scholarly journals Design of advanced airfoil for stall-regulated wind turbines

2017 ◽  
Vol 2 (2) ◽  
pp. 403-413
Author(s):  
Francesco Grasso ◽  
Domenico Coiro ◽  
Nadia Bizzarrini ◽  
Giuseppe Calise
Keyword(s):  
Wind Turbines ◽  
Design Strategy ◽  
High Wind ◽  
Pitch Control ◽  
Turbine Performance ◽  
Gradient Based ◽  
Machine Control ◽  
And Control ◽  
The Impact ◽  
Numerical Optimisation

Abstract. Nowadays, all the modern megawatt-class wind turbines make use of pitch control to optimise the rotor performance and control the turbine. However, for kilowatt-range machines, stall-regulated solutions are still attractive and largely used for their simplicity and robustness. In the design phase, the aerodynamics plays a crucial role, especially concerning the selection/design of the necessary airfoils. This is because the airfoil performance is supposed to guarantee high wind turbine performance but also the necessary machine control capabilities. In the present work, the design of a new airfoil dedicated to stall machines is discussed. The design strategy makes use of a numerical optimisation scheme, where a gradient-based algorithm is coupled with the RFOIL code and an original Bezier-curves-based parameterisation to describe the airfoil shape. The performances of the new airfoil are compared in free- and fixed-transition conditions. In addition, the performance of the rotor is analysed, comparing the impact of the new geometry with alternative candidates. The results show that the new airfoil offers better performance and control than existing candidates do.

scholarly journals Design of advanced airfoil for stall-regulated wind turbines

2017 ◽  
Author(s):  
Francesco Grasso ◽  
Domenico Coiro ◽  
Nadia Bizzarrini ◽  
Giuseppe Calise
Keyword(s):  
Wind Turbines ◽  
Numerical Optimization ◽  
Design Strategy ◽  
High Wind ◽  
Optimization Scheme ◽  
Pitch Control ◽  
Turbine Performance ◽  
Gradient Based ◽  
And Control ◽  
The Impact

Abstract. Nowadays, all the modern MW-class wind turbines make use of pitch control to optimize the rotor performance and control the turbine. However, for kW-range machines, stall-regulated solutions are still attractive and largely used for their simplicity and robustness. On the design phase, the aerodynamics plays a crucial role, especially concerning the selection/design of the necessary airfoils. This is because the airfoil performance should guarantee high wind turbine performance, but also the needed machine control capabilities. In the present work, the design of a new airfoil dedicated for stall machines is discussed. The design strategy makes use of numerical optimization scheme where a gradient-based algorithm is coupled with XFOIL code and an original Bezier-curves-based parameterization to describe the airfoil shape. The performances of the new airfoil are compared in free and fixed transition conditions. In addition, the performance of the rotor is analysed comparing the impact of the new geometry with alternative candidates. The results show that the new airfoil offers better performance and control than existing candidates do.

Investigating LiDAR Sensing Errors for Wind Turbines Loads Reduction

2014 ◽  
Author(s):  
Benoit Bayon ◽  
Jonathan Chauvin
Keyword(s):  
Wind Turbines ◽  
Domain Model ◽  
Control Law ◽  
Lidar Measurement ◽  
Reliable Measurement ◽  
Error Sources ◽  
Control Laws ◽  
Pitch Control ◽  
Turbine Performance ◽  
The Impact

LiDAR sensors are a promising technology for a reliable measurement of the incoming wind. This is especially useful for applications such as antennas and wind turbines. For wind turbines, the use of this sensor provides the information of the rotor wind speed which can be used in dedicated control laws to improve the wind turbine performance, mainly on the mechanical loads and extreme moments. However the provided information is not flawless. Several error sources exist and degrade the wind information. As a consequence, the performance of the blade pitch control law is reduced. In this paper, an insight of the LiDAR measurement error sources is provided through the establishment of a frequency domain model. The impact of these errors on the performance of a blade pitch control law is investigated, along with the comparison with a standard control law.

Fault Prediction of Pitch Actuator for Wind Turbines

2014 ◽  
Vol 721 ◽  
pp. 397-401
Author(s):  
Hong Shan Zhao ◽  
Sha Sha Lian ◽  
Ling Shao
Keyword(s):  
Wind Turbines ◽  
Prediction Method ◽  
Fault Isolation ◽  
Fault Prediction ◽  
False Alarms ◽  
Controlled System ◽  
Pitch Control ◽  
Prediction Scheme ◽  
The Impact ◽  
The Mathematical Model

Hydraulic pitch-controlled system is one of the components of wind turbines which are frequently prone to faults. Early fault prediction of the pitch control system can improve the operation reliability effectively and reduce the unnecessary loss. Wind turbines suffer much environmental interference; moreover, data-based fault prediction is vulnerable to occur false alarms by the impact of these factors. And it is difficult to implement the fault isolation. So this paper presents a fault prediction method for the pitch-controlled system, which is based on the mathematical model of wind turbines physical properties. The residual root mean square (RMS) is used as residual evaluation function. In the end of the paper, by the simulation using the hydraulic pitch actuator fault as the example, the effectiveness of the proposed fault prediction scheme is verified.

Effect of Flow Inclination on Wind Turbine Performance

2012 ◽  
Vol 134 (12) ◽  
Author(s):  
Christina Tsalicoglou ◽  
Sarah Barber ◽  
Ndaona Chokani ◽  
Reza S. Abhari
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Complex Terrain ◽  
Wake Flow ◽  
Test Facility ◽  
Power Coefficient ◽  
Incoming Flow ◽  
Turbine Performance ◽  
The Impact ◽  
Blade Element

This work examines the effect of flow inclination on the performance of a stand-alone wind turbine and of wind turbines operating in the wakes of upstream turbines. The experimental portion of this work, which includes performance and flowfield measurements, is conducted in the ETH dynamically-scaled wind turbine test facility, with a wind turbine model that can be inclined relative to the incoming flow. The performance of the wind turbine is measured with an in-line torquemeter, and a 5-hole steady-state probe is used to detail the inflow and wake flow of the turbine. Measurements show that over a range of tip-speed ratios of 4–7.5, the power coefficient of a wind turbine with an incoming flow of 15 deg inclination decreases on average by 7% relative to the power coefficient of a wind turbine with a noninclined incoming flow. Flowfield measurements show that the wake of a turbine with an inclined incoming flow is deflected; the deflection angle is approximately 6 deg for an incoming flow with 15 deg inclination. The measured wake profiles are used as inflow profiles for a blade element momentum code in order to quantify the impact of flow inclination on the performance of downstream wind turbines. In comparison to the case without inclination in the incoming flow, the combined power output of two aligned turbines with incoming inclined flow decreases by 1%, showing that flow inclination in complex terrain does not significantly reduce the energy production.

Decentralised Control Design for Load Mitigation in Horizontal Axis Wind Turbines (HAWTS)

2011 ◽  
Author(s):  
Fredrik Sandquist ◽  
Geir Moe ◽  
Olimpo Anaya-Lara
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Direct Method ◽  
Modeling And Control ◽  
Energy Capture ◽  
Pitch Control ◽  
Operating Region ◽  
Horizontal Axis Wind Turbines ◽  
Decentralised Control ◽  
And Control

In modern MW-size machines it has become a common practice to introduce controllers that provide active damping of turbine components to reduce blade, tower and drive-train loads, whilst optimising energy capture. However, as wind turbines become larger and more flexible, these controllers have to be designed with great care as the coupling between flexible modes increases and so does the potential to destabilise the turbine. The most direct method to address the above issues has been to exploit the pitch control capabilities. Individual Pitch Control (IPC) has been proposed many times over the last few years for load mitigation. Bearing this in mind, this paper investigates two different approaches to design a controller to pitch each blade individually in the wind turbine operating region III. The first one is a decentralised control algorithm and the second one is an H∞ loop shaping design. A controllability analysis of the wind turbine is also included in the paper. The investigation is conducted based on the NREL 5MW benchmark wind turbine. Turbine modeling and control is conducted in FAST and Simulink.

scholarly journals Peaks in bat activity at turbines and the implications for mitigating the impact of wind energy developments on bats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suzanne M. Richardson ◽  
Paul R. Lintott ◽  
David J. Hosken ◽  
Theo Economou ◽  
Fiona Mathews
Keyword(s):  
Wind Energy ◽  
Wind Turbines ◽  
Wind Farms ◽  
Minimal Impact ◽  
Bat Activity ◽  
Environmental Impact Assessments ◽  
Global Increase ◽  
And Control ◽  
The Impact ◽  
Large Wind

AbstractWind turbines are a relatively new threat to bats, causing mortalities worldwide. Reducing these fatalities is essential to ensure that the global increase in wind-energy facilities can occur with minimal impact on bat populations. Although individual bats have been observed approaching wind turbines, and fatalities frequently reported, it is unclear whether bats are actively attracted to, indifferent to, or repelled by, the turbines at large wind-energy installations. In this study, we assessed bat activity at paired turbine and control locations at 23 British wind farms. The research focussed on Pipistrellus species, which were by far the most abundant bats recorded at these sites. P. pipistrellus activity was 37% higher at turbines than at control locations, whereas P. pygmaeus activity was consistent with no attraction or repulsion by turbines. Given that more than 50% of bat fatalities in Europe are P. pipistrellus, these findings help explain why Environmental Impact Assessments conducted before the installation of turbines are poor predictors of actual fatality rates. They also suggest that operational mitigation (minimising blade rotation in periods of high collision risk) is likely to be the most effective way to reduce collisions because the presence of turbines alters bat activity.

scholarly journals Analisis Regresi Kecepatan Angin Terhadap Daya Turbin Angin Jenis VAWT Tipe Darrieus-Savonius

2018 ◽  
Vol 1 (02) ◽  
pp. 15-20
Author(s):  
Luthfi - Hakim ◽  
Achmad Rijano ◽  
Mochamad Muzaki
Keyword(s):  
Wind Speed ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Maximum Power ◽  
High Wind ◽  
High Wind Speed ◽  
Low Wind Speed ◽  
Turbine Performance

 The Darrieus-Savonius (DS) wind turbine has been widely developed with the aim of improving turbine performance that has been designed. DS wind turbine is a combination of two type of wind turbines, that is Darrieus and Savonius turbine, both turbines are intentionally developed In order to get self-starting on turbine Savonius with low wind speed and able to extract the speed of engine into energy well at high wind speed through Cherrie Darrieus. This study was conducted to analyze the performance of the DS turbine in the wind speed to be energized through the turbine rotation and power to be generated. The DS wind turbine is designed to start rotating at a speed of 8 m/s in velocity of wind, meanwhile the maximum power generated by turbine is 48,23 Watts. 

Effect of Flow Inclination on Wind Turbine Performance

2012 ◽  
Author(s):  
C. Tsalicoglou ◽  
S. Barber ◽  
N. Chokani ◽  
R. S. Abhari
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Field Measurements ◽  
Wake Flow ◽  
Test Facility ◽  
Power Coefficient ◽  
Incoming Flow ◽  
Turbine Performance ◽  
The Impact ◽  
Blade Element

This work examines the effect of flow inclination on the performance of a stand-alone wind turbine and of wind turbines operating in the wakes of upstream turbines. The experimental portion of this work, which includes performance and flow-field measurements, is conducted in the ETH dynamically-scaled wind turbine test facility, with a wind turbine model that can be inclined relative to the incoming flow. The performance of the wind turbine is measured with an in-line torque-meter and a 5-hole steady-state probe is used to detail the inflow and wake flow of the turbine. Measurements show that over a range of tip-speed ratios of 4–7.5, the power coefficient of a wind turbine with an incoming flow of 15-degrees inclination decreases on average by 7% relative to the power coefficient of a wind turbine with a non-inclined incoming flow. Flowfield measurements show that the wake of a turbine with an inclined incoming flow is deflected; the deflection angle is approximately 6-degrees for an incoming flow with 15-degrees inclination. The measured wake profiles are used as inflow profiles for a Blade Element Momentum code in order to quantify the impact of flow inclination on the performance of downstream wind turbines. In comparison to the case without inclination in the incoming flow, the combined power output of two aligned turbines with incoming inclined flow decreases by 1%, showing that flow inclination in complex terrain does not significantly reduce the energy production.

Effect of Solidity on Performance of Vertical Axis Wind Turbine Using Constant Chord Reynolds Number

2021 ◽  
Author(s):  
Anirudh P ◽  
Ratna Kishore Velamati ◽  
Srinath K S ◽  
Unnikrishnan D
Keyword(s):  
Reynolds Number ◽  
Wind Turbine ◽  
Wind Turbines ◽  
Cfd Simulation ◽  
Vertical Axis ◽  
Coefficient Of Performance ◽  
Vertical Axis Wind Turbine ◽  
Number Range ◽  
Turbine Performance ◽  
The Impact

Abstract The demand for wind turbines has increased ever since fossil fuels showed signs of quick depletion. Among wind turbines, Vertical Axis Wind Turbine (VAWT) is compact, produces less noise, is omnidirectional, resilient to turbulent flow, and is easy to maintain. The power generated by a VAWT is a function of a non-dimensional geometric parameter known as solidity (s), which is a function of turbine diameter (D), blade chord (c) and the number of blades (n). The present work analyses the impact of solidity (0.12 and 0.18) as a complete non-dimensional parameter on wind turbine performance. Each parameter of solidity is varied, keeping any one of the parameters constant and numerically studied for its performance across a range of tip speed ratios (TSR). For each solidity, six different combinations of VAWT geometric parameters were analyzed. In all the cases, the chord Reynolds number is kept constant. CFD simulation was performed on the Darrieus H-type (NACA0018 airfoil) VAWT. Two dimensional (2D) computational domains are used to study the effect on the turbine’s performance as the solidity studied is less than 0.4. Unsteady Reynolds-Averaged Navier-strokes (URANS) equation is used to solve the CFD model using ANSYS Fluent 19.1 with 4-equation transition SST k-ω for turbulence modelling. The comprehensive study of the turbine performance keeping the turbine operation within a constant Re number range shows the Coefficient of Performance (Cp) overlaps for a given solidity.

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