Initial Design of Tension Leg Platform for Offshore Wind Farm

As a floating foundation for wind turbine, dynamic response of offshore structure to external forces should be as small as possible because the motion of the structure imposes inertial force to a wind turbine system. Generally, a TLP (Tension Leg Platform) has favorable characteristics that its dynamic response in waves is negligibly small compared to other type of floating foundation. Our conceptual design of TLP for wind turbine was carried out in consideration of mooring force and easy maintenance. Numerical analyses were performed on dynamic response and tension deviation of leg in waves, natural frequency of vibration, and dynamic response to seismic load. As a result, it is found that natural periods of heave and pitch are rather short and amplitudes of motions are very small. It is also found that it keeps sufficient safety factor to extreme environmental conditions including earthquake, and is free from resonance with a wind turbine system.