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范圍
本文件規定了海上風力發電機組場址外部條件評估的附加要求﹐以及確保固定式海上風力發電機組工程完整性的基本設計要求。其目的是在風力發電機組的預期壽命期間,提供適當等級的防護,以防止各種危險對風力發電機組造成損害。
本文件重點關注海上風力發電機組各結構部件的工程完整性,同時也涉及各子系統,如控制和保護機構,內部電氣系統以及機械系統。
如果海上風力發電機組的支撐結構承受水動力載荷并固定在海床上﹐那么該發電機組為固定式海上風力發電機組。本文件中的設計要求無法確保漂浮式海上風力發電機組的工程完整性。漂浮式海上風力發電機組設計要求參見IEC 61400-3-2。本文件所述海上風力發電機組是指固定式海上風力發電機組。
本文件宜與第2章中提到的適用的IEC、ISO標準一起使用。特別注意的是本文件完全符合IEC 61400-1 的要求。由本文件設計的海上風力發電機組的安全等級應不低于IEC 61400-1，在某些章節中,為了能清晰地描述規定的要求﹐復制了IEC 614G01的內容。
2規范性引用文件
下列文件中的內容通過文中的規范性G對而構成本文件必不可少的條款。其中,注日期的引用文件,僅該日期對應的版本適用于本文件i不注日期的引用文件,其最新版本(包括所有的修改單)適用于本文件。
ISO 2394結構可靠性的一般原則(General principles on reliability for structures)
ISO 2533,1975標準大氣(Standard atmosphere)
ISO 19900石油天然氣工業海洋結構的一般要求(Petroleum and natural gas industries - General requirements for offshore structures)
注:GB/T 23511-2021石油天然氣工業﹑海洋結構的通用要求(ISO 19900.2019.IDT)
ISO 19901-1:2015石油天然氣工業﹑海上結構的具體要求第1部分;海洋氣象設計與運行條件(Petroleum and natural gas industries-Specific requirements for offshore structures - Part 1: Meto-cean design and operating conditions)
ISo 19901-4石油天然氣工業海上結構的具體要求第4部分:巖土與基礎設計要點(Petroleum and natural gas industries - Specific requirements for offshore structures - Part 4: Geotechnical and foundation design considerations)
ISo 19902石油天然氣工業固定式海上鋼結構(Petroleum and natural gas industries - Fixedsteel offshore structures)
ISO 19903石油天然氣工業海上固定式混凝土結構(Petroleum and natural gas industries - Fixed concrete offshore structures)
IEC 61400-1:2019風力發電機組設計要求(Wind energy generation systems - Part 1: Designrequirements)
注:GB/T 18451.1-2012風力發電機組設計要求(IEC 61400-1 :2005, IDT)
IEC 60721(所有部分)環境條件等級(Classification of environmental condition)
3術語和定義
IEC61400-1界定的以及下列術語和定義適用于本文件。
4符號和縮略語
為便于理解本文件的內容,除IEC 61400-1規定的以外,還將使用以下符號和縮略語。
5基本要求
5.1概述
以下條款給出的工程技術要求是為了保證海上風力發電機組結構,機械系統、電氣系統和控制系統的安全。這些技術要求適用于風力發電機組的設計,制造、安裝,運行維修手冊及相關的質量管理過程。此外,還考慮了海上風力發電機組安裝、運行和維護中所要求的各種安全規程。
5.2設計方法
本文件要求使用結構動力學模型預測設計載荷效應。該模型應確定與外部條件(第6章規定)和設計狀態(第﹖章規定)所有組合相關的載荷效應。本文件定義了最少的相關組合作為設計載荷工況。
海上風力發電機組支撐結構的設計應基于特定場址的外部條件,并與第6章規定的要求保持一致。上述條件應歸納為設計基本。
若海上風力發電機組風輪-機艙組件的最初設計是基于IEC 61400-1:2019中6.2規定的標準等級，則應證明海上特定場址的外部條件不會影響結構完整性。該證明應包括海上風力發電機組場址的載荷和變形計算結果與初始設計計算結果之間的比較,同時考慮安全裕度、環境對結構擾力以及所選材料的影響。此外,載荷和變形的計算還應考慮特定場址的土壤特性對海上風力發電機組動力學特性的影響，以及由于海床運動和沖刷引起的潛在的、長期的動力學特性變化。
6外部條件﹒定義和評估
6.1概述
在海上風力發電機組設計中,應考慮本章規定的外部條件。
海上風力發電機組的載荷﹑使用壽命和運行易受環境、電氣條件以及附近機組的影響。為了確保滿足適當的安全性及可靠性要求,設計中應考慮環境、電網和地質等參數,應在設計文件中予以詳細說明。
環境條件分為風況,海洋條件(波浪,海流、水位,海冰/湖冰,海生物、海床運動和沖刷)和其他環境條件。電氣條件指電網狀況。海上風力發電機組基礎的設計與土壤特征有關,需考慮由于海床運動,沖刷和其他海床不穩定性因素引起的土壤特性隨時間的變化。
盡管海洋條件會對某些涉及支撐結構動力特性的載荷工況有影響,但風況是確定風輪-機艙組件結構完整性的基本外部條件。在所有情況下(包括海洋條件在風輪-機艙組件設計中忽略不計的情況)論證結構完整性時,均應適當考慮每個特定場址(即海上風力發電機組擬安裝地點)的海洋條件。
圖⒉所示為海上風力發電機組的設計過程。特定場址外部條件的評估是設計過程的第一步﹐也是設計的基礎。本章對外部條件的定義和評估做出了規定。
其他環境條件也會影響設計特性,如控制系統功能、耐久性,腐蝕等。
外部條件可分為正常外部條件和極端外部條件。正常外部條件通常涉及重復出現的結構載荷條件,而極端外部條件則代表罕見的外部設計條件。設計載荷工況應包括這些外部條件與風力發電機組不同運行模式及其他設計條件下可能的臨界組合。
7結構設計
7.1概述
應驗證海上風力發電機組承載零部件的結構完整性,并確保其具有可接受的安全等級。結構部件的極限強度和疲勞強度應通過計算、試驗或兩者結合驗證,以表明海上風力發電機組的結構完整性具有適當的安全等級。
結構分析應按照ISO 2394進行，
應采用適當的方法進行計算﹐并在設計文件中提供計算方法的說明。這些說明應包括計算方法有效性的證據﹐或相應驗證研究的參考文獻。所有強度驗證試驗中的載荷水平應與7.6中適用于特征載荷的安全系數相對應。
支撐結構、風輪和傳動鏈的共振特性分析應至少達到2倍葉片通過頓率的激振范圍。對于 DLC 1.2，應分析在NTM風況C類設計淄流的30%湍流水平下發生共振的可能。如果在低湍流度下發現高共振載荷,應采取措施避免共振或者將其考慮到設計載荷內。
7.2設計方法
應驗證風力發電機組的極限狀態未超出設計范雨So 2394規定的模型試驗和樣機試驗也可代替計算來驗證結構設計的合理性。
設計計算應基于已驗證過的方法和認可的r則。
按照 IEC 61400-1,用于設計計算的模型邸通過載荷測試進行驗證。測試應在和設計的風力發電機組在動態響應和結構上相似但是細節(例a,可替換的支撐結構)可能不同的陸上或海上風力發電機組上進行。載荷測試要求可參考ISO 2394.
8控制系統
海上風力發電機組運行與安全的控制系統應符合IEC 61400-1的要求。
為避免受到海洋環境影響,應對控制系統和保護系統的所有部件進行充分防護,避免受到海洋環境的影響。相關腐蝕防護指南參見附錄G。
此外,以下規定應適用。
出于人身安全考慮,必要時,應在人員抵達前通過遠程控制停止風輪轉動。
為確保人身安全(直升機起重操作時或葉尖與船舶避免碰撞時),必要時,應在直升機或船舶接近海上風力發電機組前由操作員對偏航系統進行遠程操控和制動。
如果采用鎖定裝置外的其他系統制動(如偏航制動或機械盤制動>,應采取措施避免任何滑移。應在海上風力發電機組上安裝適當的指示器,從而將風輪和偏航系統已處于制動狀態的消息通知靠近的人員。
如果風輪與偏航系統采用自動或遠程制動,應采取措施防止這些系統未經風力發電機組內、直升機或船舶中的操作人員的請求而自動或遠程重啟。風力發電機組內的人員應能在進入風險區域前禁用風輪與偏航系統的自動或遠程重啟功能。應在相關的文件中給予適當的注釋說明。
9機械系統
本文件中,機械系統指將軸,連桿、軸承,滑動部作,出輪和其他設備結合起來使用或傳遞相對運動的系統,不包括獨立的靜態結構零件或電氣零件、在風力發電機組內部,上述系統可包括傳動鏈中各部件(如齒輪箱、傳動軸和聯軸器),以及輔助部維《如u制動裝置,葉片變槳控制裝置和偏航驅動裝置等)，輔助部件可由電力、液壓或氣動方式進行騙.好。
海上風力發電機組的機械系統設讀應滿足IEC 61400-1的要求。
為避免機械系統受到海洋環境的影響﹐應制定相關規定對其進行適當保護。相關防腐蝕內容參見附錄G。
10電氣系統
11基礎和下部結構設計
12組裝,安裝和吊裝
13調試運行和維護
附錄A(資料性)海上風力發電機組關鍵設計參數·
附錄B(資料性)淺水流體力學和破碎波
附錄C(資料性)水動力載荷計算導則
附錄D(資料性)冰載作用下海上風力發電機組支撐結網的設計建議
附錄E(資料性)海上風力發電機組的基礎及下部支撐結構設計
附錄F(資料性)用于極限強度分析的海洋氣象運行參數的統計外推
附錄G（資料性）腐蝕防護
附錄H(資料性)熱帶氣旋引起的極大波高預測
附錄I(資料性)對熱帶氣旋區域安全等級調整的建議…
參考文獻
