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风机装备中存在大量螺栓连接结构,螺栓孔一旦出现缺陷,可能导致整个基体断裂,造成重大事故,但目前螺栓孔缺陷检测方法存在漏检和误判的情况。针对该问题,经过调研、理论分析和实物研究,研制出专用工装与探头结合的直射法、扇扫描偏转法2种螺栓孔缺陷检测方法。以风机变桨轴承螺栓孔为研究对象,采用CIVA软件对2种检测方法进行模拟,可检测出矩形模拟裂纹。采用实际变桨轴承螺栓孔加工矩形槽缺陷进行试验,结果表明直射法可实现对螺栓孔裂纹的缺陷检测。研究为螺栓孔的服役状态监控提出了新的方法,有利于保证螺栓连接结构的安全服役。 相似文献
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杆部直径不同的变桨轴承螺栓的耐疲劳性能会直接影响风力发电机的使用寿命。采用静态拉伸试验、螺栓结合面拉开试验和疲劳试验等方法对杆部直径不同的变桨轴承的疲劳性能进行分析。结果表明,在相同运行工况下,缩小变桨轴承螺栓的杆部直径,降低螺栓与被连接件的刚度比,可有效改善螺栓的疲劳性能。 相似文献
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超声相控阵检测技术的发展及应用 总被引:3,自引:0,他引:3
超声相控阵是近年来发展起来的一门新的工业无损检测技术,通过对各阵元的有序激励可得到灵活的偏转及聚焦声束,联合线性扫查、扇形扫查、动态聚焦等独特的工作方式,使其比传统超声检测具有更快的检测速度与更高的灵敏度,成为目前无损检测领域的研究热点之一。介绍了超声相控阵的检测原理及特点,综述了其国内外发展及研究现状,总结了目前超声相控阵研究热点及发展趋势,最后以汽轮机叶轮轮缘裂纹的检测和焊缝的检测为例,介绍了超声相控阵在实际工程中的应用。 相似文献
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为实现在役风力发电机组变桨轴承高黏润滑油脂附着状态下轮齿齿面的高效精准检测,采用仿形阵列涡流技术,研究不同线圈排布方式和提离距离对轴承轮齿齿面缺陷检测结果的影响。结果表明:Z字型和复合型线圈排布方式的边缘效应范围不同,复合型仿形探头较Z字型明显缩短;通过检测10.00 mm×0.50 mm×1.00 mm(槽长×槽宽×槽深)人工槽缺陷,得出内、外齿型轴承的提离距离极限分别为1.04 mm和1.43 mm;对在役风机轴承在表面有高黏润滑油脂条件下进行了试验验证,检测缺陷尺寸与位置结果准确,误差小于5%。该研究成果可为变桨轴承轮齿齿面在役状态下的监督检测提供技术支撑及新思路。 相似文献
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变速变桨风力机的自适应变桨及转矩控制 总被引:1,自引:0,他引:1
针对风力机特性仿真结果的不准确性,风力机在运行过程中运行参数的变化导致最初选定的名义桨距角可能不是最优值,以及传统变桨可能导致电机转矩波动过大的问题,提出自适应变桨控制策略和线性二次型调节(linear quadratic regulator,LQR)转矩控制策略。以5 MW变速变桨风力发电机组为验证对象,使用Matlab/Simulink和FAST软件进行联合仿真,仿真结果表明所提出的控制策略能很好地解决桨距角最优值的确定以及在额定风速以上电机转矩波动过大的问题。 相似文献
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风电场风机变桨系统故障分析 总被引:2,自引:0,他引:2
统计分析风电场风机变桨系统常见故障,针对变桨系统故障致使风机在台风中的受损机理进行了阐述,根据运行经验,在设计、制造、安装及生产运行中,减少变桨系统故障,提高风机可利用率及风电场应对台风气候,提出改进方法和措施。 相似文献
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风力发电机整机气动性能数值模拟计算与仿真研究 总被引:1,自引:0,他引:1
利用Fluent软件对风力机整机在额定风速和7个非额定风速的工况下进行气动性能的数值模拟计算,分析多个风速的工况下的风力机整机气动性能的特点和差异,仿真叶片气动流场流态,并计算叶轮的受力、扭转力矩、输出轴功率和风能利用效率等性能参数,验证风力机气动性能数值模拟的可靠性,观察其叶轮表面以及整机的压强分布、流速分布、湍流强度、流速矢量等流态图.对风力发电机叶片的设计和气动数值模拟计算分析的工作可深化对风力发电机叶片及整机的气动性能的了解,仿真风力发电机组气动流场,并能为风力机叶片及整机的设计、改型和研发工作提供技术参数和指导意见. 相似文献
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针对管道受限空间焊接接头难以检测的问题,提出相控阵超声检测方法。采用CIVA仿真软件对相控阵超声检测的探头和换能器参数进行设计优化,开发了受限空间相控阵超声检测工艺,并将本文相控阵超声检测与X射线检测进行仿真对比。仿真结果表明:本文设计开发的相控阵超声检测方法可以有效检出缺陷,缺陷定位及各缺陷幅值响应规律与实测值相似;本文检测方法相较于X射线检测,在缺陷定性上基本一致,在缺陷深度及高度的测量更具优势,但上表面存在小于5 mm的盲区;对于本文检测方法表面及近表面盲区缺陷可采用增加相控阵超声探头检测位置和其他方法作为补充检测工艺。 相似文献
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Abdelwahab D. Bebars Abdelfattah A. Eladl Gabr M. Abdulsalam Ebrahim A. Badran 《电力系统保护与控制》2022,7(2):265-286
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 com
ponents cannot be avoided, especially for doubly-fed induction generator (DFIG) based WTs, which are operating
in severe environments. The maintenance need increases due to unexpected faults, which in turn leads to higher
operating cost and poor reliability. Extensive investigation into DFIG internal fault detection techniques has been
carried out in the last decade. This paper presents a detailed review of these techniques. It discusses the methods that
can be used to detect internal electrical faults in a DFIG stator, rotor, or both. A novel sorting technique is presented
which takes into consideration different parameters such as fault location, detection technique, and DFIG modelling.
The main mathematical representation used to detect these faults is presented to allow an easier and faster under
standing of each method. In addition, a comparison is carried out in every section to illustrate the main differences,
advantages, and disadvantages of every method and/or model. Some real monitoring systems available in the market
are presented. Finally, recommendations for the challenges, future work, and main gaps in the field of internal faults
in a DFIG are presented. This review is organized in a tutorial manner, to be an effective guide for future research for
enhancing the reliability of DFIG-based WTs. 相似文献
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Abdelwahab D. Bebars Abdelfattah A. Eladl Gabr M. Abdulsalam Ebrahim A. Badran 《电力系统保护与控制》2022,7(1):265-286
Offshore wind farms (OWFs) have received widespread attention for their abundant unexploited wind energy potential and convenient locations conditions. They are rapidly developing towards having large capacity and being located further away from shore. It is thus necessary to explore effective power transmission technologies to connect large OWFs to onshore grids. At present, three types of power transmission technologies have been proposed for large OWF integration. They are: high voltage alternating current (HVAC) transmission, high voltage direct current (HVDC) transmission, and low-frequency alternating current (LFAC) or fractional frequency alternating current transmission. This work undertakes a comprehensive review of grid connection technologies for large OWF integration. Compared with previous reviews, a more exhaustive summary is provided to elaborate HVAC, LFAC, and five HVDC topologies, consisting of line-commutated converter HVDC, voltage source converter HVDC, hybrid-HVDC, diode rectifier-based HVDC, and all DC transmission systems. The fault ride-through technologies of the grid connection schemes are also presented in detail to provide research references and guidelines for researchers. In addition, a comprehensive evaluation of the seven grid connection technologies for large OWFs is proposed based on eight specific indicators. Finally, eight conclusions and six perspectives are outlined for future research in integrating large OWFs. 相似文献
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Meng‐Jen Chen Yu‐Chi Wu Guo‐Tsair Liu Sen‐Fong Lin 《International Journal of Numerical Modelling》2015,28(5):522-539
High penetration of renewable energy in a power system may cause the problem of power dispatching and stability. The detailed dynamic behavior analysis for such a system is therefore important to the planning and operation of the power system. This study discussed the dynamic characteristics of an island power system with variable‐pitch wind turbines under high wind speed and high small hydraulic output power. The system primarily consisted of three diesel engine power generation systems, three constant‐speed variable‐pitch wind turbines, a small hydraulic induction generation system, and lumped static loads. The maximum penetration of renewable energy in this system could reach almost 60%. Detailed models based on MATLAB/Simulink were developed to cater for the dynamic behavior of the system. The results suggested that this island power system can operate stably in this operational mode with the help of variable‐pitch wind turbines. This study can serve as an important reference for planning, operation, and further expansion of island power systems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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本文以变桨距控制为切入点,根据直驱永磁风力发电机组的特点,基于MATLAB/SIMULINK构建了直驱式风电机组的仿真模型,并将其与一台火力发电机组并联,以桨距角为被调量进行电力系统的二次调频,分别对引入变桨距控制前和控制后的情况进行了仿真。仿真结果表明,引入桨距角控制之后,风电机组能更好的适应系统的负荷扰动来维持系统的频率稳定,从而为实现直驱式风电机组的自动发电控制(AGC)提供了理论研究依据。 相似文献
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《电子测量与仪器学报》2015,(9)
为解决超声相控阵汽车发动机腐蚀检测系统中全通道采集带来的存储传输数据量大的问题,进行压缩传感理论在超声相控阵发动机检测系统中的应用研究。根据超声相控阵成像的方式,首先对单阵元接收到的回波信号进行压缩传感:对回波信号在稀疏变换域中的稀疏度进行分析,并应用随机高斯矩阵进行测量采样,正交匹配追踪算法进行信号重构;然后依据超声相控阵的成像原理,对腐蚀缺陷进行压缩传感下的B扫描成像;最后分析结果表明,压缩传感下的缺陷图像具有较高的重构精度,此研究为降低超声相控阵发动机缸体检测系统复杂度以及数据采样传输对硬件的要求提供了新的思路。 相似文献
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风电机组参与一次调频缓解了传统同步机组的调频压力,但其调频性能受功率跟踪方法的影响,不利于系统频率稳定。为此提出了基于改进转子转速和桨距角协调控制的一次调频策略,在全风速范围内预留调频所需功率裕度,在系统频率波动时能够提供快速且持久的有功支撑,实现对风电机组静调差系数的整定。对比分析不同减载控制策略下机组疲劳载荷和损伤等效载荷,结果表明所提策略可有效降低机组的疲劳载荷,延长使用寿命。最后,通过仿真验证了所提一次调频策略的有效性,频率改善效果优于传统一次调频控制,提高了风电场参与系统频率调节服务的一致性和可预测性。 相似文献