1 Scope
This document specifies additional requirements for the assessment of the external conditions of offshore wind turbine sites and basic design requirements to ensure the engineering integrity of stationary offshore wind turbines. The aim is to provide an appropriate level of protection against damage caused by various hazards during the expected lifetime of the wind turbine.
This document focuses on the engineering integrity of the structural components of an offshore wind turbine, but also addresses subsystems such as control and protection mechanisms, internal electrical systems and mechanical systems.
If the support structure of an offshore wind turbine is subject to hydrodynamic loads and is fixed to the seabed, then the turbine is a fixed offshore wind turbine. The design requirements in this document do not ensure the engineering integrity of floating offshore wind turbines. The design requirements for floating offshore wind turbines can be found in IEC 61400-3-2. The offshore wind turbines described in this document refer to fixed offshore wind turbines.
It is appropriate to use this document in conjunction with the applicable IEC and ISO standards referred to in Chapter 4. Particular attention is paid to the fact that this document is fully compliant with the requirements of IEC 61400-1. The safety class of offshore wind turbines designed by this document should be no less than IEC 61400-1. In some sections, IEC 614G01 has been reproduced in order to clearly describe the specified requirements.
2 Normative references
The contents of the following documents constitute essential provisions of this document by means of the normative G-pairs in the text. Where a reference is dated, only the version corresponding to that date applies to this document i Where a reference is not dated, the latest version (including all amendments) applies to this document.
ISO 2394 General principles on reliability for structures)
ISO 2533,1975 Standard atmosphere
ISO 19900 Petroleum and natural gas industries - General requirements for offshore structures
ISO 19901-1:2015 Petroleum and natural gas industries - Specific requirements for offshore structures - Part 1 : Meto-cean design and operating conditions
ISo 19901-4 Petroleum and natural gas industries - Specific requirements for offshore structures - Part 4: Geotechnical and foundation design considerations
ISo 19902 Petroleum and natural gas industries - Fixedsteel offshore structures
ISO 19903 Petroleum and natural gas industries - Fixed concrete offshore structures
IEC 61400-1:2019 Wind energy generation systems - Part 1: Designrequirements
IEC 60721 Classification of environmental condition
3 Terms and definitions
The terms defined in IEC 61400-1 and the following terms and definitions apply to this document.
4 Symbols and abbreviations
To facilitate understanding of the content of this document, the following symbols and abbreviations will be used in addition to those specified in IEC 61400-1.
5 Basic requirements
5.1 Overview
The engineering requirements given in the following clauses are intended to ensure the safety of the structure, mechanical systems, electrical systems and control systems of offshore wind turbines. These technical requirements apply to the design, manufacture, installation, operation and maintenance manuals and related quality management processes of wind turbines. In addition, the various safety procedures required for the installation, operation and maintenance of offshore wind turbines have been considered.
5.2 Design methods
This document requires the use of a structural dynamics model to predict design load effects. The model shall determine the load effects associated with all combinations of external conditions (specified in Chapter 6) and design states (specified in Chapter ?). This document defines the minimum relevant combinations as design load conditions.
The design of the support structure for an offshore wind turbine shall be based on site-specific external conditions and be consistent with the requirements specified in Chapter 6. These conditions should be summarised as design basics.
Where the initial design of the wind turbine - nacelle assembly of an offshore wind turbine is based on the standard class specified in IEC 61400-1:2019, 6.2, it shall be demonstrated that the site-specific external conditions at sea do not affect the structural integrity. This demonstration shall include a comparison between the results of the load and deformation calculations for the offshore wind turbine site and the initial design calculations, taking into account safety margins, environmental disturbances to the structure and the influence of the selected materials. In addition, the calculation of loads and deformations should consider the effect of site-specific soil properties on the dynamics of the offshore wind turbine and the potential long-term changes in dynamics due to seabed movement and scour.
6 Definition and assessment of external conditions
6.1 Overview
The external conditions specified in this chapter should be considered in the design of an offshore wind turbine.
The loads, service life and operation of offshore wind turbines are susceptible to environmental and electrical conditions as well as to the influence of nearby units. In order to ensure that appropriate safety and reliability requirements are met, environmental, grid and geological parameters should be considered in the design and should be detailed in the design documentation.
Environmental conditions are classified as wind conditions, marine conditions (waves, currents, water levels, sea ice/lake ice, sea life, seabed movement and scouring) and other environmental conditions. Electrical conditions refer to grid conditions. The design of offshore wind turbine foundations is related to soil characteristics, taking into account changes in soil properties over time due to seabed movement, scouring and other seabed instabilities.
Wind conditions are fundamental external conditions for determining the structural integrity of the wind turbine - nacelle assembly, although ocean conditions can have an impact on certain load conditions that relate to the dynamic characteristics of the supporting structure. In all cases (including those where ocean conditions are negligible in the design of the wind turbine-nacelle assembly), due consideration should be given to the ocean conditions at each particular site (i.e. the proposed location of the offshore wind turbine) when demonstrating structural integrity.
The design process for an offshore wind turbine is illustrated in Figure Peal. The assessment of the external conditions at a particular site is the first step in the design process and is the basis for the design. The definition and assessment of external conditions is provided in this chapter.
Other environmental conditions can also affect design characteristics such as control system function, durability, corrosion, etc.
External conditions can be divided into normal and extreme external conditions. Normal external conditions usually relate to recurring structural load conditions, while extreme external conditions represent rare external design conditions. The design load conditions should include possible critical combinations of these external conditions with different operating modes of the wind turbine and other design conditions.
7 Structural design
7.1 Overview
The structural integrity of the load-bearing components of the offshore wind turbine shall be verified and ensured to have an acceptable safety rating. The ultimate strength and fatigue strength of the structural components shall be verified by calculation, test or a combination of both to demonstrate that the structural integrity of the offshore wind turbine has an appropriate safety rating.
Structural analysis shall be carried out in accordance with ISO 2394.
Calculations shall be carried out using appropriate methods and a description of the calculation methods shall be provided in the design documentation. These descriptions should include evidence of the validity of the calculation method or references to the appropriate validation studies. The load levels in all strength verification tests should correspond to the safety factors applicable to the characteristic loads in 7.6.
Resonance characterisation of the support structure, wind turbine and drive chain shall be analysed to a minimum of 2 times the excitation range of the blade through the tonnage. For DLC 1.2, the possibility of resonance at 30% turbulence level for the NTM wind condition Class C design Ziz flow shall be analysed. If high resonance loads are found at low turbulence levels, measures should be taken to avoid resonance or to take it into account in the design loads.
7.2 Design methods
Model tests and prototype tests to verify that the limit states of the wind turbine are within the design limits specified in So 2394 can also be used instead of calculations to verify the soundness of the structural design.
Design calculations shall be based on validated methods and approved rules.
In accordance with IEC 61400-1, the model used for the design calculations shall be verified by means of load tests. The tests shall be carried out on onshore or offshore wind turbines that are similar in dynamic response and structure to the designed wind turbine, but where the details (e.g. interchangeable support structures) may differ. The load test requirements can be found in ISO 2394.
8 Control systems
The control system for the operation and safety of the offshore wind turbine shall comply with the requirements of IEC 61400-1.
To avoid exposure to the marine environment, all components of the control system and protection system should be adequately protected from the effects of the marine environment. See Appendix G for relevant corrosion protection guidelines.
In addition, the following provisions shall apply.
For reasons of personal safety, wind turbine rotation should be stopped, if necessary, by remote control prior to the arrival of personnel.
To ensure personal safety (during helicopter lifting operations or when avoiding collision between the blade tip and the vessel), the yaw system should be remotely operated and braked by the operator, if necessary, before the helicopter or vessel approaches the offshore wind turbine.
If braking by a system other than a locking device is used (e.g. yaw brake or mechanical disc brake>, measures should be taken to avoid any slippage. Appropriate indicators should be installed on the offshore wind turbine to inform approaching personnel that the wind turbine and yaw system are in braking mode.
If the wind turbine and yaw systems are automatically or remotely braked, measures should be taken to prevent these systems from being automatically or remotely restarted without the request of the operator in the wind turbine, in the helicopter or on board the vessel. Personnel in the wind turbine should be able to disable the automatic or remote restart function of the wind turbine and yaw system before entering the risk area. Appropriate annotations should be given in the relevant documentation.
9 Mechanical systems
For the purposes of this document, mechanical systems are systems that combine shafts, connecting rods, bearings, sliding parts, wheels and other equipment for use or transfer of relative motion, and do not include separate static structural or electrical components. The auxiliary components can be electrically, hydraulically or pneumatically operated. Good.
The mechanical system of an offshore wind turbine should be designed to meet the requirements of IEC 61400-1.
To prevent the mechanical system from being affected by the marine environment, provisions should be made for its proper protection. See Appendix G for relevant corrosion protection.
10 Electrical system
11 Foundation and substructure design
12 Assembly, installation and lifting
13 Commissioning operation and maintenance
Appendix A (informative) Key design parameters for offshore wind turbines -
Appendix B (Informative) Shallow water hydrodynamics and breaking waves
Appendix C (Informative) Guidelines for the calculation of hydrodynamic loads
Appendix D (Informative) Design recommendations for offshore wind turbine support nets under ice loads
Appendix E (Informative) Design of foundations and substructures for offshore wind turbines
Appendix F (Informative) Statistical extrapolation of marine meteorological operating parameters for ultimate strength analysis
Appendix G (informative) Corrosion protection
Appendix H (Informative) Prediction of extreme wave heights due to tropical cyclones
Appendix I (Informative) Recommendations for regional safety level adjustments for tropical cyclones...
Bibliography
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and abbreviations
5 Basic requirements
6 Definition and assessment of external conditions
7 Structural design
8 Control systems
9 Mechanical systems
10 Electrical system
11 Foundation and substructure design
12 Assembly, installation and lifting
13 Commissioning operation and maintenance
Appendix A (informative) Key design parameters for offshore wind turbines -
Appendix B (Informative) Shallow water hydrodynamics and breaking waves
Appendix C (Informative) Guidelines for the calculation of hydrodynamic loads
Appendix D (Informative) Design recommendations for offshore wind turbine support nets under ice loads
Appendix E (Informative) Design of foundations and substructures for offshore wind turbines
Appendix F (Informative) Statistical extrapolation of marine meteorological operating parameters for ultimate strength analysis
Appendix G (informative) Corrosion protection
Appendix H (Informative) Prediction of extreme wave heights due to tropical cyclones
Appendix I (Informative) Recommendations for regional safety level adjustments for tropical cyclones...
Bibliography
1范围
本文件规定了海上风力发电机组场址外部条件评估的附加要求﹐以及确保固定式海上风力发电机组工程完整性的基本设计要求。其目的是在风力发电机组的预期寿命期间,提供适当等级的防护,以防止各种危险对风力发电机组造成损害。
本文件重点关注海上风力发电机组各结构部件的工程完整性,同时也涉及各子系统,如控制和保护机构,内部电气系统以及机械系统。
如果海上风力发电机组的支撑结构承受水动力载荷并固定在海床上﹐那么该发电机组为固定式海上风力发电机组。本文件中的设计要求无法确保漂浮式海上风力发电机组的工程完整性。漂浮式海上风力发电机组设计要求参见IEC 61400-3-2。本文件所述海上风力发电机组是指固定式海上风力发电机组。
本文件宜与第2章中提到的适用的IEC、ISO标准一起使用。特别注意的是本文件完全符合IEC 61400-1 的要求。由本文件设计的海上风力发电机组的安全等级应不低于IEC 61400-1，在某些章节中,为了能清晰地描述规定的要求﹐复制了IEC 614G01的内容。
2规范性引用文件
下列文件中的内容通过文中的规范性G对而构成本文件必不可少的条款。其中,注日期的引用文件,仅该日期对应的版本适用于本文件i不注日期的引用文件,其最新版本(包括所有的修改单)适用于本文件。
ISO 2394结构可靠性的一般原则(General principles on reliability for structures)
ISO 2533,1975标准大气(Standard atmosphere)
ISO 19900石油天然气工业海洋结构的一般要求(Petroleum and natural gas industries - General requirements for offshore structures)
注:GB/T 23511-2021石油天然气工业﹑海洋结构的通用要求(ISO 19900.2019.IDT)
ISO 19901-1:2015石油天然气工业﹑海上结构的具体要求第1部分;海洋气象设计与运行条件(Petroleum and natural gas industries-Specific requirements for offshore structures - Part 1: Meto-cean design and operating conditions)
ISo 19901-4石油天然气工业海上结构的具体要求第4部分:岩土与基础设计要点(Petroleum and natural gas industries - Specific requirements for offshore structures - Part 4: Geotechnical and foundation design considerations)
ISo 19902石油天然气工业固定式海上钢结构(Petroleum and natural gas industries - Fixedsteel offshore structures)
ISO 19903石油天然气工业海上固定式混凝土结构(Petroleum and natural gas industries - Fixed concrete offshore structures)
IEC 61400-1:2019风力发电机组设计要求(Wind energy generation systems - Part 1: Designrequirements)
注:GB/T 18451.1-2012风力发电机组设计要求(IEC 61400-1 :2005, IDT)
IEC 60721(所有部分)环境条件等级(Classification of environmental condition)
3术语和定义
IEC61400-1界定的以及下列术语和定义适用于本文件。
4符号和缩略语
为便于理解本文件的内容,除IEC 61400-1规定的以外,还将使用以下符号和缩略语。
5基本要求
5.1概述
以下条款给出的工程技术要求是为了保证海上风力发电机组结构,机械系统、电气系统和控制系统的安全。这些技术要求适用于风力发电机组的设计,制造、安装,运行维修手册及相关的质量管理过程。此外,还考虑了海上风力发电机组安装、运行和维护中所要求的各种安全规程。
5.2设计方法
本文件要求使用结构动力学模型预测设计载荷效应。该模型应确定与外部条件(第6章规定)和设计状态(第﹖章规定)所有组合相关的载荷效应。本文件定义了最少的相关组合作为设计载荷工况。
海上风力发电机组支撑结构的设计应基于特定场址的外部条件,并与第6章规定的要求保持一致。上述条件应归纳为设计基本。
若海上风力发电机组风轮-机舱组件的最初设计是基于IEC 61400-1:2019中6.2规定的标准等级，则应证明海上特定场址的外部条件不会影响结构完整性。该证明应包括海上风力发电机组场址的载荷和变形计算结果与初始设计计算结果之间的比较,同时考虑安全裕度、环境对结构扰力以及所选材料的影响。此外,载荷和变形的计算还应考虑特定场址的土壤特性对海上风力发电机组动力学特性的影响，以及由于海床运动和冲刷引起的潜在的、长期的动力学特性变化。
6外部条件﹒定义和评估
6.1概述
在海上风力发电机组设计中,应考虑本章规定的外部条件。
海上风力发电机组的载荷﹑使用寿命和运行易受环境、电气条件以及附近机组的影响。为了确保满足适当的安全性及可靠性要求,设计中应考虑环境、电网和地质等参数,应在设计文件中予以详细说明。
环境条件分为风况,海洋条件(波浪,海流、水位,海冰/湖冰,海生物、海床运动和冲刷)和其他环境条件。电气条件指电网状况。海上风力发电机组基础的设计与土壤特征有关,需考虑由于海床运动,冲刷和其他海床不稳定性因素引起的土壤特性随时间的变化。
尽管海洋条件会对某些涉及支撑结构动力特性的载荷工况有影响,但风况是确定风轮-机舱组件结构完整性的基本外部条件。在所有情况下(包括海洋条件在风轮-机舱组件设计中忽略不计的情况)论证结构完整性时,均应适当考虑每个特定场址(即海上风力发电机组拟安装地点)的海洋条件。
图⒉所示为海上风力发电机组的设计过程。特定场址外部条件的评估是设计过程的第一步﹐也是设计的基础。本章对外部条件的定义和评估做出了规定。
其他环境条件也会影响设计特性,如控制系统功能、耐久性,腐蚀等。
外部条件可分为正常外部条件和极端外部条件。正常外部条件通常涉及重复出现的结构载荷条件,而极端外部条件则代表罕见的外部设计条件。设计载荷工况应包括这些外部条件与风力发电机组不同运行模式及其他设计条件下可能的临界组合。
7结构设计
7.1概述
应验证海上风力发电机组承载零部件的结构完整性,并确保其具有可接受的安全等级。结构部件的极限强度和疲劳强度应通过计算、试验或两者结合验证,以表明海上风力发电机组的结构完整性具有适当的安全等级。
结构分析应按照ISO 2394进行，
应采用适当的方法进行计算﹐并在设计文件中提供计算方法的说明。这些说明应包括计算方法有效性的证据﹐或相应验证研究的参考文献。所有强度验证试验中的载荷水平应与7.6中适用于特征载荷的安全系数相对应。
支撑结构、风轮和传动链的共振特性分析应至少达到2倍叶片通过顿率的激振范围。对于 DLC 1.2，应分析在NTM风况C类设计淄流的30%湍流水平下发生共振的可能。如果在低湍流度下发现高共振载荷,应采取措施避免共振或者将其考虑到设计载荷内。
7.2设计方法
应验证风力发电机组的极限状态未超出设计范雨So 2394规定的模型试验和样机试验也可代替计算来验证结构设计的合理性。
设计计算应基于已验证过的方法和认可的r则。
按照 IEC 61400-1,用于设计计算的模型邸通过载荷测试进行验证。测试应在和设计的风力发电机组在动态响应和结构上相似但是细节(例a,可替换的支撑结构)可能不同的陆上或海上风力发电机组上进行。载荷测试要求可参考ISO 2394.
8控制系统
海上风力发电机组运行与安全的控制系统应符合IEC 61400-1的要求。
为避免受到海洋环境影响,应对控制系统和保护系统的所有部件进行充分防护,避免受到海洋环境的影响。相关腐蚀防护指南参见附录G。
此外,以下规定应适用。
出于人身安全考虑,必要时,应在人员抵达前通过远程控制停止风轮转动。
为确保人身安全(直升机起重操作时或叶尖与船舶避免碰撞时),必要时,应在直升机或船舶接近海上风力发电机组前由操作员对偏航系统进行远程操控和制动。
如果采用锁定装置外的其他系统制动(如偏航制动或机械盘制动>,应采取措施避免任何滑移。应在海上风力发电机组上安装适当的指示器,从而将风轮和偏航系统已处于制动状态的消息通知靠近的人员。
如果风轮与偏航系统采用自动或远程制动,应采取措施防止这些系统未经风力发电机组内、直升机或船舶中的操作人员的请求而自动或远程重启。风力发电机组内的人员应能在进入风险区域前禁用风轮与偏航系统的自动或远程重启功能。应在相关的文件中给予适当的注释说明。
9机械系统
本文件中,机械系统指将轴,连杆、轴承,滑动部作,出轮和其他设备结合起来使用或传递相对运动的系统,不包括独立的静态结构零件或电气零件、在风力发电机组内部,上述系统可包括传动链中各部件(如齿轮箱、传动轴和联轴器),以及辅助部维《如u制动装置,叶片变桨控制装置和偏航驱动装置等)，辅助部件可由电力、液压或气动方式进行骗.好。
海上风力发电机组的机械系统设读应满足IEC 61400-1的要求。
为避免机械系统受到海洋环境的影响﹐应制定相关规定对其进行适当保护。相关防腐蚀内容参见附录G。
10电气系统
11基础和下部结构设计
12组装,安装和吊装
13调试运行和维护
附录A(资料性)海上风力发电机组关键设计参数·
附录B(资料性)浅水流体力学和破碎波
附录C(资料性)水动力载荷计算导则
附录D(资料性)冰载作用下海上风力发电机组支撑结网的设计建议
附录E(资料性)海上风力发电机组的基础及下部支撑结构设计
附录F(资料性)用于极限强度分析的海洋气象运行参数的统计外推
附录G（资料性）腐蚀防护
附录H(资料性)热带气旋引起的极大波高预测
附录I(资料性)对热带气旋区域安全等级调整的建议…
参考文献
