THE POSSIBILITY OF EXCEEDING THE BETZ-JOUKOWSKY MAXIMUM EFFICIENCY OF WIND TURBINES

2013 ◽  
Vol 44 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Viktor Fedorovich Molchanov
Keyword(s):  
Wind Turbines ◽  
Maximum Efficiency

scholarly journals Control and Investigation of Operational Characteristics of Variable Speed Wind Turbines with Doubly Fed Induction Generators

2021 ◽  
Vol 18 (4) ◽  
Author(s):  
Abdelali AARIB ◽  
Aymane EL MOUDDEN ◽  
Abdelhadi EL MOUDDEN ◽  
Abdelhamid HMIDAT
Keyword(s):  
Wind Turbines ◽  
Control Strategy ◽  
Reactive Power ◽  
Maximum Efficiency ◽  
Percentage Error ◽  
Modeling And Control ◽  
Induction Generators ◽  
Nominal Voltage ◽  
Doubly Fed ◽  
And Control

This article deals with the analysis, modeling, and control of the doubly-fed induction generator (DFIG) for wind turbines. The DFIG wind turbine can deliver more energy to the grid. There are some different methods to modify the DFIG system in order to accomplish the stator reactive power proposed. One of these methods is to modify the DFIG system for nominal voltage to evaluate cost and materials-efficiency consequences. A specific control strategy is implemented according to the vector control strategy. The proportional-integral (PI) regulators used are simple and precise controllers. This type of regulation, which is closed-loop rotor currents, allows adjustment of the sliding of the DFIG. This gives a good adjustment of the powers of the stator and the rotor. The percentage error of the simulation is less than 2 %. The results obtained in these investigations show that it is possible to adjust the powers of the stator, even with a variation of the parameters. The developed method will allow achieving the maximum efficiency of the wind energy conversion chain. The objective of this article is to optimize the quality of energy generated by wind turbines by controlling the reactive stator power and reducing the losses of the energy of the reactive stator power, which must be a physically minimal value. The results will be presented in the Matlab - Simulink environment.

scholarly journals Investigasi Performa Turbin Angin Crossflow Dengan Simulasi Numerik 2D

2020 ◽  
Vol 8 (1) ◽  
pp. 7-12
Author(s):  
Diniar Mungil Kurniawati
Keyword(s):  
Numerical Simulation ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Turbine Blades ◽  
Slope Angle ◽  
Electrical Energy ◽  
Diameter Ratio ◽  
Cfd Modeling ◽  
Maximum Efficiency ◽  
Multiple Interactions

Wind turbine is a solution to harness of renewable energy because it requires wind as the main energy. Wind turbine work by extracting wind energy into electrical energy. Crossflow wind turbine is one of the wind turbines that are developed because it does not need wind direction to produce maximum efficiency. Crossflow wind turbines work with the concept of multiple interactions, namely in the first interaction the wind hits the first level of turbine blades, then the interaction of the two winds, the remainder of the first interaction enters the second level blades before leaving the wind turbine. In the design of crossflow wind turbine the diameter ratio and slope angle are important factors that influence to determine of performance in crossflow wind turbine. In this study varied the angle of slope 90 ° and variations in diameter ratio of 0.6 and 0.7. The study aimed to analyze the effect of diameter ratio and slope angle in performance of the crossflow wind turbine. This research was conducted with numerical simulation through 2D CFD modeling. The results showed that the best performance of crossflow wind turbine occurred at diameter ratio variation 0.7 in TSR 0.3 with the best CP value 0.34.

scholarly journals Scientific basis for design low-speed synchronous permanent magnet generators for wind power plants

2021 ◽  
pp. 32-38
Author(s):  
A. A. Tatevosyan ◽  
Keyword(s):  
Wind Power ◽  
Wind Turbines ◽  
Power Plants ◽  
Energy Performance ◽  
Scientific Basis ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Synchronous Generators ◽  
Low Speed ◽  
Wind Power Plants

In this paper, the scientific basis for designing wind power plants (WPP) with low-speed synchronous generators on permanent magnets (SGPM) is understood as a system of scientific knowledge that forms the theoretical basis for the practice of designing a complex object, such as WPP consisting of interconnected equipment and structures designed to convert wind energy into electrical energy. Currently, the development of advanced WPP designs is receiving increased attention around the world. For example, in the Russian Federation, a promising direction is the creation of Autonomous WPP with low-speed medium- and low- power SGPMs that have the maximum range of applications by type of activity and climate zones throughout the territory. However, engineering approaches to the design of individual components of the WPP indicate the difficulties of developing a scientifically based methodology for optimizing the parameters of the WPP as a whole taking into account the mutual influence of individual components on each other. At the same time, the methodology for optimizing the parameters of WPP is understood as a tool for the scientific basis of design, which takes into account quality indicators and optimality criteria, energy and technical characteristics, as well as design stages with the results of preliminary and verification calculations. For the stage of verification calculations of VEU parameters, the scientific basis of design is determined by the construction of mathematical models and their research using application software packages for PCs, while for the stage of preliminary calculations, the development of analytical methods of analysis is important. This article discusses the scientific basis for designing wind turbines at the stage of preliminary calculations, formulated the problem of optimizing the parameters of low-speed WPP, proposed equations for the relationship of design parameters with the energy performance of wind turbines, providing the maximum efficiency of synchronous generators, taking into account the specified technical conditions

scholarly journals COUNTER-ROTATING DUAL ROTOR WIND TURBINE LAYOUT OPTIMISATION

2021 ◽  
Vol 61 (2) ◽  
pp. 342-349
Author(s):  
Csaba Hetyei ◽  
Ferenc Szlivka
Keyword(s):  
Fluid Dynamics ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Theoretical Basis ◽  
Energy Demand ◽  
Smart Cities ◽  
Maximum Efficiency ◽  
General Energy ◽  
Turbine Design ◽  
Day By Day

General energy demand is continuously increasing, thus the energy generating assets need to be optimised for higher efficiency. Wind turbines are no exception. Their maximum efficiency can be determined on a theoretical basis. The limit is approached by researches day by day, utilizing the latest developments in airfoil design, blade structure and new and improved ideas in conventional and unconventional wind turbine layouts. In this paper, we are reviewing the conventional and unconventional wind turbines and their place in smart cities. Then, an unconventional wind turbine design, the CO-DRWT (counter-rotating dual rotor wind turbine) is analysed with a CFD (computational fluid dynamics) code, varying the axial and radial distances between the two turbines. After the simulations, the power coefficients for the different turbine configurations is calculated. At the end of this paper, the simulations results are summarized and consequences are drawn for the CO-DRWT layouts.

scholarly journals Optimum Solidity on Downwind Thai Sail Windmill

2021 ◽  
Vol 18 (22) ◽  
pp. 42
Author(s):  
Teerawat Klabklay ◽  
Wikanda Sridech
Keyword(s):  
Wind Turbines ◽  
Maximum Efficiency ◽  
Horizontal Axis Wind Turbine ◽  
Testing Method ◽  
Wide Range ◽  
Blade Area ◽  
Low Efficiency ◽  
Enhance Efficiency ◽  
Swept Area ◽  
Cord Length

Solidity was a significant parameter affecting the efficiency of wind turbines. It is defined as the ratio between the projected area of all blades and the swept area of the rotor. The solidity could be improved by modifying the shape, cord length, or the number of blades. Research studies mentioned that higher solidity seemed to provide more power due to more blade area. However, it can be argued that if the solidity was too high, it would cause the airflow to be more obstructed and disrupted, causing the gained power to drop down instead. Thus, the optimum solidity, which made the wind turbines maximum effective, must be existent in itself and must be in the range between 0 - 100 %. Thai sail windmill is a kind of horizontal axis wind turbine currently used to pump seawater in salt farms in Thailand, where the general solidity is in the quite wide range of about 15 - 60 %. Mostly, the Thai sail windmill was designed by a rule of thumb. Hence, it has quite a low efficiency, which is only about 10 %. This study aims to investigate the optimum solidity of Thai sail windmill in the downwind type to enhance efficiency. The 4-blade and 6-blade rotors of 1-m radii were used as the prototypes for experiments using the tow testing method. The results showed that the optimum solidity of 4-blade and 6-blade rotors was 28 %, respectively, whereby the maximum efficiency of the 2 rotors was 17 and 25 %.

scholarly journals Concept design and numerical analysis of hybrid solar–wind turbine

2021 ◽  
Vol 850 (1) ◽  
pp. 012032
Author(s):  
K S Ackshaya Varshini ◽  
Alenkar K Aswin ◽  
H Rajan ◽  
K S Maanav Charan
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Fluid Dynamic ◽  
Mechanical Energy ◽  
Vertical Axis ◽  
Horizontal Axis ◽  
Maximum Efficiency ◽  
Concept Design ◽  
Lower Efficiency ◽  
Axis Orientation

Abstract A wind turbine is a device that converts wind energy to electrical energy. External factors such as wind speed and direction shift, as well as turbine blade design considerations, cause a significant amount of energy to be wasted throughout the conversion process. Considering all these losses, a turbine’s average efficiency is roughly 45 percent. The blades of a wind turbine are one of the most crucial factors in determining the turbine’s efficiency. The design and geometry of the blades have a direct impact on performance since it determines how much kinetic energy from the wind is converted into mechanical energy. Many concepts and technologies are being used to improve the efficiency of wind turbines while lowering their maintenance costs. Wind turbines based on their axis orientation are classified as vertical axis and horizontal axis. Vertical axis wind turbines are not as widespread as their horizontal-axis counterparts due to their lower efficiency. In this study, we will use a Savonius vertical axis wind turbine to investigate a way of enhancing its efficiency by installing solar panels on its vertical blades and determining the best performance angle at which the turbine should be kept achieving maximum efficiency. Computation fluid dynamic analysis and thermal and structural analysis has been performed to check the efficiency of the designed blade. As a result, an optimized wind turbine design has been developed.

scholarly journals Pengaruh Kelengkungan Sudu Terhadap Kinerja Turbin Angin Savonius

2019 ◽  
Vol 6 (2) ◽  
pp. 139
Author(s):  
Jamal Jamal ◽  
A. M. Shiddiq Yunus ◽  
Lewi Lewi
Keyword(s):  
Wind Speed ◽  
Wind Turbines ◽  
Power Output ◽  
Input Power ◽  
Load Force ◽  
Maximum Efficiency ◽  
Wind Speeds ◽  
Energy Needs ◽  
Turbine Shaft ◽  
Lower Torque

Savonius wind turbine is one of the wind turbines that is more widely used for low energy needs, with more energy needs, this turbine type is very feasible to be developed. This research aims to improve the performance of Savonius wind turbines with variations in turbine blade curvature and variations in wind speed. The research method is a laboratory experiment on the fan test, the blade curvature test variation is 1R; 1.5R and 2R, another variation is the wind speed which are 4.0; 5.5; 7.0 and 8.5 m/s. The experiement results shows that the greater the wind speed, the input power, air mass flow velocity, power output, and efficiency will be even greater; the greater the load force on the turbine shaft, the torque on the turbine shaft will also be greater; the relationship of force loads to power output and turbine efficiency is to construct a parabolic curve; for the same wind speed, the 2R turbine has the lowest rotation, power output and efficiency compared to the 1R and 1.5R turbines; at the same wind speed the 1R turbine produces a higher rotation but requires lower torque than the 1.5R turbine; at low wind speeds (4 m / s) the 1.5R turbine has better efficiency than the 1R turbine, whereas at the high wind speed (8.5 m/s) the 1R turbine has a better efficiency than the 1.5R turbine; The maximum efficiency is obtained at 89.56% in the 1R curvature turbine with a wind speed of 8.5 m / s.

Development of the algorithm for the selection of a wind generator-based autonomous power supply system

2019 ◽  
Vol 2 (1) ◽  
pp. 8-16 ◽  
Author(s):  
P. A. Khlyupin ◽  
G. N. Ispulaeva
Keyword(s):  
Wind Turbines ◽  
Power Supply ◽  
Alternative Energy ◽  
Power Supply System ◽  
Supply System ◽  
Power Generators ◽  
Energy Devices ◽  
Wind Generator ◽  
Alternative Energy Sources ◽  
Selection Of

Introduction: The co-authors provide an overview of the main types of wind turbines and power generators installed into wind energy devices, as well as advanced technological solutions. The co-authors have identified the principal strengths and weaknesses of existing wind power generators, if applied as alternative energy sources. The co-authors have proven the need to develop an algorithm for the selection of a wind generator-based autonomous power supply system in the course of designing windmill farms in Russia. Methods: The co-authors have analyzed several types of wind turbines and power generators. Results and discussions: The algorithm for the selection of a wind generator-based autonomous power supply system is presented as a first approximation. Conclusion: The emerging algorithm enables designers to develop an effective wind generator-based autonomous power supply system.

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