scholarly journals Lightning protection of wind turbines – a comparison of measured data with required protection levels

2011 ◽  
Vol 5 (1) ◽  
pp. 48 ◽  
Author(s):  
V. Peesapati ◽  
I. Cotton ◽  
T. Sorensen ◽  
T. Krogh ◽  
N. Kokkinos
Keyword(s):  
Wind Turbines ◽  
Measured Data ◽  
Lightning Protection

Aeroelastic Analysis of NREL Wind Turbine

2017 ◽  
Author(s):  
Yaozhi Lu ◽  
Fanzhou Zhao ◽  
Loic Salles ◽  
Mehdi Vahdati
Keyword(s):  
Numerical Model ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Gas Turbines ◽  
High Cycle Fatigue ◽  
Turbine Blades ◽  
Measured Data ◽  
Forced Response ◽  
Cycle Fatigue ◽  
Aeroelastic Analysis

The current development of wind turbines is moving toward larger and more flexible units, which can make them prone to fatigue damage induced by aeroelastic vibrations. The estimation of the total life of the composite components in a wind turbine requires the knowledge of both low and high cycle fatigue (LCF and HCF) data. The first aim of this study is to produce a validated numerical model, which can be used for aeroelastic analysis of wind turbines and is capable of estimating the LCF and HCF loads on the blade. The second aim of this work is to use the validated numerical model to assess the effects of extreme environmental conditions (such as high wind speeds) and rotor over-speed on low and high cycle fatigue. Numerical modelling of this project is carried out using the Computational Fluid Dynamics (CFD) & aeroelasticity code AU3D, which is written at Imperial College and developed over many years with the support from Rolls-Royce. This code has been validated extensively for unsteady aerodynamic and aeroelastic analysis of high-speed flows in gas turbines, yet, has not been used for low-speed flows around wind turbine blades. Therefore, in the first place the capability of this code for predicting steady and unsteady flows over wind turbines is studied. The test case used for this purpose is the Phase VI wind turbine from the National Renewable Energy Laboratory (NREL), which has extensive steady, unsteady and mechanical measured data. From the aerodynamic viewpoint of this study, AU3D results correlated well with the measured data for both steady and unsteady flow variables, which indicated that the code is capable of calculating the correct flow at low speeds for wind turbines. The aeroelastic results showed that increase in crosswind and shaft speed would result in an increase of unsteady loading on the blade which could decrease the lifespan of a wind turbine due to HCF. Shaft overspeed leads to significant increase in steady loading which affects the LCF behaviour. Moreover, the introduction of crosswind could result in significant dynamic vibration due to forced response at resonance.

scholarly journals Earth-termination system for onshore wind Turbines.

2020 ◽  
Vol 11 (7-2020) ◽  
pp. 66-72
Author(s):  
Liubov A. Belova ◽  
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Lightning Strike ◽  
Lightning Protection ◽  
Protection Measures ◽  
Lightning Strikes ◽  
Grounding System ◽  
Initial Stage ◽  
Wind Turbine Towers ◽  
Surge Protection

The earth-termination system for towers of ground-based wind turbines in addition to protective and functional grounding provides lightning protection grounding, which is especially important since the wind turbine is susceptible to lightning strikes. If insufficient protective measures are taken, the risk of damage to a wind turbine due to a lightning strike increases. Therefore, a well-thought-out built-in grounding system for wind turbine towers is needed, which would function as necessary and guarantee long-term mechanical strength and corrosion resistance. The configuration of grounding systems for wind turbines is discussed in IEC 61400-24, which deals with the topic of lightning protection for wind turbines, including detailed information on the choice of lightning protection measures and surge protection. It is advisable to create a lightning protection concept at the initial stage of planning a wind turbine in order to avoid later costly repairs and retrofitting.

A204 Lightning Protection of Wind Turbines

2012 ◽  
Vol 2012.17 (0) ◽  
pp. 219-222
Author(s):  
Masaru IDENO ◽  
Keita SAGARA ◽  
Kzuichi SEKI
Keyword(s):  
Wind Turbines ◽  
Lightning Protection

STUDYING THE EFFECT OF THE SCHEME OF EXPOSURE TO MICROWAVE ELECTROMAGNETIC FIELDS ON THE HARDNESS OF THE CURED CARBON FIBER-REINFORCED PLASTIC WITH LIGHTNING-PROTECTION GRID APPLIED ON ITS SURFACE

2020 ◽  
Vol 0 (4) ◽  
pp. 12-18
Author(s):  
I.V. ZLOBINA ◽  
Keyword(s):  
Electromagnetic Field ◽  
Carbon Fiber ◽  
Wind Turbines ◽  
Field Research ◽  
Carbon Plastic ◽  
Lightning Protection ◽  
Fiber Reinforced ◽  
Short Term ◽  
Short Term Exposure ◽  
Carbon Fiber Reinforced

Currently, the use of fiber-reinforced polymer composite materials (PCM), in particular, carbon plastic and fiberglass, is much promising in manufacturing structural elements of aircrafts and wind turbines. In order to increase the resistance of these materials to static electricity and lightning strikes when passing storm fronts, the structure of the PCM includes various lightning protection coatings (LPC). The most common LPC are in the form of copper grids. The fin assembly and planes of aircrafts and also large-sized blades of wind turbines are exposed to cyclic high-amplitude and low-frequency bending loads as well as vibrations. Collisions with solid objects are quite possible. Thus, hardness is one of the key characteristics of PCM that determines their performance properties. Strength and endurance of PCM components can be increased by short-term exposure to a microwave electromagnetic field. The presence of a built-in metallic structure brings additional uncertainty in the tolerance to operating loads by anisotropic PCM, as well as in the process of their interaction with an ultrahigh frequency electromagnetic field. Research was performed on the hardness of carbon fiber-reinforced plastics with built-in LPC using various exposure schemes to a microwave electromagnetic field: from the side of the LPC, from the side opposite to the LPC and sequential processing from both sides. It was found that short-term processing in a microwave electromagnetic field with energy flux density of (17-18)×104mW/cm2 did not lead to any change in the initial hardness of the surface of the samples. However, the uniformity of hardness distribution on the surface of the samples in- creased by 35.8-70%, thus ensuring a more adequate tolerance to loads of different nature. The obtained results can be used in the development of finishing technologies to post-process PCM components and improve the latter’s stability to dynamic loading.

scholarly journals Lightning protection for wind turbines in Vietnam

2017 ◽  
Vol 7 (1) ◽  
pp. 29-33 ◽  
Author(s):  
Thuan Nguyen ◽  
Thinh Pham ◽  
Top V. Tran ◽  
Thang Huu Tran
Keyword(s):  
Wind Turbines ◽  
Lightning Protection

scholarly journals Lightning protection of wind turbines.

2020 ◽  
Vol 11 (7-2020) ◽  
pp. 32-40
Author(s):  
Liubov A. Belova ◽  
Keyword(s):  
Developing Countries ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Lightning Strike ◽  
Lightning Protection ◽  
Reliable Operation

Damage from a lightning strike is the cause of 25% of accidents and breakdowns of wind turbines. To reduce wind turbine damage from lightning and to ensure overall safety around wind turbines, it is important to improve the performance of wind turbines associated with lightning protection and minimize the likelihood of damage to them. The experience of developing countries, actively replenishing the base of windturbines, has led to progress in technologies for the application of countermeasures in the field of wind energy. This article presents the latest trends in technology for reliable operation of wind turbines in thunderstorms.

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