HXD3型电力机车主断路器可靠性分析

HXD3型大功率交流传动电力机车是我国重载铁路运输系统中的主力型机车。作为HXD3型大功率电力机车高压电器的重要组成部件,主断路器用于接通牵引传动电路,同时对机车进行过载以及短路保护,其可靠性直接影响机车的安全运行。因此,本文针对HXD3型电力机车主断路器可靠性进行分析研究,并提出改善主断路器可靠度的措施。     

HXD2型机车车体的强度计算与试验研究

从对“和谐2”HXD2型交流传动重载货运电力机车车体的设计要求出发,重点分析了HXD2机车车体强度计算和型式试验的特点和优势．介绍了车体静强度、疲劳强度、动力模态和设备紧固件强度计算以及车体强度型式试验。试验表明,车体的强度和模态满足设计要求。     

HXD1B型电力机车4QC运用故障分析

HXD1B型电力机车是大功率交流传动六轴干线货运用电力机车。武汉铁路局江岸机务段自运用HXD1B型电力机车以来,四象限整流器(4QC)故障成为引起机破和临修的重要原因,有必要对4QC运用中出现的故障进行分析,并提出处理方案。     

精细化工艺设计，提高中自货运1型机车竞争力

中白货运1型机车是中国北车集团大同电力机车有限责任公司在白俄罗斯国际招标采购中标的大功率干线货运机车项目。该项目于2010年3月23日由大同电力机车有限责任公司与中国电气进出口有限公司、白俄罗斯铁路联盟在明斯克共同签署了《中白货运1型机车供货合同》。该型机车基于HXD2机车技术平台进行设计，应用HXD2系列机车的成熟技术和结构，进行大量适应性设计，以满足白俄罗斯宽轨铁路和机车车辆标准体系的相关要求。     

适于货运的异步牵引电机构思

中国铁路货运重载正急需发展大功率交流传动电力机车,笔者针对货运电力机车设计选用六极和四极电动机进行了对比论述,指出采用六极电动机是最佳技术选择,并提出了建议研制的六极电动机主要技术参数.     

引进大功率电力机车牵引齿轮对于热处理工艺与装备的要求

法国阿尔斯通大功率交流传动货运电力机车HXD2为铁道部技术引进机车项目。HXD2牵引主、从动齿轮使用寿命要求不得低于100万km。     

HX_D1B型交流传动货运电力机车牵引齿轮修形计算分析

针对HXD1B型交流传动货运电力机车驱动装置结构,指出了影响小齿轮轴修形的各种因素,并通过对各种因素建模分析,得出了小齿轮轴的综合修形量。     

HXD1D型机车车轮防护板缓冲垫失效原因分析及整改措施

HXD1D型交流传动电力机车是由中车集团株洲电力机车有限公司组织研发的准高速干线客运电力机车,持续功率7200kW,最高速度160km/h新型干线客运电力机车。武汉铁路局武昌南机务段自2012至今,共配属HXD1D型机车66台,担当旅客列车牵引任务。主要运行区间为武昌-金华-沪宁杭,武昌-福州,武昌-成都/重庆等线路。2018年6月份,我段HXD1D型机车相继出现车轮防护板缓冲垫骨架与橡胶体分离故障,车轮防护板随时有脱落的安全隐患。     

中国铁路的“超级大力士”

新一代和谐型大功率电力机车是我国自主研制轴重最大的电力机车产品,标志着我国在大轴重货运机车及铁路重载运输方面取得重大突破。     

HXD3型电力机车四象限变流器分析

本文用对比的方法对HXD3型电力机车牵引变流器中的四象限变流器和韶山系列电力机车中普遍采用的相控整流器进行分析．来说明交流传动机车的特点。     

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...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

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。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

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.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.