Modeling and Analysis of an Offshore Wind Turbine With Fluid Power Transmission for Centralized Electricity Generation

This paper presents a mathematical model of an innovative offshore wind turbine with fluid power transmission. The proposed concept is a variable-speed, pitch controlled turbine which differs from conventional technology by using fluid power technology as a medium to transfer the energy from the wind. The final aim is to use several turbines to centralize electricity generation. Unlike conventional variable speed concepts, the proposed turbine comprises a passive-torque control method which allows the turbine to operate at optimal aerodynamic performance for different wind speeds. A numerical model of a single turbine is developed and time-domain simulations are used to analyze the dynamic response of the different operational parameters to a turbulent wind speed input. The results are compared with those of a reference offshore wind turbine with similar characteristics. It is shown that operation below rated wind speed with a passive control is possible for a single turbine with a better dynamic performance than the reference in terms of transmission torque. However, the efficiency of the energy transmission is reduced throughout the operational range. The addition and simulation of more turbines to the hydraulic network is necessary to determine to which extent the benefits of a centralized wind farm compensate for the relatively lower efficiency.