scholarly journals Quantifying Raptors' Flight Behavior to Assess Collision Risk and Avoidance Behavior to Wind Turbines

Author(s):  
Anne Cathrine Linder ◽  
Henriette Lyhne ◽  
Bjarke Laubek ◽  
Dan Bruhn ◽  
Cino Pertoldi

Some wind farms have implemented automated camera\textendash based monitoring systems e.g. IdentiFlight to mitigate the impact of wind turbines on protected raptors. These systems have effectuated the collection of large amounts of data that can be used to describe flight behavior in a novel way. This data uniquely provides both flight trajectories and images of individual birds throughout their flight trajectories. The aim of this study was to evaluate how this unique data could be used to create a robust quantitative behavioral analysis, that could be used to identify risk prone flight behavior and avoidance behavior thereby in the future assess collision risk. This was attained through a case study at a wind farm on the Swedish island Gotland, where golden eagles (Aquila chrysaetos), white-tailed eagles (Haliaeetus albicilla), and red kites (Milvus milvus), were chosen as the selected bird species. The results demonstrate that flight trajectories and bird images can be used to identify high risk flight behavior and thereby also used to evaluate collision risk and avoidance behavior. This study presents a promising framework for future research, demonstrating how data from camera\textendash based monitoring systems can be utilized to quantitatively describe risk prone behavior and thereby assess collision risk and avoidance behavior.

2012 ◽  
pp. 1896-1912
Author(s):  
Jinglan Zhang ◽  
Paul Roe ◽  
Binh Pham ◽  
Richard Mason ◽  
Michael Towsey ◽  
...  

The impact of urban development and climate change has created the impetus to monitor changes in the environment, particularly, the behaviour, habitat and movement of fauna species. The aim of this chapter is to present the design and development of a sensor network based on Smartphones to automatically collect and analyse acoustic and visual data for environmental monitoring purposes. Due to the communication and sophisticated programming facilities offered by Smartphones, software tools can be developed to allow data to be collected, partially processed and sent to a remote server over the network for storage and further processing. This sensor network which employs a client-server architecture has been deployed in three applications: monitoring a rare bird species near Brisbane Airport, study of koalas behaviour at St Bees Island, and detection of fruit flies. The users of this system include scientists (e.g. ecologists, ornithologists, computer scientists) and community groups participating in data collection or reporting on the environment (e.g. students, bird watchers). The chapter focuses on the following aspects of our research: issues involved in using Smartphones as sensors; the overall framework for data acquisition, data quality control, data management and analysis; current and future applications of the Smartphone-based sensor network, and our future research directions.


2020 ◽  
pp. 21-47
Author(s):  
Graham Scott

This chapter covers two themes: feathers and flight. It takes a close look at the many aspects of feathers—their evolution, structure, growth, maintenance, and their replacement through moult. The broad range of functions of feathers in display (including how different pigmentations arise), for insulation, and in flight are considered. Moult strategies are compared and discussed. The second part of the chapter describes the anatomical adaptations of birds to flight, and the process of flight itself. The basic physics, physiology and metabolism, and energetics of flight are covered in some detail. A review of studies on the neurological control of collision avoidance by flying birds and the implications in relation to wind-farm collision risk is given. The chapter ends with a discussion on the evolution of flight and subsequent flightlessness of some bird species.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2035 ◽  
Author(s):  
Liang Chen ◽  
Heng Nian ◽  
Yunyang Xu

The sequence domain impedance modeling of wind turbines (WTs) has been widely used in the stability analysis between WTs and weak grids with high line impedance. An aggregated impedance model of the wind farm is required in the system-level analysis. However, directly aggregating WT small-signal impedance models will lead to an inaccurate aggregated impedance model due to the mismatch of reference frame definitions among different WT subsystems, which may lead to inaccuracy in the stability analysis. In this paper, we analyze the impacts of the reference frame mismatch between a local small-signal impedance model and a global one on the accuracy of aggregated impedance and the accuracy of impedance-based stability analysis. The results revealed that the impact is related to the power distribution of the studied network. It was found that that the influence of mismatch on stability analysis became subtle when subsystems were balanced loaded. Considering that balanced loading is a common configuration of the practical application, direct impedance aggregation by local small-signal models can be applied due to its acceptable accuracy.


2020 ◽  
Vol 10 (20) ◽  
pp. 7282
Author(s):  
Zicong Zhang ◽  
Junghun Lee ◽  
Gilsoo Jang

With the continuous development of power electronics technology, variable-speed offshore wind turbines that penetrated the grid system caused the problem of inertia reduction. This study investigates the frequency stability of synchronous, offshore wind-farm integration through a modular-multilevel-converter high-voltage direct-current (MMC–HVDC) transmission system. When full-scale converter wind turbines (type 4) penetrate the AC grid, the AC system debilitates, and it becomes difficult to maintain the AC system frequency stability. In this paper, we present an improved inertial-response-control method to solve this problem. The mathematical model of the synchronous generator is based on the swing equation and is theoretically derived by establishing a MMC–HVDC. Based on the above model, the inertia constant is analyzed using a model that integrates the MMC–HVDC and offshore synchronous generator. With the new improved control method, a more sensitive and accurate inertia index can be obtained using the formula related to the effective short-circuit ratio of the AC system. Moreover, it is advantageous to provide a more accurate inertial control evaluation for AC systems under various conditions. Furthermore, the impact of the MMC–HVDC on system safety is assessed based on the capacitor time constant. This simulation was implemented using the PSCAD/EMTDC platform.


Author(s):  
E. Muljadi ◽  
C. P. Butterfield

Wind power generation has increased very rapidly in the past few years. The total U.S. wind power capacity by the end of 2001 was 4,260 megawatts. As wind power capacity increases, it becomes increasingly important to study the impact of wind farm output on the surrounding power networks. In this paper, we attempt to simulate a wind farm by including the properties of the wind turbine, the wind speed time series, the characteristics of surrounding power network, and reactive power compensation. Mechanical stress and fatigue load of the wind turbine components are beyond the scope this paper. The paper emphasizes the impact of the wind farms on the electrical side of the power network. A typical wind farm with variable speed wind turbines connected to an existing power grid is investigated. Different control strategies for feeding wind energy into the power network are investigated, and the advantages and disadvantages are presented.


Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Davide Astolfi

Pitch angle control is the most common means of adjusting the torque of wind turbines. The verification of its correct function and the optimization of its control are therefore very important for improving the efficiency of wind kinetic energy conversion. On these grounds, this work is devoted to studying the impact of pitch misalignment on wind turbine power production. A test case wind farm sited onshore, featuring five multi-megawatt wind turbines, was studied. On one wind turbine on the farm, a maximum pitch imbalance between the blades of 4.5 ° was detected; therefore, there was an intervention for recalibration. Operational data were available for assessing production improvement after the intervention. Due to the non-stationary conditions to which wind turbines are subjected, this is generally a non-trivial problem. In this work, a general method was formulated for studying this kind of problem: it is based on the study, before and after the upgrade, of the residuals between the measured power output and a reliable model of the power output itself. A careful formulation of the model is therefore crucial: in this work, an automatic feature selection algorithm based on stepwise multivariate regression was adopted, and it allows identification of the most meaningful input variables for a multivariate linear model whose target is the power of the wind turbine whose pitch has been recalibrated. This method can be useful, in general, for the study of wind turbine power upgrades, which have been recently spreading in the wind energy industry, and for the monitoring of wind turbine performances. For the test case of interest, the power of the recalibrated wind turbine is modeled as a linear function of the active and reactive power of the nearby wind turbines, and it is estimated that, after the intervention, the pitch recalibration provided a 5.5% improvement in the power production below rated power. Wind turbine practitioners, in general, should pay considerable attention to the pitch imbalance, because it increases loads and affects the residue lifetime; in particular, the results of this study indicate that severe pitch misalignment can heavily impact power production.


Ring ◽  
2014 ◽  
Vol 35 (1) ◽  
pp. 3-30
Author(s):  
Przemysław Busse

ABSTRACT Even though the proportion of wind farm victims compared to general bird species mortality is relatively low, there is necessity to limit direct and indirect losses to the bird populations caused by this kind of human activity. Estimation of threats to the birds resulting from building of wind farms is a very difficult task and it must take into account several constrains. The basic task is to build farms in localities that are the safest to birds. This can be achieved by pre-investment monitoring and direct observations at the spot and then evaluation of potential threats and risks. Field methods typical for the studies on bird populations are usually applied in such monitoring. The procedure described below includes four steps: screening (starts the process and sets preliminary constrains of the location), monitoring (standardised data are collected at the location), estimations of potential collision risk and evaluation of the location. The key parameters determining collision risk of bird species are: (1) the number of individuals utilising the monitored area in different seasons, (2) air space utilization (height and directions of flights), as well as (3) characteristics of the species behaviour. The starting data set contains: species name, number of individuals, height of flight (three layers - below, in, above the rotor), and distance from the observer. The final estimation of the collision index (the most probable number of collisions per turbine a year) is based on (1) estimation of the total number of individuals that use the defined area during a year and (2) estimation of probability that the individual will collide. In the latter (i.e. 2) the most important is that birds can actively avoid passing through the rotor swept (active avoidance rate) and that even birds, which crossed the rotor swept area not necessarily will be killed. Calculations are performed for each species separately and then are summarised to get the farm index as well as season indices. Some values of indices for raptors studied at 76 localities in Poland are given in the table. The final evaluation of the site is made as shown in a parametric analysis table, discussion of cumulative and barrier effects and the discussion of species specific risk to species of high conservation concern.


Author(s):  
Bryan E. Kaiser ◽  
Svetlana V. Poroseva ◽  
Michael A. Snider ◽  
Rob O. Hovsapian ◽  
Erick Johnson

A relatively high free stream wind velocity is required for conventional horizontal axis wind turbines (HAWTs) to generate power. This requirement significantly limits the area of land for viable onshore wind farm locations. To expand a potential for wind power generation and an area suitable for onshore wind farms, new wind turbine designs capable of wind energy harvesting at low wind speeds are currently in development. The aerodynamic characteristics of such wind turbines are notably different from industrial standards. The optimal wind farm layout for such turbines is also unknown. Accurate and reliable simulations of a flow around and behind a new wind turbine design should be conducted prior constructing a wind farm to determine optimal spacing of turbines on the farm. However, computations are expensive even for a flow around a single turbine. The goal of the current study is to determine a set of simulation parameters that allows one to conduct accurate and reliable simulations at a reasonable cost of computations. For this purpose, a sensitivity study on how the parameters variation influences the results of simulations is conducted. Specifically, the impact of a grid refinement, grid stretching, grid cell shape, and a choice of a turbulent model on the results of simulation of a flow around a mid-sized Rim Driven Wind Turbine (U.S. Patent 7399162) and in its near wake is analyzed. This wind turbine design was developed by Keuka Energy LLC. Since industry relies on commercial software for conducting flow simulations, STAR-CCM+ software [1] was used in our study. A choice of a turbulence model was made based on the results from our previous sensitivity study of flow simulations over a rotating disk [2].


Author(s):  
Victoria Attridge ◽  
Nicolle Bonar ◽  
Christina Butz ◽  
Celeste Connell ◽  
Rachel Curtis

This study was undertaken in order to explore the extent of migratory bat fatalities and assess the ecological impact stemming from the Wolfe Island wind facility near Kingston, Ontario. As the Wolfe Island wind project is the second largest wind farm in Canada, our research and proposed solutions may bridge the gap between local interests in reducing bat mortality and maximizing energy production. Additionally, bat populations are critical to local agriculture; increased mortality could lead to significant agricultural losses as well as potential impacts on components of the bats’ food web. First, information will be gathered, through the use of peer-reviewed journal articles and news items to support our project focus, to assess the magnitude of local bat population change following the construction of wind turbines on Wolfe Island. Further, we will explore the consequences of bat population decline on the local Kingston area ecosystem. Lastly, possible realistic solutions will be investigated in order to lessen the environmental impact of the existing wind turbines, and possibly to alter future policy regarding turbine construction and location. Preliminary results will be presented and discussed with the appropriate representatives from local and provincial bodies relevant to wind energy, environmental policy and conservation efforts.  


2015 ◽  
Vol 8 (2) ◽  
pp. 593-609 ◽  
Author(s):  
L. Norin

Abstract. In many countries wind turbines are rapidly growing in numbers as the demand for energy from renewable sources increases. The continued deployment of wind turbines can, however, be problematic for many radar systems, which are easily disturbed by turbines located in the radar line of sight. Wind turbines situated in the vicinity of Doppler weather radars can lead to erroneous precipitation estimates as well as to inaccurate wind and turbulence measurements. This paper presents a quantitative analysis of the impact of a wind farm, located in southeastern Sweden, on measurements from a nearby Doppler weather radar. The analysis is based on 6 years of operational radar data. In order to evaluate the impact of the wind farm, average values of all three spectral moments (the radar reflectivity factor, absolute radial velocity, and spectrum width) of the nearby Doppler weather radar were calculated, using data before and after the construction of the wind farm. It is shown that all spectral moments, from a large area at and downrange from the wind farm, were impacted by the wind turbines. It was also found that data from radar cells far above the wind farm (near 3 km altitude) were affected by the wind farm. It is shown that this in part can be explained by detection by the radar sidelobes and by scattering off increased levels of dust and turbulence. In a detailed analysis, using data from a single radar cell, frequency distributions of all spectral moments were used to study the competition between the weather signal and wind turbine clutter. It is shown that, when weather echoes give rise to higher reflectivity values than those of the wind farm, the negative impact of the wind turbines is greatly reduced for all spectral moments.


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