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BS EN IEC 61400-3-1:2019 Wind energy generation systems - Design requirements for fixed offshore wind turbines, 2019
- undefined
- CONTENTS
- FOREWORD
- INTRODUCTION
- 1 Scope
- 2 Normative references
- 3 Terms and definitions
- Figures [Go to Page]
- Figure 1 – Parts of a fixed offshore wind turbine
- 4 Symbols and abbreviated terms [Go to Page]
- 4.1 Symbols and units
- 4.2 Abbreviations
- 5 Principal elements [Go to Page]
- 5.1 General
- 5.2 Design methods
- 5.3 Safety classes
- 5.4 Quality assurance
- Figure 2 – Design process for an offshore wind turbine
- 5.5 Rotor–nacelle assembly markings
- 6 External conditions – definition and assessment [Go to Page]
- 6.1 General
- 6.2 Wind turbine classes
- 6.3 Definition of external conditions at an offshore wind turbine site [Go to Page]
- 6.3.1 General
- 6.3.2 Wind conditions
- 6.3.3 Marine conditions
- Figure 3 – Definition of water levels [Go to Page]
- 6.3.4 Electrical power network conditions
- 6.3.5 Other environmental conditions
- 6.4 Assessment of external conditions at an offshore wind turbine site [Go to Page]
- 6.4.1 General
- 6.4.2 The metocean database
- 6.4.3 Assessment of wind conditions
- Tables [Go to Page]
- Table 1 – Conversion between extreme wind speeds of different averaging periods [Go to Page]
- 6.4.4 Assessment of marine conditions
- 6.4.5 Assessment of other environmental conditions
- 6.4.6 Assessment of electrical network conditions
- 6.4.7 Assessment of soil conditions
- 7 Structural design [Go to Page]
- 7.1 General
- 7.2 Design methodology
- 7.3 Loads [Go to Page]
- 7.3.1 General
- 7.3.2 Gravitational and inertial loads
- 7.3.3 Aerodynamic loads
- 7.3.4 Actuation loads
- 7.3.5 Hydrodynamic loads
- 7.3.6 Sea/lake ice loads
- 7.3.7 Other loads
- 7.4 Design situations and load cases [Go to Page]
- 7.4.1 General
- Table 2 – Design load cases [Go to Page]
- 7.4.2 Power production (DLC 1.1 to 1.6)
- 7.4.3 Power production plus occurrence of fault or loss of electrical network connection (DLC 2.1 – 2.5)
- 7.4.4 Start up (DLC 3.1 to 3.3)
- 7.4.5 Normal shutdown (DLC 4.1 to 4.2)
- 7.4.6 Emergency stop (DLC 5.1)
- 7.4.7 Parked (standstill or idling) (DLC 6.1 to 6.4)
- 7.4.8 Parked plus fault conditions (DLC 7.1 to 7.2)
- 7.4.9 Transport, assembly, maintenance and repair (DLC 8.1 to 8.4)
- 7.4.10 Sea/lake ice design load cases
- 7.5 Load and load effect calculations [Go to Page]
- 7.5.1 General
- 7.5.2 Relevance of hydrodynamic loads
- Table 3 – Design load cases for sea/lake ice [Go to Page]
- 7.5.3 Calculation of hydrodynamic loads
- 7.5.4 Calculation of sea/lake ice loads
- 7.5.5 Overall damping assessment for support structure response evaluations
- 7.5.6 Simulation requirements
- 7.5.7 Other requirements
- 7.6 Ultimate limit state analysis [Go to Page]
- 7.6.1 Method
- Figure 4 – The two approaches to calculate the design load effect [Go to Page]
- 7.6.2 Ultimate strength analysis
- 7.6.3 Fatigue failure
- 7.6.4 Special partial safety factors
- 7.6.5 Assessment of cyclic loading for foundation assessment
- 8 Control system
- 9 Mechanical systems
- 10 Electrical system
- 11 Foundation and substructure design
- 12 Assembly, installation and erection [Go to Page]
- 12.1 General
- 12.2 Planning
- 12.3 Installation conditions
- 12.4 Site access
- 12.5 Environmental conditions
- 12.6 Documentation
- 12.7 Receiving, handling and storage
- 12.8 Support structure systems
- 12.9 Assembly of offshore wind turbine
- 12.10 Erection of offshore wind turbine
- 12.11 Fasteners and attachments
- 12.12 Cranes, hoists and lifting equipment
- 13 Commissioning, operation and maintenance [Go to Page]
- 13.1 General
- 13.2 Design requirements for safe operation, inspection and maintenance
- 13.3 Instructions concerning commissioning [Go to Page]
- 13.3.1 General
- 13.3.2 Energization
- 13.3.3 Commissioning tests
- 13.3.4 Records
- 13.3.5 Post commissioning activities
- 13.4 Operator’s instruction manual [Go to Page]
- 13.4.1 General
- 13.4.2 Instructions for operations and maintenance record
- 13.4.3 Instructions for unscheduled automatic shutdown
- 13.4.4 Instructions for diminished reliability
- 13.4.5 Work procedures plan
- 13.4.6 Emergency procedures plan
- 13.5 Maintenance manual
- Annex A (informative)Key design parameters for an offshore wind turbine [Go to Page]
- A.1 Offshore wind turbine identifiers [Go to Page]
- A.1.1 General
- A.1.2 Rotor-nacelle assembly (machine) parameters
- A.1.3 Support structure parameters
- A.1.4 Wind conditions (based on a 10-min reference period and including wind farm wake effects where relevant)
- A.1.5 Marine conditions (based on a 3-hour reference period where relevant)
- A.1.6 Electrical network conditions at turbine
- A.2 Other environmental conditions
- A.3 Limiting conditions for transport, erection and maintenance
- Annex B (informative)Shallow water hydrodynamics and breaking waves [Go to Page]
- B.1 Selection of suitable wave theories
- Figure B.1 – Regular wave theory selection diagram
- B.2 Modelling of irregular wave trains
- B.3 Wave height distributions [Go to Page]
- B.3.1 General
- B.3.2 The Goda model for maximum wave height
- B.3.3 The Battjes and Groenendijk wave height distribution
- Table B.1 – Constants h1 and h2 andnormalised wave heights hx % as a function of Htr [Go to Page]
- B.3.4 The Forristall wave and crest height distributions
- B.4 Breaking waves
- Figure B.2 – Comparison of wave height distribution results
- Table B.2 – Breaking wave type
- B.5 Reference documents
- Annex C (informative)Guidance on calculation of hydrodynamic loads [Go to Page]
- C.1 General
- C.2 Morison’s equation
- C.3 Diffraction
- C.4 Slap and slam loading
- Figure C.1 – Breaking wave and cylinder parameters
- Figure C.2 – Oblique inflow parameters
- C.5 Vortex-induced vibrations [Go to Page]
- C.5.1 General
- Figure C.3 – Distribution over height of the maximum impact line force (γ = 0°) [Go to Page]
- C.5.2 Critical velocities for cross-flow motion
- C.5.3 Critical velocities for in-line motion
- Figure C.4 – Response of model and full-scale cylinder in-line and cross-flow
- C.6 Appurtenances [Go to Page]
- C.6.1 General
- C.6.2 Alternative method for estimating hydrodynamic coefficients accounting for appurtenances and marine growth
- Figure C.5 – Geometrical definition of blocking and shielding
- Figure C.6 – Influence of a fixed boundary on the drag coefficient on a circular cylinder in oscillatory supercritical flow KC > 20, Re = 105 – 2 x 106
- Figure C.7 – Shielding factors
- C.7 Calculation methods [Go to Page]
- C.7.1 General
- Figure C.8 – Recommended value for the added mass coefficient Cmof a circular cylinder; influence of a fixed boundary [Go to Page]
- C.7.2 Explicit approach
- C.7.3 Constrained wave approach
- C.8 Reference documents
- Annex D (informative)Recommendations for design of offshore wind turbinesupport structures with respect to ice loads [Go to Page]
- D.1 Introductory remarks
- D.2 General
- D.3 Choice of ice thickness
- D.4 Load cases [Go to Page]
- D.4.1 General
- D.4.2 Horizontal load from fast ice cover originating from temperature fluctuations (DLC D1)
- D.4.3 Horizontal load from fast ice cover originating from water level fluctuations and arch effect (DLC D2)
- D.4.4 Horizontal load from moving ice (DLC D3, D4, D7 and D8)
- Figure D.1 – Ice force coefficients for plastic limit analysis [Go to Page]
- D.4.5 Vertical load from fast ice cover (DLC D5)
- D.4.6 Pressure from ice ridges (DLC D6)
- D.4.7 Dynamic loading (DLC D3, D4, D7, and D8)
- Figure D.2 – Ice load history for frequency lock-in conditions
- Figure D.3 – Time history of horizontal force componentof ice load acting on a conical structure
- D.5 Requirements on stochastic simulation
- D.6 Requirements on model testing
- D.7 Reference documents
- D.8 Databases for ice conditions
- Annex E (informative)Offshore wind turbine foundation and substructure design
- Annex F (informative)Statistical extrapolation of operational metocean parameters for ultimate strength analysis [Go to Page]
- F.1 General
- F.2 Use of IFORM to determine 50-yr significant wave height conditional on mean wind speed
- Figure F.1 – Example of the construction of the 50-year environmental contour for a 3-hour sea state duration.
- F.3 Examples of joint distributions of V and Hs and approximations to the environmental contour
- F.4 Choice of sea state duration
- F.5 Determination of the extreme individual wave height to be embedded in SSS
- F.6 Reference documents
- Annex G (informative)Corrosion protection [Go to Page]
- G.1 General
- G.2 The marine environment
- G.3 Corrosion protection considerations
- G.4 Corrosion protection systems – Support structures
- G.5 Corrosion protection in the rotor–nacelle assembly
- G.6 Reference documents
- Annex H (informative)Prediction of extreme wave heights during tropical cyclones [Go to Page]
- H.1 General
- H.2 Wind field estimation for tropical cyclones
- H.3 Wave estimation for tropical cyclones
- H.4 Reference documents
- H.5 Databases for tropical storms conditions
- Annex I (informative)Recommendations for alignment of safety levels in tropical cyclone regions [Go to Page]
- I.1 General
- I.2 Global robustness level criteria
- I.3 Design load cases
- Table I.1 – Additional load cases for tropical cyclone affected regions
- Bibliography [Go to Page]