Teeter design for lowest extreme loads during end impacts

Schorbach, Vera; Dalhoff, Peter; Gust, Peter

doi:10.1002/we.2140

Cited by 10 publications

(9 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Aerodynamic design was performed using two inverse design tools: PROPID and PROFOIL. PROPID (Selig and Tangler, 1995;Selig, 1995) is an inverse rotor design tool that enables a rotor geometry to be designed based on desired performance specifications like available power, tip speed ratio, wind speed distribution, axial induction, airfoils used, and desired lift distribution along the blade. PROFOIL (Drela and Giles, 1987) is an inverse airfoil design tool.…”

Section: Design and Simulation Tools Wind Turbine Environmentmentioning

confidence: 99%

See 1 more Smart Citation

System-level design studies for large rotors

et al. 2019

View full text Add to dashboard Cite

Abstract. We examine the effect of rotor design choices on the power capture and structural loading of each major wind turbine component. A harmonic model for structural loading is derived from simulations using the National Renewable Energy Laboratory (NREL) aeroelastic code FAST to reduce computational expense while evaluating design trade-offs for rotors with radii greater than 100 m. Design studies are performed, which focus on blade aerodynamic and structural parameters as well as different hub configurations and nacelle placements atop the tower. The effects of tower design and closed-loop control are also analyzed. Design loads are calculated according to the IEC design standards and used to create a mapping from the harmonic model of the loads and quantify the uncertainty of the transformation. Our design studies highlight both industry trends and innovative designs: we progress from a conventional, upwind, three-bladed rotor to a rotor with longer, more slender blades that is downwind and two-bladed. For a 13 MW design, we show that increasing the blade length by 25 m, while decreasing the induction factor of the rotor, increases annual energy capture by 11 % while constraining peak blade loads. A downwind, two-bladed rotor design is analyzed, with a focus on its ability to reduce peak blade loads by 10 % per 5∘ of cone angle and also reduce total blade mass. However, when compared to conventional, three-bladed, upwind designs, the peak main-bearing load of the upscaled, downwind, two-bladed rotor is increased by 280 %. Optimized teeter configurations and individual pitch control can reduce non-rotating damage equivalent loads by 45 % and 22 %, respectively, compared with fixed-hub designs.

show abstract

Section: Design and Simulation Tools Wind Turbine Environmentmentioning

confidence: 99%

“…This free-teetering setup would provide the best configuration for reducing blade loads. A more realistic teeter hinge must account for friction, damping, and end stops (see, e.g., Schorbach et al, 2017).…”

Section: Teeter and Individual Pitch Controlmentioning

confidence: 99%

System-level design studies for large rotors

et al. 2019

View full text Add to dashboard Cite

show abstract

“…This free teeter setup would provide the best configuration for reducing blades loads. A more realistic teeter hinge must account for friction, damping, and end stops (see, e.g., Schorbach et al (2017)).…”

mentioning

confidence: 99%

System-level design studies for large rotors

Zalkind¹,

Ananda²,

Chetan³

et al. 2019

Preprint

View full text Add to dashboard Cite

Abstract. We examine the effect of rotor design choices on the power capture and structural loading of each major wind turbine component. A steady-state, harmonic model derived from simulations using the NREL aeroelastic code FAST is developed to reduce computational expense while evaluating design trade-offs for rotors with radii greater than 100 m. Design studies are performed, which focus on blade aerodynamic and structural parameters as well as different hub configurations and nacelle placements atop the tower. The effects of tower design and closed-loop control are also analyzed. Design loads are calculated according to the IEC design standards and used to calibrate the harmonic model and quantify uncertainty. Our design studies highlight both industry trends and innovative designs: we progress from a conventional, upwind, 3-bladed rotor, to a rotor with longer, more slender blades that is downwind and 2-bladed. For a 13 MW design, we show that increasing the blade length by 25 m while decreasing the induction factor of the rotor increases annual energy capture by 11 % while constraining peak blade loads. A downwind, 2-bladed rotor design is analyzed, with a focus on its ability to reduce peak blade loads by 10 % per 5 deg. of cone angle, and also reduce total blade mass. However, when compared to conventional, 3-bladed, upwind designs, the peak main bearing load of the up-scaled, downwind, 2-bladed rotor is increased by 280 %. Optimized teeter configurations and individual pitch control can reduce non-rotating damage equivalent loads by 45 % and 22 %, respectively, compared with fixed-hub designs.

show abstract

“…The previous studies have mainly investigated and compared the structural loads for two‐bladed wind turbines with rigid and teetered rotors [11, 14, 39]. A few papers have investigated the power quality of two‐bladed WTs; however, comparison of power quality issues for two‐bladed WTs with rigid and teetered rotors has not been the contribution and focus of these studies [19, 20, 26].…”

Section: Introductionmentioning

confidence: 99%

Investigation of power quality and structural loads for two‐bladed wind turbines with rigid and teetered rotors using a wind turbine emulator

Mohammadi¹,

Fadaeinedjad²,

Moschopoulos³

2020

IET Electric Power Applications

View full text Add to dashboard Cite

Two‐bladed wind turbines (WTs) are recently discussed as a potential alternative to reduce the cost of energy in offshore wind farms which have a higher cost compared to onshore wind farms. However, the dynamic response and performance of these WTs are different from the three‐bladed WTs. In this study, new and comprehensive models for rigid and teetered rotor WTs are developed in FAST and emulated with a setup of the previous simulation‐based works. Then, the power quality issues are discussed and compared for two‐bladed WTs with rigid and teetered rotors as the main contribution of this study. The performance of a WT with different rotors is evaluated and compared in terms of power fluctuations, voltage fluctuations, flicker emission level. In addition, the structural loads of the turbine are studied and compared with both rotor types. This was done in emulation and simulation by varying linear horizontal and logarithmic vertical wind shear as well as utilising a turbulent wind time series without shear. The study presents results obtained by simulation and by emulation, using a scaled‐down WT emulator. It presents conclusions as to which type of rotor offers better performance for various operating conditions.

show abstract

Teeter design for lowest extreme loads during end impacts

Cited by 10 publications

References 24 publications

System-level design studies for large rotors

System-level design studies for large rotors

System-level design studies for large rotors

Investigation of power quality and structural loads for two‐bladed wind turbines with rigid and teetered rotors using a wind turbine emulator

Contact Info

Product

Resources

About