BS EN 61400-3:2009 Wind turbines. Design requirements for offshore wind turbines
BS EN 61400-3 specifies additional requirements for assessment of the external conditions at an offshore wind turbine site and it specifies essential design requirements to ensure the engineering integrity of offshore wind turbines. Its purpose is to provide an appropriate level of protection against damage from all hazards during the planned lifetime.
BS EN 61400-3 focuses on the engineering integrity of the structural components of an offshore wind turbine but is also concerned with subsystems such as control and protection mechanisms, internal electrical systems and mechanical systems.
A wind turbine shall be considered as an offshore wind turbine if the support structure is subject to hydrodynamic loading. The design requirements specified in BS EN 61400-3 are not necessarily sufficient to ensure the engineering integrity of floating offshore wind turbines.
BS EN 61400-3 should be used together with the appropriate IEC and ISO standards. In particular, this standard is fully consistent with the requirements of BS IEC 61400-1. The safety level of the offshore wind turbine designed according to this standard shall be at or exceed the level inherent in BS IEC 61400-1. In some clauses, where a comprehensive statement of requirements aids clarity, replication of text from BS IEC 61400-1 is included.
Contents of BS EN 61400-3:
- Introduction
- Scope
- Normative references
- Terms and definitions
- Symbols and abbreviated terms
- Symbols and units
- Abbreviations
- Principal elements
- General
- Design methods
- Safety classes
- Quality assurance
- Rotor – nacelle assembly markings
- External conditions
- General
- Wind turbine classes
- Wind conditions
- Marine conditions
- Other environmental conditions
- Electrical power network conditions
- Structural design
- General
- Design methodology
- Loads
- Design situations and load cases
- Load and load effect calculations
- Ultimate limit state analysis
- Control and protection system
- Mechanical systems
- Electrical system
- Foundation design
- Assessment of the external conditions at an offshore wind turbine site
- The metocean database
- Assessment of wind conditions
- Assessment of waves
- Assessment of currents
- Assessment of water level, tides and storm surges
- Assessment of sea ice
- Assessment of marine growth
- Assessment of seabed movement and scour
- Assessment of wake effects from neighbouring wind turbines
- Assessment of other environmental conditions
- Assessment of earthquake conditions
- Assessment of weather windows and weather downtime
- Assessment of electrical network conditions
- Assessment of soil conditions
- Assembly, installation and erection
- General
- Planning
- Installation conditions
- Site access
- Environmental conditions
- Documentation
- Receiving, handling and storage
- Foundation/anchor systems
- Assembly of offshore wind turbine
- Erection of offshore wind turbine
- Fasteners and attachments
- Cranes, hoists and lifting equipment
- Commissioning, operation and maintenance
- General
- Design requirements for safe operation, inspection and maintenance
- Instructions concerning commissioning
- Operator’s instruction manual
- Maintenance manual
- Key design parameters for an offshore wind turbine
- Wave spectrum formulations
- Shallow water hydrodynamics and breaking waves
- Guidance on calculation of hydrodynamic loads
- Recommendations for design of offshore wind turbine support structures with respect to ice loads
- Offshore wind turbine foundation design
- Statistical extrapolation of operational metocean parameters for ultimate strength analysis
- Corrosion protection
- Bibliography
