Improved methodology for design of low wind speed specific wind turbine blades

2015 ◽  
Vol 119 ◽  
pp. 677-684 ◽  
Author(s):  
R.H. Barnes ◽  
E.V. Morozov ◽  
K. Shankar
2020 ◽  
Vol 194 ◽  
pp. 03008
Author(s):  
Xin GAO ◽  
Xiaoyu WANG ◽  
Jiahuan HE

In order to improve the power output of wind turbine at low wind speed, this paper studies the aerodynamic performance of wind turbine blades at different installation angles. It is found that the optimal pitch angle of wind turbine can be switched between different installation angles when wind speed changes by introducing wind turbine speed differential feedback signal in PI controller of variable pitch, so as to track the optimal wind energy utilization coefficient The purpose of improving wind turbine power output. In order to verify the reliability of the analysis results, bladed is used to simulate the model of a 1.5MW unit with pitch differential control signal. At the same time, the research results are applied to the actual operation of the unit. The results show that the power curve of the wind turbine unit at low wind speed can be improved and the annual power generation can be increased by 1.24%.


Author(s):  
Salete Alves ◽  
Luiz Guilherme Vieira Meira de Souza ◽  
Edália Azevedo de Faria ◽  
Maria Thereza dos Santos Silva ◽  
Ranaildo Silva

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2319
Author(s):  
Hyun-Goo Kim ◽  
Jin-Young Kim

This study analyzed the performance decline of wind turbine with age using the SCADA (Supervisory Control And Data Acquisition) data and the short-term in situ LiDAR (Light Detection and Ranging) measurements taken at the Shinan wind farm located on the coast of Bigeumdo Island in the southwestern sea of South Korea. Existing methods have generally attempted to estimate performance aging through long-term trend analysis of a normalized capacity factor in which wind speed variability is calibrated. However, this study proposes a new method using SCADA data for wind farms whose total operation period is short (less than a decade). That is, the trend of power output deficit between predicted and actual power generation was analyzed in order to estimate performance aging, wherein a theoretically predicted level of power generation was calculated by substituting a free stream wind speed projecting to a wind turbine into its power curve. To calibrate a distorted wind speed measurement in a nacelle anemometer caused by the wake effect resulting from the rotation of wind-turbine blades and the shape of the nacelle, the free stream wind speed was measured using LiDAR remote sensing as the reference data; and the nacelle transfer function, which converts nacelle wind speed into free stream wind speed, was derived. A four-year analysis of the Shinan wind farm showed that the rate of performance aging of the wind turbines was estimated to be −0.52%p/year.


2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Bhavana Valeti ◽  
Shamim N. Pakzad

Rotor blades are the most complex structural components in a wind turbine and are subjected to continuous cyclic loads of wind and self-weight variation. The structural maintenance operations in wind farms are moving towards condition based maintenance (CBM) to avoid premature failures. For this, damage prognosis with remaining useful life (RUL) estimation in wind turbine blades is necessary. Wind speed variation plays an important role influencing the loading and consequently the RUL of the structural components. This study investigates the effect of variable wind speed between the cutin and cut-out speeds of a typical wind farm on the RUL of a damage detected wind turbine blade as opposed to average wind speed assumption. RUL of wind turbine blades are estimated for different initial crack sizes using particle filtering method which forecasts the evolution of fatigue crack addressing the non-linearity and uncertainty in crack propagation. The stresses on a numerically simulated life size onshore wind turbine blade subjected to the above wind speed loading cases are used in computing the crack propagation observation data for particle filters. The effects of variable wind speed on the damage propagation rates and RUL in comparison to those at an average wind speed condition are studied and discussed.


2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Weijun Wang ◽  
Stéphane Caro ◽  
Fouad Bennis ◽  
Oscar Roberto Salinas Mejia

The aim of designing wind turbine blades is to improve the power capture ability. Since rotor control technology is currently limited to controlling rotational speed and blade pitch, an increasing concern has been given to morphing blades. In this paper, a simplified morphing blade is introduced, which has a linear twist distribution along the span and a shape that can be controlled by adjusting the twist of the blade's root and tip. To evaluate the performance of wind turbine blades, a numerical code based on the blade element momentum theory is developed and validated. The blade of the NREL Phase VI wind turbine is taken as a reference blade and has a fixed pitch. The optimization problems associated with the control of the morphing blade and a blade with pitch control are formulated. The optimal results show that the morphing blade gives better results than the blade with pitch control in terms of produced power. Under the assumption that at a given site, the annual average wind speed is known and the wind speed follows a Rayleigh distribution, the annual energy production of wind turbines was evaluated for three types of blade, namely, morphing blade, blade with pitch control and fixed pitch blade. For an annual average wind speed varying between 5 m/s and 15 m/s, it turns out that the annual energy production of the wind turbine containing morphing blades is 24.5% to 69.7% higher than the annual energy production of the wind turbine containing pitch fixed blades. Likewise, the annual energy production of the wind turbine containing blades with pitch control is 22.7% to 66.9% higher than the annual energy production of the wind turbine containing pitch fixed blades.


Author(s):  
Ohad Gur ◽  
Aviv Rosen

The optimal aerodynamic design of Horizontal Axis Wind Turbine (HAWT) is investigated. The Blade-element/Momentum model is used for the aerodynamic analysis. In the first part of the paper a simple design method is derived, where the turbine blade is optimized for operation at a specific wind speed. Results of this simple optimization are presented and discussed. Besides being optimized for operation at a specific wind speed, without considering operation at other wind speeds, the simple model is also limited in the choice of design goals (cost functions), design variables and constraints. In the second part of the paper a comprehensive design method that is based on a mixed numerical optimization strategy, is presented. This method can handle almost any combination of: design goal, design variables, and constraints. Results of this method are presented, compared with the results of the simple optimization, and discussed.


Author(s):  
Vasishta Bhargava ◽  
Rahul Samala

Research on broadband aerodynamic noise from wind turbine blades is becoming important in several countries. In this work, computer simulation of acoustic emissions from wind turbine blades are predicted using quasi empirical model for a three-bladed horizontal axis 3 MW turbine with blade length ~47 m. Sound power levels are investigated for source and receiver height of 80 m and 2 m above ground and located at a distance equal to total turbine height. The results are validated using existing experimental data for Siemens SWT-2.3 MW turbine having blade length of 47 m, as well as with 2.5 MW turbine. Aerofoil self-noise mechanisms are discussed in present work and results are demonstrated for wind speed of 8 m/s. Overall sound power levels for 3 MW turbine showed good agreements with the existing experiment data obtained for SWT-2.3 MW turbine. Noise map of single source sound power level, dBA of an isolated blade segment located at 75 %R for single blade is illustrated for wind speed of 8 m/s. The results demonstrated that most of the noise production occurred from outboard section of blade and for blade azimuth positions between 80° and 170°.


2014 ◽  
Author(s):  
Jobaidur R. Khan ◽  
Mosfequr Rahman

Amidst of high demand of energy, the world is seeking alternative energy sources. Wind alone can fulfill most of the energy requirement of the world by its efficient conversion into energy. On efficiency measurement, Horizontal Axis Wind Turbines (HAWT) is the popular to the researchers, but it works best in places where the wind is not disturbed and has high wind power. The inherent advantage of facing the wind direction, design simplicity, less expensive technology for construction, lower wind start-up speeds, easier maintenance, and relatively quietness are turning the focus to Vertical Axis Wind Turbine (VAWT). The low wind speed and non-smooth wind flow regions are attracted for these machines. Savonius turbine is the simplest form of VAWT and operation is based on the difference of the drag force on its blades. The main objective of this study is to analyze a perfect mixture of new and innovative designs of Savonius turbine blades, which can make VAWT more attractive, efficient, durable and sustainable. This is studied by using blade with different numbers in operating in different wind speed. A Computational Fluid Dynamics (CFD) analysis has been used. 2D CAD models of various VAWT geometries are created and tested with CFD software ANSYS/FLUENT with a similar flow-driven motion in a wind tunnel. These simulations provided the aero-dynamic characteristics like shear stress, velocity distribution and pressure distribution. Some physical models with desired properties needed to be fabricated and tested inside tunnel to find the effect of different shapes in real.


2016 ◽  
Vol 78 (8-4) ◽  
Author(s):  
Muhammad Hafidz Ariffudin ◽  
Fazila Mohd Zawawi ◽  
Haslinda Mohamed Kamar ◽  
Nazri Kamsah

There has been an increasing demand for renewable energy in order to create a sustainable society as the non-renewable energies such as fossil fuel resources are limited. Modern wind turbines claim that they have a high efficiency in term of wind energy extraction. However, there are still having losses due to tip vortex causing to a reduction in performance.  Motivated by this reason, this research aims at exploring the possibility to increase the performance of low speed small-scaled horizontal axis wind turbine with various tip devices using Computational Fluid Dynamics (CFD). Four wind turbine blades with different tip devices which consist of sword tip, swept tip, upwind winglet and downwind winglet are compared with wind turbine blade without tip device in term of CP. The application of tip device can significantly reduce induced tip vortex and improve wind turbine performance. For TSR below than 4, adding a sword tip increases CP about 7.3%, swept tip increases CP about 9.1%, upwind winglet increases CP about 1.8% and downwind winglet increases CP about 3.2%. It is observed that the best tip device for low wind speed application is swept tip as it give the highest performance increment compared to without tip device.


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