Energy-flow direction control of grid-connected IGBT inverters for wind energy extraction

2002 ◽  
Author(s):  
Hong Huang ◽  
Liuchen Chang
Keyword(s):  
Wind Energy ◽  
Energy Flow ◽  
Flow Direction ◽  
Energy Extraction ◽  
Direction Control

Implementation Issues in 3D Wind Flow Predictions Over Complex Terrain

2006 ◽  
Vol 128 (4) ◽  
pp. 539-553 ◽  
Author(s):  
John Prospathopoulos ◽  
Spyros G. Voutsinas
Keyword(s):  
Wind Energy ◽  
Boundary Conditions ◽  
Complex Terrain ◽  
Flow Direction ◽  
Region Of Interest ◽  
Field Measurements ◽  
Navier Stokes ◽  
Wind Flow ◽  
Computational Domain

Practical aspects concerning the use of 3D Navier-Stokes solvers as prediction tools for micro-siting of wind energy installations are considered. Micro-siting is an important issue for a successful application of wind energy in sites of complex terrain. There is a constantly increasing interest in using mean wind flow predictions based on Reynolds averaged Navier-Stokes (RANS) solvers in order to minimize the number of required field measurements. In this connection, certain numerical aspects, such as the extent of the numerical flow domain, the choice of the appropriate inflow boundary conditions, and the grid resolution, can decisively affect the quality of the predictions. In the present paper, these aspects are analyzed with reference to the Askervein hill data base of full scale measurements. The objective of the work is to provide guidelines with respect to the definition of appropriate boundary conditions and the construction of an adequate and effective computational grid when a RANS solver is implemented. In particular, it is concluded that (a) the ground roughness affects the predictions significantly, (b) the computational domain should have an extent permitting the full development of the flow before entering the region of interest, and (c) the quality of the predictions at the local altitude maxima depends on the grid density in the main flow direction.

Maximum Wind Energy Extraction by Using Neural Network Estimation and Predictive Control of Boost Converter

2018 ◽  
Vol 7 (1) ◽  
pp. 59 ◽  
Author(s):  
Mahdi Heidari
Keyword(s):  
Neural Network ◽  
Wind Energy ◽  
Synchronous Generator ◽  
Maximum Energy ◽  
Boost Converter ◽  
Energy Extraction ◽  
Permanent Magnet Synchronous Generator ◽  
Predictive Controller ◽  
Network Estimation ◽  
Artificial Neural Network Ann

This paper proposes a new method to extract maximum energy from wind turbine systems. The artificial neural network (ANN) is used to estimate the wind speed based on the rotor speed and the output power. In addition to ANN, a predictive controller is used to maximize the efficiency of the boost converter. The method has been developed and analyzed by utilizing a turbine directly driven permanent-magnet synchronous generator (PMSG). The simulation results verify the performance of the proposed method. Results show that this method maximizes wind energy extraction with more accuracy and fastness.

An Application of the Autogyro Theory to Airborne Wind Energy Extraction

2013 ◽  
Author(s):  
Sigitas Rimkus ◽  
Tuhin Das
Keyword(s):  
Energy Harvesting ◽  
Wind Energy ◽  
Wind Field ◽  
Preliminary Investigation ◽  
Energy Extraction ◽  
Blade Element Theory ◽  
Simulation Results ◽  
Element Theory ◽  
Aerodynamic Torque ◽  
Blade Element

Auto-rotation or autogyro is a well-known phenomenon where a rotor in a wind field generates significant lift while the wind induces considerable aerodynamic torque on the rotor. The principle has been studied extensively for applications in aviation. However, with recent works indicating immense, persistent, and pervasive, available wind energy at high altitudes, the principle of autogyro could potentially be exploited for energy harvesting. In this paper, we carry out a preliminary investigation on the viability of using autogyros for energy extraction. We mainly focus on one of the earliest documented works on modeling of autogyro and extend its use to explore energy harvesting. The model is based on blade element theory. We provide simulation results of the concept. Although the results are encouraging, there are various practical aspects that need to be investigated to build confidence on this approach of energy harvesting. This work aims to build a framework upon which more comprehensive research can be conducted.

Drag reduction of energy-efficient buildings and wind energy extraction due to bleeding effect

2015 ◽  
Vol 53 (6) ◽  
pp. 873-876 ◽  
Author(s):  
S. A. Isaev ◽  
N. I. Vatin ◽  
S. V. Guvernyuk ◽  
V. G. Gagarin ◽  
B. I. Basok ◽  
...  
Keyword(s):  
Wind Energy ◽  
Drag Reduction ◽  
Energy Efficient ◽  
Energy Extraction ◽  
Energy Efficient Buildings ◽  
Bleeding Effect

scholarly journals Coupling strength assumption in statistical energy analysis

2017 ◽  
Vol 473 (2200) ◽  
pp. 20160927 ◽  
Author(s):  
T. Lafont ◽  
N. Totaro ◽  
A. Le Bot
Keyword(s):  
Coupling Strength ◽  
Energy Flow ◽  
Energy Analysis ◽  
Flow Direction ◽  
Statistical Energy Analysis ◽  
Coupling Loss ◽  
Indirect Coupling ◽  
Random Forces ◽  
Statistical Ensembles ◽  
Coupled Plates

This paper is a discussion of the hypothesis of weak coupling in statistical energy analysis (SEA). The examples of coupled oscillators and statistical ensembles of coupled plates excited by broadband random forces are discussed. In each case, a reference calculation is compared with the SEA calculation. First, it is shown that the main SEA relation, the coupling power proportionality, is always valid for two oscillators irrespective of the coupling strength. But the case of three subsystems, consisting of oscillators or ensembles of plates, indicates that the coupling power proportionality fails when the coupling is strong. Strong coupling leads to non-zero indirect coupling loss factors and, sometimes, even to a reversal of the energy flow direction from low to high vibrational temperature.

scholarly journals 0408 Flow Direction Control for Nano-Hydraulic Turbine utilizing Waterfalls

2012 ◽  
Vol 2012.49 (0) ◽  
pp. 040801-040802
Author(s):  
Kaika KIMOTO ◽  
Masahiro YAMAZAKI ◽  
Shingo OOIKE ◽  
Shouichiro IIO ◽  
Toshihiko IKEDA
Keyword(s):  
Flow Direction ◽  
Hydraulic Turbine ◽  
Direction Control
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