CN-122017437-A - Fatigue performance testing method and device for blade lightning protection system

CN122017437ACN 122017437 ACN122017437 ACN 122017437ACN-122017437-A

Abstract

The invention belongs to the technical field of wind driven generator blade lightning protection system test application, and relates to a method and a device for testing fatigue performance of a blade lightning protection system, wherein the method directly verifies the electrical performance and mechanical fatigue performance of key conductive components such as lightning protection wires, lightning receptors, connecting components and the like in the lightning protection system by simulating the performance of the lightning protection system under the impact of multiple lightning current; the method comprises the steps of obtaining strain level data of each lightning protection system component in the blade based on a finite element simulation analysis method, carrying out a test by taking the strain level data as a mechanical loading condition, verifying mechanical fatigue properties of lightning protection wires, lightning receptors and connecting components in the lightning protection system, and finally combining the mechanical property test with a plurality of lightning stroke current impact tests to respectively verify the mechanical property stability of the lightning protection system after current impact and the electrical property after the mechanical test.

Inventors

HAN ZIHAO
SUN ANKANG
YOU HUIPENG
ZHANG XIAOPING
LIANG XIAOJIE
GAO MENG

Assignees

中车山东风电有限公司

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (10)

1. The method for testing the fatigue performance of the blade lightning protection system is characterized by comprising the following steps of: Step S1, a finite element mechanical simulation model is established according to the design of a blade lightning protection system, and strain data and equivalent load data at a connecting position under the operating condition of the blade are extracted; S2, preparing a lightning protection lead test sample and a connecting part test sample; step S3, carrying out lightning current impulse test on the lightning protection lead test sample and the connecting part test sample, if failure occurs, judging the test sample as an unqualified product, otherwise, executing step S4; S4, carrying out mechanical fatigue performance test on the lightning protection lead test sample and the connecting part test sample according to the strain data and the equivalent load data obtained in the step S1, and judging the test sample as an unqualified product if a failure condition occurs; s5, carrying out lightning current impact test retest on the lightning protection lead test sample and the connecting part test sample, if failure occurs, judging the test sample as an unqualified product, otherwise, executing the step S6; And S6, judging the test sample passing the mechanical fatigue performance test and the current impact test, if the test result meets the qualification condition specified by the standard, the test sample is qualified, and if not, the test sample is unqualified.
2. The method for testing the fatigue performance of the blade lightning protection system according to claim 1, wherein the step S1 specifically comprises: S11, establishing a finite element mechanical simulation model of a blade lightning protection system, wherein the finite element mechanical simulation model of the blade lightning protection system comprises a wiring terminal, a lightning protection wire connecting pipe, a lightning receiver and a lightning receiver base; The lightning arrester is arranged at the top of the lightning arrester base, the lightning arrester base is fixed in the blade shell and is connected with a first section of lightning-proof wire, the first section of lightning-proof wire is connected with a second section of lightning-proof wire through a connecting terminal, the second section of lightning-proof wire penetrates into a lightning-proof wire connecting pipe, and two ends of the second section of lightning-proof wire are connected with other parts of the lightning-proof system through the connecting terminal; s12, importing a finite element mechanical simulation model of the blade lightning protection system into the finite element mechanical simulation model of the blade, and performing mechanical simulation calculation under fatigue load; s13, judging a high-strain area of the lightning protection system under the operating condition of the blade through mechanical simulation calculation, and extracting strain data and equivalent load data of the high-strain area; the strain data is the maximum strain value of each measuring point; The equivalent load data are equivalent tensile pressure, bending moment or torque of each connecting position in the lightning protection system under fatigue load; And S14, taking the strain data and the equivalent load data as input conditions of a subsequent mechanical fatigue test.
3. The method for testing fatigue performance of a blade lightning protection system according to claim 1, wherein the lightning protection wire test sample and the connecting component test sample in step S2 are specifically: the lightning-proof wire test sample piece comprises a lightning-proof wire and a wiring terminal; The connecting part test sample piece comprises a lightning receiving device connecting part and a flow guiding device connecting part, wherein the lightning receiving device connecting part comprises a lightning receiving device base and a wiring terminal, and the flow guiding device connecting part comprises a wiring terminal and a lightning protection wire connecting pipe.
4. The method for testing the fatigue performance of the blade lightning protection system according to claim 1, wherein the step S3 specifically comprises: Step S31, according to lightning current parameters specified in section 7.2 and test methods specified in sections 8.2.2 and 8.2.3 of IEC 61400-24:2010, carrying out lightning current impulse test with the amplitude of 200kA on a lightning protection wire test sample piece and a connecting part test sample piece for 3 times or more; and step S32, verifying whether the electrical performance of the lightning protection system before the stress fatigue action does not meet the standard requirement, judging whether any component in the test sample piece of the connecting part is separated from the lightning protection wire, judging that the test sample piece is a defective product if the component is separated, and executing the step S4 if the component is not separated.
5. The method for testing fatigue performance of a blade lightning protection system according to claim 2, wherein the step S4 specifically includes: s41, carrying out mechanical fatigue performance test on the lightning protection lead test sample according to the strain data obtained in the step S1; and S42, carrying out mechanical fatigue performance test on the test sample piece of the connecting part according to the equivalent load data obtained in the step S1.
6. The method for testing fatigue performance of a blade lightning protection system according to claim 5, wherein the step S41 specifically comprises: Step S411, installing a lightning protection lead test sample between a mechanical actuator and a special tool; step S412, pasting a strain gauge on the outer surface of the lightning-proof wire test sample piece, wherein the strain gauge is used for monitoring strain data of the lightning-proof wire in real time; Step S413, controlling the mechanical actuator to apply displacement control loading to the lightning protection lead test sample until the reading of the strain gauge reaches the maximum strain value of each measuring point extracted by simulation calculation in step S13; step S414, determining equivalent cycle times according to the design life of the blade, and carrying out cyclic loading; And step S415, continuously monitoring strain change in the test process, observing whether the lightning protection wire test sample piece has failure conditions of wire breakage, loose or falling off of a connecting end, judging that the lightning protection wire test sample piece is a defective product if the failure conditions occur, and executing the step S5 if the failure conditions occur.
7. The method for testing fatigue performance of a blade lightning protection system according to claim 5, wherein the step S42 specifically comprises: Step S421, mounting a connecting part test sample between a fixed end and a loading end of the fatigue performance tester; Step S422, setting loading parameters of the fatigue performance testing machine according to the equivalent load data extracted by simulation calculation in step S13, wherein the loading parameters comprise load amplitude, frequency and waveform; Step S423, carrying out cyclic drawing or stretching loading, wherein the loading times are equivalently determined according to the actual working cycle times of the blade; And step S424, observing whether the following failure conditions occur, namely, the connecting piece is separated from the lightning protection wire, the lightning receptor is cracked, the wiring terminal is loose or falls off, if the conditions occur, judging that the lightning protection wire test sample piece is a defective product, otherwise, executing step S5.
8. The method for testing the fatigue performance of the blade lightning protection system according to claim 1, wherein the step S5 specifically comprises: step S51, carrying out repeated lightning current impact test on the test sample piece subjected to the mechanical fatigue test in the step S4, wherein the lightning current impact test is carried out on the lightning protection wire test sample piece and the connecting part test sample piece for 3 times or more according to the lightning current parameters specified in section 7.2 and the test method specified in section 8.2.2 of the IEC 61400-24:2010 standard; And step S52, verifying whether the lightning protection system still keeps stable electrical performance after being subjected to mechanical fatigue, judging whether any component in the connecting part test sample piece is separated from the lightning protection wire, judging that the test sample piece is a defective product if the component is separated, and executing the step S6 if the component is not separated.
9. The method for testing fatigue performance of a blade lightning protection system according to claim 1, wherein the standard specification in step S6 comprises: In terms of electrical performance, meets acceptance requirements of the specifications of section 8.2.2, 8.2.3 and section 10 of IEC 61400-24:2010 standard on the integrity, the resistance change rate and the physical damage degree of a conductive path after lightning current impact; In terms of mechanical properties, the lightning protection wire is not broken or the connecting parts are not separated or loosened before the design equivalent cycle times are reached.
10. The utility model provides a blade lightning protection system fatigue performance testing arrangement which characterized in that includes: a simulation load extraction module, wherein: Establishing a finite element mechanical simulation model according to the design of the blade lightning protection system, and extracting strain data under the operating condition of the blade and equivalent load data at the connecting position; test sample preparation module, in which: preparing a lightning protection lead test sample and a connecting part test sample; an electrical performance testing module, wherein: Carrying out lightning current impulse test on the lightning-proof lead test sample and the connecting part test sample, judging the test sample as an unqualified product if failure occurs, otherwise, entering a mechanical fatigue performance test module; Mechanical fatigue performance test module, in this module: According to the strain data and equivalent load data obtained by the simulation load extraction module, carrying out mechanical fatigue performance test on the lightning protection lead test sample piece and the connecting part test sample piece, if failure occurs, judging the test sample piece as an unqualified product, otherwise, entering an electrical performance retest module; an electrical performance retest module, wherein: Carrying out lightning current impulse test retest on the lightning protection lead test sample piece and the connecting component test sample piece, judging the test sample piece as an unqualified product if failure occurs, otherwise, entering a comprehensive qualification judging module; A comprehensive qualification module, wherein: and judging the test sample passing the mechanical fatigue performance test and the current impact test, if the test result meets the qualification condition specified by the standard, the test sample is qualified, and if not, the test sample is unqualified.

Description

Fatigue performance testing method and device for blade lightning protection system Technical Field The invention belongs to the technical field of test application of lightning protection systems of wind driven generator blades, and particularly relates to a fatigue performance test method and device of a lightning protection system of a blade. Background The blades are core components for capturing wind energy of the wind turbine, the length of the blades is continuously increased, and the height of the tower and the diameter of the wind wheel are also increased in order to improve the power generation efficiency. The reliability of the blade Lightning Protection System (LPS) is directly related to the running stability and service life of the whole machine. Lightning strikes not only lead to high maintenance costs and long-term shutdown, but also can cause structural damage or fire in extreme cases, threatening personnel and equipment safety. The LPS system is used as a first defense line for resisting blade lightning stroke, and the performance of the LPS system directly determines the running reliability and economy of the whole machine. The existing lightning protection system design has the defects of insufficient simulation verification experience, single test condition and the like, the existing lightning protection system test and verification means are difficult to meet the fine lightning protection requirement of the ultra-long blade in a complex service environment, and particularly, the fatigue performance test of the lightning protection system is not mature and specific test schemes exist in the industry. The conventional method generally separates an electrical performance test from a mechanical fatigue test, and cannot truly reflect the performance evolution rule of the lightning protection system when the lightning protection system bears lightning current impact and long-term mechanical load in actual operation. In view of the above, the present invention provides a method and apparatus for testing fatigue performance of a blade lightning protection system, which solves the above-mentioned drawbacks of the prior art. Disclosure of Invention The invention aims to provide a method and a device for testing fatigue performance of a blade lightning protection system, aiming at the defects of insufficient simulation and verification experience, single testing condition and lack of a performance testing scheme combining electrical performance testing and mechanical fatigue testing of the lightning protection system in the prior art. In order to achieve the above purpose, the present invention provides the following technical solutions: a fatigue performance test method of a blade lightning protection system comprises the following steps: Step S1, a finite element mechanical simulation model is established according to the design of a blade lightning protection system, and strain data and equivalent load data at a connecting position under the operating condition of the blade are extracted; S2, preparing a lightning protection lead test sample and a connecting part test sample; step S3, carrying out lightning current impulse test on the lightning protection lead test sample and the connecting part test sample, if failure occurs, judging the test sample as an unqualified product, otherwise, executing step S4; S4, carrying out mechanical fatigue performance test on the lightning protection lead test sample and the connecting part test sample according to the strain data and the equivalent load data obtained in the step S1, and judging the test sample as an unqualified product if a failure condition occurs; s5, carrying out lightning current impact test retest on the lightning protection lead test sample and the connecting part test sample, if failure occurs, judging the test sample as an unqualified product, otherwise, executing the step S6; And S6, judging the test sample passing the mechanical fatigue performance test and the current impact test, if the test result meets the qualification condition specified by the standard, the test sample is qualified, and if not, the test sample is unqualified. Preferably, the step S1 specifically includes: S11, establishing a finite element mechanical simulation model of a blade lightning protection system, wherein the finite element mechanical simulation model of the blade lightning protection system comprises a wiring terminal, a lightning protection wire connecting pipe, a lightning receiver and a lightning receiver base; The lightning arrester is arranged at the top of the lightning arrester base, the lightning arrester base is fixed in the blade shell and is connected with a first section of lightning-proof wire, the first section of lightning-proof wire is connected with a second section of lightning-proof wire through a connecting terminal, the second section of lightning-proof wire penetrates into a lightning-proof wire connecting pipe, and two ends