweights at both ends fall synchronously, with a falling height difference of ≤5mm.

[0008] The calibration error of the height-adjustable optical ranging probe is ≤ ±0.5 mm, and the calibration data is included in the test record.

[0009] The vibration amplitude of the damping base is controlled to be ≤0.1mm.

[0010] The intelligent data acquisition terminal has a sampling frequency of 1 time / 10s and stores dynamic data of bending deformation in real time.

[0011] The sheath is subjected to non-destructive testing using an ultrasonic non-destructive testing instrument, which can detect microcracks with a diameter ≥0.1mm.

[0012] The stress-free treatment involves placing the sample horizontally and straight under standard conditions without any external force constraints.

[0013] The qualification criteria include two indicators: the arc length must meet the standard and the sheath must be free of cracks. Failure to meet either standard will result in disqualification.

[0014] The test method is applicable to a full range of large-section wind power aluminum alloy cables specifically designed for wind turbine nacelles and laid with a 4D bending radius.

[0015] Cables that fail the retest must be physically isolated and a traceability log for non-conforming products must be established.

[0016] The beneficial effects of this invention are: (1) The environmental control of the present invention is more precise: by limiting the temperature and humidity as dual parameters, the interference of environmental factors on the deformation of cable material is eliminated, and the consistency and repeatability of the test are significantly improved; 2) More realistic sample condition: The addition of a stress-free pretreatment step eliminates residual stress from cable winding, and the test results accurately reflect the inherent flexibility of the cable; 3) Higher device precision: The surface roughness of the supporting cylinder is quantified, the shock-absorbing base reduces environmental vibration interference, and the synchronous hanging device ensures uniform force distribution and avoids deformation distortion; 4) More reliable measurement results: Equipped with an adjustable optical ranging probe to eliminate tool system errors, and an intelligent data acquisition terminal to achieve dynamic monitoring and automatic recording, eliminating human error; 5) More comprehensive detection dimensions: Added 1×400mm 2 Specification thresholds cover mainstream large-section cables for wind power, combined with ultrasonic non-destructive testing to screen for micro-cracks in the sheath and eliminate potential operational hazards; 6) More rigorous judgment process: adopts dual judgment standards of arc length and sheath integrity, and is equipped with retesting and traceability mechanisms to ensure that non-conforming products do not enter the site; 7) Enhanced engineering adaptability: Fully compatible with the 4D bending and confined space laying conditions of wind turbine nacelles, effectively avoiding installation difficulties and sheath cracking, while taking into account cost reduction, material saving and engineering safety. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] Figure 1 This is a schematic diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the experimental device in this invention.

[0020] In the diagram: 1. Supporting cylinder; 2. Cable under test; 3. Counterweight; 4. Synchronous hanging device; 5. Vibration damping base; 6. Height-adjustable optical ranging probe; 7. Non-destructive testing instrument; 8. Intelligent data acquisition terminal. Detailed Implementation

[0021] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0023] like Figure 1 and Figure 2 The method for bending wind power aluminum alloy cables includes: test conditions and sample preparation: ambient temperature 20℃±2℃, relative humidity 45%~65%, cable reel pretreatment and static setting for ≥24h, sample horizontal straightening stress-free treatment for ≥4h; 2m samples are taken from the first and last ends of every 500m / reel; the effective length of the sample is 2.0m, with 20cm reserved at each end for hanging weights; the sample is kept straight, without twisting, and without sheath damage; Test setup: A rigid fixed support cylinder 1 with a diameter of 18cm is used. The bottom of the support cylinder 1 is equipped with a shock-absorbing base 5 with a surface roughness Ra≤0.8μm. A counterweight 3 of 20kg is loaded at both ends of the cable through a synchronous hanging weight device 4. A height-adjustable optical ranging probe 6, a non-destructive testing instrument 7 and an intelligent data acquisition terminal 8 are configured. Test Procedure: Before the test, calibrate the accuracy of the height-adjustable optical ranging probe 6 and adjust its height; gently place the 1m midpoint of the sample at the top of the supporting cylinder 1, and suspend the counterweight 3 through the synchronous weight-hanging device 4 and let it stand still for ≥30s until stable; the intelligent data acquisition terminal 8 automatically collects the arc length of the outer arc at the 1m midpoint at 30s, 30min, 1h, and 2h after loading; after the test, use a non-destructive testing instrument 7 to detect microcracks in the sheath. Acceptance criteria: Based on 1 hour measurement, 1×400mm 2 ≤54cm, 1×500mm 2 ≤57cm, 1×630mm2 ≤61cm is acceptable, and the sheath must be free of cracks; if it exceeds the tolerance or has cracks, it is considered unacceptable. Two more sections from the same reel will be taken for retesting. If they are still unacceptable, the entire reel will be rejected. Recording and Safety: The intelligent data acquisition terminal 8 automatically and completely records the test data; the counterweight 3 prevents falls, the support column 1 is fixed, the shock-absorbing base 5 is locked, there is no forced bending, and the test area is dry and free from strong vibration.

[0024] Example 1, Sample: Rated voltage 1.8 / 3kV, 1×400 mm 2 Wind power aluminum alloy cable, Class II soft aluminum conductor, rubber insulating sheath.

[0025] Test conditions: ambient temperature 20℃, relative humidity 50%, cable reel left to stand for 25 hours, and sample horizontally stretched without stress for 4.5 hours.

[0026] Test setup: Support cylinder 1 with a diameter of 18cm and a surface roughness Ra=0.6μm; shock-absorbing base 5 installed at the bottom with a vibration amplitude of 0.08mm; synchronous hanging weight device 4 with a counterweight 3 of 20kg; standard gauge block 6 to calibrate the flexible ruler with an error of 0.3mm; equipped with an ultrasonic non-destructive testing instrument 7 and an intelligent data acquisition terminal 8 with a sampling frequency of 1 time / 10s.

[0027] Test procedure: First, calibrate the flexible ruler using standard gauge block 6; align the 1m midpoint M of the cable under test 2 with the top of the supporting cylinder 1 and gently place it, simultaneously suspending the counterweight 3 through the synchronous hanging device 4, and let it stand for 30s until the bending is stable; the intelligent data acquisition terminal 8 automatically collects the outer arc length L at 30s, 30min, 1h, and 2h after loading; after the test, use a non-destructive testing instrument 7 to detect microcracks in the sheath.

[0028] Measurement results: Arc length L is 52cm at 30s, 52.5cm at 30min, 53cm at 1h, and 53cm at 2h.

[0029] Non-destructive testing: The sheath has no microcracks with a diameter ≥0.1mm.

[0030] Acceptance criteria: Arc length ≤ 54cm in 1 hour, no cracks in the sheath, deemed acceptable.

[0031] Example 2, Sample: Rated voltage 1.8 / 3kV, 1×500 mm 2 Wind power aluminum alloy cable, Class II soft aluminum conductor, rubber insulating sheath.

[0032] The test conditions and apparatus are the same as in Example 1.

[0033] Test procedure: Complete calibration, sample placement, synchronous loading, dynamic measurement and non-destructive testing according to Example 1.

[0034] Measurement results: Arc length L is 55cm at 30s, 55.5cm at 30min, 56cm at 1h, and 56cm at 2h.

[0035] Non-destructive testing: The sheath has no cracks.

[0036] Pass / Fail Criterion: Arc length ≤ 57cm in 1 hour, pass / fail.

[0037] Example 3, Sample: Rated voltage 1.8 / 3kV, 1×630 mm 2 Wind power aluminum alloy cable, Class II soft aluminum conductor, rubber insulating sheath.

[0038] The test conditions and apparatus are the same as in Example 1.

[0039] Experimental procedure: Complete the full-process experiment according to Example 1.

[0040] Measurement results: Arc length L is 59cm at 30s, 60cm at 30min, 60.5cm at 1h, and 60.5cm at 2h.

[0041] Non-destructive testing: The sheath has no cracks.

[0042] Pass / Fail Criterion: Arc length ≤ 61cm in 1 hour is considered pass / fail.

[0043] Example 4 (Comparative Example 1), Sample: Rated voltage 1.8 / 3kV, 1×630 mm 2 The conductor hardness of the wind power aluminum alloy cable exceeds the standard.

[0044] The test conditions and apparatus are the same as in Example 1.

[0045] Experimental procedure: Complete the full-process experiment according to Example 1.

[0046] Measurement results: The arc length L in 1 hour is 64cm, which exceeds the threshold of 61cm.

[0047] Non-destructive testing: A 0.15mm microcrack was found in the sheath.

[0048] Acceptance criteria: If the arc length exceeds the standard and the sheath has cracks, the first test result is unacceptable. Two more samples from the same reel are taken for retesting. The arc lengths are 62.5cm and 63cm respectively, both exceeding the tolerance and accompanied by micro-cracks. The entire reel is deemed unacceptable. Physical isolation markings are made and a traceability log for unacceptable products is established.

[0049] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A bending test method for wind power aluminum alloy cables, characterized in that, Suitable for rated voltage 1.8 / 3kV, size 1×400mm 2 1×500mm 2 1×630mm 2 Category II soft aluminum conductor, rubber insulation / sheath, wind turbine nacelle aluminum alloy cable that meets 4D bending requirements, including: Test conditions and sample preparation: Ambient temperature 20℃±2℃, relative humidity 45%~65%, cable reel pretreatment and static treatment ≥24h, sample horizontal straightening stress-free treatment ≥4h; 2m samples from the first and last ends of every 500m / reel; effective sample length 2.0m, with 20cm reserved at each end for hanging weight; sample kept straight, without twisting or sheath damage; Test apparatus: A rigid fixed support cylinder (1) with a diameter of 18cm is used. The bottom of the support cylinder (1) is equipped with a shock-absorbing base (5) with a surface roughness Ra≤0.8μm. A counterweight (3) of 20kg is loaded at both ends of the cable through a synchronous hanging device (4). A height-adjustable optical ranging probe (6), a non-destructive testing instrument (7) and an intelligent data acquisition terminal (8) are configured. Test steps: Before the test, calibrate the accuracy of the height-adjustable optical ranging probe (6) and adjust the height of the height-adjustable optical ranging probe (6); gently place the sample with the 1m midpoint aligned with the top of the supporting cylinder (1), suspend the counterweight (3) through the synchronous hanging weight device (4) and let it stand for ≥30s until stable; the intelligent data acquisition terminal (8) automatically collects the arc length of the outer arc at the 1m midpoint 30s, 30min, 1h and 2h after loading; after the test, use a non-destructive testing instrument (7) to detect microcracks in the sheath; Acceptance criteria: Based on 1 hour measurement, 1×400mm 2 ≤54cm, 1×500mm 2 ≤57cm, 1×630mm 2 ≤61cm is acceptable, and the sheath must be free of cracks; if it exceeds the tolerance or has cracks, it is considered unacceptable. Two more sections from the same reel will be taken for retesting. If they are still unacceptable, the entire reel will be rejected. Recording and Safety: The intelligent data acquisition terminal (8) automatically and completely records the test data; the counterweight (3) prevents falling, the support column (1) is fixed, the shock-absorbing base (5) is locked, there is no forced bending, and the test area is dry and free from strong vibration.

2. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The synchronous hanging device (4) ensures that the counterweights (3) at both ends fall synchronously, with a falling height difference of ≤5mm.

3. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The calibration error of the height-adjustable optical ranging probe (6) is ≤ ±0.5 mm, and the calibration data is included in the test record.

4. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The vibration amplitude of the damping base (5) is controlled to be ≤0.1mm.

5. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The intelligent data acquisition terminal (8) has a sampling frequency of 1 time / 10s and stores dynamic data of bending deformation in real time.

6. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The sheath is subjected to non-destructive testing using an ultrasonic non-destructive testing instrument (7), which can detect microcracks with a diameter ≥0.1mm.

7. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The stress-free treatment involves placing the sample horizontally and straight under standard conditions without any external force constraints.

8. The bending test method for wind power aluminum alloy cables according to claim 1, characterized in that, The qualification criteria include two indicators: the arc length must meet the standard and the sheath must be free of cracks. Failure to meet either standard will result in disqualification.

9. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, The test method is applicable to a full range of large-section wind power aluminum alloy cables specifically designed for wind turbine nacelles and laid with a 4D bending radius.

10. The method for bending test of wind power aluminum alloy cable according to claim 1, characterized in that, Cables that fail the retest must be physically isolated and a traceability log for non-conforming products must be established.

Images