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垂直轴风力机叶尖速比分析研究 被引量:12
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作者 陈忠维 《可再生能源》 CAS 2008年第5期76-79,82,共5页
分析了垂直轴风力机叶尖速比选择的特点和影响因素;给出了垂直轴风力机叶片攻角与旋转位置的关系式;计算并分析了各种叶尖速比下的攻角分布情况;得出了垂直轴风力机最佳叶尖速比和相应的叶片设计要求。如果只考虑提高风能利用系数,垂直... 分析了垂直轴风力机叶尖速比选择的特点和影响因素;给出了垂直轴风力机叶片攻角与旋转位置的关系式;计算并分析了各种叶尖速比下的攻角分布情况;得出了垂直轴风力机最佳叶尖速比和相应的叶片设计要求。如果只考虑提高风能利用系数,垂直轴达里厄型风力机叶尖速比值应选择4。 展开更多
关键词 垂直轴 风力机 叶尖速比
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分流导叶垂直轴风力机气动性能研究
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作者 朱致远 叶舟 +1 位作者 欧华浩 李春 《热能动力工程》 CAS CSCD 北大核心 2024年第3期166-172,共7页
为提高垂直轴风力机气动性能,提出一种随相位角变化而改变相对夹角的分流导叶结构。以NACA0021为基础翼型,采用计算流体力学方法对分流导叶作用下垂直轴风力机风能利用系数、单叶片瞬时转矩、压力系数及速度场进行数值分析。结果表明:... 为提高垂直轴风力机气动性能,提出一种随相位角变化而改变相对夹角的分流导叶结构。以NACA0021为基础翼型,采用计算流体力学方法对分流导叶作用下垂直轴风力机风能利用系数、单叶片瞬时转矩、压力系数及速度场进行数值分析。结果表明:静态和动态分流导叶均可提高垂直轴风力机气动性能,且动态分流导叶提升效果更为显著;相较于静态分流导叶,动态分流导叶垂直轴风力机在尖速比为2.33时风能利用系数最高可提升23%,在尖速比为2.03时静态分流导叶垂直轴风力机较原始垂直轴风力机风能利用系数提高37%;分流导叶也可使最佳尖速比前移,稳定叶片转矩波动,提升垂直轴风力机的运行稳定性。 展开更多
关键词 垂直轴风力机 主动控制 分流导叶 尖速比 气动性能
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Control of Doubly Fed Induction Generator Supplied via Matrix Converter for Wind Energy Conversion System
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作者 Zakaria Kara Kamel Barra 《International Journal of Modern Nonlinear Theory and Application》 2014年第3期98-112,共15页
The present paper deals with the modeling and control of Wind Energy Conversion System WECS based Doubly Fed Induction Generator DFIG using the slip energy recovery principle. The proposed drive system uses a Matrix C... The present paper deals with the modeling and control of Wind Energy Conversion System WECS based Doubly Fed Induction Generator DFIG using the slip energy recovery principle. The proposed drive system uses a Matrix Converter (MC) to transfer the slip energy of the rotor into the mains instead of using cascaded ac-dc-ac converter whilst the stator side is fixed to the grid. Operation at both sub-synchronous and super-synchronous regions is possible with the proposed drive system. The different level control strategies for maximum power point tracking and active-reactive power are discussed. Simulation results of the proposed doubly fed induction generator drive system show the good performance of the control system strategy for both transient and steadystate conditions. 展开更多
关键词 WECS DFIG tip speed ratio (tsr) PI CONTROL Matrix CONVERTER
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Increasing the Efficiency of Grid Tied Micro Wind Turbines in Low Wind Speed Regimes
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作者 Kshitij Tiwari Tirumalachetty Harinarayana 《Smart Grid and Renewable Energy》 2014年第10期249-257,共9页
Major problem with grid tied micro wind turbine is synchronization and wind variability. Due to this problem the stability of available grid gets reduced. The stability can be achieved by output power control of the t... Major problem with grid tied micro wind turbine is synchronization and wind variability. Due to this problem the stability of available grid gets reduced. The stability can be achieved by output power control of the turbine. Major part of many countries like India, the annual mean wind speed is not high. The rated wind speed of turbine remain around 11 m/s and cut in is around 3.5 m/s. Due to this problem we aimed to develop a sustainable wind energy system that can provide stable power supply even at the locations of low wind speed of 2 - 4 m/s. To address this issue, a momentary impulse or external torque to the rotor by external motor is one of the good options to maintain the momentum of blades and thus provide stability for sufficient time. Various theoretical calculations and experiments are conducted on the above method. This would increase the output power and also the efficiency of wind turbine. We show that Return-On-Investment will be high as compared with other grid connected turbines. Our proposed concept in the present study, if implemented properly, can help the installation of number of wind turbines even at domestic level. It also makes the consumers energy independent and promotes the use of wind as a source of energy and may enter as a rooftop energy supply system similar to solar. 展开更多
关键词 GRID Tied Rooftop MICRO WIND TURBINE Small External DC Motor WIND Variability tip-speed ratio (tsr) STABILIZED GRID Supply
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Condition monitoring of a wind turbine generator using a standalone wind turbine emulator
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作者 Himani Ratna DAHIYA 《Frontiers in Energy》 SCIE CSCD 2016年第3期286-297,共12页
The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator (WTE) with open source technology from graze required for the condition monitoring to diagnose rotor and stato... The intend of this paper is to give a description of the realization of a low-cost wind turbine emulator (WTE) with open source technology from graze required for the condition monitoring to diagnose rotor and stator faults in a wind turbine generator (WTG). The WTE comprises of a 2.5 kW DC motor coupled with a 1 kW squirrel-cage induction machine. This paper provides a detailed overview of the hardware and software used along with the WTE control strategies such as MPPT and pitch control. The emulator reproduces dynamic characteristics both under step variations and arbitrary variation in the wind speed of a typical wind turbine (WT) of a wind energy conversion system (WECS). The usefulness of the setup has been benchmarked with previously verified WT test rigs made at the University of Manchester and Durham University in UK. Considering the fact that the rotor blades and electric subassemblies direct drive WTs are most susceptible to damage in practice, generator winding faults and rotor unbalance have been introduced and investigated using the terminal voltage and generated current. This wind turbine emulator (WTE) can be reconfigured or analyzed for condition monitoring without the need for real WTs. 展开更多
关键词 condition monitoring (CM) wind turbine emulator (WTE) wind turbine generator (WTG) maximum power point tracking (MPPT) tip speed ratio tsr rotor faults stator faults
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一种新型垂直轴风力机的气动性能分析
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作者 宋磊 马超 张明柱 《机械设计与制造》 北大核心 2020年第5期145-147,151,共4页
传统阻力型垂直轴风力机具有结构简单、低风速启动、成本低等优点,但其风能转换效率较低。为改善传统阻力型风力机的风能转换效率,基于仿生原理提出了一种新型叶片结构的风力机,其结构设计借鉴了鱼脊线结构和Savonius型风力机的叶片结... 传统阻力型垂直轴风力机具有结构简单、低风速启动、成本低等优点,但其风能转换效率较低。为改善传统阻力型风力机的风能转换效率,基于仿生原理提出了一种新型叶片结构的风力机,其结构设计借鉴了鱼脊线结构和Savonius型风力机的叶片结构的特点。通过二维数值模拟方法研究两种风力机的气动特性,并对两种风力机进行对比分析。结果表明,在风速8m/s条件下,新型风力机的扭矩和效率系数优于传统Savonius型风力机,且在较低叶尖速比时达到最高效率,该风轮的三叶片结构布局可引导气流进行二次驱动,从而实现风能转换效率的提升。 展开更多
关键词 垂直轴风力机 气动性能 叶尖速比 数值模拟
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基于时间分辨粒子图像测速技术的水平轴风力机近尾迹特性的实验研究(英文)
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作者 Jian-wen WANG Ren-yu YUAN +7 位作者 Xue-qing DONG San-xia ZHANG Yang SONG Zhi-ying GAO Kun LUO Kun-zan QIU Ming-jiang NI Ke-fa CEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2015年第7期586-595,共10页
目的:探索风力机运行在不同尖速比下近尾迹流场的瞬态和时均特性,揭示风力机近尾迹场的涡量、流速、湍流和雷诺应力演化规律,为相关的数值模拟提供实验对比数据支撑。创新点:将时间分辨粒子图像测速技术应用于风力机近尾迹测量可以捕... 目的:探索风力机运行在不同尖速比下近尾迹流场的瞬态和时均特性,揭示风力机近尾迹场的涡量、流速、湍流和雷诺应力演化规律,为相关的数值模拟提供实验对比数据支撑。创新点:将时间分辨粒子图像测速技术应用于风力机近尾迹测量可以捕捉到较高时间分辨率和高精度的流动信息,进而揭示风力机近尾迹详细的流动机理。方法:实验在风洞里面进行,利用时间分辨粒子图像测速技术获得风力机瞬时流场(图1-3),通过调节风力机配套电机的负荷输出可以得到不同的运行尖速比。对测量得到的瞬时速度的后处理可以得到瞬时涡量以及湍动能和雷诺应力的时均值。结论:1.风力机近尾迹区域沿径向可分为速度增益区、速度保持区和速度亏损区,不同尖速比下速度恢复到主流速度的径向位置基本相同;2.在后半个半径长度区域内,径向平均速度沿径向方向有增加的趋势,而在叶尖以上,径向平均速度沿径向减小;3.近尾迹湍动能在径向方向上0.3倍和0.9倍半径高度处会出现峰值,而在0.6倍半径附近位置会出现湍动能最低值;4.在风力机近尾迹,雷诺剪切应力小于雷诺正应力,在叶根附近,轴向雷诺正应力大于径向雷诺正应力以及雷诺剪切应力,而在叶尖处,径向雷诺正应力大于轴向雷诺正应力以及雷诺剪切应力。 展开更多
关键词 时间分辨粒子图像测速 风力机 尖速比 近尾迹 流动特性
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