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The stability of the electrical grid depends on enough generators being able to provide appropriate responses to sudden losses in generation capacity, increases in power demand or similar events. Within the United States, wind turbines largely do not provide such generation support, which has been acceptable because the penetration of wind energy into the grid has been relatively low. However, frequency support capabilities may need to be built into future generations of wind turbines to enable high penetration levels over approximately 20%. In this paper, we describe control strategies that can enable power reserve by leaving some wind energy uncaptured. Our focus is on the control strategies used by an operating turbine, where the turbine is asked to track a power reference signal supplied by the wind farm operator. We compare the strategies in terms of their control performance as well as their effects on the turbine itself, such as the possibility for increased loads on turbine components. It is assumed that the wind farm operator has access to the necessary grid information to generate the power reference provided to the turbine, and we do not simulate the electrical interaction between the turbine and the utility grid. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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"渤海海上风力发电示范工程"于2007年初批准正式立项,建设国内第一台海上风力发电机组,容量为1.5MW。由于风能具有间歇性和随机性的特点,为了实现绥中36-1CEP平台孤立电网与风电机组互补发电,并且保证该电网的平稳运行,进行了海上平台孤立小电网的稳定性研究。海上石油平台电网允许的正常频率波动范围为±0.25Hz,频率偏差报警为±0.5Hz,电网频率将随着透平发电机组输出有功功率的变化而波动。当风力发电机组在额定输出有功功率跳闸退出电网时,对电网频率的影响最大;当风力发电机组在额定风速启动并网时,对电网频率的影响较大。在特定的风燃互补孤立小电网中,采用电网负荷频率调节方程,可以计算风力发电机组容量与电网总负荷之比和频率波动的关系。海上平台风燃互补发电孤立小电网稳定运行的条件为风力发电机组的容量与平台电网总容量的比值小于10%。在满足风力发电机组引起平台电网最大频率波动范围为±0.25Hz的条件下,额定有功功率为1.5MW的风力发电机组,可并入最低总有功功率为15MW的电网。将稳定性研究结论应用于渤海风力发电示范项目,保证了示范工程的顺利进行,实现了国内第一台海上风力发电机组与生产平台并网发电的稳定运行。 相似文献
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An observational case study of a wind ramp event at Enel Green Power North America's wind plant in Oklahoma is presented. Using coordinated measurements collected by the Texas Tech University Ka‐band radars, dual‐Doppler‐synthesized wind fields are merged with data from a meteorological tower and 32 operational turbines to document the evolution and impact of the wind ramp on turbine behavior and performance over a 1 h period. During the event, average power output for turbines within the dual‐Doppler analysis domain increases from 18.3% of capacity to 98.9% of capacity, emphasizing the abrupt impact wind ramp events can have on the electrical grid. The presented measurements and analyses highlight the insights remote sensing technologies can offer towards documenting transient wind ramps and assisting modeling efforts used to forecast such events. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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This paper deals with the analysis of the possible adoption of a static synchronous compensator (STATCOM) with grid-connected constant-speed wind turbines. Three different cases are simulated using Matlab/Simulink for investigating wind-power impact on a power grid connected to wind turbines. The simulations yield information on (i) how the faults impact on the wind turbines and (ii) how the STATCOM influences the post-fault behaviour of the power system. In this paper, an attempt is made to compare the impact, in terms of voltages and active and reactive powers, of adding wind turbines and STATCOM to an electrical power grid. The simulations show that the goal of keeping turbines operational can be achieved. 相似文献
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从汽轮机热耗率计算公式入手,通过老化后循环吸热量和热耗率的变化,导出了汽轮机老化对出力影响的关系式,简单实用。研究表明,大型汽轮机老化后,对出力的影响来自两个方面,一是因老化使热耗率增加而导致出力降低,二是因老化使高压缸漏汽增加、高压缸效率降低而引起的再热蒸汽吸热量减少,进而会导致汽轮机做功能力减少,故老化对出力的影响要大于对热耗率的影响。式(8)揭示了出力变化率与高压缸漏汽变化、高压缸效率变化及热耗率变化率之间的相互关系,可用于评估汽轮机老化后对出力的影响。 相似文献
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One of the main concerns in the grid integration of large wind farms is their ability to behave as active controllable components in the power system. This article presents the design of a new integrated power control system for a wind farm made up exclusively of active stall wind turbines with AC grid connection. The designed control system has the task of enabling such a wind farm to provide the best grid support. It is based on two control levels: a supervisory control level, which controls the power production of the whole farm by sending out reference signals to each individual wind turbine, and a local control level, which ensures that the reference power signals at the wind turbine level are reached. The ability of active stall wind farms with AC grid connection to control the power production to the reference power ordered by the operators is assessed and discussed by means of simulations. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
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In this study, the aerodynamic noise characteristics of Savonius wind turbines were investigated using hybrid computational aero-acoustics techniques, and low-noise designs were proposed based on the understanding of the noise generation mechanism. First, the flow field around the turbine was analyzed in detail by solving three-dimensional unsteady incompressible Reynolds-averaged Navier–Stokes equations using computational fluid dynamics techniques. Then, the aerodynamic noise radiating from the wind turbine was predicted using the Ffowcs Williams and Hawkings equation with the obtained flow field information. Two distinct harmonic noise components—the blade passing frequency (BPF) and harmonics with a fundamental frequency that is much higher than the BPF—were identified in the predicted noise spectrum. The origin of the higher harmonic components was found to be related to vortex shedding from the rotating turbine. Based on this finding, the proposed low-noise design for Savonius wind turbines uses S-shaped blades. S-shaped blades were found to reduce the noise levels of Savonius wind turbines by up to 2.7 dB. 相似文献
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Jennifer Annoni Pieter M. O. Gebraad Andrew K. Scholbrock Paul A. Fleming Jan‐Willem van Wingerden 《风能》2016,19(6):1135-1150
Wind turbines are typically operated to maximize their performance without considering the impact of wake effects on nearby turbines. Wind plant control concepts aim to increase overall wind plant performance by coordinating the operation of the turbines. This paper focuses on axial‐induction‐based wind plant control techniques, in which the generator torque or blade pitch degrees of freedom of the wind turbines are adjusted. The paper addresses discrepancies between a high‐order wind plant model and an engineering wind plant model. Changes in the engineering model are proposed to better capture the effects of axial‐induction‐based control shown in the high‐order model. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
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An active grid is used to generate a variety of turbulent shear profiles in a wind tunnel. The vertical bars are set to flap through varying angles across the test section producing a variation in the perceived solidity, resulting in a mean shear. The horizontal bars are used in a fully random operational mode to set the background turbulence level. It is demonstrated that mean velocity profiles with approximately the same shear can be produced with different turbulence intensities and local turbulent Reynolds numbers based on the Taylor microscale, λ. Conversely, it is also demonstrated that flows can be produced with similar turbulence intensity profiles but different mean shear. It is confirmed that the length scales and dynamics, the latter being assessed through the velocity spectra and probability density functions, do not vary significantly across the investigation domain. Such flows are of particular relevance for studies investigating the effect of in‐flow conditions on obstacles where these studies wish to decouple the effects of turbulence intensity and mean shear, a feat previously unattainable in experimental facilities. Given that the power output of wind turbines is known to be a function of both mean shear and turbulence intensity, the experimental methodology presented herein is invaluable to the wind turbine model testing community who, at present, cannot exert such control authority over the in‐flow conditions. 相似文献
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为研究风气互补发电系统对电网的影响,首先搭建了由风电机组、燃气轮机、电网线路、静止无功补偿器、电力系统稳定器和大型水力发电机组成的仿真系统,并对该系统的负载侧和电网线路中部节点进行了稳定性分析。仿真结果表明,电网在加载了风气互补系统后运行能保持稳定,并能在发生短时故障后恢复到原来状态。该文为进一步研究风气互补系统与电网的相互影响提供了良好的模型基础。 相似文献
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Agbetuyi Ayoade Felix Awosope Cladius Ojo Aremu Awelewa Ayokunle Ajibola Adoghe Uwakhonye Anthony Odigwe Ani Ishioma Samuel Adekunle Isaac 《能源与动力工程:英文版》2014,(10):1811-1815
A distribution grid is generally characterized by a high R/X （resistance/reactance） ratio and it is radial in nature. By design, a distribution grid system is not an active network, and it is normally designed in such a way that power flows from transmission system via distribution system to consumers. But in a situation when wind turbines are connected to the distribution grid, the power source will change from one source to two sources, in this case, network is said to be active. This may probably have an impact on the distribution grid to whenever the wind turbine is connected. The best way to know the impact of wind turbine on the distribution grid in question is by carrying out load flow analysis on that system with and without the connection of wind turbines. Two major fundamental calculations： the steady-state voltage variation at the PCC （point of common coupling） and the calculation of short-circuit power of the grid system at the POC （point of connection） are necessary before carrying out the load flow study on the distribution grid. This paper, therefore, considers these pre-load flow calculations that are necessary before carrying out load flow study on the test distribution grid. These calculations are carded out on a test distribution system. 相似文献
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The aim of the work is to derive a steady state PQ‐diagram for a variable speed wind turbine equipped with a Doubly Fed Induction Generator. Firstly, the dependency between optimal rotor speed and wind speed is presented. Secondly, the limitations in reactive power production, caused by the rotor current, the rotor voltage and the stator current are derived. Thirdly, the influence of switching from Δ to Y coupling of the stator is investigated. Finally, a complete PQ diagram for a wind turbine is plotted. It is concluded that the limiting factor regarding reactive power production will typically be the rotor current limit, and that the limit for reactive power absorption will be the stator current limit. Further, it is concluded that the rotor voltage will only have a limiting effect at high positive and negative slips, but near the limitation, the reactive power capability is very sensitive to small changes in the slip. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
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This paper presents a summary of the mechanical features and the medium term operating experience from three small horizontal axis wind energy conversion systems covering a range of 500 to 5000 Watt, intented for rural and isolated communities. These turbines have a new regulator which reduces gyroscopic loads, is easy to adjust and could be manufactured stronger and in smaller sizes than the conventional tail vanes. It is concluded that is feasible to build cheaps and reliable wind turbine generators with an acceptable efficiency employing common-use elements, but is needed a careful and optimized design. 相似文献
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虽然产能有所过剩,但由于地方政府采取了以资源换税收的政策,仍使得整机生产基地的数量在不断增加。本文对我国整机生产基地的近期情况做了简单介绍,并对未来整机生产基地的发展方向做了调研与分析。 相似文献
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Economic load dispatch (ELD), used as part of the modern energy management system basically minimizes the total generation fuel cost of thermal plants while satisfying various system constraints. However, ELD alone is not sufficient to reduce the pollutant emissions caused by fossil fuel burning for power generation. Thus, it becomes necessary to implement economic emission dispatch (EED) model, which aims to minimize both generation fuel cost and emissions simultaneously. Myanmar Power System is used as a case study in this model. The types of emissions considered in the study are carbon dioxide (CO2) and nitrogen oxides (NOx). A practical ramp‐rate of turbine generator units is also formulated and studied in the model. Total emission constraint on the whole system is further implemented to investigate the effect of emission limit on the variation of generation schedule among generating plants. It is found that whenever minimum cost of operation is taken as sole objective in the model, the corresponding emission level increases. Similarly, minimum emission dispatch results in higher operating cost. Therefore, both objectives are conflicting in nature and some weights must be assigned to obtain a non‐inferior solution. The case where the ramp‐rate is considered in problem formulation incurs higher cost than that without it. Several trade‐off curves obtained can be taken as guidelines to fix the desired level of cost and emission together by the operators. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
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The aim of this article is to investigate the market penetration and share of different wind turbine concepts during the years 1995–2004, a period that represents the maturational era of the modern wind power industry. A detailed overview is given based on suppliers' market data and concept evaluation for each individual wind turbine type sold by the Top Ten suppliers over the selected decade. The investigation is processing information on approximately 160 wind turbine types from 22 different manufacturers that have featured in the Top Ten list of wind turbine suppliers during 1995–2004. The analysis is based on comprehensive data covering approximately 97% of the cumulative wind power installed worldwide at the end of 2004. The article also provides an overall perspective on contemporary wind turbine concepts, classified with respect to both their speed control ability and power control type. Current and future trends for wind turbine concepts are discussed. Copyright © 2006 John Wiley &Sons, Ltd. 相似文献
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风能是世界存量大、绿色无污染的可再生能源之一.由于风力机旋转工况复杂,翼型的相对攻角变化剧烈,导致翼型容易失速,风机的风能利用率低.变桨距主动控制技术是目前最常用的提高升力型垂直轴风力机性能的方法.针对近年来变桨距技术的最新研究进展情况进行了综述.通过全面的文献检索和阅读,总结和阐述了不同变桨距控制策略的设计与实现方法... 相似文献
