scholarly journals Prospects for Increasing the Dynamic Efficiency of Asynchronous Double-Feed Machines and Wind Power Generators Using Structural Methods and Solutions

2021 ◽  
Author(s):  
Vladimir L. Kodkin ◽  
Alexandr S. Anikin ◽  
Alexandr A. Baldenkov
Keyword(s):  
Wind Power ◽  
High Efficiency ◽  
Transfer Functions ◽  
Power Generators ◽  
Electric Generator ◽  
Stator Current ◽  
Asynchronous Machines ◽  
Wide Range ◽  
Wind Power Generators ◽  
Structural Methods

The chapter proposes to consider the problems of control of asynchronous machines with dual power supply, as a nonlinear structure, the transfer functions of which depend on the frequency of the stator voltage and the relative slip. The authors cite the results of research confirming the high efficiency of control of asynchronous electric motors, using cross-dynamic connections on the developed torque or a signal close to it (active component of the motor stator current). The proposed correction operates in a wide range of changes in the rotation and sliding speeds of the asynchronous electric generator. This is especially important for wind turbines that need to remain efficient at different speeds. As a justification, the results of experiments, modeling and industrial application of control algorithms with positive torque coupling are presented. Research results suggest that such algorithms will improve the efficiency of wind power by 5–10%.

scholarly journals Airflow Characteristics According to the Change in the Height and Porous Rate of Building Roofs for Efficient Installation of Small Wind Power Generators

2021 ◽  
Vol 13 (10) ◽  
pp. 5688
Author(s):  
Jangyoul You ◽  
Kipyo You ◽  
Minwoo Park ◽  
Changhee Lee
Keyword(s):  
Wind Speed ◽  
Wind Power ◽  
Turbulence Intensity ◽  
Flow Characteristics ◽  
High Porosity ◽  
Power Generators ◽  
Speed Reduction ◽  
Reduction Effect ◽  
Wind Power Generators ◽  
The Impact

In this paper, the air flow characteristics and the impact of wind power generators were analyzed according to the porosity and height of the parapet installed in the rooftop layer. The wind speed at the top was decreasing as the parapet was installed. However, the wind speed reduction effect was decreasing as the porosity rate increased. In addition, the increase in porosity significantly reduced turbulence intensity and reduced it by up to 40% compared to no railing. In the case of parapets with sufficient porosity, the effect of reducing turbulence intensity was also increased as the height increased. Therefore, it was confirmed that sufficient parapet height and high porosity reduce the effect of reducing wind speed by parapets and significantly reducing the turbulence intensity, which can provide homogeneous wind speed during installation of wind power generators.

Effect of Metal Coating on FRP Blade Lightning Failure for Wind Power Generators

2005 ◽  
Author(s):  
H. Sakamoto ◽  
A. Takebayashi ◽  
M. Hanai
Keyword(s):  
Wind Power ◽  
Experimental Situation ◽  
Metal Coating ◽  
Testing Laboratory ◽  
Power Generators ◽  
Full Size ◽  
Wind Power Generator ◽  
Power Testing ◽  
Blade Failure ◽  
Wind Power Generators

In Japan, with the recent increase in wind power generator installations, the incidence of lightning damage to FRP blades is increasing. Lightning damage is a significant issue in Japan since lightning in Japan seems severer than that in Europe or the US. In Kochi, Japan, six 600-750 kW grade generators have been installed, and some have been damaged by lightning several times. To resolve this problem, the Kochi University of Technology received a request in 2002 from the Kochi prefectural government for research into lightning protection. After surveying the literature and questioning related organizations such as NREL and Toray USA, experiments to protect against lightning damage to FRP blades of wind power generators were planned. Half size models and two 1/4 parts of a full size 250kW blade were prepared as specimens for this research. The method investigated to protect against lightning damage was metal coating. The aim being to protect against blade failure by using metal coating in actual field situations; by using a 1/2 size model and the full size blade specimens in an experimental situation. As in previous experiments, these ones were mainly conducted in the Toshiba Hamakawasaki High Voltage High Power Testing Laboratory. This Testing Laboratory is one of the biggest test laboratories for experiments involving high voltages and large currents.

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