Design methods

In this document, “design” is considered to include the choice of a wind turbine configuration and the sizing of the machine and all of its principal components, including rotor, drivetrain, nacelle, tower and support structures, as well as the choice of the generator, pitch and yaw systems. The design of a wind turbine implies the evaluation of the aerodynamic performance, loads, dynamic response, and stability in normal and extreme operating conditions, including the occurrence of faults. The design problem does not end at the level of the single wind turbine but expands to also include the design of the complete wind power plant, where the machines operate together and interact among themselves and with the environment. The disciplines involved in these complex processes include aerodynamics and flow physics, structures and materials, dynamics, and controls, as well as hydrodynamics in the case of offshore applications. For each of these disciplines, knowledge and design models have been and still are being developed as discussed in this document. However, these models have reached different levels of fidelity, applicability and computational costs, and cannot always be combined. The design of a wind turbine and of a wind power plant is therefore characterised by a marked multidisciplinarity with strong couplings among the various disciplines covered by models which may be different in complexity and proven validity.