Overview presentation on the impact of atmospheric turbulence on the dynamic response of wind turbines derived from 20 years of research at the National Renewable Energy Laboratory.
The stable atmospheric boundary layer a challenge for wind turbine operatio...ndkelley
An overview presentation of the impact and challenge of the stable atmospheric boundary layer on wind turbine dynamics presented to AGU Fall Meeting 2008
Nwtc turb sim workshop september 22 24, 2008- site specific modelsndkelley
1) The document describes several inflow turbulence models available in the TurbSim code developed by NREL, including models based on standard IEC conditions, smooth homogeneous terrain, specific wind farm sites, complex mountainous terrain, and a North American high plains site.
2) Comparisons of simulation results using the IEC, Great Plains, and NWTC models show differences in predicted blade loads, rotor torque, bending moments and tip deflections when applied to the NREL 5 MW reference turbine.
3) In particular, the Great Plains model including a low-level jet produced significantly higher loads and deflections compared to the standard IEC model, demonstrating the importance of using site-specific models.
This document summarizes an empirical study on enhancing convective heat transfer using aluminum oxide nanoaerosols. The study aims to experimentally investigate heat transfer enhancement at low particle concentrations compared to nanofluids. An experimental setup is used to measure the Nusselt number with and without nanoparticles injected into an air flow over a range of Reynolds numbers. Results show increases in Nusselt number with higher particle mass loading that depend on the Reynolds number. A continuum model is presented to predict the enhancement based on increased thermal capacity. Models for free molecular and transition regimes are also discussed to predict behavior at different particle sizes and concentrations.
Understanding of the geomagnetic storm environment for high voltage power gridsPower System Operation
Geomagnetic disturbances (GMDs) on the Earth originate at the
Sun and can cause many different impacts on critical systems
including power grids, metallic communications systems,
railways, and pipelines, among others
• The focus in this study was on high-voltage power systems,
which are defined by the IEC as transmission grids operating at
voltages above 100 kV (and usually at much higher voltages)
• The emphasis on high voltage is because at the present time
most of the power delivered to end users is concentrated in the
delivery system from large power plants to the cities where the
power is used
• In order to understand the effect of GMDs on the power system,
we need to understand the basic types of geomagnetic storms,
the B-fields they create and how they may affect the power
system
Larry Hebert has over 30 years of experience as a senior electrical and controls engineer working on projects in industries including oil and gas pipelines, mining, manufacturing, semiconductor fabrication, and cleanrooms. He has extensive experience designing electrical systems, instrumentation and control systems, and substations for facilities and projects across North America and Asia. Some of his representative projects include serving as the electrical lead for pump stations on the Enbridge Wood Buffalo Extension Project in Alberta, Canada and high voltage substation design for the Enbridge Alberta Clipper project pipeline connecting Alberta to Chicago.
This report summarizes wind data collected from two meteorological towers over a 32 month period from 2006-2009. The data was used to assess the wind resource and estimate potential energy production from a horizontal axis and vertical axis wind turbine. Key findings include:
- Average monthly wind capacity at the tower location was 31% for a horizontal axis turbine and 17% for a vertical axis turbine during the initial 12 month study period.
- Wind capacity averaged 27% for the horizontal axis turbine and 15% for the vertical axis turbine during the 2008-2009 study period.
- June, July and August typically had the lowest wind velocities of the year according to the historical data collected.
Edward X. Ruebling is a mechanical engineer with over 30 years of experience in process and power equipment design, construction support, field engineering, project management, and equipment installation. He has worked on oil and gas projects in Alaska for ConocoPhillips, Chevron, ASRC Energy Services, and BP. He is a registered professional engineer in Alaska and Missouri.
The stable atmospheric boundary layer a challenge for wind turbine operatio...ndkelley
An overview presentation of the impact and challenge of the stable atmospheric boundary layer on wind turbine dynamics presented to AGU Fall Meeting 2008
Nwtc turb sim workshop september 22 24, 2008- site specific modelsndkelley
1) The document describes several inflow turbulence models available in the TurbSim code developed by NREL, including models based on standard IEC conditions, smooth homogeneous terrain, specific wind farm sites, complex mountainous terrain, and a North American high plains site.
2) Comparisons of simulation results using the IEC, Great Plains, and NWTC models show differences in predicted blade loads, rotor torque, bending moments and tip deflections when applied to the NREL 5 MW reference turbine.
3) In particular, the Great Plains model including a low-level jet produced significantly higher loads and deflections compared to the standard IEC model, demonstrating the importance of using site-specific models.
This document summarizes an empirical study on enhancing convective heat transfer using aluminum oxide nanoaerosols. The study aims to experimentally investigate heat transfer enhancement at low particle concentrations compared to nanofluids. An experimental setup is used to measure the Nusselt number with and without nanoparticles injected into an air flow over a range of Reynolds numbers. Results show increases in Nusselt number with higher particle mass loading that depend on the Reynolds number. A continuum model is presented to predict the enhancement based on increased thermal capacity. Models for free molecular and transition regimes are also discussed to predict behavior at different particle sizes and concentrations.
Understanding of the geomagnetic storm environment for high voltage power gridsPower System Operation
Geomagnetic disturbances (GMDs) on the Earth originate at the
Sun and can cause many different impacts on critical systems
including power grids, metallic communications systems,
railways, and pipelines, among others
• The focus in this study was on high-voltage power systems,
which are defined by the IEC as transmission grids operating at
voltages above 100 kV (and usually at much higher voltages)
• The emphasis on high voltage is because at the present time
most of the power delivered to end users is concentrated in the
delivery system from large power plants to the cities where the
power is used
• In order to understand the effect of GMDs on the power system,
we need to understand the basic types of geomagnetic storms,
the B-fields they create and how they may affect the power
system
Larry Hebert has over 30 years of experience as a senior electrical and controls engineer working on projects in industries including oil and gas pipelines, mining, manufacturing, semiconductor fabrication, and cleanrooms. He has extensive experience designing electrical systems, instrumentation and control systems, and substations for facilities and projects across North America and Asia. Some of his representative projects include serving as the electrical lead for pump stations on the Enbridge Wood Buffalo Extension Project in Alberta, Canada and high voltage substation design for the Enbridge Alberta Clipper project pipeline connecting Alberta to Chicago.
This report summarizes wind data collected from two meteorological towers over a 32 month period from 2006-2009. The data was used to assess the wind resource and estimate potential energy production from a horizontal axis and vertical axis wind turbine. Key findings include:
- Average monthly wind capacity at the tower location was 31% for a horizontal axis turbine and 17% for a vertical axis turbine during the initial 12 month study period.
- Wind capacity averaged 27% for the horizontal axis turbine and 15% for the vertical axis turbine during the 2008-2009 study period.
- June, July and August typically had the lowest wind velocities of the year according to the historical data collected.
Edward X. Ruebling is a mechanical engineer with over 30 years of experience in process and power equipment design, construction support, field engineering, project management, and equipment installation. He has worked on oil and gas projects in Alaska for ConocoPhillips, Chevron, ASRC Energy Services, and BP. He is a registered professional engineer in Alaska and Missouri.
This document summarizes the key findings and recommendations from a research project on design methods for offshore wind turbines installed at exposed sites. The project involved detailed measurements and analysis of environmental conditions and structural loads on a turbine in the Blyth offshore wind farm. Key findings include: waves in shallow water require non-linear modeling; site-specific wave and wind data should be used; design tools were enhanced and validated; foundation models need to account for soil properties; hydrodynamic loading models were evaluated. Recommendations include: revising certification rules to specify wave modeling and extreme loads; developing standard machinery designs while customizing support structures; accounting for water depth and non-linear waves in design.
This document discusses wind resource assessment for wind farm development. It covers how wind is generated, accessing wind resources through measurement and modeling, and estimating energy production with uncertainties. Key steps include measuring wind speeds on site, correlating to long-term reference stations to predict long-term distributions, modeling wind flows, planning turbine layouts, and estimating annual energy yields while accounting for production losses and uncertainties. Accurate wind assessment is critical for maximizing energy production estimates and ensuring project viability.
The Havsnäs Pilot Project had three main goals: 1) to help remove barriers to large scale onshore wind development in northern Sweden by studying nature impacts, project finance, and foundation design; 2) to research technical areas like high hub heights and cold climate effects; and 3) to improve knowledge of wind resource assessment, power performance, and icing impacts. Key findings included that mast spacing affected flow modelling uncertainty, multi-point shear methods best characterized profiles, and remote sensing validated shear above measurement heights. Icing reduced annual yield by an estimated 4.1%.
This document provides a resume for Stephen L. Davidson, a mechanical engineer with over 30 years of experience managing projects in petroleum refining, petrochemical, power generation, and hazardous waste industries. It lists his education, licenses, skills, and extensive work history managing complex capital projects from inception through commissioning. His background includes expertise in process engineering, piping, mechanical, electrical, and instrumentation systems with a strong emphasis on safety.
HELICAL & STRUCTURAL SYSTEMS, LLC installs structural foundation support for various clients/projects, including environmental, new construction and repair type projects. Such as house razing/new footings, retaining well construction/repair, sea walls, bulkhead, piers, cell tower installations, solar lighting field installations, bridge, walkway and ramp installations.
The document provides an overview of wind turbine design from an aerodynamic perspective. It discusses that wind turbine design is an interdisciplinary optimization problem that involves choosing parameters like the number of blades, blade radius, twist distribution, airfoils, and RPM based on considerations of cost, noise, fatigue, and other factors. It also reviews existing wind turbine concepts and references on rotor design studies to help inform the design process.
This document provides an overview of the BLACKBIRD concept, which is a hybrid floating offshore wind turbine and wave energy converter system. The key elements discussed include a vertical axis wind turbine, uniaxial submerged tension leg buoy float, linear magnetic geared interior permanent magnet generator, integrated power takeoff units, single vertical damped tether, subsea ball and taper connector, subsea concrete storage and electrolysis unit, and seabed rock anchored foundation template. The document also discusses challenges with existing offshore wind technologies and the potential benefits of the BLACKBIRD concept.
Vortex generators were installed on over 500 turbines in 2014 to study their effects on reliability and performance. Trials showed that VGs provided production gains compared to unmodified turbines, though the gains were small and validation is challenging. VGs were found to positively impact airflow attachment along turbine blades to reduce stall effects. Testing also indicated that VGs may impact wind sensor readings on nacelles.
5 ijcmes dec-2015-3-investigation of traffic induced vibrations and luminaire...INFOGAIN PUBLICATION
Since the mid-1980s there has been numerous research on vibration and fatigue of traffic signal and sign structures. Recently, it has been recognized that both wind and traffic can cause vibration problems in roadway lighting and that the more severe problems usually exist on bridges where both wind and traffic provide exciting forces. Lighting manufacturers are primarily concerned with damaging fatigue that can cause structural failure of luminaires, but departments of transportation also are interested in excessive lamp failures. Usually excessive lamp failures are found in bridge lighting installations for poles located away from bridge supports. This paper summarizes research efforts made in the recent past to investigate the relationship between traffic induced vibrations and luminaire failures on a cable-stayed bridge.
1115161Wind Power Now, Tomorrow C.P. (Case) .docxpaynetawnya
11/15/16
1
Wind Power:
Now, Tomorrow
C.P. (Case) van Dam
EME-1
Mechanical Engineering
November 14, 2016
How does it function?
11/15/16
2
Wind Turbine Power
• The amount of power generated by a turbine depends on the power in
the wind and the efficiency of the turbine:
• Power in wind
• Efficiency or Power Coefficient, Cp:
– Rotor (Conversion of wind power to mechanical power)
– Gearbox (Change in rpm)
– Generator & Inverter (Conversion of mechanical power to electrical power)
Power
Turbine
!
"#
$
%&
=
Efficiency
Factor
!
"#
$
%&
×
Power
Wind
!
"#
$
%&
P
w
= 1
2
ρA
d
V
w
3
Basic Rotor Performance
(Momentum Theory)
Wind speed, Vw
Air density, ρ
Disk area, Ad
Power in wind, Pw = 1/2 ρ Vw3 Ad
Maximum rotor power, P = 16/27 Pw
Rotor efficiency, Cp = P / Pw
Betz limit, max Cp = 16/27 = 59.3%
11/15/16
3
Region 4
• Region 1
Turbine is stopped or
starting up
• Region 2
Efficiency maximized
by maintaining
optimum rotor RPM
(for variable speed
turbine)
• Region 3
Power limited through
blade pitch
• Region 4
Turbine is stopped
due to high winds
(loads)
HAWT Power Characteristics
Johnson et al (2005)
• Peak Cp at TSR = 9
• This Cp is maintained in Region II of power curve by controlling rotor RPM
• In Region III power is controlled by changing blade pitch.
HAWT Cp-TSR Curve
Jackson (2005)
11/15/16
4
• Cp = Protor / (1/2 ρ Vw3 Ad)
• Solidity = Blade Area / Ad
• TSR = Tip Speed / Vw
• High power efficiency for
rotors with low solidity and
high TSR
• Darrieus (VAWT) is less
efficient than HAWT
Efficiency of Various Rotor
Designs
Butterfield (2008)
Cp
Tip Speed Ratio TSR = π D RPM / (60 Vw)
kidwind.org
C.P. van Dam
Dutch Mill
16th century
Water pumping, Grinding materials/grain
W. Gretz, DOE/NREL
Persian grain mill
9th century
American Multi-blade
19th century
Water pumping - irrigation
Brush Mill
1888
First wind turbine
12 kW
17 m rotor diameter
Charles F. Brush Special Collection,
Case Western Reserve University
telos.net/wind
Gedser Mill
1956, Denmark
Forerunner to modern wind
turbines
11/15/16
5
Evolution of U.S. Utility-Scale
Wind Turbine Technology
NREL
Wind Turbine Scale-Up and Impact on Cost
U.S. DOE, Wind Vision, March 2015
• Scale-up has been effective in reducing cost but uncertain if this trend can continue
11/15/16
6
Modern Wind
Turbines
• 1.0-3.0 MW
• Wind speeds: 3-25 m/s
– Rated power at 11-12 m/s
• Rotor
– Lift driven
– 3 blades
– Upwind
– Full blade pitch
– 70–120 m diameter
– 5-20 RPM
– Fiberglass, some carbon fiber
• Active yaw
• Steel tubular tower
• Installed in plants/farms of 100-200 MW
• ~40% capacity factor
– 1.5 MW wind turbine would generate
about 5,250,000 kWh per year
– Average household in California uses
about 6,000 kWh per year
Vestas
V90-3.0
MW
11/15/16
7
Technical Specificat ...
This document provides an overview of wind energy and the wind industry in Quebec and Canada. It discusses the basics of how wind is generated and how that kinetic energy is captured by wind turbines to generate electricity. It describes the major components of modern wind turbines, including foundations, towers, nacelles, rotors, and hubs. The document outlines how wind farms are constructed and how the electricity is integrated into the grid. It also addresses the intermittency of wind and how geographical dispersion of turbines can help reduce variability. The document reviews environmental permitting requirements and potential impacts of wind projects as well as life cycle analyses. It provides details on the Vents du Kempt wind farm project in Quebec and discusses future plans for wind development in
This document provides an overview of wind energy and wind turbines. It discusses the advantages of wind energy such as being clean and having an abundant domestic source. It also discusses disadvantages like intermittency and land use impacts. The document describes different types of wind turbines including horizontal and vertical axis designs. It provides information on wind resources and wind power potential in the United States. Key concepts in wind turbine operation and aerodynamics are explained like Betz's law. Cost trends for wind power and the future outlook of the industry are also summarized.
Vortex bladeless wind energy works by maximizing vortex shedding from a vertical mast to generate electricity. As wind flows past the mast, vortices are shed at specific frequencies depending on wind speed. The mast oscillates from the vortex shedding, and this kinetic energy is converted to electricity by a generator located at the base. Vortex bladeless has advantages over traditional wind turbines in that it has no moving parts high above the ground, is more bird-friendly, and can operate at lower wind speeds. While efficiency can be improved, it provides an innovative new approach to harnessing wind power without blades.
IRJET - Design & Construction of Combined Axis Wind Turbine with Solar Power ...IRJET Journal
This document describes the design and construction of a combined horizontal and vertical axis wind turbine with solar panels. It begins with an introduction to renewable energy sources and the benefits of wind and solar power. It then provides details on the components and operation of horizontal axis wind turbines, followed by vertical axis wind turbines. The materials and components used in this combined design are outlined. Diagrams and tables showing the setup and power generated from each energy source are included. The conclusions discuss the results and benefits of generating clean electricity from renewable wind and solar energy.
Excipio Energy offshore renewables 2016Roy Robinson
Excipio Energy aims to harness offshore renewable energy, starting with steady ocean currents in the Gulf of Mexico using existing oil and gas infrastructure. Its mission is to make offshore renewable energy the most profitable, safe and reliable global energy source. It plans to initially generate power from ocean currents and later expand to technologies like offshore wind, waves and OTEC. Excipio believes offshore renewable platforms can serve as bases for aquaculture and research while avoiding many risks associated with oil and gas extraction.
OZ Assignment Help leading in Assignment services in Australia, ECE464 Power Electronics Assignment Solution discuss renewable energy source, energy facility
Engineering challenges for future wind energy development, 11th h.t. person l...ndkelley
The document discusses engineering challenges for future wind energy development. It outlines goals of providing 20% of US electricity from wind by 2030, but barriers like transmission, resource assessment accuracy, and turbine response to turbulence must be overcome. Key challenges are understanding turbulence's impact on turbine loads, collaborating with meteorologists on wind forecasts, and developing offshore wind platforms and solutions for the complex offshore environment. Success will require a multidisciplinary approach across engineering and atmospheric science.
The document discusses wind energy engineering and wind resource assessment in India. It provides details on topics like the history of wind power, types of wind turbines, wind data collection using anemometers, India's wind power potential sites and installed capacity. It also summarizes the process of wind resource assessment implemented in India through agencies like the Centre for Wind Energy Technology to study wind patterns and identify viable locations for wind farms.
- The document describes the design and testing of a homemade PVC wind turbine by students at Sagar Institute of Research & Technology in Bhopal.
- It includes sections on the components of wind turbines, how PVC was used for the turbine blades, and the experimental setup testing the turbine's ability to generate power from wind energy using PVC blades.
- The students found that the PVC blade profile generated better power capacity as the rotational speed of the rotor increased. Further testing is needed to confirm these initial results showing the potential of PVC blades for small wind turbines.
CONTRIBUTEDP A P E RHigh-Power Wind EnergyConversion S.docxdonnajames55
CONTRIBUTED
P A P E R
High-Power Wind Energy
Conversion Systems:
State-of-the-Art and
Emerging Technologies
Wind energy installed capacity increased exponentially over the past three decades,
and has become a real alternative to increase renewable energy penetration
into the energy mix.
By Venkata Yaramasu, Member IEEE, Bin Wu, Fellow IEEE, Paresh C. Sen, Life Fellow IEEE,
Samir Kouro, Member IEEE, and Mehdi Narimani, Member IEEE
ABSTRACT | This paper presents a comprehensive study on the
state-of-the-art and emerging wind energy technologies from
the electrical engineering perspective. In an attempt to de-
crease cost of energy, increase the wind energy conversion
efficiency, reliability, power density, and comply with the strin-
gent grid codes, the electric generators and power electronic
converters have emerged in a rigorous manner. From the mar-
ket based survey, the most successful generator-converter
configurations are addressed along with few promising topol-
ogies available in the literature. The back-to-back connected
converters, passive generator-side converters, converters for
multiphase generators, and converters without intermediate
dc-link are investigated for high-power wind energy conver-
sion systems (WECS), and presented in low and medium voltage
category. The onshore and offshore wind farm configurations
are analyzed with respect to the series/parallel connection of
wind turbine ac/dc output terminals, and high voltage ac/dc
transmission. The fault-ride through compliance methods used
in the induction and synchronous generator based WECS are
also discussed. The past, present and future trends in megawatt
WECS are reviewed in terms of mechanical and electrical tech-
nologies, integration to power systems, and control theory. The
important survey results, and technical merits and demerits of
various WECS electrical systems are summarized by tables. The
list of current and future wind turbines are also provided along
with technical details.
KEYWORDS | ac-ac; ac-dc; dc-ac; dc-dc power conversion;
doubly fed induction generator (DFIG); fault-ride through (FRT);
grid codes; low voltage (LV); medium voltage (MV); multilevel
converters; permanent magnet synchronous generator (PMSG);
power electronics; squirrel cage induction generator (SCIG);
wind energy conversion systems (WECS); wind farms; wound
rotor induction generator (WRIG); wound rotor synchronous
generator (WRSG)
I . I N T R O D U C T I O N
Due to depleting fossil fuels and environmental concerns
about global warming, renewable energy sources have
emerged as a new paradigm to fulfill the energy needs of
our society. In recent years, electricity production from the
hydro, solar, wind, geothermal, tidal, wave and biomass
energy sources has come under increasing attention [1],
[2]. By 2012, the power production from renewable energy
sources worldwide exceeded 1470 gigawatt (GW) repre-
senting approximately 19% of global energy co.
This document summarizes the key findings and recommendations from a research project on design methods for offshore wind turbines installed at exposed sites. The project involved detailed measurements and analysis of environmental conditions and structural loads on a turbine in the Blyth offshore wind farm. Key findings include: waves in shallow water require non-linear modeling; site-specific wave and wind data should be used; design tools were enhanced and validated; foundation models need to account for soil properties; hydrodynamic loading models were evaluated. Recommendations include: revising certification rules to specify wave modeling and extreme loads; developing standard machinery designs while customizing support structures; accounting for water depth and non-linear waves in design.
This document discusses wind resource assessment for wind farm development. It covers how wind is generated, accessing wind resources through measurement and modeling, and estimating energy production with uncertainties. Key steps include measuring wind speeds on site, correlating to long-term reference stations to predict long-term distributions, modeling wind flows, planning turbine layouts, and estimating annual energy yields while accounting for production losses and uncertainties. Accurate wind assessment is critical for maximizing energy production estimates and ensuring project viability.
The Havsnäs Pilot Project had three main goals: 1) to help remove barriers to large scale onshore wind development in northern Sweden by studying nature impacts, project finance, and foundation design; 2) to research technical areas like high hub heights and cold climate effects; and 3) to improve knowledge of wind resource assessment, power performance, and icing impacts. Key findings included that mast spacing affected flow modelling uncertainty, multi-point shear methods best characterized profiles, and remote sensing validated shear above measurement heights. Icing reduced annual yield by an estimated 4.1%.
This document provides a resume for Stephen L. Davidson, a mechanical engineer with over 30 years of experience managing projects in petroleum refining, petrochemical, power generation, and hazardous waste industries. It lists his education, licenses, skills, and extensive work history managing complex capital projects from inception through commissioning. His background includes expertise in process engineering, piping, mechanical, electrical, and instrumentation systems with a strong emphasis on safety.
HELICAL & STRUCTURAL SYSTEMS, LLC installs structural foundation support for various clients/projects, including environmental, new construction and repair type projects. Such as house razing/new footings, retaining well construction/repair, sea walls, bulkhead, piers, cell tower installations, solar lighting field installations, bridge, walkway and ramp installations.
The document provides an overview of wind turbine design from an aerodynamic perspective. It discusses that wind turbine design is an interdisciplinary optimization problem that involves choosing parameters like the number of blades, blade radius, twist distribution, airfoils, and RPM based on considerations of cost, noise, fatigue, and other factors. It also reviews existing wind turbine concepts and references on rotor design studies to help inform the design process.
This document provides an overview of the BLACKBIRD concept, which is a hybrid floating offshore wind turbine and wave energy converter system. The key elements discussed include a vertical axis wind turbine, uniaxial submerged tension leg buoy float, linear magnetic geared interior permanent magnet generator, integrated power takeoff units, single vertical damped tether, subsea ball and taper connector, subsea concrete storage and electrolysis unit, and seabed rock anchored foundation template. The document also discusses challenges with existing offshore wind technologies and the potential benefits of the BLACKBIRD concept.
Vortex generators were installed on over 500 turbines in 2014 to study their effects on reliability and performance. Trials showed that VGs provided production gains compared to unmodified turbines, though the gains were small and validation is challenging. VGs were found to positively impact airflow attachment along turbine blades to reduce stall effects. Testing also indicated that VGs may impact wind sensor readings on nacelles.
5 ijcmes dec-2015-3-investigation of traffic induced vibrations and luminaire...INFOGAIN PUBLICATION
Since the mid-1980s there has been numerous research on vibration and fatigue of traffic signal and sign structures. Recently, it has been recognized that both wind and traffic can cause vibration problems in roadway lighting and that the more severe problems usually exist on bridges where both wind and traffic provide exciting forces. Lighting manufacturers are primarily concerned with damaging fatigue that can cause structural failure of luminaires, but departments of transportation also are interested in excessive lamp failures. Usually excessive lamp failures are found in bridge lighting installations for poles located away from bridge supports. This paper summarizes research efforts made in the recent past to investigate the relationship between traffic induced vibrations and luminaire failures on a cable-stayed bridge.
1115161Wind Power Now, Tomorrow C.P. (Case) .docxpaynetawnya
11/15/16
1
Wind Power:
Now, Tomorrow
C.P. (Case) van Dam
EME-1
Mechanical Engineering
November 14, 2016
How does it function?
11/15/16
2
Wind Turbine Power
• The amount of power generated by a turbine depends on the power in
the wind and the efficiency of the turbine:
• Power in wind
• Efficiency or Power Coefficient, Cp:
– Rotor (Conversion of wind power to mechanical power)
– Gearbox (Change in rpm)
– Generator & Inverter (Conversion of mechanical power to electrical power)
Power
Turbine
!
"#
$
%&
=
Efficiency
Factor
!
"#
$
%&
×
Power
Wind
!
"#
$
%&
P
w
= 1
2
ρA
d
V
w
3
Basic Rotor Performance
(Momentum Theory)
Wind speed, Vw
Air density, ρ
Disk area, Ad
Power in wind, Pw = 1/2 ρ Vw3 Ad
Maximum rotor power, P = 16/27 Pw
Rotor efficiency, Cp = P / Pw
Betz limit, max Cp = 16/27 = 59.3%
11/15/16
3
Region 4
• Region 1
Turbine is stopped or
starting up
• Region 2
Efficiency maximized
by maintaining
optimum rotor RPM
(for variable speed
turbine)
• Region 3
Power limited through
blade pitch
• Region 4
Turbine is stopped
due to high winds
(loads)
HAWT Power Characteristics
Johnson et al (2005)
• Peak Cp at TSR = 9
• This Cp is maintained in Region II of power curve by controlling rotor RPM
• In Region III power is controlled by changing blade pitch.
HAWT Cp-TSR Curve
Jackson (2005)
11/15/16
4
• Cp = Protor / (1/2 ρ Vw3 Ad)
• Solidity = Blade Area / Ad
• TSR = Tip Speed / Vw
• High power efficiency for
rotors with low solidity and
high TSR
• Darrieus (VAWT) is less
efficient than HAWT
Efficiency of Various Rotor
Designs
Butterfield (2008)
Cp
Tip Speed Ratio TSR = π D RPM / (60 Vw)
kidwind.org
C.P. van Dam
Dutch Mill
16th century
Water pumping, Grinding materials/grain
W. Gretz, DOE/NREL
Persian grain mill
9th century
American Multi-blade
19th century
Water pumping - irrigation
Brush Mill
1888
First wind turbine
12 kW
17 m rotor diameter
Charles F. Brush Special Collection,
Case Western Reserve University
telos.net/wind
Gedser Mill
1956, Denmark
Forerunner to modern wind
turbines
11/15/16
5
Evolution of U.S. Utility-Scale
Wind Turbine Technology
NREL
Wind Turbine Scale-Up and Impact on Cost
U.S. DOE, Wind Vision, March 2015
• Scale-up has been effective in reducing cost but uncertain if this trend can continue
11/15/16
6
Modern Wind
Turbines
• 1.0-3.0 MW
• Wind speeds: 3-25 m/s
– Rated power at 11-12 m/s
• Rotor
– Lift driven
– 3 blades
– Upwind
– Full blade pitch
– 70–120 m diameter
– 5-20 RPM
– Fiberglass, some carbon fiber
• Active yaw
• Steel tubular tower
• Installed in plants/farms of 100-200 MW
• ~40% capacity factor
– 1.5 MW wind turbine would generate
about 5,250,000 kWh per year
– Average household in California uses
about 6,000 kWh per year
Vestas
V90-3.0
MW
11/15/16
7
Technical Specificat ...
This document provides an overview of wind energy and the wind industry in Quebec and Canada. It discusses the basics of how wind is generated and how that kinetic energy is captured by wind turbines to generate electricity. It describes the major components of modern wind turbines, including foundations, towers, nacelles, rotors, and hubs. The document outlines how wind farms are constructed and how the electricity is integrated into the grid. It also addresses the intermittency of wind and how geographical dispersion of turbines can help reduce variability. The document reviews environmental permitting requirements and potential impacts of wind projects as well as life cycle analyses. It provides details on the Vents du Kempt wind farm project in Quebec and discusses future plans for wind development in
This document provides an overview of wind energy and wind turbines. It discusses the advantages of wind energy such as being clean and having an abundant domestic source. It also discusses disadvantages like intermittency and land use impacts. The document describes different types of wind turbines including horizontal and vertical axis designs. It provides information on wind resources and wind power potential in the United States. Key concepts in wind turbine operation and aerodynamics are explained like Betz's law. Cost trends for wind power and the future outlook of the industry are also summarized.
Vortex bladeless wind energy works by maximizing vortex shedding from a vertical mast to generate electricity. As wind flows past the mast, vortices are shed at specific frequencies depending on wind speed. The mast oscillates from the vortex shedding, and this kinetic energy is converted to electricity by a generator located at the base. Vortex bladeless has advantages over traditional wind turbines in that it has no moving parts high above the ground, is more bird-friendly, and can operate at lower wind speeds. While efficiency can be improved, it provides an innovative new approach to harnessing wind power without blades.
IRJET - Design & Construction of Combined Axis Wind Turbine with Solar Power ...IRJET Journal
This document describes the design and construction of a combined horizontal and vertical axis wind turbine with solar panels. It begins with an introduction to renewable energy sources and the benefits of wind and solar power. It then provides details on the components and operation of horizontal axis wind turbines, followed by vertical axis wind turbines. The materials and components used in this combined design are outlined. Diagrams and tables showing the setup and power generated from each energy source are included. The conclusions discuss the results and benefits of generating clean electricity from renewable wind and solar energy.
Excipio Energy offshore renewables 2016Roy Robinson
Excipio Energy aims to harness offshore renewable energy, starting with steady ocean currents in the Gulf of Mexico using existing oil and gas infrastructure. Its mission is to make offshore renewable energy the most profitable, safe and reliable global energy source. It plans to initially generate power from ocean currents and later expand to technologies like offshore wind, waves and OTEC. Excipio believes offshore renewable platforms can serve as bases for aquaculture and research while avoiding many risks associated with oil and gas extraction.
OZ Assignment Help leading in Assignment services in Australia, ECE464 Power Electronics Assignment Solution discuss renewable energy source, energy facility
Engineering challenges for future wind energy development, 11th h.t. person l...ndkelley
The document discusses engineering challenges for future wind energy development. It outlines goals of providing 20% of US electricity from wind by 2030, but barriers like transmission, resource assessment accuracy, and turbine response to turbulence must be overcome. Key challenges are understanding turbulence's impact on turbine loads, collaborating with meteorologists on wind forecasts, and developing offshore wind platforms and solutions for the complex offshore environment. Success will require a multidisciplinary approach across engineering and atmospheric science.
The document discusses wind energy engineering and wind resource assessment in India. It provides details on topics like the history of wind power, types of wind turbines, wind data collection using anemometers, India's wind power potential sites and installed capacity. It also summarizes the process of wind resource assessment implemented in India through agencies like the Centre for Wind Energy Technology to study wind patterns and identify viable locations for wind farms.
- The document describes the design and testing of a homemade PVC wind turbine by students at Sagar Institute of Research & Technology in Bhopal.
- It includes sections on the components of wind turbines, how PVC was used for the turbine blades, and the experimental setup testing the turbine's ability to generate power from wind energy using PVC blades.
- The students found that the PVC blade profile generated better power capacity as the rotational speed of the rotor increased. Further testing is needed to confirm these initial results showing the potential of PVC blades for small wind turbines.
CONTRIBUTEDP A P E RHigh-Power Wind EnergyConversion S.docxdonnajames55
CONTRIBUTED
P A P E R
High-Power Wind Energy
Conversion Systems:
State-of-the-Art and
Emerging Technologies
Wind energy installed capacity increased exponentially over the past three decades,
and has become a real alternative to increase renewable energy penetration
into the energy mix.
By Venkata Yaramasu, Member IEEE, Bin Wu, Fellow IEEE, Paresh C. Sen, Life Fellow IEEE,
Samir Kouro, Member IEEE, and Mehdi Narimani, Member IEEE
ABSTRACT | This paper presents a comprehensive study on the
state-of-the-art and emerging wind energy technologies from
the electrical engineering perspective. In an attempt to de-
crease cost of energy, increase the wind energy conversion
efficiency, reliability, power density, and comply with the strin-
gent grid codes, the electric generators and power electronic
converters have emerged in a rigorous manner. From the mar-
ket based survey, the most successful generator-converter
configurations are addressed along with few promising topol-
ogies available in the literature. The back-to-back connected
converters, passive generator-side converters, converters for
multiphase generators, and converters without intermediate
dc-link are investigated for high-power wind energy conver-
sion systems (WECS), and presented in low and medium voltage
category. The onshore and offshore wind farm configurations
are analyzed with respect to the series/parallel connection of
wind turbine ac/dc output terminals, and high voltage ac/dc
transmission. The fault-ride through compliance methods used
in the induction and synchronous generator based WECS are
also discussed. The past, present and future trends in megawatt
WECS are reviewed in terms of mechanical and electrical tech-
nologies, integration to power systems, and control theory. The
important survey results, and technical merits and demerits of
various WECS electrical systems are summarized by tables. The
list of current and future wind turbines are also provided along
with technical details.
KEYWORDS | ac-ac; ac-dc; dc-ac; dc-dc power conversion;
doubly fed induction generator (DFIG); fault-ride through (FRT);
grid codes; low voltage (LV); medium voltage (MV); multilevel
converters; permanent magnet synchronous generator (PMSG);
power electronics; squirrel cage induction generator (SCIG);
wind energy conversion systems (WECS); wind farms; wound
rotor induction generator (WRIG); wound rotor synchronous
generator (WRSG)
I . I N T R O D U C T I O N
Due to depleting fossil fuels and environmental concerns
about global warming, renewable energy sources have
emerged as a new paradigm to fulfill the energy needs of
our society. In recent years, electricity production from the
hydro, solar, wind, geothermal, tidal, wave and biomass
energy sources has come under increasing attention [1],
[2]. By 2012, the power production from renewable energy
sources worldwide exceeded 1470 gigawatt (GW) repre-
senting approximately 19% of global energy co.
An Overview of Wind Power Generation and Design Aspects in Indiaijiert bestjournal
There is huge activity in wind power,pan-India with the instal led capacity increasing to 10,000MW. India today has the fifth largest installed capacity of wind power in the world w ith 11087MW installed capacity and potential for on-shore capabilities of 65000MW. However the plant load factor (PLF) in wi nd power generation is very low,often in the single digits. The increase in interest in wind energy is due to inves tment subsidies,tax holidays,and government action towards renewable energy playing a big part in nation�s energy system. T here is a need to generate environment friendly power that not only raises energy efficiency and is sustainable too. The time has come for moving to generation based subsidies and understanding the drawbacks associated with wind power in India. The capital cost of wind power is third higher than Conventional thermal power;further electrical problems like v oltage flicker and variable frequency affect the implementation of wind farm. However advances in technologies such as offshore construction of wind turbines,advanced control methodologies,and simulation of wind energy affecting over all grid performance are making a case for wind energy.
Lloyd's Register Energy presented on modelling techniques for tidal arrays. They discussed their previous work modelling single turbines and arrays using computational fluid dynamics. Their goals for array simulations were to investigate turbine loading, power performance, and wakes with and without waves. They demonstrated steady state simulations of a 3x3 tidal turbine array using multiple rotating reference frames with and without kinematic waves included. The results showed the turbine wake was influenced by waves and their choice of wave modelling depended on parameters like wave height and period. They concluded by discussing continuing their investigation of turbines' influence on free surfaces and comparing simulation software.
This document discusses using weather prediction models to simulate complex wind flow interactions with wind turbines. It presents a case study validating the Weather Research and Forecast model coupled with a wind farm parameterization against SCADA data. Key results show the model predicted wake losses within 16% of observations for an onshore wind farm, while engineering models underestimated losses. It also simulated offshore wakes extending 100km with significant energy losses.
Wind energy is a form of solar energy that is converted into electrical or mechanical energy using wind turbines. Wind turbines convert the kinetic energy of the wind into mechanical power using rotating blades, which then turn a generator to produce electricity. The amount of energy wind turbines can capture depends on three main factors: wind speed, air density, and the swept area of the turbine's blades. Government agencies and programs aim to improve wind power technologies and increase their adoption in the United States.
This document provides an overview of harnessing tidal energy. It discusses the different types of tidal energy capture systems including tidal barrages, tidal stream generators, and dynamic tidal power. Tidal barrages involve dams that capture tidal flows, the largest existing example is the La Rance Tidal Barrage in France. Tidal stream generators are similar to wind turbines, capturing energy from tidal currents. Dynamic tidal power uses a partial dam and turbines to harness tidal differences. The document also covers environmental impacts, economics, and the regulatory steps needed for tidal energy development in the US.
Onshore Wind Turbines Market Is Dazzling Worldwide |shikhasony666
Onshore wind turbines are large structures that convert wind energy into electrical power by using three rotor blades attached to a hub to capture kinetic energy from the wind. The blades spin a generator housed in a nacelle mounted atop a tower. Before installing turbines, developers assess wind resources to find optimal locations with strong, consistent winds where turbines can efficiently generate electricity. Onshore wind power is a growing renewable energy source that helps reduce dependence on fossil fuels.
Similar to Nwtc seminar overview of the impact of turbulence on turbine dynamics, september 14, 2011 (20)
Maruthi Prithivirajan, Head of ASEAN & IN Solution Architecture, Neo4j
Get an inside look at the latest Neo4j innovations that enable relationship-driven intelligence at scale. Learn more about the newest cloud integrations and product enhancements that make Neo4j an essential choice for developers building apps with interconnected data and generative AI.
A tale of scale & speed: How the US Navy is enabling software delivery from l...sonjaschweigert1
Rapid and secure feature delivery is a goal across every application team and every branch of the DoD. The Navy’s DevSecOps platform, Party Barge, has achieved:
- Reduction in onboarding time from 5 weeks to 1 day
- Improved developer experience and productivity through actionable findings and reduction of false positives
- Maintenance of superior security standards and inherent policy enforcement with Authorization to Operate (ATO)
Development teams can ship efficiently and ensure applications are cyber ready for Navy Authorizing Officials (AOs). In this webinar, Sigma Defense and Anchore will give attendees a look behind the scenes and demo secure pipeline automation and security artifacts that speed up application ATO and time to production.
We will cover:
- How to remove silos in DevSecOps
- How to build efficient development pipeline roles and component templates
- How to deliver security artifacts that matter for ATO’s (SBOMs, vulnerability reports, and policy evidence)
- How to streamline operations with automated policy checks on container images
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
“An Outlook of the Ongoing and Future Relationship between Blockchain Technologies and Process-aware Information Systems.” Invited talk at the joint workshop on Blockchain for Information Systems (BC4IS) and Blockchain for Trusted Data Sharing (B4TDS), co-located with with the 36th International Conference on Advanced Information Systems Engineering (CAiSE), 3 June 2024, Limassol, Cyprus.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Building RAG with self-deployed Milvus vector database and Snowpark Container...Zilliz
This talk will give hands-on advice on building RAG applications with an open-source Milvus database deployed as a docker container. We will also introduce the integration of Milvus with Snowpark Container Services.
20 Comprehensive Checklist of Designing and Developing a WebsitePixlogix Infotech
Dive into the world of Website Designing and Developing with Pixlogix! Looking to create a stunning online presence? Look no further! Our comprehensive checklist covers everything you need to know to craft a website that stands out. From user-friendly design to seamless functionality, we've got you covered. Don't miss out on this invaluable resource! Check out our checklist now at Pixlogix and start your journey towards a captivating online presence today.
Communications Mining Series - Zero to Hero - Session 1DianaGray10
This session provides introduction to UiPath Communication Mining, importance and platform overview. You will acquire a good understand of the phases in Communication Mining as we go over the platform with you. Topics covered:
• Communication Mining Overview
• Why is it important?
• How can it help today’s business and the benefits
• Phases in Communication Mining
• Demo on Platform overview
• Q/A
Climate Impact of Software Testing at Nordic Testing DaysKari Kakkonen
My slides at Nordic Testing Days 6.6.2024
Climate impact / sustainability of software testing discussed on the talk. ICT and testing must carry their part of global responsibility to help with the climat warming. We can minimize the carbon footprint but we can also have a carbon handprint, a positive impact on the climate. Quality characteristics can be added with sustainability, and then measured continuously. Test environments can be used less, and in smaller scale and on demand. Test techniques can be used in optimizing or minimizing number of tests. Test automation can be used to speed up testing.
Introducing Milvus Lite: Easy-to-Install, Easy-to-Use vector database for you...Zilliz
Join us to introduce Milvus Lite, a vector database that can run on notebooks and laptops, share the same API with Milvus, and integrate with every popular GenAI framework. This webinar is perfect for developers seeking easy-to-use, well-integrated vector databases for their GenAI apps.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Sudheer Mechineni, Head of Application Frameworks, Standard Chartered Bank
Discover how Standard Chartered Bank harnessed the power of Neo4j to transform complex data access challenges into a dynamic, scalable graph database solution. This keynote will cover their journey from initial adoption to deploying a fully automated, enterprise-grade causal cluster, highlighting key strategies for modelling organisational changes and ensuring robust disaster recovery. Learn how these innovations have not only enhanced Standard Chartered Bank’s data infrastructure but also positioned them as pioneers in the banking sector’s adoption of graph technology.
Nwtc seminar overview of the impact of turbulence on turbine dynamics, september 14, 2011
1. NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC.
Overview of the Impact of Turbulence on
Turbine Dynamics
NWTC Seminar
Neil D. Kelley
September 14, 2011
Innovation for Our Energy Future
2. Innovation for Our Energy Future
Seminar Objective
• To provide a very brief overview
of NREL research into the impact
of atmospheric turbulence and its
simulation conducted between
1989 and 2011.
• The material for this series of two
lectures is contained within the
report on the right which is
currently in final editing.
3. Innovation for Our Energy Future
Outline
3
• Background
• Evolution of Inflow Stochastic Turbulence Simulators
• Research Approach
• Data Sources
• Defining Turbulence and Turbine Response Scaling Parameters
• Concept of Atmospheric Stability
• Correlating Turbulence Scaling Parameters with Turbine Dynamic Response
• Impact of Turbulent Coherent Structures on Turbine Drivetrain
• Conclusions
5. Innovation for Our Energy Future
MOD-0A
200 kW
WWG-0600
600 kW
MOD-1
2000 kW
MOD-2
2500 kW
MOD-5B
3200 kW
WTS-4
4000 kW
Capacity Evolution of Federal Wind Program
Horizontal Axis Turbines 1975-1985
6. Innovation for Our Energy Future
Hamilton-
Standard
BoeingBoeingGeneral
Electric
Westinghouse Boeing
Rotor Diameter and Hub Height Evolution
latest
generation
turbine
hub height
range
7. Innovation for Our Energy Future
Results . . .
7
• None of the large, multi-megawatt turbine prototypes reached
full production status
• Post analysis revealed that the structural fatigue damage to
these machines far exceeded the original design estimates in
virtually all cases
• These excessive loads were attributed to atmospheric
turbulence
• In the late 1980’s and early 1990’s the industry concentrated on
the development wind farms employing large numbers of
turbines in the 25 to 200 kW range
8. Innovation for Our Energy Future
The Turbine Operating Situation in the mid 1980’s
8
In California:
• Significant number
of equipment
failures
• Poor performance
due to the installed
density of turbines
In Hawaii:
• High maintenance costs and
poor availability for
Westinghouse turbines on
Oahu
• Poor performance of wind
farms on the Island of Hawaii
9. Innovation for Our Energy Future
Hawaiian Experience
9
• 15 Westinghouse 600 kW Turbines 1985-1996
• DOE/NASA 3.2 MW Boeing MOD-5B Prototype
1987-1993
• Installed on uphill terrain at Kuhuku Point
with predominantly upslope, onshore flow but
occasionally experienced downslope flows
(Kona Winds)
• Chronic underproduction relative to
projections for both turbine designs
• Significant numbers of faults and failures
occurred during the nighttime hours
particularly on the Westinghouse turbines.
Serious loading issues with MOD-5B during
Kona Winds required turbine lock out
because of excessive vibrations
Oahu
10. Innovation for Our Energy Future
Hawaiian Experience – cont’d
10
• 81 Jacobs 17.5 and 20 kW
turbines installed in mountain
pass on the Kahua Ranch 1985-
• Wind technicians reported in
1986 a significant number of
failures that occurred
exclusively at night
• At some locations turbines
could not be successfully
maintained downwind of local
terrain features and were
abandoned
Hawaii
11. Innovation for Our Energy Future
Today
11
• The U.S. has the greatest installed wind energy capacity in
the world
• New turbine designs are now reaching or surpassing the
capacities of the earlier prototypes
• New turbines are being designed to capture energy from
lower wind resource sites which increases their rotor
diameters and hub heights
• The new machines are being constructed of lighter and
stronger materials in order to reduce the cost of energy but
they are also more dynamically active.
12. Innovation for Our Energy Future
However There is a Down Side . . .
• The aggregate performance of currently operating wind U.S. wind farms has been estimated
to be in the neighborhood of 10% below project design estimates
• Maintenance and operations (M&O) costs are seen as approaching equivalency with the
production tax credit
(Example: Gearbox failures have reached epidemic proportions)
• M&O costs are major contributors to a continuance of a higher than targeted COE
10% Wind Farm Power
Underproduction & Possible Sources
Source: American Wind Energy Association; G. Poulos, V-Bar
$
High Maintenance & Repair Costs Contribution to M&O
Expected annual M&R costs over a 20 year turbine lifetime
Courtesy: Matthias Henke, Lahmeyer International
presented at Windpower 2008
13. Innovation for Our Energy Future
An Interpretation . . .
13
$
Turbines, as designed, are not
compatible with their operating
environments
This incompatibility manifests
itself as increasing cumulative
costs as the turbines age
• We believe atmospheric turbulence continues to play a
major role in this incompatibility
• The larger and more flexible turbines being designed
and installed today when coupled with a much different
atmospheric operating environment at these heights are
being challenged
• We will now overview our research into the effects of
turbulence on wind turbines conducted over the past 20
years
14. Innovation for Our Energy Future
Research Goals 1989-Present
14
• Develop a physical understanding the role
atmospheric turbulence plays in the dynamic
response of wind turbines and its relationship to
fatigue accumulation
• Describe the atmospheric dynamics responsible for
creating the inflow turbulent conditions most
damaging to wind turbines
• Develop a numerical simulation of such conditions
that can be used to drive turbine dynamic design
codes in order to engineer ameliorating design
solutions
15. Innovation for Our Energy Future
Evolution of Stochastic Turbulence Inflow Simulators
15
SNLWIND
Paul Veers
1988
SNLWIND-3D
Neil Kelley
1992, 1996
TurbSim
Neil Kelley
Bonnie Jonkman
2005
16. Innovation for Our Energy Future
Research Approach
16
• Make simultaneous, detailed measurements of both the
turbulent inflow and the corresponding turbine response!
• Interpret the results in terms of how various turbulent fluid
dynamics parameters influence the response of the turbine
(loads, fatigue, etc.)
• Let the turbines tell us what they do not not like!
• Develop the ability to include these important characteristics in
numerical inflow simulations used as inputs to the turbine
design codes
• Adjust the turbulent inflow simulation to reflect site-specific
characteristics or at least general site characteristics; i.e.,
complex vs homogeneous terrain, mountainous vs Great Plains,
etc.
17. Innovation for Our Energy Future
Data Sources
17
We have had two sources of measurements of both
the detailed characteristics of the turbulent inflow
and the resulting dynamic response of wind
turbines
• Field campaign with Developer SeaWest deep within a 41-
row wind farm in San Gorgonio Pass, California that
contained nearly 1000 turbines in 1989-1990
• LIST Project field campaign at the National Wind Technology
Center in 1999-2000
Great Plains turbine operating environment only
• Lamar Low-Level Jet Project in 2002-2003 with Enron Wind
(will be discussed in 2nd lecture)
18. Innovation for Our Energy Future18
San Gorgonio Pass California
• Large, 41-row wind farm located downwind of
the San Gorgonio Pass near Palm Springs
• Wind farm had good production on the upwind
(west) side and along the boundaries but
degraded steadily with each increasing row
downstream as the cost of turbine maintenance
increased
• Frequent turbine faults occurred during period
from near local sunset to midnight
• Significant amount of damage to turbine
components including blades and yaw drives
19. Innovation for Our Energy Future
San Gorgonio Wind Farm
19
Palm Springs
Mt. Jacinto
(
downwind
tower
(76 m, 200 ft)
upwind
tower
(107 m, 250 ft)
row 37
San Gorgonio Pass
nocturnal
canyon flow
(3166 m, 10834 ft)
20. Innovation for Our Energy Future
Micon 65/13 Test Turbines
20
Original
Equipment
AeroStar Rotor
Rotor with NREL
Thin Airfoil
Blade Design
21. Innovation for Our Energy Future
The National Wind Technology Center
21
NWTC
(1841 m – 6040 ft)
NWTC
Great Plains
Terrain Profile Near NWTC in Direction of Prevailing Wind
ection
Denver
Boulder
•Strong downslope
winds (Chinooks)
from the 13,000
foot Front Range
Mountains that
occur during the
fall, winter, and
spring months
•The winds have a
distinct pulsating
characteristic that
contain strong,
turbulent bursts
22. Innovation for Our Energy Future
Measurements at the NWTC
22
• Measurements were made with the naturally-
occurring wind flows, no upstream turbine wakes
• Data was taken in flows that originated over the
Front Range of the Rocky Mountains to the West
• Objective was to compare the turbine response to
natural turbulent flows with those measured in the
multi-row wind farm
23. Innovation for Our Energy Future
3-axis sonic anemometers/thermometers
Details of Inflow Turbulence
Dynamics Measured By
Planar Array of Sonic
Anemometers
Measured the Resulting
Dynamic Responses
of the ART Turbine
Using An Upwind Planar Inflow Array and a 600 kW Turbine
80-m mean wind speed, V80 (m/s)
80-mturbulence
intensity,I80
rated wind
speed range
The NWTC is a Very Turbulent Site!
Turbulence intensity Standard deviation
Nov 1999-April 2000 CART2
ART
24. Innovation for Our Energy Future24
Correlating Turbulence Scaling Parameters
with Turbine Dynamic Response
25. Innovation for Our Energy Future
Defining Turbulence-Turbine Dynamics Scaling
Parameters
25
• We chose the primary parameters to correlate with
turbine dynamics that influence the creation and
destruction of turbulent kinetic energy (K.E. or ET) in the
atmospheric boundary layer flows that wind turbines
operate in
• Using the following variables, the turbulent K.E. budget
equation that relates these parameters to the local rate
of change of K.E. (ET ) within the atmospheric layer in
which turbine rotors reside can be expressed as . . .
26. Innovation for Our Energy Future
Definition of variables
26
u = streamwise wind component (along turbine main shaft)
v = crosswind or lateral wind component
w = vertical wind component
T = temperature
t = time
z = height above the ground surface
Overbar = mean
Primed quantities have mean removed
27. Innovation for Our Energy Future
Turbulent K.E. Budget
27
( ' ') ( ' ') ( ' )
T
T
E u g
u w w T w E
t z zT
ε
∂ ∂ ∂
=− + − −
∂ ∂ ∂
mechanical
shear stress
production
buoyant
production/
damping
vertical flux
(transport)
viscous
dissipation
rate
local rate
of change in
turbulent
K.E.
T iso cohE E E= +
total
turbulent
K.E.
isotropic
contribution
2 2 2 1/2
1/ 2[( ' ') ( ' ') ( ' ') ]cohE u w u v v w= + +
instantaneous coherent kinetic energy
coherent
contribution
28. Innovation for Our Energy Future
Candidate Turbine Response Turbulence Local Scaling
Parameters
28
*' 'u w u=
/u z∂ ∂
, , /u u uu I uσ σ=
, ', ww w σ
( )( )' 'g T w T
( )( )
( )
2
/ /
/
g T T z
u z
∂ ∂
∂ ∂
turbulence generated/damped by buoyancy
turbulence generated by shear=
( )( )
2
/ ' '
( ' ') ( / )
g T w T
u w u z∂ ∂
= turbulence generated/damped by buoyancy
turbulence generated by shear
Rate
of
gradient
Richardson
number, Ri
=
= Mean shearing stress or friction velocity (measure of turbulence level)
important parameters in
turbulence K.E. budget
Measures
of
Dynamic
Stability
=
flux
Richardson
number, Rif
+ = stable
− = unstable
0 = neutral
29. Innovation for Our Energy Future
Concept of Atmospheric Stability
29
• Static Stability
• Dynamic Stability
30. Innovation for Our Energy Future
Schematically
cold, dense air
warm,
less
dense
air
IT IS STABLE
But if . . .
IT IS UNSTABLE
31. Innovation for Our Energy Future
Static Stability and Atmospheric Buoyancy
Height
Temperature
Parcel has
positive buoyancy
and will continue
to rise
Parcel has
no net buoyancy
and will remain at
this height
Parcel has
negative buoyancy
and will return
to its original level
It is Unstable It is Neutral It is Stable
If we vertically displace the air parcels below .. .
Height
Height
Temperature Temperature
warm air cold air
constant
temperature
with height
(isothermal)
cold air warm air
32. Innovation for Our Energy Future
Buoyancy Creates Dynamic Stability or Instability
Time
An example of dynamic instability
Height
warm air
cold air
The right combination of temperature stratification and wind shear
can produce an oscillatory or resonant response in the vertical wind field.
33. Innovation for Our Energy Future
Turbulence-Induced Turbine Dynamic Loads
33
• The fluctuating structural loads created by the
varying velocity of turbulent flow across the turbine
rotor blades are the primary source of cyclic stresses
in the mechanical components of the turbine
• These cyclic stresses cumulatively induce
component fatigue damage that continues to
increase until failure
• We will now look at what we found in our research
that relates turbulent flow properties to fatigue
damage accumulation.
34. Innovation for Our Energy Future
Turbine Response
Dynamic Load
Statistical
Distribution
Model
Dominant Inflow
Turbulence Scaling
Parameter(s)
Percent
Variance
Explained#
Blade root out-of-plane bending Exponential , Ri 89
Low-speed shaft torque Exponential , Ri 78
Low-speed shaft bending Exponential , Ri 94
Yaw drive torque Exponential , Ri 87
Tower top torque Exponential , 88
Tower axial bending Exponential σH 78
Nacelle inplane thrust Exponential , Ri 77
Tower inplane thrust Exponential 69
Blade root inplane bending Extreme value 86
1/2
(| ' '|)u w
1/2
(| ' '|)u w
1/2
(| ' '|)u w
1/2
(| ' '|)u w
1/2
(| ' '|)u w
1/2
(| ' '|)u w
HU
1/2 1/2 1/2
(| ' '|) ,(| ' '|) ,(| ' '|)u w u v v w
1/2 1/2
(| ' '|) , (| ' '|)u w v w
#includes both turbines, values greater for turbine equipped with NREL blades
Multivariate Analysis Results of San Gorgonio Micon 65/13
Turbine Response Variables and Turbulence Scaling Parameters
35. Innovation for Our Energy Future
Micon 65/13 rotor dynamic response with scaling
parameters
35
RiTL
-0.10 -0.05 0.00 0.05 0.10
3-bladeaveragedFBMDEL(kNm)
13
14
15
16
17
18
19
NREL rotor
AeroStar rotor
DEL = damage equivalent (fatigue) load
Remembering u* = ' 'u w
RiTL
-0.3 -0.2 -0.1 0.0 0.1 0.2
Hublocalu*(ms-1
)
1.6
1.8
2.0
2.2
2.4
2.6
2.8
8
10
12
14
16
FBM DEL
(kNm)
NREL rotor
neutral
stability
Ri = 0 peak dynamic
response
+0.01 < Ri < +0.025
decaying
dynamic
response
Ri > + 0.05
unstable stable
Conclusion:
Peak turbulent dynamic response
occurs in flow conditions that are
highly sheared and weakly stable!
36. Innovation for Our Energy Future
Initial Simulation Attempts Inadequate
36
• Simulated San Gorgonio
turbulent inflow into Micon 65
turbine with SNLWIND-3D
• Reproduced body of cyclic
load distribution
• Failed to create the largest
observed load cycles
• RESULT: Simulated fatigue
damage was well below
observed
37. Innovation for Our Energy Future
Comparing Micon and NWTC ART Turbine Responses Sensitivities
to Richardson Number Stability Parameter
37
Flow Deep within A Multi-row Wind Farm
Natural Turbulent Inflow to ART Turbine
38. Innovation for Our Energy Future
Turbine Blade Response Due to Turbulence-Induced
Unsteady Aerodynamic Response Stress Cycles!
NREL blade
Found Organized or Coherent Turbulent Structures Were The
Source of the Damaging and Under Predicted Cyclic Loads
Inflow turbulence characteristics
coherent structure
39. Innovation for Our Energy Future
Strong Correlation with Peak Coherent Turbulent
Kinetic Energy
39
RiTL
-0.3 -0.2 -0.1 0.0 0.1 0.2HubPeakEcoh(m2
s-2
)
20
30
40
50
60
6
8
10
12
14
16
18
20
22
24
26
kNm
NREL rotor
2 2 2 1/2
1/ 2[( ' ') ( ' ') ( ' ') ]cohE u w u v v w= + +
40. Innovation for Our Energy Future
Upwind array
inflow CTKE
m
2
/s
2
0
20
40
60
80
100
120
0
20
40
60
80
100
120
rotor top (58m)
rotor hub (37m)
rotor left (37m)
rotor right (37m)
rotor bottom (15m)
IMU velocity components
0 2 4 6 8 10 12
mm/s
-20
-10
0
10
20
-20
-10
0
10
20
Time (s)
492 494 496 498 500 502 504
vertical (Z)
side-to-side (Y)
fore-aft (X)
zero-mean
root flap
bending
moment
kNm
-400
-300
-200
-100
0
100
200
300
400
-400
-300
-200
-100
0
100
200
300
400
Blade 1
Blade 2
Response to Intense Coherent Inflow Event Measured
on NWTC ART Turbine
40
Intense coherent structure
encountered at center of
rotor disk (80 m2/s2)
Significant blade root out-of-plane
bending excursions (~ 500 kNm)
response
Upwind Planar Array
Sonic Measurements
Out-of-Plane
Blade Root
Loads
High frequency resonant response
in lateral and vertical directions
of low-speed shaft forward
support bearing
Orthogonal Velocity
Measurements Into
Low-Speed Shaft
41. Innovation for Our Energy Future
Comparing Micon 65 & ART Responses
41
San Gorgonio Micon 65s NWTC ART
Richardson number stability parameter
critical stability range
Hub peak Ecoh
Root flapwise bending
damage equivalent load
(DEL)
Hub vertical velocity
standard deviation
σw
42. Innovation for Our Energy Future
Role of Vertical Transport of Coherent Turbulent
Kinetic Energy in Turbine Dynamic Response
42
Vertical Transport (Flux) of
Coherent Kinetic Energy, w’Ecoh
Peak [w’Ecoh ]
w’Ecoh
San Gorgonio Row 37 NWTC ART
Peak[w’Ecoh]FlapBMDEL(kNm)FlapBMDEL(kNm)
w’Ecoh
Wind farm flow has a negative
mean downward flux of Ecoh
not seen at the NWTC
Peaks in downward Ecoh flux
are only associated with
negative means in wind farm
43. Innovation for Our Energy Future
Conclusions from Measurements from San Gorgonio
Pass Wind Farm and at the NWTC
43
• Similar load sensitivities to vertical
stability (Ri) and vertical wind
motions were found at both
locations
• We found that the turbine loads
were also responsive to the new
inflow scaling parameter, Coherent
Turbulent Kinetic Energy (Ecoh or
CTKE) with greater levels of fatigue
damage occurring with high values
and vertical fluxes of this variable
• In both locations, the peak damage
equivalent load occurred at a
slightly stable value of Ri in the
vicinity of +0.02
• Clearly, based on both sets of
measurements, coherent or
organized turbulence played a major
role in causing increased fatigue
damage on wind turbine rotors
San Gorgonio
Micon 65/13
NWTC 600 kW ART
44. Innovation for Our Energy Future44
The Impact of a Coherent Turbulent
Structure on a Turbine Drivetrain
45. Innovation for Our Energy Future
ART Turbine Rotor/Drive Train Time Series Parameters
Associated with Intense Inflow Coherent Event
Blade 1 root zero-mean inplane bending load
Bearing Fore-aft
velocity
Bearing Side-Side
velocity
Bearing Vertical
velocity
Low-Speed Shaft
torque
Low-Speed Shaft Forward Support Bearing
Time Series Data
Measured by an Inertial Measurement Unit (IMU)
Mounted on Top of Bearing and Aligned with Low-Speed Shaft
46. Innovation for Our Energy Future
Turbulence-induced KE Flux from ART Rotor into Low-
Speed Shaft Associated with Coherent Event – cont’d
46
Blade in-plane response
Bearing response
KE flux into bearing
Co-Scalograms
Scalograms
Scalograms
47. Innovation for Our Energy Future
Conclusions
47
• The encountering of a coherent turbulent structure
simultaneously excites many vibrational (modal)
frequencies in the turbine blade as it passes through
• The KE energy associated with each frequency sums
coherently creating a highly energetic burst
• This burst is applied to the structure as an impulse
which can be more damaging than cyclic loading
because of the energy density is greater
• Thus conditions that produce coherent turbulent
structures can be hard on wind turbine structures and
decrease component life if frequently encountered.
The atmospheric processes that produce such
conditions will be discussed in the next lecture.
48. Innovation for Our Energy Future
Conclusions – cont’d
48
• Spatiotemporal turbulent structures exhibit strong transient
features which in turn induce complex transient loads in wind
turbine structures
• The encountering of patches of coherent turbulence by wind
turbine blades can cause amplification of high frequency
structural modes and perhaps increased local dynamic stresses
in turbine components that are not being adequately modeled
with the inflow simulations used by turbine designers
• Current wind turbine engineering design practice employs
turbulence inflow simulations that are based on neutral,
homogeneous flows that do not reflect the diabatic
heterogeneity that is particularly present in the stable boundary
layer as we discussed today
• We believe this disconnect is a major contributor to the
observed wind farm production underperformance and
cumulative maintenance and repair costs
49. Innovation for Our Energy Future
Conclusions – cont’d
49
• Physics-based CFD simulations have the capability of
providing accurate and realistic inflows but 1000s of
simulations are often needed in the turbine design process
and their computational cost makes them feasible for only
a small class of specific problems
• Purely Fourier-based stochastic inflow simulation
techniques cannot adequately reproduce the transient,
spatiotemporal velocity field associated with coherent
turbulent structures
• The NREL TurbSim stochastic inflow simulator has been
designed to provide such a capability for both general and
site specific environments