Field Testing of a Wind Turbine Tubular Tower and Structural Design of a Space Frame Steel Tower

Wind energy industry has been growing tremendously in recent years. Tubular steel towers are currently dominant supporting structures for wind turbines. With the increase of the converter capacity, there is a great demand for higher supporting towers. However, structural vibrations in extreme wind events tend to become a major concern during tower design. To study wind turbine tower dynamics, an existing tubular steel tower was tested. Vibrational frequencies and damping ratios were identified. To avoid unexpected dynamic problems, a space frame steel tower has been proposed for supporting larger wind turbines. It is a structural system that can be assembled on-site by using prefabricated beams, columns, and brace members. A typical space frame steel tower was designed in this paper. Static loading, modal and buckling analyses of the tower were presented. It is expected to introduce engineers and designers more options for wind turbine tower design.