Method and device for testing fatigue performance of blade lightning protection system
By establishing a finite element mechanical simulation model and combining lightning current impact testing with mechanical fatigue testing, the problem of insufficient simulation verification of lightning protection systems was solved, enabling refined evaluation of the fatigue performance and life prediction of lightning protection systems, and providing a reliable verification method.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CRRC WIND POWER(SHANDONG) CO LTD
- Filing Date
- 2026-04-15
- Publication Date
- 2026-05-12
AI Technical Summary
There is insufficient experience in the simulation and verification of existing lightning protection systems, the test conditions are limited, and there is a lack of combination of electrical performance testing and mechanical fatigue testing. This makes it impossible to truly reflect the performance evolution of lightning protection systems under complex service environments, especially since there is a lack of mature solutions for fatigue performance testing.
A fatigue performance testing method for blade lightning protection systems is designed. By establishing a finite element mechanical simulation model, strain data and equivalent load data are extracted. Combined with lightning current impact testing and mechanical fatigue testing, the method adopts a process of initial testing, mechanical testing, and retesting to simulate actual operating conditions and evaluate the fatigue performance of the lightning protection system.
It achieves an effective closed loop between simulation and testing, enabling comprehensive evaluation of the fatigue performance of lightning protection systems, identification of the impact of mechanical fatigue on electrical performance, and providing data support for life prediction and design optimization. It overcomes the limitations of existing technologies and ensures the refinement and comprehensiveness of test conditions.
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Figure CN122017437A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of testing and application of lightning protection systems for wind turbine blades, specifically relating to a method and apparatus for testing the fatigue performance of a lightning protection system for wind turbine blades. Background Technology
[0002] Blades are the core component of wind turbines for capturing wind energy. To improve power generation efficiency, their length is constantly increasing, along with tower height and rotor diameter. The reliability of the blade lightning protection system (LPS) directly affects the stability and lifespan of the entire turbine. Lightning strikes not only lead to high maintenance costs and prolonged downtime, but in extreme cases, they can also cause structural damage or fire, threatening the safety of personnel and equipment.
[0003] As the first line of defense against lightning strikes to the blades, the performance of the LPS system directly determines the reliability and economy of the entire system. Existing lightning protection system designs suffer from limitations such as insufficient simulation verification experience and limited testing conditions. Current testing and verification methods are insufficient to meet the refined lightning protection requirements of ultra-long blades in complex service environments, particularly regarding fatigue performance testing, for which there is a lack of mature and specific testing schemes in the industry. Existing methods typically separate electrical performance testing from mechanical fatigue testing, failing to accurately reflect the performance evolution of the lightning protection system under simultaneous lightning current impacts and long-term mechanical loads during actual operation.
[0004] In view of this, it is very necessary to provide a method and apparatus for testing the fatigue performance of a blade lightning protection system to solve the above-mentioned defects in the prior art. Summary of the Invention
[0005] The purpose of this invention is to address the limitations of existing technologies, such as insufficient experience in simulation verification of lightning protection systems, limited testing conditions, and a lack of performance testing schemes that combine electrical performance testing and mechanical fatigue testing. This invention provides a method and apparatus for testing the fatigue performance of blade lightning protection systems to solve the aforementioned technical problems.
[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for testing the fatigue performance of a blade lightning protection system includes the following steps: Step S1: Establish a finite element mechanical simulation model based on the design of the blade lightning protection system, and extract strain data and equivalent load data at the connection position under the blade operating conditions. Step S2: Prepare test samples of lightning protection conductors and connection components; Step S3: Perform lightning current impulse tests on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be a defective product; otherwise, proceed to step S4. Step S4: Based on the strain data and equivalent load data obtained in step S1, perform mechanical fatigue performance tests on the lightning protection conductor test specimen and the connecting component test specimen. If failure occurs, the test specimen is determined to be a defective product; otherwise, proceed to step S5. Step S5: Retest the lightning current impulse test on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be unqualified; otherwise, proceed to step S6. Step S6: Determine the test specimens that have passed the mechanical fatigue performance test and the current impact test. If the test results meet the qualified product conditions specified in the standard, the test specimen is a qualified product; otherwise, the test specimen is a non-qualified product.
[0007] Preferably, step S1 specifically includes: Step S11: Establish a finite element mechanical simulation model of the blade lightning protection system; the finite element mechanical simulation model of the blade lightning protection system includes: wiring terminals, lightning protection wires, lightning protection wire connecting pipes, lightning arresters, and lightning arrester bases. The lightning arrester is installed on top of the lightning arrester base; the lightning arrester base is fixed in the blade housing and connected to the first section of the lightning protection conductor; the first section of the lightning protection conductor is connected to the second section of the lightning protection conductor through a terminal block; the second section of the lightning protection conductor passes through the inside of the lightning protection conductor connecting pipe, and both ends of the second section of the lightning protection conductor are connected to other components of the lightning protection system through terminal blocks. Step S12: Import the finite element mechanical simulation model of the blade lightning protection system into the finite element mechanical simulation model of the blade, and perform mechanical simulation calculations under fatigue load. Step S13: Through mechanical simulation calculation, determine the high strain region of the lightning protection system under the blade operating conditions, and extract the strain data and equivalent load data of the high strain region. The strain data are the maximum strain values at each measuring point; The equivalent load data refers to the equivalent tensile, compressive, bending, or torque values at each connection point in the lightning protection system under fatigue load. Step S14: Use strain data and equivalent load data as input conditions for subsequent mechanical fatigue testing.
[0008] Preferably, the lightning protection conductor test specimen and the connection component test specimen in step S2 are specifically: The lightning protection conductor test specimen includes a lightning protection conductor and a terminal block; The test sample of the connection component includes: a lightning arrester connection component and a current diverter connection component; the lightning arrester connection component includes: a lightning arrester base and a terminal block; the current diverter connection component includes: a terminal block and a lightning protection wire connection pipe.
[0009] Preferably, step S3 specifically includes: Step S31: According to the lightning current parameters specified in Section 7.2 and the test methods specified in Sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, conduct three or more lightning current impulse tests with an amplitude of 200kA on the lightning protection conductor test specimen and the connection component test specimen. Step S32: Verify whether the electrical performance of the lightning protection system before it is subjected to mechanical fatigue meets the standard requirements, and determine whether any component in the test sample of the connecting parts is separated from the lightning protection conductor: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S4.
[0010] Preferably, step S4 specifically includes: Step S41: Based on the strain data obtained in step S1, perform mechanical fatigue performance testing on the lightning protection conductor test specimen. Step S42: Based on the equivalent load data obtained in step S1, perform mechanical fatigue performance testing on the test specimen of the connecting component.
[0011] Preferably, step S41 specifically includes: Step S411: Install the lightning protection conductor test sample between the mechanical actuator and the special tooling; The special tooling includes: a slider, an actuator, a terminal block, a spring, and a slide rail; the slider is mounted on the top of the slide rail, the first end of the slider is connected to the spring, and the second end of the slider is connected to the terminal block; the terminal block is connected to the lightning protection wire; the actuator is placed in the middle section of the lightning protection wire, acts on the lightning protection wire, and applies pressure to the lightning protection wire; Step S412: Strain gauges are attached to the outer surface of the lightning protection conductor test sample for real-time monitoring of the strain data of the lightning protection conductor. Step S413: Control the mechanical actuator to apply displacement control loading to the lightning protection conductor test sample until the strain gauge readings reach the maximum strain values of each measuring point extracted by simulation calculation in step S13. Step S414: Determine the equivalent number of cycles based on the blade's design life, and perform cyclic loading; Step S415: During the test, continuously monitor the strain changes and observe whether the lightning protection conductor test sample exhibits the following failure conditions: conductor breakage, loose or detached connection. If the above conditions occur, the lightning protection conductor test sample is determined to be unqualified; otherwise, proceed to step S5.
[0012] Preferably, step S42 specifically includes: Step S421: Install the test sample of the connecting component between the fixed end and the loading end of the fatigue performance testing machine; Step S422: Based on the equivalent load data extracted from the simulation calculation in step S13, set the loading parameters of the fatigue performance testing machine. The loading parameters include: load amplitude, frequency, and waveform. Step S423: Perform cyclic pulling or stretching loading, the number of loading times being determined equivalent to the actual working cycle number of the blade; Step S424: During the test, observe whether the following failure conditions occur: the connector separates from the lightning protection wire, the lightning arrester cracks, or the wiring terminal becomes loose or falls off. If the above conditions occur, the lightning protection wire test sample is determined to be unqualified; otherwise, proceed to step S5.
[0013] Preferably, step S5 specifically includes: Step S51: For the test specimens that have completed the mechanical fatigue test in step S4, a lightning current impulse test is performed again: In accordance with the lightning current parameters specified in Section 7.2 and the test methods specified in Section 8.2.2 of IEC 61400-24:2010, the lightning protection conductor test specimens and the connecting component test specimens are subjected to three or more lightning current impulse tests with an amplitude of 200kA. Step S52: Verify whether the lightning protection system maintains stable electrical performance after undergoing mechanical fatigue, and determine whether any component in the test sample of the connecting parts separates from the lightning protection wire: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S6.
[0014] Preferably, the standard specifications in step S6 include: In terms of electrical performance, it meets the acceptance requirements for the integrity of the conductive path, the rate of change of resistance, and the degree of physical damage after lightning current impulse as specified in Sections 8.2.2, 8.2.3, and 10 of IEC 61400-24:2010. In terms of mechanical performance, the lightning protection conductors are not broken and the connecting parts are not separated or loosened before reaching the design equivalent number of cycles.
[0015] Furthermore, the present invention also provides a fatigue performance testing device for a blade lightning protection system, comprising: The simulation load extraction module contains: A finite element mechanical simulation model was established based on the design of the blade lightning protection system, and strain data and equivalent load data at the connection points were extracted under the blade operating conditions. The test sample preparation module contains: Prepare test specimens for lightning protection conductors and test specimens for connecting components; The electrical performance testing module contains: Lightning current impulse tests are conducted on the lightning protection conductor test specimens and connection component test specimens. If a failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the mechanical fatigue performance test module. The mechanical fatigue performance testing module contains: Based on the strain data and equivalent load data obtained by the simulation load extraction module, mechanical fatigue performance tests are conducted on the lightning protection conductor test specimen and the connection component test specimen. If failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the electrical performance retest module. The electrical performance retest module contains: The lightning current impulse test is retested on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is judged to be unqualified; otherwise, it enters the comprehensive qualification judgment module. The comprehensive qualification assessment module includes: Test specimens that pass the mechanical fatigue performance test and the current impact test are judged. If the test results meet the qualified product conditions specified in the standard, the test specimen is a qualified product; otherwise, the test specimen is a non-qualified product.
[0016] Preferably, the simulation load extraction module specifically includes: A finite element mechanical simulation model of the blade lightning protection system is established; the finite element mechanical simulation model of the blade lightning protection system includes: terminal block, lightning protection wire, lightning protection wire connecting pipe, lightning arrester, and lightning arrester base. The lightning arrester is installed on top of the lightning arrester base; the lightning arrester base is fixed in the blade housing and connected to the first section of the lightning protection conductor; the first section of the lightning protection conductor is connected to the second section of the lightning protection conductor through a terminal block; the second section of the lightning protection conductor passes through the inside of the lightning protection conductor connecting pipe, and both ends of the second section of the lightning protection conductor are connected to other components of the lightning protection system through terminal blocks. The finite element mechanical simulation model of the blade lightning protection system is imported into the finite element mechanical simulation model of the blade to perform mechanical simulation calculations under fatigue loads. Through mechanical simulation calculations, the high-strain region of the lightning protection system under the operating conditions of the blade is identified, and strain data and equivalent load data of the high-strain region are extracted; the strain data is the maximum strain value of each measuring point; the equivalent load data is the equivalent tensile, compressive, bending, or torsional moment of each connection position in the lightning protection system under fatigue load. Strain data and equivalent load data are used as input conditions for subsequent mechanical fatigue tests.
[0017] Preferably, the lightning protection conductor test sample and the connecting component test sample in the test sample preparation module are specifically: The lightning protection conductor test specimen includes a lightning protection conductor and a terminal block; The test sample of the connection component includes: a lightning arrester connection component and a current diverter connection component; the lightning arrester connection component includes: a lightning arrester base and a terminal block; the current diverter connection component includes: a terminal block and a lightning protection wire connection pipe.
[0018] As a preferred option, the electrical performance testing module specifically includes: According to the lightning current parameters specified in Section 7.2 and the test methods specified in Sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, the lightning protection conductor test specimen and the connection component test specimen shall be subjected to three or more lightning current impulse tests with an amplitude of 200kA. Verify whether the electrical performance of the lightning protection system before it is subjected to mechanical fatigue meets the standard requirements, and determine whether any component in the test sample of the connecting parts separates from the lightning protection conductor: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to the mechanical fatigue performance test module.
[0019] Preferably, the mechanical fatigue performance testing module specifically includes: Based on the strain data obtained by the simulation load extraction module, the mechanical fatigue performance of the lightning protection conductor test specimen was tested. Based on the equivalent load data obtained by the simulation load extraction module, the mechanical fatigue performance of the test specimen of the connecting component is tested.
[0020] Preferably, in the mechanical fatigue performance testing module, the mechanical fatigue performance of the lightning protection conductor test sample is tested based on the strain data obtained by the simulation load extraction module, specifically including: The lightning protection conductor test sample is installed between the mechanical actuator and the special tooling; The special tooling includes: a slider, an actuator, a terminal block, a spring, and a slide rail; the slider is mounted on the top of the slide rail, the first end of the slider is connected to the spring, and the second end of the slider is connected to the terminal block; the terminal block is connected to the lightning protection wire; the actuator is placed in the middle section of the lightning protection wire, acts on the lightning protection wire, and applies pressure to the lightning protection wire; Strain gauges are attached to the outer surface of the lightning protection conductor test specimen to monitor the strain data of the lightning protection conductor in real time. The mechanical actuator is controlled to apply displacement control loading to the lightning protection conductor test specimen until the strain gauge readings reach the maximum strain values of each measuring point extracted by the mechanical simulation calculation in the simulation load extraction module. Based on the blade's design life, determine the equivalent number of cycles and perform cyclic loading; During the test, strain changes are continuously monitored, and the following failure conditions are observed in the lightning protection conductor test sample: conductor breakage, loose or detached connection. If the above conditions occur, the lightning protection conductor test sample is determined to be unqualified; otherwise, it proceeds to the electrical performance retest module.
[0021] Preferably, in the mechanical fatigue performance testing module, the mechanical fatigue performance of the connecting component test sample is tested based on the equivalent load data obtained by the simulation load extraction module, specifically including: The test specimen of the connecting component is installed between the fixed end and the loading end of the fatigue performance testing machine; Based on the equivalent load data extracted from the mechanical simulation calculation in the simulation load extraction module, the loading parameters of the fatigue performance testing machine are set. The loading parameters include: load amplitude, frequency, and waveform. The number of cyclic pulling or stretching loads is determined based on the actual number of working cycles of the blade. During the test, observe whether the following failures occur: the connector separates from the lightning protection wire, the lightning arrester cracks, or the wiring terminals become loose or fall off. If any of the above occurs, the lightning protection wire test sample is determined to be unqualified; otherwise, proceed to the electrical performance retest module.
[0022] Preferably, the electrical performance retest module specifically includes: For the test specimens that have completed the mechanical fatigue test, a lightning current impulse test is performed again: in accordance with the lightning current parameters specified in Section 7.2 and the test methods specified in Section 8.2.2 of IEC61400-24:2010, the lightning protection conductor test specimens and the connecting component test specimens are subjected to three or more lightning current impulse tests with an amplitude of 200kA. To verify whether the lightning protection system maintains stable electrical performance after undergoing mechanical fatigue, determine whether any component in the test sample of the connecting parts separates from the lightning protection conductor: if separation occurs, the test sample is deemed unqualified; if separation does not occur, proceed to the comprehensive qualification judgment module.
[0023] Preferably, the standard provisions in the comprehensive qualification judgment module include: In terms of electrical performance, it meets the acceptance requirements for the integrity of the conductive path, the rate of change of resistance, and the degree of physical damage after lightning current impulse as specified in Sections 8.2.2, 8.2.3, and 10 of IEC 61400-24:2010. In terms of mechanical performance, the lightning protection conductors are not broken and the connecting parts are not separated or loosened before reaching the design equivalent number of cycles.
[0024] The beneficial effects of this invention are as follows: By establishing a finite element simulation model of the lightning protection system, extracting strain data and equivalent load data at connection positions under blade operating conditions, and using these as input conditions for mechanical fatigue testing, an effective closed loop between simulation and testing is achieved. This solves the problem of insufficient simulation verification experience in existing lightning protection system designs and provides a reliable verification method for the refined design of lightning protection systems. Furthermore, by organically combining lightning current impulse testing and mechanical fatigue testing, and adopting a composite testing process of "initial test, mechanical test, and retest," this invention simulates the actual service conditions of a lightning protection system simultaneously subjected to lightning current impulses and long-term mechanical loads during actual operation, overcoming the limitations of existing testing conditions. Overcoming the limitations of separate electrical and mechanical performance testing, this approach enables a more comprehensive evaluation of the fatigue performance of lightning protection systems. Two mechanical fatigue testing methods—displacement-controlled loading and force-controlled loading—were designed for lightning protection conductors and connecting components respectively. Combined with multiple lightning current impulse tests, a complete performance evaluation system was formed, filling the technological gap in fatigue performance testing schemes for lightning protection systems. The process design, which involves screening out defective products through initial electrical testing and then conducting electrical retesting after mechanical testing, effectively identifies the degree of impact of mechanical fatigue on electrical performance, reveals the performance evolution patterns of lightning protection systems during service, and provides data support for life prediction and design optimization of lightning protection systems.
[0025] Furthermore, the design principle of this invention is reliable, the structure is simple, and it has a very wide range of application prospects.
[0026] Therefore, it is evident that the present invention has outstanding substantive features and significant progress compared with the prior art, and the beneficial effects of its implementation are also obvious. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0028] Figure 1 This is a flowchart of a fatigue performance testing method for a blade lightning protection system provided by the present invention.
[0029] Figure 2 This is a schematic diagram of a fatigue performance testing device for a blade lightning protection system provided by the present invention.
[0030] Figure 3 This is a schematic diagram of the blade lightning protection system provided by the present invention.
[0031] Figure 4 This is a schematic diagram of the finite element mechanical simulation verification of the blade lightning protection system provided by the present invention.
[0032] Figure 5 This is a strain data diagram of the blade lightning protection system provided by the present invention.
[0033] Figure 6 This is a schematic diagram of the mechanical test of the blade lightning protection conductor provided by the present invention.
[0034] Figure 7 This is a schematic diagram of the mechanical testing of the connecting components of the blade lightning protection system provided by the present invention.
[0035] Among them, 1-simulation load extraction module, 2-test sample preparation module, 3-electrical performance testing module, 4-mechanical fatigue performance testing module, 5-electrical performance retest module, 6-comprehensive qualification judgment module, 7-terminal connector, 8-lightning protection wire, 9-lightning protection wire connecting pipe, 10-lightning arrester, 11-lightning arrester base, 12-slider, 13-actuator, 14-spring, 15-slide rail, 16-loading end, 17-fixed end. Detailed Implementation
[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following implementation methods.
[0037] Example 1: like Figure 1 As shown in the figure, this embodiment provides a fatigue performance testing method for a blade lightning protection system, which includes the following steps: Step S1: Establish a finite element mechanical simulation model based on the design of the blade lightning protection system, and extract strain data and equivalent load data at the connection position under the blade operating conditions. Step S1 specifically includes: Step S11: Establish a finite element mechanical simulation model of the blade lightning protection system; such as Figure 3 As shown, the finite element mechanical simulation model of the blade lightning protection system includes: terminal block 7, lightning protection wire 8, lightning protection wire connecting pipe 9, lightning arrester 10, and lightning arrester base 11. The lightning arrester 10 is installed on top of the lightning arrester base 11; the lightning arrester base 11 is fixed in the blade housing and connected to the first section of lightning protection wire 8; the first section of lightning protection wire 8 is connected to the second section of lightning protection wire 8 through the terminal block 7; the second section of lightning protection wire 8 is inserted into the lightning protection wire connecting pipe 9, and the two ends of the second section of lightning protection wire 8 are connected to other components of the lightning protection system through the terminal block 7. Step S12: Import the finite element mechanical simulation model of the blade lightning protection system into the finite element mechanical simulation model of the blade, such as... Figure 4 As shown, mechanical simulation calculations are performed under fatigue loads. Step S13: Through mechanical simulation calculations, determine the high-strain region of the lightning protection system under blade operating conditions, such as... Figure 4 The blue area is used to extract strain data and equivalent load data from the high-strain region, resulting in the following: Figure 5 The strain data curve shown is shown below; The strain data are the maximum strain values at each measuring point; The equivalent load data refers to the equivalent tensile, compressive, bending, or torsional moments under fatigue loads at various connection points in the lightning protection system, such as the connection between the lightning arrester 10 and the lightning protection conductor 8, and the connection between the lightning protection conductor 8 and the grounding terminal. Step S14: Use strain data and equivalent load data as input conditions for subsequent mechanical fatigue testing.
[0038] Step S2: Prepare test samples of lightning protection conductors and connection components; The lightning protection conductor test specimen and the connection component test specimen in step S2 are specifically as follows: The lightning protection conductor test specimen includes a lightning protection conductor 8 and a terminal block 7; The test specimens for the connecting components include: a lightning arrester connecting component and a flow guiding device connecting component; such as Figure 7 As shown in the right figure, the lightning arrester connection components include: a lightning arrester base 11 and a wiring terminal 7; as Figure 7 As shown in the left figure, the connecting components of the flow guiding device include: a wiring terminal 7 and a lightning protection wire connecting pipe 9.
[0039] Step S3: Perform lightning current impulse tests on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be a defective product; otherwise, proceed to step S4. Step S3 specifically includes: Step S31: According to the lightning current parameters specified in Section 7.2 and the test methods specified in Sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, conduct three or more lightning current impulse tests with an amplitude of 200kA on the lightning protection conductor test specimen and the connection component test specimen. Step S32: Verify whether the electrical performance of the lightning protection system before it is subjected to mechanical fatigue meets the standard requirements, and determine whether any component in the test sample of the connecting parts is separated from the lightning protection wire 8: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S4.
[0040] Step S4: Based on the strain data and equivalent load data obtained in step S1, perform mechanical fatigue performance tests on the lightning protection conductor test specimen and the connecting component test specimen. If failure occurs, the test specimen is determined to be a defective product; otherwise, proceed to step S5. Step S4 specifically includes: Step S41: Based on the strain data obtained in step S1, perform mechanical fatigue performance testing on the lightning protection conductor test specimen. Step S42: Based on the equivalent load data obtained in step S1, perform mechanical fatigue performance testing on the test specimen of the connecting component.
[0041] Step S41 specifically includes: Step S411, as follows Figure 6 As shown, the lightning protection conductor test sample is installed between the mechanical actuator 13 and the special tooling. The special tooling includes: a slider 12, an actuator 13, a terminal block 7, a spring 14, and a slide rail 15; the slider 12 is mounted on the top of the slide rail 15, the first end of the slider 12 is connected to the spring 14, and the second end of the slider 12 is connected to the terminal block 7; the terminal block 7 is connected to the lightning protection wire 8; the actuator 13 is placed in the middle section of the lightning protection wire 8, acts on the lightning protection wire 8, and applies pressure to the lightning protection wire 8; Step S412: Strain gauges are attached to the outer surface of the lightning protection conductor test sample for real-time monitoring of the strain data of the lightning protection conductor 8. Step S413: Control the mechanical actuator 13 to apply displacement control loading to the lightning protection conductor test sample until the strain gauge readings reach the maximum strain values of each measuring point extracted by simulation calculation in step S13. Step S414: Determine the equivalent cycle number based on the blade's design life. In this embodiment, the blade life is 20 years, corresponding to the equivalent cycle number of... Repeat the loading process; Step S415: During the test, continuously monitor the strain change and observe whether the lightning protection conductor test sample exhibits the following failure conditions: conductor breakage, loose or detached connection. If the above conditions occur, the lightning protection conductor test sample is determined to be unqualified; otherwise, proceed to step S5. Step S42 specifically includes: Step S421, as follows Figure 7 As shown, the test sample of the connecting component is installed between the fixed end 17 and the loading end 16 of the fatigue performance testing machine; Step S422: Based on the equivalent load data extracted from the simulation calculation in step S13, set the loading parameters of the fatigue performance testing machine. The loading parameters include: load amplitude, frequency, and waveform. Step S423: Perform cyclic pulling or stretching loading, the number of loading times being determined equivalent to the actual working cycle number of the blade; Step S424: During the test, observe whether the following failures occur: the connector separates from the lightning protection wire 8, the lightning arrester 10 cracks, or the terminal 7 becomes loose or falls off. If any of the above occurs, the lightning protection wire test sample is determined to be unqualified; otherwise, proceed to step S5. Step S5: Retest the lightning current impulse test on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be unqualified; otherwise, proceed to step S6. Step S5 specifically includes: Step S51: For the test specimens that have completed the mechanical fatigue test in step S4, a lightning current impulse test is performed again: In accordance with the lightning current parameters specified in Section 7.2 and the test methods specified in Section 8.2.2 of IEC 61400-24:2010, the lightning protection conductor test specimens and the connecting component test specimens are subjected to three or more lightning current impulse tests with an amplitude of 200kA. Step S52: Verify whether the lightning protection system still maintains stable electrical performance after undergoing mechanical fatigue, and determine whether any component in the test sample of the connecting parts separates from the lightning protection wire 8: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S6.
[0042] Step S6: Determine the test specimens that have passed the mechanical fatigue performance test and the current impact test. If the test results meet the qualified product conditions specified in the standard, the test specimen is a qualified product; otherwise, the test specimen is a non-qualified product.
[0043] The standard provisions in step S6 include: In terms of electrical performance, it meets the acceptance requirements for the integrity of the conductive path, the rate of change of resistance, and the degree of physical damage after lightning current impulse as specified in Sections 8.2.2, 8.2.3, and 10 of IEC 61400-24:2010. In terms of mechanical performance, before reaching the design equivalent number of cycles, the lightning protection conductor 8 showed no breakage, and the connecting parts showed no separation or loosening.
[0044] Example 2: like Figure 2 As shown in the figure, this embodiment provides a fatigue performance testing device for a blade lightning protection system, comprising: Simulation load extraction module 1, in which: A finite element mechanical simulation model was established based on the design of the blade lightning protection system, and strain data and equivalent load data at the connection points were extracted under the blade operating conditions. The simulation load extraction module 1 specifically includes: A finite element mechanical simulation model of the blade lightning protection system is established; the finite element mechanical simulation model of the blade lightning protection system includes: terminal block 7, lightning protection wire 8, lightning protection wire connecting pipe 9, lightning arrester 10, and lightning arrester base 11. The lightning arrester 10 is installed on top of the lightning arrester base 11; the lightning arrester base 11 is fixed in the blade housing and connected to the first section of lightning protection wire 8; the first section of lightning protection wire 8 is connected to the second section of lightning protection wire 8 through the terminal block 7; the second section of lightning protection wire 8 is inserted into the lightning protection wire connecting pipe 9, and the two ends of the second section of lightning protection wire 8 are connected to other components of the lightning protection system through the terminal block 7. The finite element mechanical simulation model of the blade lightning protection system is imported into the finite element mechanical simulation model of the blade to perform mechanical simulation calculations under fatigue loads. Through mechanical simulation calculations, the high-strain region of the lightning protection system under the blade operating conditions is determined, and the strain data and equivalent load data of the high-strain region are extracted; the strain data is the maximum strain value of each measuring point; the equivalent load data is the equivalent tensile, compressive, bending, or torque under fatigue load at each connection position in the lightning protection system, such as the connection between the lightning arrester 10 and the lightning protection wire 8, and the connection between the lightning protection wire 8 and the grounding terminal. Strain data and equivalent load data are used as input conditions for subsequent mechanical fatigue tests.
[0045] Test sample preparation module 2, in which: Prepare test specimens for lightning protection conductors and test specimens for connecting components; The lightning protection conductor test sample and the connecting component test sample in the test sample preparation module 2 are specifically as follows: The lightning protection conductor test specimen includes a lightning protection conductor 8 and a terminal block 7; The test sample of the connection component includes: a lightning arrester connection component and a current diverter connection component; the lightning arrester connection component includes: a lightning arrester base 11 and a terminal block 7; the current diverter connection component includes: a terminal block 7 and a lightning protection wire connection pipe 9.
[0046] Electrical performance testing module 3, in which: Lightning current impulse tests are conducted on the lightning protection conductor test specimens and connection component test specimens. If a failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the mechanical fatigue performance test module 4. Electrical performance testing module 3 specifically includes: According to the lightning current parameters specified in Section 7.2 and the test methods specified in Sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, the lightning protection conductor test specimen and the connection component test specimen shall be subjected to three or more lightning current impulse tests with an amplitude of 200kA. Verify whether the electrical performance of the lightning protection system before it is subjected to mechanical fatigue meets the standard requirements, and determine whether any component in the test sample of the connecting parts is separated from the lightning protection conductor 8: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to the mechanical fatigue performance test module 4.
[0047] Mechanical fatigue performance testing module 4, in which: Based on the strain data and equivalent load data obtained by the simulation load extraction module 1, mechanical fatigue performance tests are conducted on the lightning protection conductor test specimen and the connection component test specimen. If failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the electrical performance retest module 5. The mechanical fatigue performance testing module 4 specifically includes: Based on the strain data obtained by the simulation load extraction module 1, the mechanical fatigue performance of the lightning protection conductor test specimen was tested. Based on the equivalent load data obtained by the simulation load extraction module 1, the mechanical fatigue performance of the test sample of the connecting component is tested.
[0048] In the mechanical fatigue performance testing module 4, based on the strain data obtained by the simulation load extraction module 1, the mechanical fatigue performance of the lightning protection conductor test sample is tested, specifically including: The lightning protection conductor test sample is installed between the mechanical actuator 13 and the special tooling; The special tooling includes: a slider 12, an actuator 13, a terminal block 7, a spring 14, and a slide rail 15; the slider 12 is mounted on the top of the slide rail 15, the first end of the slider 12 is connected to the spring 14, and the second end of the slider 12 is connected to the terminal block 7; the terminal block 7 is connected to the lightning protection wire 8; the actuator 13 is placed in the middle section of the lightning protection wire 8, acts on the lightning protection wire 8, and applies pressure to the lightning protection wire 8; Strain gauges were attached to the outer surface of the lightning protection conductor test specimen to monitor the strain data of the lightning protection conductor 8 in real time. The mechanical actuator 13 is controlled to apply displacement control loading to the lightning protection conductor test specimen until the strain gauge readings reach the maximum strain values of each measuring point extracted by the mechanical simulation calculation in the simulation load extraction module 1. Based on the blade's design life, the equivalent cycle number is determined. In this embodiment, the blade life is 20 years, corresponding to the following equivalent cycle number: Repeat the loading process; During the test, strain changes are continuously monitored, and the following failure conditions are observed in the lightning protection conductor test sample: conductor breakage, loose or detached connection. If the above conditions occur, the lightning protection conductor test sample is determined to be unqualified; otherwise, it proceeds to the electrical performance retest module 5.
[0049] In the mechanical fatigue performance testing module 4, based on the equivalent load data obtained by the simulation load extraction module 1, the mechanical fatigue performance of the connecting component test sample is tested, specifically including: The test specimen of the connecting component is installed between the fixed end 17 and the loading end 16 of the fatigue performance testing machine; Based on the equivalent load data extracted from the mechanical simulation calculation in the simulation load extraction module 1, the loading parameters of the fatigue performance testing machine are set. The loading parameters include: load amplitude, frequency, and waveform. The number of cyclic pulling or stretching loads is determined based on the actual number of working cycles of the blade. During the test, observe whether the following failures occur: the connector separates from the lightning protection wire 8, the lightning arrester 10 cracks, or the terminal 7 becomes loose or falls off. If any of the above occurs, the lightning protection wire test sample is determined to be unqualified. Otherwise, proceed to the electrical performance retest module 5.
[0050] Electrical performance retest module 5, in which: The lightning current impulse test is retested on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is judged to be unqualified; otherwise, it proceeds to the comprehensive qualification judgment module 6. The electrical performance retest module 5 specifically includes: For the test specimens that have completed the mechanical fatigue test, a lightning current impulse test is performed again: in accordance with the lightning current parameters specified in Section 7.2 and the test methods specified in Section 8.2.2 of IEC61400-24:2010, the lightning protection conductor test specimens and the connecting component test specimens are subjected to three or more lightning current impulse tests with an amplitude of 200kA. Verify whether the lightning protection system maintains stable electrical performance after undergoing mechanical fatigue, and determine whether any component in the test sample of the connecting parts separates from the lightning protection conductor 8: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to the comprehensive qualification judgment module 6.
[0051] Comprehensive qualification assessment module 6, in which: Test specimens that pass the mechanical fatigue performance test and the current impact test are judged. If the test results meet the qualified product conditions specified in the standard, the test specimen is a qualified product; otherwise, the test specimen is a non-qualified product.
[0052] The standards specified in the comprehensive qualification assessment module 6 include: In terms of electrical performance, it meets the acceptance requirements for the integrity of the conductive path, the rate of change of resistance, and the degree of physical damage after lightning current impulse as specified in Sections 8.2.2, 8.2.3, and 10 of IEC 61400-24:2010. In terms of mechanical performance, before reaching the design equivalent number of cycles, the lightning protection conductor 8 showed no breakage, and the connecting parts showed no separation or loosening.
[0053] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. The methods disclosed in the embodiments are described simply because they correspond to the systems disclosed in the embodiments; relevant details can be found in the method section.
[0054] Those skilled in the art will further recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.
[0055] In the embodiments provided by this invention, it should be understood that the disclosed systems, methods, and approaches can be implemented in other ways. For example, the system embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between systems or units may be electrical, mechanical, or other forms.
[0056] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.
[0057] In addition, the functional modules in the various embodiments of the present invention can be integrated into one processing unit, or each module can exist physically separately, or two or more modules can be integrated into one unit.
[0058] Similarly, in the various embodiments of the present invention, each processing unit can be integrated into a functional module, or each processing unit can exist physically, or two or more processing units can be integrated into a functional module.
[0059] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.
[0060] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0061] The above-disclosed embodiments are merely preferred embodiments of the present invention, but the present invention is not limited thereto. Any non-creative variations that can be conceived by those skilled in the art, as well as any improvements and modifications made without departing from the principles of the present invention, should fall within the protection scope of the present invention.
Claims
1. A method for testing the fatigue performance of a blade lightning protection system, characterized in that, Includes the following steps: Step S1: Establish a finite element mechanical simulation model based on the design of the blade lightning protection system, and extract strain data and equivalent load data at the connection position under the blade operating conditions. Step S2: Prepare test samples of lightning protection conductors and connection components; Step S3: Conduct lightning current impulse tests on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be a defective product. Otherwise, proceed to step S4; Step S4: Based on the strain data and equivalent load data obtained in step S1, mechanical fatigue performance tests are conducted on the lightning protection conductor test specimen and the connecting component test specimen. If failure occurs, the test specimen is determined to be a defective product. Otherwise, proceed to step S5; Step S5: Retest the lightning current impulse test on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is determined to be a defective product. Otherwise, proceed to step S6; Step S6: Determine the test specimens that have passed the mechanical fatigue performance test and the current impact test. If the test results meet the qualified product conditions specified in the standard, the test specimens are qualified products. Otherwise, the test sample is considered defective.
2. The fatigue performance testing method for a blade lightning protection system according to claim 1, characterized in that, Step S1 specifically includes: Step S11: Establish a finite element mechanical simulation model of the blade lightning protection system; the finite element mechanical simulation model of the blade lightning protection system includes: wiring terminals, lightning protection wires, lightning protection wire connecting pipes, lightning arresters, and lightning arrester bases. The lightning arrester is installed on top of the lightning arrester base; the lightning arrester base is fixed in the blade housing and connected to the first section of the lightning protection conductor; the first section of the lightning protection conductor is connected to the second section of the lightning protection conductor through a terminal block; the second section of the lightning protection conductor passes through the inside of the lightning protection conductor connecting pipe, and both ends of the second section of the lightning protection conductor are connected to other components of the lightning protection system through terminal blocks. Step S12: Import the finite element mechanical simulation model of the blade lightning protection system into the finite element mechanical simulation model of the blade, and perform mechanical simulation calculations under fatigue load. Step S13: Through mechanical simulation calculation, determine the high strain region of the lightning protection system under the blade operating condition, and extract the strain data and equivalent load data of the high strain region. The strain data are the maximum strain values at each measuring point; The equivalent load data refers to the equivalent tensile, compressive, bending, or torque values at each connection point in the lightning protection system under fatigue load. Step S14: Use strain data and equivalent load data as input conditions for subsequent mechanical fatigue testing.
3. The fatigue performance testing method for a blade lightning protection system according to claim 1, characterized in that, The lightning protection conductor test specimen and the connection component test specimen in step S2 are specifically as follows: The lightning protection conductor test specimen includes a lightning protection conductor and a terminal block; The test sample of the connection component includes: a lightning arrester connection component and a current diverter connection component; the lightning arrester connection component includes: a lightning arrester base and a terminal block; the current diverter connection component includes: a terminal block and a lightning protection wire connection pipe.
4. The fatigue performance testing method for a blade lightning protection system according to claim 1, characterized in that, Step S3 specifically includes: Step S31: According to the lightning current parameters specified in Section 7.2 and the test methods specified in Sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, conduct three or more lightning current impulse tests with an amplitude of 200kA on the lightning protection conductor test specimen and the connection component test specimen. Step S32: Verify whether the electrical performance of the lightning protection system before it is subjected to mechanical fatigue meets the standard requirements, and determine whether any component in the test sample of the connecting parts is separated from the lightning protection conductor: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S4.
5. The fatigue performance testing method for a blade lightning protection system according to claim 2, characterized in that, Step S4 specifically includes: Step S41: Based on the strain data obtained in step S1, perform mechanical fatigue performance testing on the lightning protection conductor test specimen. Step S42: Based on the equivalent load data obtained in step S1, perform mechanical fatigue performance testing on the test specimen of the connecting component.
6. The fatigue performance testing method for a blade lightning protection system according to claim 5, characterized in that, Step S41 specifically includes: Step S411: Install the lightning protection conductor test sample between the mechanical actuator and the special tooling; Step S412: Strain gauges are attached to the outer surface of the lightning protection conductor test sample for real-time monitoring of the strain data of the lightning protection conductor. Step S413: Control the mechanical actuator to apply displacement control loading to the lightning protection conductor test sample until the strain gauge readings reach the maximum strain values of each measuring point extracted by simulation calculation in step S13. Step S414: Determine the equivalent number of cycles based on the blade's design life, and perform cyclic loading; Step S415: During the test, continuously monitor the strain changes and observe whether the lightning protection conductor test sample exhibits the following failure conditions: conductor breakage, loose or detached connection. If the above conditions occur, the lightning protection conductor test sample is determined to be unqualified; otherwise, proceed to step S5.
7. The fatigue performance testing method for a blade lightning protection system according to claim 5, characterized in that, Step S42 specifically includes: Step S421: Install the test sample of the connecting component between the fixed end and the loading end of the fatigue performance testing machine; Step S422: Based on the equivalent load data extracted from the simulation calculation in step S13, set the loading parameters of the fatigue performance testing machine. The loading parameters include: load amplitude, frequency, and waveform. Step S423: Perform cyclic pulling or stretching loading, the number of loading times being determined equivalent to the actual working cycle number of the blade; Step S424: During the test, observe whether the following failure conditions occur: the connector separates from the lightning protection wire, the lightning arrester cracks, or the wiring terminal becomes loose or falls off. If the above conditions occur, the lightning protection wire test sample is determined to be unqualified; otherwise, proceed to step S5.
8. The fatigue performance testing method for a blade lightning protection system according to claim 1, characterized in that, Step S5 specifically includes: Step S51: For the test specimens that have completed the mechanical fatigue test in step S4, a lightning current impulse test is performed again: In accordance with the lightning current parameters specified in Section 7.2 and the test methods specified in Section 8.2.2 of IEC 61400-24:2010, the lightning protection conductor test specimens and the connecting component test specimens are subjected to three or more lightning current impulse tests with an amplitude of 200kA. Step S52: Verify whether the lightning protection system maintains stable electrical performance after undergoing mechanical fatigue, and determine whether any component in the test sample of the connecting parts separates from the lightning protection wire: if separation occurs, the test sample is determined to be unqualified; if separation does not occur, proceed to step S6.
9. The fatigue performance testing method for a blade lightning protection system according to claim 1, characterized in that, The standard provisions in step S6 include: In terms of electrical performance, it meets the acceptance requirements for the integrity of the conductive path, the rate of change of resistance, and the degree of physical damage after lightning current impulse as specified in Sections 8.2.2, 8.2.3, and 10 of IEC 61400-24:2010. In terms of mechanical performance, the lightning protection conductors are not broken and the connecting parts are not separated or loosened before reaching the design equivalent number of cycles.
10. A fatigue performance testing device for a blade lightning protection system, characterized in that, include: The simulation load extraction module contains: A finite element mechanical simulation model was established based on the design of the blade lightning protection system, and strain data and equivalent load data at the connection points were extracted under the blade operating conditions. The test sample preparation module contains: Prepare test specimens for lightning protection conductors and test specimens for connecting components; The electrical performance testing module contains: Lightning current impulse tests are conducted on the lightning protection conductor test specimens and connection component test specimens. If a failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the mechanical fatigue performance test module. The mechanical fatigue performance testing module contains: Based on the strain data and equivalent load data obtained by the simulation load extraction module, mechanical fatigue performance tests are conducted on the lightning protection conductor test specimen and the connection component test specimen. If failure occurs, the test specimen is determined to be unqualified; otherwise, it proceeds to the electrical performance retest module. The electrical performance retest module contains: The lightning current impulse test is retested on the lightning protection conductor test sample and the connection component test sample. If a failure occurs, the test sample is judged to be unqualified; otherwise, it enters the comprehensive qualification judgment module. The comprehensive qualification assessment module includes: Test specimens that pass the mechanical fatigue performance test and the current impact test are judged. If the test results meet the qualified product conditions specified in the standard, the test specimen is a qualified product; otherwise, the test specimen is a non-qualified product.