1.5MW风电变桨减速机性能测试试验研究

为了准确高效地测试1.5MW风电变桨减速机的传动性能,将减速机置于一种多功能数控机械传动试验台中进行传动试验。该试验台通过一台工控计算机对电动机调速、加载器加载、数据采集进行集成控制;采用交流电动机驱动,由交流变频调速系统实现无级调速,数字加载系统控制磁粉加载器实现无级加载,转矩转速传感器来测试减速机的转速和输入、输出轴的转矩,噪声仪和温度测试仪来测试减速机运转过程中的温升和噪声。通过试验,测试了变桨减速机的传动效率、运转过程中的温度和噪声,并对试验数据进行了分析,对减速机的性能进行了评估,提出了改进和优化措施。     

MW级风电机组变桨柜的强度分析研究

针对兆瓦级风电机组变桨柜焊缝开裂问题,将多体动力学分析与有限元分析技术应用于变桨柜体强度分析中,对变桨柜进行了结构优化和强度评估。首先采用动力学分析软件Simpack对变桨柜总体结构进行了动力学建模和仿真分析,确定了变桨柜应力幅变化最大的危险位置,作为有限元分析的计算工况;接着采用有限元分析软件ANSYS对不同计算工况下的变桨柜及其支架进行了有限元建模与静强度分析;然后依据GL规范与国际焊接协会IIW规范,利用焊缝热点应力法,得到了变桨柜焊缝热点的外推应力,进而对变桨柜焊缝进行了极限强度评估;最后利用疲劳分析软件Fesafe并结合变桨柜疲劳载荷谱及焊缝的S/N曲线,对其进行了疲劳强度评估。研究结果表明:优化后的变桨柜焊缝的极限与疲劳强度安全系数均大于1,满足GL规范强度设计要求。     

浅谈偏航变桨用四点接触球轴承锥销结构设计改进

随着现代科学技术的不断发展,风电偏航变桨用四点接触球轴承的相关应用逐渐受到社会各界的广泛关注,但是,当今时代关于风电偏航变桨用四点接触球轴承锥销结构设计当中仍然存在着许多需要改善的地方。本文主要对风电偏航变桨用四点接触球轴承在其使用过程中关于锥销设计的现状进行了观察研究,并针对其锥销结构设计的问题提出了相关的改进设计措施。     

MW级风机变桨轴承与轮毂连接螺栓的强度分析

针对某MW级风电机组变桨轴承与轮毂连接螺栓强度设计问题,利用ANSYS软件建立了该变桨轴承与轮毂连接螺栓仿真模型,通过对变桨轴承的受力分析和变桨轴承、螺栓有限元模拟方法的研究,基于GL规范分别利用有限元方法和理论分析方法对该连接螺栓进行了强度分析和接触面滑移分析。研究结果表明,螺栓的极限强度和疲劳强度满足设计要求,极限计算中有限元分析结果和理论分析结果基本一致,接触面之间不会发生使螺栓承受剪切力的滑移。该研究结果为风机变桨轴承和轮毂连接螺栓设计提供了参考。     

MW级风电机组轮毂与变桨挡块强度分析

针对MW级风力发电机组轮毂强度安全问题,使用有限元分析软件ANSYS和疲劳分析软件FE-safe,在考虑变桨轴承非线性影响情况下,采用风轮总体模型与轮毂子模型相结合以及临界平面法与最大主应力算法相结合的计算方法,对某大型风力发电机组轮毂的极限强度与疲劳强度进行了评估;为使叶片变桨时准确停留在顺桨位置,在轮毂装配系统中设计了变桨缓冲装置,并对装置组成件变桨挡块和挡块凸台在顺桨工况下的极限强度进行了分析。研究结果表明:轮毂的极限和疲劳强度以及变桨挡块和挡块凸台的极限强度均能满足设计要求,为风电机组轮毂和变桨缓冲装置的设计提供了参考依据。     

风电机组变桨轴承漏脂分析及改进措施

针对风电机组变桨轴承漏脂问题,从密封圈密封性能、变桨轴承内部结构设计、润滑脂的选择及填充用量等方面进行分析,通过选择抗老化和抗磨损性能好的密封圈材料,把密封圈的双唇结构改为多唇结构,沟底增加矩形沟槽,改善轴承脂孔尺寸与分布,增加轴承排脂孔外侧连接螺纹孔的直径和深度,改善润滑系统控制策略,设计变桨轴承运行时注脂的频率、时间等指标,增加废脂清除系统等措施,基本上可以杜绝变桨轴承漏脂现象。     

浅谈风电机组变桨齿圈磨损原因分析及修复方法

变桨齿圈是风电机组的核心部件之一.风电机组经过长时间的运行后,变桨齿圈易发生磨损.本文以我公司某风场风机为例,分析了其变桨齿圈磨损的原因,并针对该原因设计了修复方法.通过修复,可以确保风机继续稳定运行,同时降低了风场运维成本,提高了风场的经济性.     

风电变桨轴承摩擦力矩的测量

通过试验机对风电变桨轴承加载径向和轴向压力,模拟风电轴承的实际工况,通过工控机直接测量并实时记录输出试验数据,从而得到变桨轴承的启动摩擦力矩及旋转状态时的即时摩擦力矩,并分析测试数据以判定风电变桨轴承是否满足设计要求。     

风电变桨轴承密封圈密封性的研究

风力发电机使用过程中变桨轴承频繁出现漏脂现象,既污染环境,也降低了轴承的使用寿命。根据风电变桨轴承的结构特点和使用工况,通过改进密封圈结构设计、改变密封方式和增加密封槽,提高密封圈的密封性,满足风电变桨轴承的使用要求。     

风电机组变桨轴承的动态柔性特性研究

针对传统变桨轴承方法中的刚性假设不能反应变桨轴承动态运行特点的问题,引入了在线测试与仿真分析技术,对变桨轴承动态柔性特性进行了研究。分析了变桨轴承运行的受载特点,提出了一种基于应变载荷测试与位移传感器的在线测试方法,以测试风电机组不同功率下变桨轴承内外圈轴向位移、径向位移和载荷;建立了考虑周边结构与变桨轴承柔性的变桨系统有限元模型,并以在线测试所得载荷作为有限元分析输入载荷,进行了仿真分析;最终对不同功率下的变桨轴承轴向位移、径向位移测试数据与仿真数据进行了对比分析。研究结果表明:变桨轴承载荷、变桨轴承内外圈轴向位移、径向位移随风轮转动呈现周期性交替变化规律,不同位置变化规律特点不同,体现了变桨轴承的动态柔性特性;该特性可应用于变桨轴承可靠性的研究。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.