...Chen Jian; Jan Kumbernuss; Zhang Linhua; Lu Lin; Yang Hongxing This paper presents the experimental results of the vertical axis wind turbine (VAWT), especially the Savonius rotors, which are developed for application on top of buildings due to lower wind speed compared with remote areas. The VAWT...

...Mohammad A. Ayoubi; Li-Chou Tai We present two intelligent controllers for large and flexible wind turbines operating in high-speed winds, a Fuzzy-P + I and an adaptive neuro-fuzzy controller. The control objective is to regulate the rotor speed at the given rated power in region 3 (full load) via...

...Binyet Emmanuel; Wang Jun The aim of the present paper is to investigate ways of improving the efficiency of a six-bladed Savonius rotor. The efficiency of Savonius machines is low because of the “negative drag” exerted on the convex part of the blades and also because the torque of standard...

... start-up to operating speed and compared with the experimental data in order to validate the technique. A circular inner domain, containing the blades and the rotor, was allowed to undergo mesh deformation with a rotational velocity that varied with torque generated by the incoming wind. Results have...

... aerodynamic probe technology with miniaturized hardware and software for UAVs that enable autonomous UAV operation. The measurements, made to support the development of advanced wind simulation tools, are made in the near-wake (0.5D–3D, where D is rotor diameter) region of a 2 MW wind turbine that is located...

...Matthew A. Lackner; Gijs A. M. van Kuik Reducing the loads experienced by wind turbine rotor blades can lower the cost of energy of wind turbines. “Smart rotor control” concepts have emerged as a solution to reduce fatigue loads on wind turbines. In this approach, aerodynamic load control devices...

... to express this. Although this work has been developed in the context of wind energy, it will be apparent that the results are of general significance for any application of ducted rotors or propellers in a fluid stream. Consider, for example, the diffuser case of Fig. 2 . From Eq. 12 , C p m...

... direction shear profile into the fatigue analysis structures and turbulence simulation code from the National Renewable Energy Laboratory. In general, the effect on turbine power production varies with the magnitude of speed and direction shear across the turbine rotor, with the majority of simulated...

...R. Jayashri; R. P. Kumudini Devi In this paper, the dynamic performance of grid connected wind energy conversion system (WECS) is analyzed in terms of rotor speed stability. The WECS considered is a fixed-speed system that is equipped with a squirrel-cage induction generator. The drive-train...

...Ronny Ramlau; Jenny Niebsch Rotor imbalances of a wind turbine can cause severe damage of the turbine or its components and thus reduce the lifespan and security of the turbine significantly. At present, balancing of the rotor is a time consuming and expensive process due to the necessity...

.... The fundamental idea behind the method is to use certain memorized information (i.e., current rotor speed tracking error, most recent speed tracking error, and previous control experience) to directly modify the firing angle control command sequences. The salient feature of the proposed approach lies in its...

...R. P. J. O. M. van Rooij The investigation focuses on the analysis of the airfoil segment performances along rotor blades in the parked configuration. In this research, wind tunnel experiments on two twisted blade geometries with different airfoils played a dominant role. These measurements were...

... of wind speed data are relevant for megawatt-size wind turbines when seeking wind characteristics that correspond to one blade and the entire rotor, respectively. For heights exceeding 50 – 60 m , the gust factor increases with wind speed. For heights larger than 60 – 80 m , present assumptions...

...Takao Maeda; Yasunari Kamada; Jun Suzuki; Hideyasu Fujioka This study shows the results of pressure distribution measurements on a rotor blade of a horizontal axis wind turbine under various yawed operations. The experiments are carried out in a wind tunnel with a 2.4 m diameter test rotor...

...Wouter Haans; Gijs van Kuik; Gerard van Bussel To reduce the level of uncertainty associated with current rotor aerodynamics codes, improved understanding of rotor aerodynamics is required. Wind tunnel measurements on model rotors contribute to advancing our knowledge on rotor aerodynamics...

...Curran Crawford; Jim Platts The work detailed in this paper is focused on updating and refining a coning rotor wind turbine concept. The coning rotor combines the load shedding properties of flapping hinges with gross change in rotor area, via large coning angles, to affect increased energy capture...

...Mansour H. Mohamed; Kyle K. Wetzel This paper presents the design and analysis for a spar cap for a wind turbine rotor blade. The cap is formed of an integral, unitary 3D woven material ( 3 WEAVE ® ) having constant thickness; spar cap weight is varied and controlled by appropriately tapering...

... visualization of the tip vortices is also presented. Thrust measurements of the rotor were performed to understand the effect of skew on thrust variation and to compare with analytical predictions. Three different techniques were used to observe/measure the flow and performance variation with skew: Smoke...

...), a turbine specifically configured to test advanced controls. We show the design of control systems to regulate turbine speed in region 3 using rotor collective pitch and reduce dynamic loads in regions 2 and 3 using generator torque. These controls enhance damping in the first drive train torsion mode. We...

...Sven Schmitz; Jean-Jacques Chattot This paper addresses three-dimensional effects which are pertinent to wind turbine aerodynamics. Two computational models were applied to the National Renewable Energy Laboratory Phase VI Rotor under rotating and parked conditions, a vortex line method using...