Science topic

Wind - Science topic

The motion of air relative to the earth's surface.
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Publications related to Wind (10,000)
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Article
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This paper investigates the control strategy for extracting stable output power and regulating DC-link voltage in a permanent-magnet vernier generator (PMVG)-based wind turbine system (WTS). To do this, the dynamical model of PMVG-based WTS is constructed. Then, in order to maximize output power, an integral sliding mode controller (ISMC) for the m...
Article
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With increasing penetration of renewable energy in power systems, conventional unit commitment (UC) focusing on static constraints may fail to meet dynamic constraints, such as converter-driven stability. This paper proposes a practical paradigm to perform UC considering the requirement of converter-driven stability in wind generation penetrated po...
Article
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Purpose: Fibromyalgia is a contested illness with unknown aetiology and poorly understood development. The present aim is to explore the pre-diagnostic illness trajectory narrated by individuals recently diagnosed with fibromyalgia (FM). Methods: Individual interviews about the course of the illness were conducted with seven women and three men (...
Article
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Multiphase drives exhibit remarkable advantages (e.g., fault tolerance) over three-phase ones. Six-phase drives are particularly attractive, given their moderate complexity and suitability for off-the-shelf three-phase converters. Regarding the stator winding arrangement, the symmetrical one offers superior postfault capabilities in most scenarios....
Article
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The formation and development of blowouts is an important surface indication of sand drift activity in semiarid grassland areas; thus, an accurate understanding of their morphological evolution characteristics and dynamic processes is of significance for grassland desertification control. This study analyzed the long-term topographic change of a tr...
Article
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Savonius turbine is a vertical axis wind turbine (VAWT) which is suitable to operate at low wind velocities. The experimental investigation to improve its performance is a big challenge as; it is expensive, complicating and time consuming. Numerical prediction using CFD simulation could be a valuable alternative. This paper introduces a new modific...
Article
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Background Lake-terrestrial ecotone is a transition zone between terrestrial and aquatic ecosystems. Linking land and lake, it is thus highly sensitive and vulnerable to disturbances. It includes three parts, namely, radiant belt toward land, shoreline zone and radiant belt toward lake. Extending from multi-year average low water level line to open...
Article
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High penetration of renewable energy sources (RES) leads to new challenges for protection devices. Protection schemes are typically designed according to the dynamic behavior of rotating machines as generation sources, while the RES dynamic response, mainly governed by inverters, is not considered. Consequently, some relevant algorithms of transmis...
Article
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Imaging observations of OH airglow were performed at Meiji University, Japan (35.6° N, 139.5° E), from May 2018 to December 2019. Mountainous areas are located to the west of the imager, and westerly winds are dominant in the lower atmosphere throughout the year. Mountain waves (MWs) are generated and occasionally propagate to the upper atmosphere....
Article
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In this work, an estimation of the wind resource potential was calculated using the Weibull method in the Gulf of Urabá, where wind velocities reach significant and more uniform values. Particularly, this potential was calculated at the coordinates 8,713280° latitude and -77,075274° longitude, where the power density varies between 33,59 and 128,39...
Article
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Increased train speeds have led to significant train-induced wind problems. This paper describes a numerical study of the aerodynamic loads produced when a train passes under a bridge and the bridge dynamic response based on a steel box-girder cable-stayed bridge. The results indicate that the wind pressure on the bottom plate and the maximum lift...
Article
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An inter-decadal increase (1990–2009) in the western North Pacific (WNP) tropical cyclone (TC) genesis frequency in May has recently been reported. The TC decadal changes was attributed to an advanced monsoon onset over the Asian Summer Monsoon region, particularly over the South China Sea (SCS) in May. In the present study, we used 60 years (1961–...
Article
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Multi terminal VSC-HVDC systems are a promising solution to the problem of connecting offshore wind farms to AC grids. Optimal power sharing and appropriate control of DC-link voltages are essential and must be maintained during the operation of VSC-MTDC systems, particularly in post-contingency conditions. The traditional droop control methods can...
Article
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Multiphase machines are often chosen due to their enhanced fault tolerance. Six-phase ones are especially convenient because they may be fed by off-the-shelf three-phase converters. In particular, those with symmetrical windings offer superior postfault capabilities. On the other hand, estimation of the stator resistance is important for purposes s...
Article
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A series of numerical simulations with different forcing conditions are carried out, to investigate the roles played by buoyancy and wind forcing on the upper ocean gyres, and to contrast the laminar and eddying regimes. Model experiments show that the buoyancy-driven eastward geostrophic flow tends to suppress the formation of the wind-driven subp...
Article
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In mechanical self-winding movement, the center-anchored Rotating Weight rotates about its axis with physical motions of the hand. It thereby winds the mainspring only when worn and stops during lay-offs. A watch winder re-creates the physical motions to maintain the beat in the caliber, when not worn. The paper proposes a residential tourbillon wa...
Article
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In this work, the atmospheric corrosion of carbon steels was monitored at six different sites (and hence, atmospheric conditions) using Fe/Cu-type atmospheric corrosion monitoring technology over a period of 12 months. After analyzing over 3 million data points, the sensor data were interpretable as the instantaneous corrosion rate, and the atmosph...
Article
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There is still much philosophical debate about whether a frequentist or subjective view of probability should be adopted. Some uncertainties (typically aleatory uncertainties) are naturally modelled using a frequentist approach, while others (epistemic uncertainties) are clearly subjective in nature. In light of this it has been argued, for example...
Article
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The keys factor in making wind power one of the main power sources to meet the world's growing energy demands is the reliability improvement of wind turbines (WTs). However, the eventuality of fault occurrence on WT components cannot be avoided, especially for doubly-fed induction generator (DFIG) based WTs, which are operating in severe environmen...
Article
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While compound weather and climate events (CEs) can lead to significant socioeconomic consequences, their response to climate change is mostly unexplored. We report the first multi-model assessment of future changes in return periods for the co-occurrence of heatwaves and drought, and extreme winds and precipitation based on the Coupled Model Inter...
Article
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Frequency control of an interconnected power system in the presence of wind integration is complex since wind speed/power variations also affect system frequency in addition to load perturbations. Therefore, improving existing control schemes is necessary to maintain a stable frequency in such complex power system scenarios. In this paper, a new 2-...
Article
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Cold fronts passing through the mountain areas may produce continuous windstorm and cooling processes, potentially impacting the mountain areas' infrastructure. Cooling windstorms belong to the dynamically-driven wind in the mountain wind system. To accurately estimate the wind field parameters of these storms and provide a basis for structural win...
Conference Paper
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There is a growing interest in extracting marine renewable energy and contributing in this way to the green road towards a low carbon future. From this perspective, the Iberian nearshore represents a coastal environment with very high potential. In this context, the objective of the work proposed herewith is to perform a joint evaluation of the wav...
Conference Paper
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The work proposed herewith has as its main target to perform an analysis of the expected wind climate along the 21 st century in the Black Sea basin. For this purpose, the wind fields provided by the RCA4 climate wind model are processed and analysed. Three different Representative Concentration Pathway (RCP) scenarios are considered. These are RCP...
Article
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This work proposes a method for sizing and reducing power losses (MSRPL) of a hybrid photovoltaic and wind system (HPWS) in a radial distribution network (RDN) by developing an objective function, thanks to particles swarm optimization (PSO). The constraints defined on the objective function has permitted us to size the photovoltaic generator, wind...
Article
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The objective of this paper is to enhance the frequency resilience and wind penetration level of a low inertia power system by utilising frequency responsive Thyristor Controlled Series Capacitor (TCSC). In recent years, wind power integration has become prolific in numerous power grids around the world. As such, Synchronous Generators (SGs) are be...
Article
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The Vertical Axis Wind Turbines (VAWTs) have an increasing global market and this emphasis the need for to improve the performance of VAWTs, especially at relatively low wind speed. This paper utilises the Response Surface methodology to optimise the performance of a VAWT. A three bladed VAWT configuration was considered with a NACA0015 profile. Th...
Article
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Methane (CH4) and carbon dioxide (CO2) are the two most important greenhouse gases (GHGs). To examine the variation characteristics of Ch4 and CO2 in the coastal South China Sea, atmospheric CH4 and CO2 measurements were performed in Bohe (BH), Guangdong, China, in summer 2021. By using an adaptive data analysis method, the diurnal patterns of CH4...
Article
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Inerter-based tuned mass systems (ITMSs) have been successfully applied to control the vibration of structures. The control performance of ITMSs is significantly affected by their design parameters. The practical aspects such as installation location and variant type also influence the effectiveness of ITMS. How to obtain optimal parameters conside...
Article
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The conventional hard-switching converters suffer from the limitations like the upper limit on switching frequency, high electromagnetic interference (EMI), more switching losses, large size, increased weight and low efficiency. To overcome these limitations, resonant converters are popularly used in chargers of electric vehicles (EVs). However, th...
Article
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Heavy lift vessels are used to install offshore infrastructure. For floating vessels, roll responses can significantly limit their operability, especially for offshore sites where multimodal wave spectra are expected. This paper deals with a numerical study of a heavy lift vessel equipped with submerged flopper stopper (FS) templates suspended from...
Article
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This paper presents the behavior of bidding above marginal cost, called economic withholding, for price-maker generating companies under wind uncertainty. Economic withholding prevents some lower cost resources from supplying the demand, and compels the ISO to buy more costly resources to meet the load, therefore result in higher market clearing pr...
Article
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While solar farm developments contribute to sustainable energy goals, they often face high levels of local opposition due to their expected negative impacts on the direct environment. Community benefits are a promising tool to reduce local opposition, as they have proven to do so in wind farm developments. By adding multiple functions to a solar fa...
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In platform-type multi-story cross-laminated timber (CLT) buildings, gravity loads from upper floors, and vertical reaction forces from horizontal actions, like wind loads, cause substantial compressive forces in the CLT-floor elements. The combination of these high forces with a comparable low compression stiffness and strength perpendicular to th...
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Wind-induced fatigue damage is a predominant factor eventuating in structural performance degradation of transmission towers exposed to long-term environmental wind. Moreover, transmission towers may suffer from multiple extreme natural hazards (such as earthquake and strong wind) during their service lives. However, these phenomena have not been w...
Article
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This study assesses wave energy by combining long-term model reanalysis data with in situ observations in a multi-island region. A buoy was deployed in the center area of the southern South China Sea (SCS) for 16 consecutive months. Neural network models are introduced to calibrate the significant wave height and the mean wave period of the Europea...
Preprint
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Real light motion in the beam direction When light is focused into a beam, we can find the direction of that beam as the direction that represents highest intensity. This means detection based on amplitude in a direction that is described as the vector sum of ether wind, v, and wave vector, c, in relation to the ether. This represents the real moti...
Article
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Oslo, the capital of Norway, is situated in a North European cool climate zone. We investigate the effect of weather on the overall level of crime in the city, as well as the impact of different aspects of weather (temperature, wind speed, precipitation) on the spatial distribution of crime, net of both total level of crime, time of day and seasona...
Article
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This work conducted a multi-response optimization on the design parameter of a transformer winding based on the response surface methodology and desirability function approach to find a design with better combined-thermal-hydraulic performance. A numerical experiment was performed with two-dimensional axisymmetric numerical heat transfer models. Re...
Conference Paper
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Many renewable energy resources, including wind energy, are uncertain and often unavailable when needed, with high variability and dependency on atmospheric and climatic conditions. Variability and uncertainty of wind energy follow those of wind speed and occurs at multiple timescales, from seconds to minutes to hours, and require movement of other...
Article
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Experimental investigations of the fine plasma structure of interplanetary shocks are extremely difficult to conduct due to their small thickness and high speed relative to the spacecraft. We studied the variations in the parameters of twice-ionized helium ions (4He++ ions or alpha-particles) in the solar wind plasma during the passage of interplan...
Article
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In recent years, there has been renewed interest in line-start synchronous reluctance machines (LSSRMs) due to their simple construction, magnet-free rotor, and low cost. To improve control performance, design optimization, and fault diagnostic analysis of these machines, it requires accurate estimation of their electromagnetic characteristics usin...
Article
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A high-spatial-resolution coherent Doppler wind lidar (CDWL) with high modulation efficiency is reported. The pseudo-random phase coding (PRPC) links the spatial resolution to the modulation rate but suffers from the non-rectangular transition caused by the limited bandwidth. With the help of continuous phase modulation (CPM), the abrupt phase swit...
Article
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Determining Dynamic Positioning capability for an offshore vessel is mandatory to identify the environmental forces the system can counteract, together with the operability in a specific operational area of interest. Conventional predictions evaluate the capability as a maximum sustainable wind speed at a predefined encounter angle for a given wind...
Article
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Saudi Arabia consumed about 290 TWh of energy in 2019, with a per capita consumption of 9100 kWh. The majority of this energy is generated using nonrenewable energy sources, with the residential sector consuming more than half of it. This study investigates the application of a combined dispatch strategy to optimize hybrid energy systems for six re...
Article
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COVID-19 has escalated into one of the most serious crises in the 21st Century. Given the rapid spread of SARS-CoV-2 and its high mortality rate, here we investigate the impact and relationship of airborne PM2.5 to COVID-19 mortality. Previous studies have indicated that PM2.5 has a positive relationship with the spread of COVID-19. To gain insight...
Article
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Induction motors are susceptible to many types of faults that can become catastrophic and cause production stoppages. To predict emerging faults and avoid an unexpected failure, an induction motor can be diagnosed using the proposed motor current normalized residual harmonic analysis method. This method is simple and efficient. It is based on a mor...
Article
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An essential task of numerical weather prediction (NWP) is accurate surface wind speed prediction. However, current NWP models contain significant systematic errors, due in part to indeterminate ground forcing (GF). This study considers an optimal virtual GF (GFo) derived by training observed and simulated datasets of 10-m wind speeds (WS10) for su...
Article
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Cooling towers play a vital role in many large-scale process applications, and any decline in their performance has a considerable effect on the underlying process. It is known that the efficiency of a power plant is greatly affected by the temperature difference of the condenser. The objective of this paper was to produce cooling tower design reco...
Article
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The ability to assess the role of pre-existing damage on the residual (reserve) capacity and reparability of buildings following a damaging event or events is essential to achieving the goal of functional recovery. If performance-based wind design is applied, where limited nonlinear deformations in some elements are allowed under extreme wind event...
Article
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Reinforcement learning (RL) is capable of sophisticated motion planning and control for robots in uncertain environments. However, state-of-the-art deep RL approaches typically lack safety guarantees, especially when the robot and environment models are unknown. To justify widespread deployment, robots must respect safety constraints without sacrif...
Article
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Objectives: The purpose was to investigate the effects of hot and humid environments on thermoregulation and aerobic endurance capacity and whether high skin temperature serves as a more important thermoregulatory factor affecting aerobic exercise capacity. Methods: A randomized cross-over design was applied to this study, in which nine Laser sa...
Article
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Offshore wind turbine structures are commonly subjected to cyclic lateral loading, from waves and wind. The cyclic loading can cause an accumulated deformation of monopile. This study investigates cyclic accumulated deformation of offshore monopiles by using soil cyclic shear tests and numerical simulation. A series of soil axial-torsional bi-direc...
Article
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The motivation for establishing sparse communication architecture is to reduce the complexity and size of the power optimisation problem being solved by centralised controllers of a large-scale offshore wind farm. In this regard, this article introduced the sub-graph extraction technique to construct sparse communication architectures while ignorin...
Article
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Battery energy storage systems (BESSs) co-located with wind farms (WFs) can provide frequency response (FR) services to AC grids exploiting the existing connection points. The UK FR market reforms introduce the Dynamic Low High (DLH) product that is procured by 4-hourly blocks in weekly auctions. This paper develops a modelling framework to optimis...
Article
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In electric vehicle applications, the torque density of electric motor plays an important role in improving the performance of the vehicle. The main objective of this paper is to investigate a possible method for improving the torque density of a permanent magnet synchronous motor used in electric vehicles. At the same time, other machine specifica...
Article
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Electrical power transformers are the most exorbitant and tactically prominent components of the South African electrical power grid. In contrast, they are burdened by internal winding faults predominantly on account of insulation system failure. It is essential that these faults must be swiftly and precisely uncovered and suitable measures should...
Article
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Based on a two-month simultaneous in-situ wave dataset of two observational sites in the coastal regions of the northern South China Sea, the variabilities and richness of the wave energy (WE) during typhoon Lupit (2021) are studied and the discrepancies in WE responses between the two sites are also discussed. The results show that the WE of the s...
Article
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Consumer loyalty is the fundamental goal of the electrical business. The dynamic voltage restorer (DVR) recognizes and makes up for sags in the voltage of the AC power source with the goal that the loads are protected from these force unwavering quality issues. Furthermore, because of the abrupt evacuation of enormous burdens or the use of huge cap...