A method to suppress sub/super-synchronous oscillation of direct-drive wind turbines based on energy compensation is proposed. First, the transient model turbine built, and negative damping terms that lead are extracted. On this basis, expressions voltage corresponding derived by backward deduction, thus supplementary branches constructed, their impact fundamental frequency characteristics anal...

Tendencies in development of wind power industry including direct-drive small-scale wind power plants and generators have been analyzed. Synchronous generators with permanent magnet excitation for direct-drive wind power turbines are described. Primary magnetic field distribution and effect of armature reaction have been studied for design of a low-speed multipole permanent-magnet synchronous g...

Heavy, large and robust supporting structures are needed to keep the airgap clearance of direct-drive multi-MW wind turbine electrical generators open stable. As rotating pieces machinery, vibrate when their natural frequencies excited introducing potentially amplitude oscillations due forces acting on them that could cause structural fatigue, noise and, in worst-case scenario, sudden collapse....

this study analyzes wind energy potentials of zanjan province which located in northwest of iran. renewable energy plans are not fully environmentally safe and different renewable energy plans have different environmental impacts. therefore, site selection is an important issue in the wind turbine installation and therefore, selecting an appropriate wind turbine site requires consideration of m...

In order to reduce the costs of wind energy, it is necessary to improve the wind turbine availability and reduce the operational and maintenance costs. The reliability and availability of a functioning wind turbine depend largely on the protective properties of the lubrication oil for its drive train subassemblies such as the gearbox and means for lubrication oil condition monitoring and degrad...

Experimental dynamic characterization of a wind turbine, operating under variety of conditions, is a desired task as it provides useful insights that can be used for number of tasks including design optimization, validation and verification of aeroelastic and finite element codes and development of an optimal control system. However, current state of art experimental techniques are insufficient...

Wind turbines are known to produce shadow flicker by interruption of sunlight by the turbine blades. Known parameters of the seizure provoking effect of flicker, i.e., contrast, frequency, mark-space ratio, retinal area stimulated and percentage of visual cortex involved were applied to wind turbine features. The proportion of patients affected by viewing wind turbines expressed as distance in ...

Measurements have been made in the wake of a model wind turbine in both a weakly unstable and a baseline neutral atmospheric boundary layer, in the EnFlo stratified-flow wind tunnel, between 0.5 and 10 rotor diameters from the turbine, as part of an investigation of wakes in offshore winds. In the unstable case the velocity deficit decreases more rapidly than in the neutral case, largely becaus...