Numerical modelling of neutral atmospheric boundary layer flow through heterogeneous forest canopies in complex terrain (a case study of a Swedish wind farm)

Abedi, Hamidreza; Sarkar, Saptarshi; Johansson, Håkan

doi:10.1016/j.renene.2021.08.036

Cited by 19 publications

(11 citation statements)

References 91 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, the OpenFAST model prediction matches well with the measurements. In a previous paper studying this wind farm 35 , it was demonstrated that in complex terrain, the inflow wind properties varies at the different turbines situated in the same wind farm, demonstrating the importance of CFD tools to predict the wind flow in complex terrain. Along the same line of thinking, it is worth investigating how the underlying Kaimal spectrum used in TurbSim 32 compares against a site-specific flow field prediction obtained from CFD tools.…”

Section: Case Study Of a Swedish Wind Farmmentioning

confidence: 96%

Transient torque reversals in indirect drive wind turbines

Sarkar

Johansson²,

Berbyuk³

et al. 2023

Preprint

View full text Add to dashboard Cite

The adverse effect of transient torque reversals (TTRs) on wind turbine gearboxes can be severe due to their magnitude and rapid occurrence compared to other equipment. The primary damage is caused to the bearings as the bearing loaded zone rapidly changes its direction. Other components are also affected by TTRs (such as gear tooth); however, its impact on bearings is the largest. While the occurrence and severity of TTRs are acknowledged in the industry, there is a lack of academic literature on their initiation, propagation and the associated risk of damage. Furthermore, in the wide range of operation modes of a wind turbine, it is not known which modes can lead to TTRs. Further, the interdependence of TTRs on environmental loading like the wind is also not reported. This paper aims to address these unknowns by expanding on the understanding of TTRs using a high fidelity numerical model of an indirect drive wind turbine with a doubly-fed induction generator (DFIG). To this end, a multibody model of the drivetrain is developed in SIMPACK. The model of the drivetrain is explicitly coupled to state-of-the-art wind turbine simulator Open-FAST, and a grid-connected DFIG developed in MATLAB ® 's Simulink ® allowing a coupled analysis of the electromechanical system. A metric termed slip risk duration is proposed in this paper to quantify the risk associated with the TTRs. The paper first investigates a wide range of IEC design load cases to uncover which load cases can lead to TTRs. It was found that emergency stop and symmetric grid voltage drops can lead to TTRs. Next, the dependence of the TTRs on inflow wind parameters is investigated using a sensitivity analysis. It was found that the instantaneous wind speed at the onset of the grid fault or emergency shutdown was the most influential factor in the slip risk duration. The investigation enables the designer to predict the occurrence of TTRs and quantify the associated risk of damage. The paper concludes with recommendations for utility-scale wind turbines and directions for future research.

show abstract

Section: Case Study Of a Swedish Wind Farmmentioning

confidence: 96%

Transient torque reversals in indirect drive wind turbines

Sarkar

Johansson²,

Berbyuk³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…The measurement data reveals that at 60 m above the ground the dominant wind direction is about 216 degrees with respect to the North. In the previous study done for the Röbergsfjället site [72], the choice of neutral atmospheric boundary layer flow assumption was justified by comparison between the full-day mean wind speed measurement at the met mast point (60 m above ground) with those measured only in the day-time and nighttime. In addition, the computed turbulence intensity from the measured data is associated with the class C of the international standard IEC 61400-1.…”

Section: Measurement Datamentioning

confidence: 99%

“…As previously stated in Section 2, the wind farm consists of eight Vestas V90 horizontal axis wind turbines with a hub height of 90 m and a rotor diameter of 90 m, each with a capacity of 2 MW. Despite the development of a generic 2 MW wind turbine model for a Vestas V90 machine in the previous study by the author et al [72] and due to lack of official information about the power, thrust and rotational speed curves for the Vestas V90-2 MW machine, the NREL 5-MW reference wind turbine [97] will be used in this study, instead. The hub height (𝑦 ℎ𝑢𝑏 ), the rotor diameter (D) and the hub diameter of the 5-MW reference wind turbine are equal to 90 m, 126 m and 3 m, respectively.…”

Section: Simulation Set-upmentioning

confidence: 99%

“…Various studies have been performed to validate LES turbulence model against the field measurement over the Askervein hill [52][53][54][55] and Bolund hill [56][57][58][59][60][61][62]. In addition to the Askervein and Bolund as isolated hills, there are few studies on ABL flow over naturally complex terrain [63][64][65][66][67][68][69][70][71][72].…”

Section: Introductionmentioning

confidence: 99%

“…Inclusion of forest heterogeneity in numerical flow modeling has a significant impact on the variability of wind field [85,88,89] and it is more pronounced for wind farms located in a complex terrain. Apart from the recent studies [39,72,89], to the best of authors' knowledge, there are few studies comparing the flow field characteristics extracted from LES using heterogeneous forest assumption to operational or met mast data at several locations.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Assessment of Flow Characteristics Over Complex Terrain Covered by the Heterogeneous Forest at Slightly Varying Mean Flow Directions (a Case Study of a Swedish Wind Farm)

Abedi

2022

SSRN Journal

View full text Add to dashboard Cite

Transient torque reversals in indirect drive wind turbines

2023

Self Cite

View full text Add to dashboard Cite

The adverse effect of transient torque reversals (TTRs) on wind turbine gearboxes can be severe due to their magnitude and rapid occurrence compared with other equipment. The primary damage is caused to the bearings as the bearing loaded zone rapidly changes its direction. Other components are also affected by TTRs (such as gear tooth); however, its impact on bearings is the largest. While the occurrence and severity of TTRs are acknowledged in the industry, there is a lack of academic literature on their initiation, propagation and the associated risk of damage. Furthermore,

show abstract

Numerical modelling of neutral atmospheric boundary layer flow through heterogeneous forest canopies in complex terrain (a case study of a Swedish wind farm)

Cited by 19 publications

References 91 publications

Transient torque reversals in indirect drive wind turbines

Transient torque reversals in indirect drive wind turbines

Assessment of Flow Characteristics Over Complex Terrain Covered by the Heterogeneous Forest at Slightly Varying Mean Flow Directions (a Case Study of a Swedish Wind Farm)

Transient torque reversals in indirect drive wind turbines

Contact Info

Product

Resources

About