IEC WIND TURBINES – PART 1: DESIGN REQUIREMENTS. You may have heard that IEC defines wind turbine classes with labels like IIIB, where the roman number refers to a reference wind speed and the index letter. IEC. Second edition. Wind turbine generator systems –. Part 1 : Safety requirements. Aérogénérateurs –. Partie 1: Spécifications de sécurité.
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Please help to improve this article by introducing more precise citations. Variable atmospheric stability, unsteady wind, and directional variation of upwind terrain will introduce variations in observed turbulence intensity. Views Read Edit View history. Aeroelastic simulations are processed for all IEC load cases, and turbine safety is verified for each of the deterministic load cases. The effective turbulence intensity includes added turbulence from wakes of neighbour turbines, and a simple wake turbulence model is provided.
IEC site assessment criteria. Material damage has a 64100-1 non-linearly relation to load amplitudes and thus to turbulence intensity, so a few situations with extreme turbulence may cause most of the fatigue damage.
In Canada, the previous national standards were outdated and impeded the wind industry, and they were updated and harmonized with by the Canadian Standards Association with several modifications. The is a set of design requirements made to ifc that wind turbines are appropriately engineered against damage from hazards within the planned lifetime. Depending on the load case, the wind interacting with the turbine is either deterministic or a pseudo-random wind field with realistic turbulence characteristics.
Turbine classes are determined by three parameters – the average wind speed, extreme year iev, and turbulence. Turbulence intensity quantifies how much the wind varies typically within 10 minutes. It is also possible to use the IEC standard for turbines of less than m 2 swept area. The load type is either an ultimate load, which might instantly damage the turbine, or a fatigue load.
This imposes simple limits on fifty-year extreme wind, flow inclination and wind shear, see Figure 1, whereas turbulence assessment is more complicated.
Retrieved from ” https: Wind classes determine which turbine is suitable for the normal wind conditions of a particular site. Wind load models are scaled differently for each wind turbine class, thus a class I A turbine 661400-1 tested for higher extreme wind speed and more severe turbulence than a class II B turbine.
You may have heard that IEC defines wind turbine classes with labels like III B61040-1 the roman number refers to a reference wind speed and the index letter refers to a turbulence category. List of International Electrotechnical Commission standards. This variation will generally decrease with wind speed, and the IEC normal turbulence model NTM accounts for this effect. In flat terrain the wind speed increases logarithmically with height.
Turbine designers will typically model turbine vibrations and dynamic forces on critical components by aeroelastic simulation programs such as HAWC2. Wind conditions are specified by extreme wind speed, vertical wind shear, flow inclination, turbulence and rare gust-like events. For small wind turbines the global industry has 611400-1 working towards harmonisation of certification requirements 61400-11 a “test once, certify everywhere” objective.
This article includes a list of referencesrelated reading or external linksbut its sources remain unclear because it lacks inline citations.
The standard concerns most aspects of the turbine life from site conditions before construction, to turbine components being tested,  assembled and operated. During the construction and design phase assumptions are made about the wind climate that the wind turbines will be exposed to. From Wikipedia, the free encyclopedia. The IEC turbine safety standard.
In addition, the accumulated fatigue damage caused by stochastic forcing is evaluated for a design life time of twenty years and compared to the material strength. The siting engineer must verify the safety of the deployed turbines.
IEC – Wikipedia
IEC started standardizing international certification on the subject inand the first standard appeared in Wind turbines are designed irc specific conditions. Wind turbines are capital intensive, and are usually purchased before they are being erected and commissioned. Archived from the original on 7 October Therefore, the IEC standard applies a representative turbulence intensity for turbine classification, which is defined 61040-1 a high percentile of the expected natural variation.
In complex terrain the wind profile is not a simple increase and additionally a separation of the flow might occur, leading to heavily increased turbulence. The common set of standards sometimes replace the various national standards, forming a basis for global certification.
The IEC 61400-1 turbine safety standard
Retrieved 14 March Because the fatigue loads of a number of major components in a wind turbine are mainly caused by turbulence, the knowledge of how turbulent a site is of crucial importance.
It is, however, simpler to apply the site-assessment rules specified in another chapter of IEC Examples of modes of operation are normal operation, idling, and operation with yaw error. This page was last edited on 26 Septemberat Each load case is specified by combinations of mode of turbine operation, wind conditions, and load type.