快速发现电能计量装置故障的方法分析

电能计量装置在智能电网建设与运行管理中发挥着重要作用,其安全稳定运行,关系着整个电网电气设备的稳定运行以及千家万户的准确计费。而传统电能计量装置运行情况的诊断分析是通过现场校验来实现的,工作繁琐且时效性差。计量自动化系统的建立,为远程监控电能计量装置的运行情况提供了条件。现利用计量自动化系统的现有功能,在对计量装置运行特性和故障种类进行分析总结的基础上,介绍了及时发现计量装置故障的三种方法,可对提高现场计量装置运维效率,推进计量自动化系统功能完善起促进作用。     

基于dSPACE平台的电能计量实时仿真系统

在发展智能电网的新形势下,急需研究分布式能源、储能装置接入电力系统后对电能计量的影响,充电站和微网等新型负荷的电能计量,以及无功电能计量、冲击负荷计量、谐波线损等新问题.提出基于dSPACE平台构建电能计量实时仿真系统,进行电能表校验、电能计量算法优化设计、误差分析比较、电能质量分析、谐波分析、不同负荷对电能计量的影响和特种谐波源仿真等研究.介绍了电能计量实时仿真系统的基本思想和组成结构,设计了相应的硬件和软件,设计了高精度的全数字锁相环实现对电网频率的精密跟踪锁定,以减小非整周期采样带来的谐波分析误差,其锁定精度达到0.0002 Hz以上.计量仿真实验证明了用该系统开展高级电能计量研究的可行性.     

高压试验测试设备数字式校验系统的研制

研制的高压试验测试设备数字式校验系统主要针对交、直流数字高压表和分压器的校验工作,目的是提升校验工作的自动化程度和数据质量。介绍了校验系统的工作原理和核心技术,该系统是基于智能化仪器仪表、GPIB通信、同步触发、数据处理等技术实现的。经法定计量检定机构提供的试验数据,该装置性能参数达到设计要求。     

智能变电站电能计量装置在线监测系统设计

现有的电能计量装置现场检测工作中所存在分布广、路途远、效率低等问题,对智能变电站中数字计量装置缺乏现场检测手段。对IEC61850-9-2LE中电子式互感器、数字电能表的输出规约及误差产生的原因进行了分析,设计了互感器、电能表的误差在线测试系统,并对实验数据进行分析,校验误差算法的准确度。此系统不需工作人员到达现场进行测试,实现了计量装置误差在线监测。     

面向电力设备的一体化智能监控系统

为了维持偏远地区的电力设备的安全稳定的运行,需要对其运行状态进行监控。文中设计了一种以STM32F103为微处理器的远程通信系统,系统搭载了电能计量芯片、远程通信模块以及存储器模块等外设模块。系统采用SIM900A芯片作为通信芯片,电能计量芯片采用ATT7022E,ATT7022E内置的电能参数统计算法简化了程序。上位机通过局域网与电力设备状态监控系统的通信模块建立连接,是人机交互的主要渠道。实验结果表明,该系统不仅可以对电力设备运行状态实现远程监控,而且能够优化电网资源的配置。     

电能计量系统二次回路和出线电能计费表屏改造浅析

以栾川县某220 kV变电站电能计量系统二次回路和出线电能计费表屏改造为例,针对电能计量装置二次回路设计不合理及其用户出线计量屏内线不符合要求等问题进行了分析,并提出了改进方案,实施后彻底解决了电能计量系统存在的技术问题。     

电能计量数据远程传输的研究

分析电能计量远程传输系统的特点和要求,并针对学生宿舍的电能计量管理系统,提出整体的方案设计。远程电能计量计费系统一般由集中器、采集器（采集终端）及通信信道与抄表软件组成,其中集中器到抄表中心为上行信道,集中器至采集器（采集终端）或水电气表间为下行信道,分别应用了无线传输和网络传输的方案,最后分别介绍3级网络。     

基于嵌入式Linux和DSP的在线电能质量监测系统

为了对电网电能质量进行精确的实时监测和分析,讨论了一个在线电能质量监测系统的设计方案,该系统采用了ARM和DSP的双处理器设计,以运行嵌入式Linux系统的AT91SAM9261为主控单元,TMS320VC5510为核心电能质量算法处理单元,实现了对电网电能质量的在线实时监测,并能够通过与远程主机通信对电网电能质量进行远程监控和历史数据分析。     

电能计量装置在线监测系统的应用

电能计量是电力企业营销管理工作的重要组成部分,电能计量量值必须准确,电能计量装置运行必须可靠。从生产实际出发,概述了传统电能计量装置运行管理方式,介绍了计量装置在线监测系统,分析了计量装置在线监测的特点及优势,最后对在线监测系统应用情况进行案例分析,最终实现了计量装置安全可靠运行的目标。     

家庭光伏系统多工作模式电能计量装置

为了发挥家庭光伏系统提供清洁能源的优势,提高其使用效率,提升供电企业服务质量,增强家庭光伏系统使用灵活性,该文研发了一种适用于家庭光伏系统的单相多工作模式电能计量装置。文中详细介绍了该计量装置的多种工作模式及其切换方式,并制作出实物,通过对多种工作模式进行实测,验证其可以满足用户和供电企业的电能计量需求。     

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...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

Fifth International Summer School on Screw-Theory Based Methods in Robotics

正3-11 September,2014University of Bologna,Bologna,Italy www.summerscrews.org summerscrews2014.ing.unibo.it SUMMER 20SCREWS 14In 2014,our screw-theory school comes to the world's oldest university.In early September,Summer Screws'14 will gather six experts in the application of screw theory in robotics and up to 40 participants at the University of Bologna,Bologna,Italy.The school will teach attendees how to apply existing methods and empower them to develop new ones in their own research.The basic theoretical notions will be introduced in a rigorous manner,emphasizing examples,applications,and exercises.Scholarships are available.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

INDUSTRIAL ENGINEERING AND VISUALISATION-A PRODUCT DEVELOPMENT PERSPECTIVE

Taking the actual project of teaching and researching process for example, the relationship between the industrial engineering and product development is discussed. And use the novel visualization technology to support the industrial engineering and product development. How to use the new computer modeling and simulating technologies to support the product development and industrial engineering, is introduced especially. The support includes both domestic products and industrial systems. The visualization and computer technologies take a very important role in some system or multi-direction modeling, those technologies mentioned above can help the industrial engineers study the effect of design on the whole life circle, including the producing steps. So the engineers can avoid making the wrong decision which may cause bad effects on the whole industrial engineering.     

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.