Wind turbine ultrasound emission, a preliminary investigation 2 Summary Although audible acoustic emissions from wind turbines have been extensively measured (i.e., frequencies below 20 kHz), the ultrasound emissions remain uncharacterized for most wind turbines. We performed a basic characterization of ultrasound emissions from a variety of wind turbines to determine whether ultrasound emissio...

the purpose of this work is to study the conditions under which synchronisation is possible in asynchronous wind parks. Synchronisation is defined as the situation where blades of different wind turbines pass simultaneously in front of their towers. Tower shadow effect is generally considered responsible for part of power quality problems originated by wind turbines. The way of summing the effe...

Small passerines, sometimes referred to as perching birds or songbirds, are the most abundant bird group in the United States (US) and Canada, and the most common among bird fatalities caused by collision with turbines at wind energy facilities. We used data compiled from 116 studies conducted in the US and Canada to estimate the annual rate of small-bird fatalities. It was necessary for us to ...

In a wind farm, the wakes formed by upstream wind turbines decrease the power outputs of downstream wind turbines by reducing wind speed. This wake interference significantly lowers the power production of a wind farm, especially that of a large-scale wind farm. In this paper, we express wind farm power as a differentiable function of location variables. We then apply a sequential convex progra...

In the present study, an experimental study was conducted to characterize the formation and the evolution of the helical tip vortices and turbulent flow structures in the wake of a horizontal axis wind turbine model placed in an atmospheric boundary layer wind. A high-resolution particle image velocimetry system was used to make detailed flow field measurements to quantify the time evolution of...

Small scale wind turbines can be used in indoor facilities that are mainly either stand-alone or gridconnected systems. With grid contiguous turbines, the output from the wind turbine is directly connected to the existing mains electricity supply. For this purpose Improved Honey Bee Mating Optimization (IHBMO) technique is considered as an optimization algorithm to power system. Also the wind f...

An experimental study was conducted to investigate the interferences of wind turbines sited over hilly terrains in order to elucidate the underlying physics to explore/optimize design of wind turbines sitting over complex terrains for higher power yield and better durability. The experiments were conducted in an atmospheric boundary layer wind tunnel with wind turbines sited over two-dimensiona...

An inverse design process is applied to determine blade shapes used in vertical axis wind turbines (VAWTs). The method is based on the modified Garabedian-McFadden technique that uses the deviation of the pressure distribution or the velocity distribution on the surface from a target pressure or velocity distribution, and modifies the blade surface in order to reduce this deviation. The method ...

This paper introduces two discrete-time controllers for horizontal axis wind turbines (HAWTs): a Linear Quadratic Gaussian (LQG) one and a model predictive (MPC) one. The LQG controller aims to strongly attenuate the disturbances influence on the system output. The control objective consists of keeping the output power constant, despite the wind variation, and thus reducing the fatigue that inv...

OBJECTIVE In recent years, claims have proliferated in cyberspace that wind turbines cause a large variety of symptoms and diseases. One of these, "vibroacoustic disease" (VAD) is frequently mentioned. The aim of this study is to examine the quality of the evidence on how VAD came to be associated with wind turbine exposure by wind farm opponents. METHODS Searches of the web (Google advanced)...