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自动化相关的论文题目
自动化是一门涉及学科较多、应用广泛的综合性科学技术。作为一个系统工程，它由5个单元组成。下面，我为大家分享自动化相关的论文题目，希望对大家有所帮助！
.自动化专业人才培养探索
.自动化流水线实训系统的设计
.电力自动化继电保护的安全管理
.浅析电气自动化控制系统的设计思想
.基于PLC的工业自动化控制技术探讨
.工业自动化控制技术向智能家居的演进
.矿井主扇风机自动化与信息化改造
.基于IEC的变电站自动化系统安全风险评估
.浅析集控站综合自动化系统运行中存在的问题
.数字化变电站自动化技术的应用
.如何提高综合自动化变电站的抗电磁干扰能力
.自动化专业人才培养方案和课程体系的改革与实践
.配电网自动化技术问题初探
.楼宇自动化系统的监控方式及节能分析
.地铁自动化控制相关系统的对比及应用
.基于调度策略的自动化仓库系统优化问题研究
.基于组态软件的综合自动化平台的设计与实现
.基于PLC和运动控制器的电气自动化实验平台的设计
.矿井自动化项目技术管理模式浅论
.铁路变电站自动化监控系统的研制
.馈线自动化自适应快速保护控制方案
.高速制管机上的自动化系统解决方案
.智能变电站是变电站综合自动化的发展目标
.煤矿自动化与信息化技术回顾与展望
.以先进自动化技术确保中线调水畅通
.绿色理念背景下电厂自动化控制系统研究
.大型自动化控制系统故障报警技术应用研究
.煤矿电气自动化控制系统优化设计
.配网自动化相关技术的研究
.中心城市大型配电自动化设计方案与应用
.自动化专业卓越工程师课程体系的改革与实践
.综合自动化变电站电压量传输新方式
.浅谈析电气自动化中的接地及保护
.办公自动化在飞行中的应用
.天津城市核心区配电自动化技术实施与进展
.配电自动化系统中配电终端配置数量规划
.倍福科技自动化技术助力高性能设备状态监测
.渠道自动化控制系统与运行设计探析
.自动化仓储系统优化方法的研究
.配网自动化建设与运行管理问题探微
.浅谈变电站综合自动化系统的`结构形式
.变电站综合自动化通信系统运行维护分析
.无功补偿技术在电气自动化中的应用
.基于PIE的高分遥感泥石流自动化变化检测方法研究
.电力自动化技术的新发展
.配电自动化试点工程技术特点及应用成效分析
.藁城新区水厂的自动化建设
.配电自动化若干问题的探讨
.工业自动化仪表故障分析及解决方法探析
.建筑电气自动化系统安装的施工技术探讨
.浅谈自动化仪表日常维护与故障解决
.浅谈电力自动化管理系统
.浅谈自动化控制系统及热工仪表的维护与管理
.电气自动化工程控制系统的现状及其发展趋势
.动力部一降压变电站综合自动化系统改造及应用
.新型智能配电自动化终端自描述功能的实现
.水电厂电气自动化控制设备的可靠性探讨
.国外配网自动化建设模式对我国配网建设的启示
.现场总线与工厂底层自动化及信息集成技术
.铝工业电气自动化的现状与发展趋势
用于分布式在线UPS中的并联逆变器的一种无线控制器已经发送。
我有一篇我本科毕设的小论文，英文中文都有，而且是我人工翻译的，8000字左右。你要的话PM我。我是电气工程及其自动化专业的。《Analysis of thyristor-controlled phase shifter applied in damping power system oscillations》
不会写论文还这么嚣张?不就是250分吗得到了又怎么地？能吃呀？
1 电气自动化和电脑的整合运用。2 电气自动化和移动通讯的整合运用3 自动化组装机取代人工生产线的规划运用4 电气自动化的数据收集和统计分析5 电气自动化用于质量管理的规划和运用6 电气自动化运用在精益生产线的规划和分析这些都是目前比较有深度的题目
1、高压软开关充电电源硬件设计2、自动售货机控制系统的设计3、PLC控制电磁阀耐久试验系统设计4、永磁同步电动机矢量控制系统的仿真研究5、PLC在热交换控制系统设计中的应用6、颗粒包装机的PLC控制设计7、输油泵站机泵控制系统设计8、基于单片机的万年历硬件设计9、550KVGIS中隔离开关操作产生的过电压计算10、时滞网络化控制系统鲁棒控制器设计11、多路压力变送器采集系统设计12、直流电机双闭环系统硬件设计13、漏磁无损检测磁路优化设计14、光伏逆变电源设计15、胶布烘干温度控制系统的设计16、基于MATLAB的数字滤波器设计与仿真17、电镀生产线中PLC的应用18、万年历的程序设计19、变压器设计20、步进电机运动控制系统的硬件设计21、比例电磁阀驱动性能比较22、220kv变电站设计23、600A测量级电流互感器设计24、自动售货机控制中PLC的应用25、足球机器人比赛决策子系统与运动轨迹的研究26、厂区35kV变电所设计27、基于给定指标的电机设计28、电梯控制中PLC的应用29、常用变压器的结构及性能设计30、六自由度机械臂控制系统软件开发31输油泵站热媒炉PLC控制系统设计32步进电机驱动控制系统软件设计33足球机器人的视觉系统与色标分析的研究34自来水厂PLC工控系统控制站设计35永磁直流电动机磁场分析36永磁同步电动机磁场分析37应用EWB的电子表电路设计与仿真38电路与电子技术基础》之模拟电子篇CAI课件的设计39逻辑无环流直流可逆调速系统的仿真研究40机器人足球比赛图像采集与目标识别的研究41自来水厂plc工控系统操作站设计42PLC结合变频器在风机节能上的应用43交流电动机调速系统接口电路的设计44直流电动机可逆调速系统设计45西门子S7-300PLC在二氧化碳变压吸附中的应用46DMC控制器设计47电力电子电路的仿真48图像处理技术在足球机器人系统中的应用49管道缺陷长度对漏磁场分布影响的研究50生化过程优化控制方案设计51交流电动机磁场定向控制系统设计52开关电磁阀流量控制系统的硬件设计53比例电磁阀的驱动电源设计54交流电动机SVPWM控制系统设计55PLC在恒压供水控制中的应用56西门子S7-200系列PLC在搅拌器控制中的应用57基于侧抑制增强图像处理方法的研究58西门子s7-300系列plc在工业加热炉控制中的应用59西门子s7-200系列plc在电梯控制中的应用60PLC在恒压供水控制中的应用61磁悬浮系统的常规控制方法研究62建筑公司施工进度管理系统设计63网络销售数据库系统设计64生产过程设备信息管理系统的设计与实现
楼主大大要和你的文章内容适合哦
机械专业粗略分为机械制造及自动化、机电一体化工程、工业工程、机电系统智能控制等四大类。那么机械专业的论文题目怎么选呢?下面我给大家带来2021机械机电类专业论文题目有哪些，希望能帮助到大家!
机电专业 毕业 论文题目
1、机电一体化与电子技术的发展研究
2、变频技术在锅炉机电一体化节能系统中应用
3、煤矿高效掘进技术现状与发展趋势研究
4、电气自动化在煤矿生产中的应用探讨
5、产品设计与腐蚀防护的程序与内容
6、机械制造中数控技术应用分析
7、智能制造中机电一体化技术的应用
8、水利水电工程的图形信息模型研究
9、矿山地面变电站智能化改造研究
10、浅析电气控制与PLC一体化教学体系的构建
11、中国机电产品出口面临的障碍及优化对策
12、我国真空包装机械未来的发展趋势
13、煤矿皮带运输变频器电气节能技术的分析
14、钢铁企业中机电一体化技术的应用和发展
15、我国机械设计制造及其自动化发展方向研究
16、机械设计制造及其自动化发展方向的研究
17、基于BIM技术的施工方案优化研究
18、电力自动化技术在电力工程中的应用
19、电气自动化技术在火力发电中的创新应用
20、农机机械设计优化方案探究
21、区域轨道交通档案信息化建设
22、环保过滤剂自动化包装系统设计
23、元动作装配单元的故障维修决策
24、关于机械设计制造及其自动化的设计原则与趋势分析
25、试析机电一体化中的接口问题
26、汽车安全技术的研究现状和展望
27、太阳能相变蓄热系统在温室加温中的应用
28、关于在机电领域自动控制技术应用的研究
29、浅析生物制药公司物流成本核算
30、锡矿高效采矿设备的故障排除与维护管理
31、铸钢用水玻璃型砂创新技术与装备
32、空客飞行模拟机引进关键环节与技术研究
33、汽车座椅保持架滚珠自动装配系统设计
34、液压挖掘机工作装置机液仿真研究
35、基于新常态视角下的辽宁高校毕业生就业工作对策研究
36、石油机电事故影响因素与技术管理要点略述
37、基于铝屏蔽的铁磁性构件缺陷脉冲涡流检测研究
38、数控加工中心的可靠性分析与增长研究
39、数控机床机械加工效率的改进 方法 研究
40、浅析熔铸设备与机电一体化
41、冶金电气自动化控制技术探析
42、中职机电专业理实一体化教学模式探究
43、高职机电一体化技术专业课程体系现状分析和改革策略
44、高速公路机电工程施工质量及控制策略研究
45、对现代汽车维修技术 措施 的若干研究
46、建筑工程机电一体化设备的安装技术及电动机调试技术分析
47、智能家居电话控制系统的设计
48、电力系统继电保护课程建设与改革
49、PLC技术在变电站电容器控制中的应用分析
50、机电一体化技术在地质勘探工程中的应用
机械类cad毕业论文题目
1、CAD技术在机械工艺设计中的应用研究
2、Auto CAD二次开发及在机械工程中的应用
3、基于特征的机械设计CAD系统研究
4、CAD在机械工程设计中的应用分析
5、机械制造中机械CAD与机械制图结合应用研究
6、浅谈CAD在机械制造业中起到的作用
7、智能CAD技术在机械制造中的应用
8、CAD/CAM技术在机械设计与制造中的应用研究
9、CAD制图技术在机械工程中的开发和应用
10、基于CAD/CAE的机械结构设计模式研究
11、基于机械制图与机械CAD应用环节协调分析
12、浅谈CAD技术在机械工程设计中的应用
13、三维CAD技术在机械设计中的应用
14、基于CAD的偏置曲柄滑块机构的设计与研究
15、应用CAD软件绘制机械零件图的创新方法
16、应用CAD图解法设计凸轮轮廓曲线的新方法
17、浅谈CAD外部参照在机械设计中的使用
18、五杆机构的CAD系统研究与开发
19、国内双圆弧齿轮CAD/CAE研究进展
20、连杆式少齿差减速机的CAD参数化设计
21、CAD实体模型直接分层软件设计
22、基于MBD的三维CAD模型信息标注研究
23、对提高CAD绘图速度的几点建议
24、Auto CAD在机械制图中的应用
25、机械传动系统方案设计CAD专家系统的研究
26、基于数值图谱法的连杆机构尺度综合CAD系统
27、浅谈Auto CAD在机械制图中的应用
28、基于CAD的液压传动技术综合性实验研究
29、圆柱凸轮CAD/CAM研究开发及在一次性卫生用品自动生产线中的应用
30、基于Creo的轴类零件CAD/CAPP集成系统开发
31、航空齿轮泵NX/CAD系统的界面实现
32、实现滚珠丝杠副AutoCAD/CAPP一体化
33、三维CAD技术在机械设计中的应用探讨
34、基于VB的弧面分度凸轮机构CAD系统设计
35、三维CAD技术对机械设计的影响管窥
36、液压系统原理图CAD开发研究
37、基于许用压力角要求的共轭凸轮计算机辅助设计系统开发
38、关于CAD技术在机械可靠性优化设计中的应用分析
39、弧面凸轮的CAD系统研究与开发
40、本体驱动的跨CAD平台开放式零件资源库构建
41、机械制图与CAD一体化探讨
42、论机械CAD技术及发展趋势
43、行星齿轮传动CAD系统开发
44、基于CAXA的盘类凸轮CAD/CAM应用
45、基于CAD技术的法兰26963工艺工装设计
46、鼓形齿联轴器参数化CAD系统开发
47、基于改进CAD技术的机械工艺设计探析
48、基于Pro/E的剪叉式液压升降台CAD系统的研究与开发
49、基于CAD/CAE集成的起重性能计算及方案优化
50、论CAD技术的发展及其对机械制图的影响
机床夹具类毕业论文题目
1、可重构车身底盘焊装夹具设计
2、随行夹具针对柔性自动加工线适应性技术
3、智能柔性可重构焊装随行夹具系统应用研究
4、组合夹具在零件加工中的应用
5、一种电机轴承卧式安装自动化生产设备
6、拨叉零件加工工艺浅析及其铣槽夹具设计
7、盾构机法兰密封圆环件圆柱面径向孔加工钻模设计
8、角度可调式线切割机床夹具设计及有限元分析
9、数控机床及工艺装备的创新
10、机床夹具制造中组合加工法的应用
11、拨叉零件加工工艺浅析及其铣槽夹具设计
12、中职机械专业 教育 中的机床夹具问题
13、快速判断夹具过定位的方法
14、夹具设计方案的分析与优化
15、机床夹具设计改进思路分析
16、机床夹具中定位与夹紧的研究
17、试论机械加工工艺装备设计研究杨兴旺
18、基于UG的机床夹具应用研究
19、机床夹具中定位与夹紧的研究
20、油泵轴加工自动生产线方案
21、浅谈机床夹具的发展趋势
22、浅析机械加工中工装夹具的定位设计
23、基于坐标系转换的工装夹具调装技术研究孔
24、零件加工中的机床夹具设计作用
25、机床夹具设计改进思路分析
26、专用机床夹具设计的方法与技巧
27、基于DVIA Composer D动画在机床夹具CAI中的应用研究
28、机床夹具的设计探讨
29、谈机械加工工艺装备设计
30、电永磁技术在金属加工中的应用
31、柔性组合夹具在汽车零部件制造中的应用研究
32、汽车扭杆力臂尾部平面铣削新型组合夹具
33、采矿装备制造中的先进焊接工装夹具应用研究
34、基于水泵机械制造工艺的设计探究
35、可调整夹持力的多功能夹具设计卜祥正
36、中小批量偏心凸轮的数控车削加工
37、光栅尺支架夹具设计的探讨
38、零件加工中的机床夹具设计作用
39、基于ANSYS的机床夹具的静动态特性分析
40、大直径圆周均布孔加工方法的研究
41、人机操作分析在底座生产线改进中的应用
42、液压阀体主阀孔车削成组夹具的设计与应用
43、法兰盘车床组合夹具设计
44、操纵杆支架Φ孔工艺及组合夹具设计
45、基于UG参数化设计的钻模设计
46、便携式高压隔离开关触头拆卸组合夹具的设计与研究
47、旋转式磁力片自动化装配系统及关键工位设计
48、机床夹具设计方法的应用
49、数控模具零件的铣夹具设计方法研究
50、一种小型叉形接头的精密加工技术
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★ 机械电子工程方面论文
★ 机电相关毕业设计论文范文
我有一篇我本科毕设的小论文，英文中文都有，而且是我人工翻译的，8000字左右。你要的话PM我。我是电气工程及其自动化专业的。《Analysis of thyristor-controlled phase shifter applied in damping power system oscillations》
不会写论文还这么嚣张?不就是250分吗得到了又怎么地？能吃呀？
电气工程：1Electrical Engineering My decision to pursue graduate study in the United States is underscored by my desire to be a part of the graduate program at your institution. Purdue University offers the flexibility needed for such a vast and rapidly changing field. The research facilities and the faculty at the university are par excellent. Communications is an industry that has changed our lives. In a very short period it has changed the way we have looked at things since centuries. It is one industry that is going to shape our future for centuries to come. Hence my desire to do masters in electrical engineering with communications as my major. My interest in electronics blossomed during my high school years. It was the time when technology had begun to make an impact on the lives of people in India. Hence engineering with electronics as my major was the first choice for my undergraduate studies. Right since the beginning of my undergraduate study electronics is a subject that has fascinated me with its power of applications. The subjects that I have studied include Linear Electronics, Digital Electronics. These laid the foundation for my courses in Electronic Communication & Communication Systems at a later stage. My undergraduate studies already focus on the communications aspect of electronics. A masters degree in electrical engineering with communications as major field is the next logical step. For the past four months I have been working as a project trainee at the Indian Institute for Advanced Electronics. I am working on the design and development of a "PC Controlled Digital Serial Data Generator". This short stint has given me invaluable practical experience. It has given me the confidence to pursue a masters degree and also kindled a desire to do research. During the course of my work at IIAE, I have come across several scientists. Most of them work in different areas of communications. Interactions with them have made me realize the vastness and the scope of communications. My discussions with them convinced me that specializing in communications will suit me very well. The subject of research which interests me very much is spread spectrum communication systems. Coding theory and combinations is another research subject which arouses my curiosity. The subject Communication Theory which I am studying at present introduces these topics in theory. I am eager to find out more about the applications of coding theory to spread spectrum communication systems. In addition I have been a student member of the IEEE (Institute of Electrical and Electronics Engineers, Inc.) for the past three years. Through its workshops/seminars and publications like the 'The Spectrum' it has exposed me to a lot of emerging technologies in the field of communications. It is a strong belief in my family that the American education system has the best to offer in the whole world. This belief arises out of the experience that my parents had when they did their Masters of Science in the University of Pennsylvania during the years 1967-69. If I can get an opportunity to be a part of that intellectually stimulating environment, I am sure my talents will be put to optimal use. India is a developing country with an enormous potential in the information technology business. To serve the needs of this developing industry and more important its vast population, communications is going to become of utmost importance. Thus conditions here are very conducive to supplement my aspirations when I return after completing my graduate studies. 2Electrical Engineering As a graduate student, I will undertake research and coursework in Electrical Engineering to enhance my competencies in this field. I intend to complete my master's degree in order to pursue my doctorate. The research that I am most interested in pursuing at Northeastern University surrounds the optical properties of MEMS devices, and the development of substrate-based fast electro-optical interfaces. My interest in this area stems from my undergraduate study in MEMs development for tri-axial accelerometers. Engineering has been a key interest of mine since childhood. While still in grade school I enjoyed listening to my father, an electrical engineer, teach me about advances in technology, and was always eager to hear more. I was introduced to my first computer at the age of five, and have loved interacting with them ever since. My decision to study engineering as a career was no surprise to those who knew me. In college I found that I was always studying something I enjoyed. I believe it is because I enjoy my life and my work that I have been successful. Spending hours in the laboratory is not something that I dread, but instead I take pride in my work and its successful completion. One example of this that is still fresh in my mind is the successful design of a fully functional microprocessor in the Xilinx environment. All told, the project took over 150 hours of each design-team member's time. However, I did not look on it as a drain, but an experience for learning and a focus for my professional and technical development. When we finished the project we felt the sense of worth and pride in completion of a task that was once above our level of knowledge. Pursuing a graduate degree in the research field I have chosen also feels like a challenge, and I know that study will frustrate me at times. However, I feel that my commitment to learning will not be swayed. I feel confident in my ability to be creative in my perspective, and to persevere. My ultimate goal is to be an innovator in the field I have chosen to study. Professionalism and creativity are my most valued strengths. At the heart of my interest is the advancement of man in concert with his environment. My personal philosophy of life will matter greatly during my study and after its completion. That is why I devote time to reflection on my goals and their implications. Money has never been a motivator for my work, nor do I think it will be in the future. However, as a professional and a graduate, I realize that my earning potential will be significant. That is why I also commit myself to charity and fairness. In the past I have been a member of the Boy Scouts of America, and have achieved the rank of Eagle Scout. In the course of my experience in that organization, I learned respect and moral value. Now, as a member of the IEEE, I value my professional standing and its commensurate moral implications. Ethics in engineering is as important as technical skill, and as such I intend to uphold my own ethical obligations to the best of my ability. As a Northeastern University student, I would commit all that I have to offer to my study. I intend to pursue research in MEMS technology. At Rowan University as an undergraduate student I have already conducted some research and development of MEMS sensors for military applications, resulting in publication. An article, written by myself and my project member David Bowen and edited by our advisor Dr. Robert Krchnavek, was published in the NAVSEA Intelligent Ships Symposium Proceedings of 2001. The paper was titled "Designing a 3-Axis, Monolithic, MEMS-Based Accelerometer" and was under review for endorsement by the US Navy's NAVSEA facility in Philadelphia during that year. Building on my past success in MEMs design, I hope to advance my understanding. Through research at the graduate level, it is my hope to become familiar with, and innovate the design of MEMs Optics in hopes of creating a reliable and practical MEMs Electro-Optical Interface for use in consumer electronics. It is my hope, that through my research, optical waveguides for intradevice communication might be realized. Finally, my intent to pursue graduate study is laid plain. Study of MEMs optics is my intended focus, and I am committed to my goal. In pursuing a doctoral degree, I have closely analyzed myself to determine the reasons for my previous successes and my goals for the future. I have found that I do and have always enjoyed engineering, and that I have a strong desire to pursue my study further. I am prepared to commit myself to that study, and achieve what I have set out to do. 3I Wish to Pursue an MS Degree in Electrical Engineering During my senior year at Purdue University, I made a decision that has impacted the entire course of my education. While my classmates were making definite decisions about their career paths, I chose to implement a five-year plan of development and growth for myself. I designed this plan in order to examine various careers that I thought might interest me, as well as to expand upon my abilities at the time. As I was attaining a BS degree in Electrical Engineering, I decided to focus primarily on fields related to the VLSI (Very Large-Scale Integrated) circuits area. My main goals were either to gain work experience or to further my education by pursuing an MS degree in Electrical Engineering (MSEE). I saw an opportunity to both work and learn through employment at Xilinx Inc. Operating as a product engineer at a successful, high-tech semiconductor company has enabled me to utilize my technical and interpersonal skills in new and challenging ways. The position has also allowed me to interact with a multitude of departments including marketing, integrated circuit (IC) design, software/CAD development, manufacturing, reliability, accounting, and sales. I thus have gained an array of experience that extended beyond the parameters of my own responsibilities. In the workplace, I rely heavily upon the interpersonal techniques I developed as a counselor in a Purdue residence hall, as well as the organizational skills I had acquired through holding various leadership positions in cultural and engineering societies. I have also cultivated an interest in high-technology marketing that has continued to grow throughout my career. My experiences with Xilinx have heightened my hunger for knowledge in the VLSI field. Two months after joining the corporation, I applied to several part-time programs in the vicinity that would allow me to acquire an MSEE degree within two to three years. San Jose State seemed an ideal choice, for its evening MSEE courses would allow me to pursue two independent, full-time positions concurrently. The San Jose program has complimented my Xilinx duties well; both demand large levels of energy and enthusiasm while guiding me to my ultimate goal a high degree of education in VLSI sciences. The resources that I poured into both endeavors have reaped many gains. I have been promoted to a Product-Yield Engineering position within Xilinx's Coarse Grain Static Memory (CGSM) Product Engineering division. My extensive coursework plays a key role in my continued success at Xilinx. Relevant classes in advanced digital and analog VLSI design, as well as sub-micron ULSI technology, have allowed me to understand more completely the workings of Xilinx, a fab-less semiconductor company that also functions as a software and hardware design, testing, and marketing center. The gains in knowledge I have made through the combination of work experience and education have indeed been exponential. The academic records of my senior year at Purdue, coupled with my MSEE coursework, are ample proof of my dedication to learning. I feel I have overcome through hard work and dedication the brief "dry phase" I underwent at Purdue during the close of my sophomore and the first semester of my junior years. My performance at that time is in no way indicative of my usual achievements; they are instead the result of urgent family difficulties that required much foreign travel and serious attention to resolve. In May, I shall graduate with an MSEE degree from San Jose well ahead of my original estimates. This early graduation with Dean's Honors is the result of my firm belief in the value of diligence, as well as my renewed determination to strive for perfection in both work and school. I am now embarking on another five-year plan, during which I hope to fulfill several specific career goals. For instance, being part of a very dynamic and results-oriented Yield team at Xilinx calls for continuous development of computational and statistical techniques. The Yield team is divided to focus on specific process/fabrication issues and process (manufacturing) optimization. My own position is an integral part of the optimization group. Speed and cost issues continue to press high technology atmospheres towards optimization, probability and stochastic processes and systems, and rigorous simulations of mathematical models. The MS in EES&OR offered at your university will grant me the statistical knowledge that is crucial for process and production optimization in a fab-less environment. In addition, product engineering requires fundamental research on mathematical models for linear and non-linear programming, as well as the utilization of efficient computer software. I continuously employ the knowledge I gained at Purdue in Operations Research and advanced mathematics courses. Yet despite the value of these classes and my high performance in them, I now require further education to best fulfill my duties. An MS in the EES&OR field, will give me knowledge that is invaluable to a career in product development, project management and strategic planning. The program will allow me to improve decision-making skills in operations, strategy, and policy issues. I will strengthen my theory and application in countless areas:continuous, discrete, numerical optimization; probabilistic and stochastic processes; dynamic systems and simulation; economics, finance, and investment; decision analysis; dynamic programming and planning under uncertainty; operations and service; corporate and individual strategy; and private and public policy , the EES&OR program will not only help me to excel at Xilinx but will also further any future career. My commitment to work and education over the last three years proves that I will pursue this MS with enthusiasm and technical edge that the MS would provide is I will be working while attending Stanford, I shall mingle education with practical application, and bring to the table interesting problems from my experience and past education. Technical challenges encountered through projects in the EES&OR program will provide motivation and opportunity for methodological data collection, processing and presentation issues presented are integral to my future goals, and the management challenges raised will provide invaluable experience for professional practice. This will in turn build a solid foundation for a life-long career that can overcome any problem in decision-making. In addition, taking courses in economics, finance, and investment analysis will allow much growth of knowledge in investment issues in different industries. The EES&OR program thus appeals not only to my engineering, economics, science and mathematical background, but will compliment my technical abilities with the conceptual frameworks needed to analyze problems in operations, production, strategic planning, and marketing in the realm of emiconductor/IC/engineering systems. I feel that I am prepared to meet the challenges of the curriculum. My coursework in intermediate microeconomics and macroeconomics, international trade, operations research, linear algebra, and probabilistic methods, along with my extensive calculus background, will allow me to function well within the program. My long-term career goals include a move into marketing and product management. I believe that attaining this MS degree is the cornerstone to achieving my goals. It will give me the academic background necessary to succeed in product development, project management, and strategic planning. It will improve decision-making skills necessary for optimizing performance. The integration of two excellent programs in Economics Systems and Operations Research thus suits my current position and ties in with future goals perfectly by improving decision making in operations, strategy and policy. At present I desire to continue at Xilinx; attending a program that provides the flexibility and convenience of the SITN, is therefore imperative. Hence, being at Stanford as an HCP student alsoattracts me. I believe that Stanford is the best environment for me to achieve my goals while gaining exposure to and experience with a diverse student body and faculty. It is my belief that one continues to learn throughout one's life, and the most effective method of learning is through interaction with 's diversity offers an environment for learning, both inside and outside the classroom. I hope to share my varied knowledge with my classmates and to take from them a new understanding of topics that are foreign to me. I believe that no other school provides students with the combination of education and environment offered by Stanford. Its outstanding academic reputation, mingled with its diverse environment and thriving Bay Area location, creates an opportunity for growth that is second to none. I have many ambitions for myself as I embark on this stage of my life. I believe that an education from Stanford will provide invaluable experiences and skills that will allow me to become a successful and innovative business leader in the new millennium. 4Research Department of Biomedical Engineering is designed to research on and solve the bio-electrical and biomagnetic engineering problems in the field of biology and medicine with the aid of engineering principles and methods. Its main task is to explain, from perspective view of engineering, the biological and pathologic processes of the living organisms, especially human beings, and research on and develop the related medical devices and life science devices. Its research directions mainly include the modeling and emulation of the biological system, testing and analysis of biomedical signals, the biomedical imaging and processing , the biological effects of electromagnetic field and the development of artificial organs and medical devices, Bioengineering With the development and integration of electromagnetism, biology and medicine, biological electromagnetism exercises more and more influence on human life and health, environment protection and biological engineering. The research on electromagnetic bioengineering is a new research direction for IEECAS, mainly including research on rules of mutual influence between electromagnetic field and life matter, biological electromagnetic effect and its application in biology, medicine and medical equipment. At present, the research team has set up labs such as biological electromagnetic environment lab, biological electromagnetic signals & electromagnetic property testing lab, electromagnetic biological effect testing lab and biological electromagnetic simulation lab. It is equipped with various electrical and magnetic fields for experiments of biological electromagnetic effects, simulation software and biochemical experiment equipment. With such equipments, it can do biological electromagnetic experiments on live animals and detached live cells, detect, analyze and process the very weak biological electromagnetic signals, analyze and test live organism or detached cell under electromagnetic interaction with biochemical quantitative methods. The recent research work focuses on the effects 方向对不对，不知你要哪种，告诉我，我再接着找多的话email you
用于分布式在线UPS中的并联逆变器的一种无线控制器A Wireless Controller for Parallel Inverters in Distributed Online UPS SystemsJosep M. Guerrero', Luis Garcia de Vicufia", Jose Matas'*, Jaume Miret", and Miguel Castilla". Departament #Enginyeria de Sistemes, Automatica i Informhtica Industrial. Universitat Polithica de CatalunyaC. Comte d'Urgell, -Barcelona. Spain. Email: .. Departament #Enginyeria Electrbnica. Universitat Polit6cnica de CatalunyaAV. Victor BaLguer s/n. 08800I - Vilanova i la Geltrh. SpainAbsiract - In this paper, a novel controller for parallelconnectedonline-UPS inverters without control wireinterconnections is presented. The wireless control technique isbased on the well-known droop method, which consists inintroducing P-oand Q-V schemes into the inverters, in order toshare properly the power drawn to the loads. The droop methodhas been widely used in applications of load sharing betweendifferent parallel-connected inverters. However, this methodhas several drawbacks that limited its application, such as atrade-off between output-voltage regulation and power sharingaccuracy, slow transient response, and frequency and phasedeviation. This last disadvantage makes impracticable themethod in online-UPS systems, since in this case every modulemust be in phase with the utility ac mains. To overcome theselimitations, we propose a novel control scheme, endowing to theparalleled-UPS system a proper transient response, strictlyfrequency and phase synchronization with the ac mains, andexcellent power sharing. Simulation and experimental resultsare reported confirming the validity of the proposed . INTRODUCTIONThe parallel operation of distributed Uninterruptible PowerSupplies (UPS) is presented as a suitable solution to supplycritical and sensitive loads, when high reliability and poweravailability are required. In the last years, many controlschemes for parallel-connected inverters has been raised,which are derived from parallel-schemes of dc-dc converters[I], such as the master-slave control [2], or the democraticcontrol [3]. In contrast, novel control schemes have beenappeared recently, such as the chain-structure control [4], orthe distributed control [ 5 ] . However, all these schemes needcontrol interconnections between modules and, hence, thereliability of the system is reduced since they can be a sourceof noise and failures. Moreover, these communication wireslimited the physical situation ofthe modules [6].In this sense, several control techniques has been proposedwithout control interconnections, such as the droop this method, the control loop achieves good power sharingmaking tight adjustments over the output voltage frequencyand amplitude of the inverter, with the objective tocompensate the active and reactive power unbalances [7].This concept is derived from the power system theory, inwhich the frequency of a generator drops when the powerdrawn to the utility line increases [8].0-7803-7906-3/03/$ 02003 IEEE. 1637However, this control approach has an inherent trade-offbetween voltage regulation and power sharing. In addition,this method exhibits slow dynamic-response, since it requireslow-pass filters to calculate the average value of the activeand reactive power. Hence, the stability and the dynamics ofthe whole system are hardly influenced by the characteristicsof these filters and by the value of the droop coefficients,which are bounded by the maximum allowed deviations ofthe output voltage amplitude and , when active power increases, the droopcharacteristic causes a frequency deviation from the nominalvalue and, consequently, it results in a variable phasedifference between the mains and the inverter output fact can be a problem when the bypass switch mustconnect the utility line directly to the critical bus in stead ofits phase difference. In [9], two possibilities are presented inorder to achieve phase synchronization for parallel lineinteractiveUPS systems. The first one is to locate a particularmodule near the bypass switch, which must to synchronizethe output voltage to the mains while supporting overloadcondition before switch on. The second possibility is to waitfor the instant when phase matching is produced to connectthe , the mentioned two folds cannot be applied to aparallel online-UPS system, since maximum transfer timeought to be less than a % of line period, and all the modulesmust be always synchronized with the mains when it ispresent. Hence, the modules should be prepared to transferdirectly the energy from the mains to the critical bus in caseof overload or failure [lo].In our previous works [11][12], we proposed differentcontrol schemes to overcome several limitations of theconventional droop method. However, these controllers bythemselves are inappropriate to apply to a parallel online-UPS system. In this paper, a novel wireless control scheme isproposed to parallel different online UPS modules with highperformance and restricted requirements. The controllerprovides: 1) proper transient response; 2) power sharingaccuracy; 3) stable frequency operation; and 4) good phasematching between the output-voltage and the utility , this new approach is especially suitable for paralleled-UPS systems with true redundancy, high reliability andpower availability. Simulation and experimental results arereported, confirming the validity of this control . 1. Equivalenl cimuif ofan invener connecled 10 a bust"Fig. 2. P-odraop . REVlEW OF THE CONVENTIONAL DROOP METHODFig. 1 shows the equivalent circuit of an inverter connectedto a common bus through coupled impedance. When thisimpedance is inductive, the active and reactive powers drawnto the load can be expressed asEVcosQ - V2 Q=where Xis the output reactance of an inverter; Q is the phaseangle between the output voltage of the inverter and thevoltage of the common bus; E and V are the amplitude of theoutput voltage of the inverter and the bus voltage, the above equations it can be derived that the activepower P is predominately dependent on the power angle Q,while the reactive power Q mostly depends on the outputvoltageamplitude. Consequently, most of wireless-control ofparalleled-inverters uses the conventional droop method,which introduces the following droops in the amplitude Eand the frequency U of the inverter output voltageu = w -mP (3)E = E ' - n Q , (4)being W* and E' the output voltage frequency and amplitudeat no load, respectively; m and n are the droop coefficientsfor the frequency and amplitude, , a coupled inductance is needed between theinverter output and the critical bus that fixes the outputimpedance, in order to ensure a proper power flow. However,it is bulky and increase:; the size and the cost of the UPSmodules. In addition, tho output voltage is highly distortedwhen supplying nonlinezr loads since the output impedanceis a pure is well known that if droop coefficients are increased,then good power sharing is achieved at the expense ofdegrading the voltage regulation (see Fig. 2).The inherent trade-off of this scheme restricts thementioned coefficients, which can be a serious limitation interms of transient response, power sharing accuracy, andsystem the other hand, lo carry out the droop functions,expressed by (3) and (4), it is necessary to calculate theaverage value over one line-cycle of the output active andreactive instantaneous power. This can be implemented bymeans of low pass filters with a smaller bandwidth than thatof the closed-loop inverter. Consequently, the powercalculation filters and droop coefficients determine, to a largeextent, the dynamics and the stability of the paralleledinvertersystem [ conclusion, the droop method has several intrinsicproblems to be applied a wireless paralleled-system ofonline UPS, which can he summed-up as follows:Static trade-off between the output-voltage regulation(frequency and amplitude) and the power-sharingaccuracy (active an4d reactive).2) Limited transient response. The system dynamicsdepends on the power-calculation filter characteristics,the droop coefficients, and the output of ac mains synchronization. The frequency andphase deviations, due to the frequency droop, makeimpracticable this method to a parallel-connectedonline UPS system, in which every UPS should becontinuously synchronized to the public ac )3)111. PROPOSED CONTROL FOR PARALLEL ONLINE UPSINVERTERSIn this work, we will try to overcome the above limitationsand to synthesize a novel control strategy withoutcommunication wires that could be appropriate to highperformanceparalleled industrial UPS. The objective is toconnect online UPS inverters in parallel without usingcontrol interconnections. This kind of systems, also namedinverter-preferred, should be continuously synchronized tothe utility line. When an overload or an inverter failureoccurs, a static bypass switch may connect the input line tothe load, bypassing the inve:rter [14][15].Fig. 3 shows the general diagram of a distributed onlineUPS system. This system consists of two buses: the utilitybus, which is connected lo the public ac mains; and thesecure bus, connected to the distributed critical loads. Theinterface between these buses is based on a number of onlineUPS modules connected in parallel, which providescontinuously power to the: loads [16]. The UPS modulesinclude a rectifier, a set of batteries, an inverter, and a staticbypass ac mainsutility busI I Ij distributed loads !Fig. 3. Online distributed UPS /I 4(4Fig. 4. Operation modes of an online UPS.(a) Normal operation. (b) Bypass operation. (c) Mains failureThe main operation modes of a distributed online UPS1) Normal operation: The power flows to the load, fromthe utility through the distributed UPS ) Mains failure: When the public ac mains fails, theUPS inverters supply the power to the loads, from thebatteries, without operation: When an overload situation occurs,the bypass switch must connect the critical busdirectly to the ac mains, in order to guarantee thecontinuous supply of the loads, avoiding the damageof the UPS this reason, the output-voltage waveform should besynchronized to the mains, when this last is are listed below (see Fig. 5):3)Nevertheless, as we state before, the conventional droopmethod can not satisfy the need for synchronization with theutility, due to the frequency variation of the inverters, whichprovokes a phase obtain the required performance, we present a transientP-w droop without frequency-deviation in steady-state,proposed previously by OUT in [ 111w=o -mP (5)where is the active power signal without the dccomponent,which is done by. -I t -1sP= p ,( s + t - ' ) ( s + o , )being zthe time constant of the transient droop transient droop function ensures a stable frequencyregulation under steady-state conditions, and 'at the sametime, achieves active power balance by adjusting thefrequency of the modules during a load transient. Besides, toadjust the phase of the modules we propose an additionalsynchronizing loop, yieldingo=w'-m%k,A$, (7)where A$ is the phase difference between the inverter and themains; and k, is the proportional constant of the frequencyadjust. The steady-state frequency reference w* can beobtained by measuring the utility line second term of the previous equality trends to zero insteady state, leading tow = w' - k4($ -@'), (8)being $and $* the phase angles of the output voltage inverterand the utility mains, into account that w = d $ / d t , we can obtain thenext differential equation, which is stable fork, positived$ *dt dt- + km$ = - + k,$' . (9)Thus, when phase difference increases, frequency willdecrease slightly and, hence, all :he UPS modules will besynchronized with the utility, while sharing the power drawnto the . CONTROLLIEMRP LEMENTATIONFig. 5 depicts the block diagram of the proposedcontroller. The average active power P , without the dccomponent, can be obtained by means of multiplying theoutput voltage by the output current, and filtering the product........................................................................................io",.LSj'nchronirorion loop.......................................................................................Fig. 5. Block diagram of the proposed a band-pass filter. In a similar way, the averagereactive power is obtained, hut in this case the output-voltagemust be delayed 90 degrees, and using a low-pass order to adjust the output voltage frequency, equation(7) is implemented, which corresponds to the frequencymains drooped by two transient-terms: the transient activepower signal term; and the phase difference term, whichis added in order to synchronize the output voltage with theac mains, in a phase-locked loop (PLL) fashion. The outputvoltageamplitude is regulated by using the conventionaldroop method (4).Finally, the physical coupled inductance can be avoided byusing a virtual inductor [17]. This concept consists inemulated an inductance behavior, by drooping the outputvoltage proportionally to the time derivative of the outputcurrent. However, when supplying nonlinear loads, the highordercurrent-harmonics can increase too much the outputvoltageTHD. This can be easily solved by using a high-passfilter instead of a pure-derivative term of the output current,which is useful to share linear and nonlinear loads [I 1][12].Furthermore, the proper design of this output inductance canreduce, to a large extent, the unbalance line-impedanceimpact over the power sharing . SIMULATION AND EXPERIMENTARELS ULTSThe proposed control scheme, (4) and (7), was simulatedwith the parameters listed in Table 1 and the scheme shownin Fig. 6, for a two paralleled inverters system. Thecoefficients m, n, T, and kv were chosen to ensure stability,proper transient response and good phase matching. Fig. 7shows the waveforms of the frequency, circulating currents,phase difference between the modules and the utility line,and the evolution of the active and reactive powers. Note theexcellent synchronization between the modules and theACmiiinr 4 j. ...L...... ..........................B...u...n...... ................................... iFig. 6. Parallel operation oftwa online UPS modules,mains, and, at the same time, the good power sharingobtained. This characteristik let us to apply the controller tothe online UPS paralleled I-kVA UPS modules were built and tested in order toshow the validity of the proposed approach. Each UPSinverter consisted of a single-phase IGBT full-bridge with aswitching frequency of 20 kHz and an LC output filter, withthe following parameters: 1. = 1 mH, C = 20 WF, Vi" = 400V,v, = 220 V, I50 Hz. The controllers of these inverters werebased on three loops: an inner current-loop, an outer PIcontroller that ensures voltage regulation, and the loadsharingcontroller, based on (4) and (7). The last controllerwas implemented by means of a TMS320LF2407A, fixedpoint40 MHz digital sigrial processor (DSP) from TexasInstruments (see Fig. 8), using the parameters listed in TableI. The DSP-controller also includes a PLL block in order tosynchronize the inverter with the common bus. When thisoccurs, the static bypass switch is tumed on, and the droopbasedcontrol is 7 Wa\cfc)rms for , ;mnectcd in parallel. rpchrontred io Ihc ac mdnl.(a) Frequencics ufhoth UPS (b) Clrculattng currcni among modulcs. (CJ Phmc d!Nercn;: betucen ihc UPS a#>dth e ai mum(d) Ikiril uf the phze diNmncc (e) md (0 Activc and rcactlw pouerr "I ooih UPSNote that the iimc-acs arc deliheratcly JiNercni due in thc disiinct timuion*uni) ofthe \ THE PARALLELESDYS Order I IFilter Cut-off Frequency I 0, I 10 I ragsFig. 8 shows the output-current transient response of theUPS inverters. First, the two UPS are operating in parallelwithout load. Notice that a small reactive current is circlingbetween the modules, due to the measurement , a nonlinear load, with a crest factor of 3, is connectedsuddenly. This result shows the good dynamics and loadsharingof the paralleled system when sharing a . 8. Output current for the two paralleled UPS, during the connection of Bcommon nonlinear load with a crest factor of 3. (Axis-x: 20 mddiv. Axis-y:5 Mdiv.).VI. CONCLUSIONSIn this paper, a novel load-sharing controller for parallelconnectedonline UPS systems, was proposed. The controlleris based on the droop method, which avoids the use ofcontrol interconnections. In a sharp contrast with theconventional droop method, the controller presented is ableto keep the output-voltage frequency and phase strictlysynchronized with the utility ac mains, while maintaininggood load sharing for linear and nonlinear loads. This fact letus to extend the droop method to paralleled online the other hand, the proposed controller emulates aspecial kind of impedance, avoiding the use of a physicalcoupled inductance. results reported here show theeffectiveness of the proposed approach.
The main advantage of this concept is that the consecutive controller is able to control disturbances of humidifying arrangement directly, because the dew point measurement of the humidifier has got a very short response time compared with the quite longer response time of the furnace dew point. This is caused by bigger time delays of the measurement and the delay time of the process gas to come into the station for CO/CO2, H2 and O2ppm monitoring, extracting method will be multiplexed sampling An analysis station designed as a complete functional unit will be used for monitoring the composition of the atmosphere in the analysis station will be a single-cabinet unit complete with analyzers, pumps, solenoid valves and control unit. In normal operation, the sample gas switchover system will switch cyclically between the different sample gases. The system can also be switched to nitrogen for purging or to a calibration gas; this is not part of the normal sample waste gas will be fed from the sampling probe on the furnace (with filter) to the analyser or sample gas treatment system through a sample gas line routed downwards. Sample gas from each sample gas point will be extracted by the main sample gas pump to the analyser station. The sample gas 'in measurement' will be switched to the measurement line from where an additional pump pumps it to the analysers. The sample gas lines will be made from acid-resistant multiplexing analysis system has following probes:For CO/CO2 the system in an actual mode can be calibrated automatically every day using an in-built comparison probe. The calibration time is triggered using an internal period value, which can be changed manually. During calibration time no measurement values are available. A particular feature will be to switch from multiplexing measuring mode to single mode, where a certain probe gas inlet can be measured continuously and vice versa.这一进程所提供的气体，搅拌站在预热时将用换热器。天然气将在一个封闭的循环进行温度对照。预热H2/N2分配给不同的加湿器系统。在加湿器的过程中，天然气将利用富含水蒸汽的需要，在暖气炉中创造一个稳定的露点。在炉中，露点将成为衡量的加湿器。这两种测量将用于控制级联控制电路中所描述的下一章。 下面的示意图显示了控制概念的一个区的脱碳炉。 为了获得非常高的质量控制级联控制电路使用，凡有主控制器采用实际露点值精度高，手中的设置点的连续控制器作为输出。 这种控制器调整1露点的进程直接测量气体的出口加湿器。 它的主要优势是，这一概念 连续控制器能够控制骚乱直接加湿的安排，因为露点测量加湿器得到了很短的响应时间与反应时间而且很长的炉露点。这是造成更多的时间从而延迟测量和延迟气体进入炉的时间进程。 分析站CO/CO2 ， H2和O2ppm监测， 提取方法将采样： 分析站设计作为一个完整的功能单位将用于组成气氛炉中进行监测。 分析站将是一个单一完整的内阁单位与分析仪，水泵，电磁阀和控制单元。在正常操作时，样品气体切换系统将切换周期性不同样本之间的气体。该系统还可以切换到氮清洗或校准气体，这是不正常的周期。 抽样废气将美联储从取样探头的炉（带过滤器）的分析仪或样品气体处理系统通过抽样天然气管线路由向下。样品气体从每个样品天然气将是主要的提取汽油样品的分析仪站。样本气体测量中'将切换到测量线从那里额外泵泵给分析器。抽样天然气管道将来自耐酸塑料。 在复分析系统具有以下探针： 为CO/CO2该系统在实际模式可自动校准，每天使用的是内置的比较调查。校准时间是引发内部期间使用的价值，可手动改变。在校准时没有测量值。 一个特别的功能将被转换复测模式，以单一的模式，在一定的探测气体入口可以连续测量，反之亦然。 这一进程所提供的气体搅拌站将预热用换热器。温度对照的天然气将在一个封闭的循环。预热H2/N2分配给不同的加湿器系统。在加湿器的过程天然气将富含水蒸汽的需要，以创造一个稳定的露点在炉。露点将成为衡量的加湿器，并在炉。这两种测量将用于控制级联控制电路中所描述的下一章。下面的示意图显示了控制概念的一个区的脱碳炉。为了获得非常高的质量控制级联控制电路使用，凡有主控制器采用实际露点值精度高，手中的设置点的连续控制器作为输出。这种控制器调整1露点的进程直接测量气体的出口加湿器。的主要优势是，这一概念连续控制器能够控制骚乱的直接加湿的安排，因为露点测量加湿器得到了很短的响应时间与反应时间很长的炉露点。这是造成更大的时间延迟的测量和延迟时间的进程气体进入炉。分析站CO/CO2 ， H2和O2ppm监测，提取方法将复采样分析站设计作为一个完整的功能单位将用于监测的组成气氛炉。分析站将是一个单一完整的内阁单位与分析仪，水泵，电磁阀和控制单元。在正常操作时，样品气体切换系统将切换周期性不同样本之间的气体。该系统还可以切换到氮清洗或校准气体，这是不正常的周期。抽样废气将美联储从取样探头的炉（带过滤器）的分析仪或样品气体处理系统通过抽样天然气管线路由下降。样品气体从每个样品天然气将是主要的提取汽油样品的分析仪站。样本气体测量中'将切换到测量线从那里额外泵泵给分析器。抽样天然气管道将来自耐酸塑料。
People from almost all cultures throughout history have been making objects from wood. Some of the first wooden objects included weapons and tools. Early cultures also learned to make boats, buildings and tools. Early cultures also learned to make boats, buildings and furniture for home from this material. However, it is not always easy to say which wooden objects existed during a historical period tecause they often did not last as long as objects made from clay or metal. 有史以来的各个文化，人们用木头制作物品。最初的木头制品有武器和工具。早期文化（人们）还学会用这种材料造船，建筑物和家俱。然而，不好说木制品在历史长河中存在的时期，因为它们不像陶制品或金属制品一样能保存很长时间。Experts say most current woodworking tools were developed by the beginning of the Bronze Age, about five thousand years ago. These tools include the saw, ax, chisel and drill which are used to cut and shape wood in different ways. Also, there are many methods of wood-working and each culture has its own tradition. Artistic wood creations include architectural decoration on uildings, furniture for home or even carved animals. For example, in Thailand, richly-detailed carvings(雕刻) from teak and other hard wood are an important part of ancient palaces and religious buildings. 专家推断现存的木工刀具出现在约5000年前的铜器时代早期。这些锯，斧，凿，钻等工具用不同方式切削木头。而且，还有很多方式的木工刀具，每个文化都有自己的特色。木制艺术制品包括建设上的装饰，家俱或动物雕像。举个例子，在泰国，丰富精致的柚木或其它坚木的雕刻品是古代宫殿和宗教建筑的重要组成部分。Woodcarvers were a very important group of artists. A person needed many years of training with experts to be a woodcarver. Wood carvings often include plant forms such as the lotus flower as well as figures taken from Hindu and Buddhist religious stories. 木雕是艺术的重要组成部分。人们要经过专家的多年培训才能成为木雕师。木雕通常包括植物形态，如采用印度和佛教故事描述的莲花。The carvings are very detailed and must be carefully planned. Usually, a carver draws out the patterns and forms on paper. Then the artist cuts holes along the outline of the design. This paper is placed on the piece of wood then covered with chalk dust. The white chalk dust goes through the holes in the paper and marks the wood, so the carver has a visual guide to begin cutting. Finished woodcarvings are often painted, sometimes with gold to reflect the surrounding light. These expertly made golden carvings give an airy lightness to Thai buildings. 雕刻注重细节和慎重布局。通常雕刻师在纸上描画出样式和外形。然后艺术家从沿着设计的轮廓打孔。把这张纸覆盖在一块木头上，把白灰撒上去。白灰通过纸上的孔洞在木头下留下标记。这样雕刻师就可以看着指示开始切削。（制作）成品木雕经常是苦活，有时要加上金片来反射周围光线。通过这些专业加工，金晃晃的雕刻品给泰国建筑空灵的光彩。 Unit 2The stability of a continuous or discrete-time system is determined by its response to input or disturbance. Intuitively, a stable system is one that remains at rest (or in equilibrium) unless excited by an external source and returns to rest if all excitations are removed. The output will pass through a transient phase and settle down to a steady-state response that will be of the same form as, or bounded by, the input. If we apply the same input to an unstable system, the output will never settle down to a steady-state phase; it will increase in an unbounded manner, usually exponentially or with oscillation of increasing amplitude. 连续或离散系统的稳定性由其对输入或者干扰的响应决定。直观地说，如果一个系统是稳定的，则其停留在稳态（或者平衡点），除非是受到外部激励，且当外部激励去除后，输出又回到稳态点。输出经过瞬态阶段后将回到与输入有相同形式的稳态或者是在输入的附近。如果我们将同样的输入作用于不稳定的系统，其输出将不会回到稳态，而是以无界的方式增长，通常其幅值是指数增长或者振荡增长。Stability can be precisely defined in terms of the impulse response of a continuous system, Kronrcker delta response of a discrete-time system, as follows: A continuous (discrete-time) system is stable if its impulse response (Kronecker response ) approaches zero as time approaches infinity.系统的稳定性可以用连续系统的脉冲响应 或者离散系统的Kronrcker Δ 响应 来定义：一个连续（离散）系统是稳定的，如果其脉冲响应 （Kronrcker Δ 响应 ）当时间趋于无穷大时趋于零。An acceptable system must at minimum satisfy the three basic criteria of stability, accuracy, and a satisfactory transient response. These three criteria are implied in the statement that an acceptable system must have a satisfactory time response to specified inputs and disturbances. So although we work in the Laplace and frequency domains for convenience, we must be able to relate these two domains, at least qualitatively, to the time domain.一个可接受的系统必须至少满足：稳定性、精度和满意的瞬态响应这三个指标。在陈述：“一个可接受的系统对指定输入和扰动必须有满意的时域响应”已经包含了这三个指标的含义。因此尽管我们为了方便工作在拉氏域或者频率域，我们必须与时间域（至少是定性的）相联系。With the transfer function in the form of Eq.(2-2A-1), the order of the system in defined as the order of the characteristic function D(s), the highest power of s appearing in D(s) establishes the order of the system.在传递函数所在的方程(2-2A-1)中，系统的阶次定义为特征函数D(s)的阶次，因此D(s)的最高次幂决定了系统的阶次。The first term is the forced solution, due to the input, and the second the transient solution, due to the system pole. shows this transient as well as c(t). The transient is seen to be a decaying exponential, and the commonly used measured of the speed of decay is the time constant: The time constant is the time in seconds for the decaying exponential transient to be reduced to e-1= of its initial value. Since when t=T, it is seen that the time constant for a simple lag is T seconds. This is, in fact, the reason a simple lag transfer function is often written in this form. The coefficient of s then immediately indicates the speed of decay, and it takes 4T seconds for the transient to decay to of its initial value.第一项为强迫解，对应于输入；第二项为瞬态解，对应于系统的极点。 在图2-2A-2中，该瞬态解为c(t)。瞬态解看上去为指数衰减的，且通常用于衡量衰减速度的是时间常数：即指数衰减的瞬态解衰减至其初始值的所需的时间（秒数）。因为，当t=T, ，对于一阶惯性环节，时间常数是T秒。这也是为什么一阶惯性环节要写成这个形式。S的系数立即给出了衰减的速度。而且，当时间为4T时， 瞬态解衰减至初始值的。B：Steady StateA control system is designed to control the dynamic behavior( the time response) of a plant subject to commands or disturbances. The designer should be fully aware, however, of the role of the steady equations and errors in the overall process, as well as their influence on the dynamic behavior of the plant.控制系统设计就是使装置在有指令信号或者干扰时有满意的行为（时域响应）。设计者必须清楚地知道整个过程的稳态方程和误差，以及他们对装置的动态性能的影响。An accuracy of a system is a measure of how well it follows commands. It is an important performance criterion; a guidance system that cannot place spacecraft on a suitable trajectory is obviously useless no matter how well-behaved its transient response.衡量系统的精度之一，就是其如何跟踪给定命令。这是一项重要的性能指标。一个导航系统如果不能将飞行器置于合适的轨迹，那么无论有多好的动态性能，都是没有用。Actual system are also subjected to undesirable inputs, such as noise in command inputs and disturbances arising from changes in the plant parameters or changes in the environment in which the plant is operating. Noise inputs that enter the system with the command input require filtering techniques to remove or suppress them without affecting the command input itself. We shall limit our discussion to disturbance inputs which enter the system at the plant rather than at the controller.实际系统总是容易受到不希望的输入干扰，例如， 命令输入中的噪声以及由于参数改变在被控对象中产生的干扰或者被控对象工作环境变化产生的干扰。随着命令输入进入系统的噪声输入需要滤波器进行驱除或者抑制并不对输入信号产生影响。我们将限于讨论通过被控对象进行系统的噪声而不讨论通过控制器进入系统的噪声。It is often difficult to minimize both components of the error simultaneously. Obviously, it is necessary to have some knowledge as to the nature of probable disturbance inputs. Both error terms of Eq.(2-2B-7) can be set equal to zero by introducing an integrator into the controller. This additional integrator increases the type of the system ( from 1 to 2, for example) , thus eliminating the velocity error, and by being introduced ahead of the point of entry of the disturbance into the system, eliminates the steady-state error resulting from a step in the disturbance input. This additional integrator must be accompanied by at least one zero if the system is to remain stable.通常同时将误差的两个部分最小化是困难的。很明显，具有适当的干扰输入特性的一些知识是很有必要的。方程2-2B-7的两个误差项都能通过在控制器中加入积分器而消除。这些附加的积分器增加了系统的型（例如，从1型系统变为2型系统），因此可以消除速度误差，并通过在系统扰动进入点之前引入积分环节，可以消除由输入信号中包含的阶跃扰动引起的稳态误差。如果要保持系统稳定该附加的积分器必须相应增加至少一个零点。 The process gas provided by the mixing station will be preheated by using a heat exchanger. The temperature contol of the gas will be done in a closed loop. The preheated H2/N2 is distributed to the different humidifier systems. In the humidifier the process gas will be enriched with the required H2O steam in order to create a stable dew point in the furnace. The dew point will be measured in the humidifier and in the furnace. Both measurements will be used for control in a cascading control circuit as described in the following following schematic shows the control concept of one decarburizing zone in the furnace. In order to get a very high control quality a cascading control circuit is used, where a main controller uses an actual dew point value of high accuracy and hands over the set point of the consecutive controller as an output. This controller adjusts a dew point of the process gas measured directly at the outlet of the humidifier. The main advantage of this concept is that the consecutive controller is able to control disturbances of humidifying arrangement directly, because the dew point measurement of the humidifier has got a very short response time compared with the quite longer response time of the furnace dew point. This is caused by bigger time delays of the measurement and the delay time of the process gas to come into the station for CO/CO2, H2 and O2ppm monitoring, extracting method will be multiplexed sampling An analysis station designed as a complete functional unit will be used for monitoring the composition of the atmosphere in the analysis station will be a single-cabinet unit complete with analyzers, pumps, solenoid valves and control unit. In normal operation, the sample gas switchover system will switch cyclically between the different sample gases. The system can also be switched to nitrogen for purging or to a calibration gas; this is not part of the normal sample waste gas will be fed from the sampling probe on the furnace (with filter) to the analyser or sample gas treatment system through a sample gas line routed downwards. Sample gas from each sample gas point will be extracted by the main sample gas pump to the analyser station. The sample gas 'in measurement' will be switched to the measurement line from where an additional pump pumps it to the analysers. The sample gas lines will be made from acid-resistant multiplexing analysis system has following probes:For CO/CO2 the system in an actual mode can be calibrated automatically every day using an in-built comparison probe. The calibration time is triggered using an internal period value, which can be changed manually. During calibration time no measurement values are available. A particular feature will be to switch from multiplexing measuring mode to single mode, where a certain probe gas inlet can be measured continuously and vice versa.这一进程所提供的气体，搅拌站在预热时将用换热器。天然气将在一个封闭的循环进行温度对照。预热H2/N2分配给不同的加湿器系统。在加湿器的过程中，天然气将利用富含水蒸汽的需要，在暖气炉中创造一个稳定的露点。在炉中，露点将成为衡量的加湿器。这两种测量将用于控制级联控制电路中所描述的下一章。 下面的示意图显示了控制概念的一个区的脱碳炉。 为了获得非常高的质量控制级联控制电路使用，凡有主控制器采用实际露点值精度高，手中的设置点的连续控制器作为输出。 这种控制器调整1露点的进程直接测量气体的出口加湿器。 它的主要优势是，这一概念 连续控制器能够控制骚乱直接加湿的安排，因为露点测量加湿器得到了很短的响应时间与反应时间而且很长的炉露点。这是造成更多的时间从而延迟测量和延迟气体进入炉的时间进程。 分析站CO/CO2 ， H2和O2ppm监测， 提取方法将采样： 分析站设计作为一个完整的功能单位将用于组成气氛炉中进行监测。 分析站将是一个单一完整的内阁单位与分析仪，水泵，电磁阀和控制单元。在正常操作时，样品气体切换系统将切换周期性不同样本之间的气体。该系统还可以切换到氮清洗或校准气体，这是不正常的周期。 抽样废气将美联储从取样探头的炉（带过滤器）的分析仪或样品气体处理系统通过抽样天然气管线路由向下。样品气体从每个样品天然气将是主要的提取汽油样品的分析仪站。样本气体测量中'将切换到测量线从那里额外泵泵给分析器。抽样天然气管道将来自耐酸塑料。 在复分析系统具有以下探针： 为CO/CO2该系统在实际模式可自动校准，每天使用的是内置的比较调查。校准时间是引发内部期间使用的价值，可手动改变。在校准时没有测量值。 一个特别的功能将被转换复测模式，以单一的模式，在一定的探测气体入口可以连续测量，反之亦然。 这一进程所提供的气体搅拌站将预热用换热器。温度对照的天然气将在一个封闭的循环。预热H2/N2分配给不同的加湿器系统。在加湿器的过程天然气将富含水蒸汽的需要，以创造一个稳定的露点在炉。露点将成为衡量的加湿器，并在炉。这两种测量将用于控制级联控制电路中所描述的下一章。下面的示意图显示了控制概念的一个区的脱碳炉。为了获得非常高的质量控制级联控制电路使用，凡有主控制器采用实际露点值精度高，手中的设置点的连续控制器作为输出。这种控制器调整1露点的进程直接测量气体的出口加湿器。的主要优势是，这一概念连续控制器能够控制骚乱的直接加湿的安排，因为露点测量加湿器得到了很短的响应时间与反应时间很长的炉露点。这是造成更大的时间延迟的测量和延迟时间的进程气体进入炉。分析站CO/CO2 ， H2和O2ppm监测，提取方法将复采样分析站设计作为一个完整的功能单位将用于监测的组成气氛炉。分析站将是一个单一完整的内阁单位与分析仪，水泵，电磁阀和控制单元。在正常操作时，样品气体切换系统将切换周期性不同样本之间的气体。该系统还可以切换到氮清洗或校准气体，这是不正常的周期。抽样废气将美联储从取样探头的炉（带过滤器）的分析仪或样品气体处理系统通过抽样天然气管线路由下降。样品气体从每个样品天然气将是主要的提取汽油样品的分析仪站。样本气体测量中'将切换到测量线从那里额外泵泵给分析器。抽样天然气管道将来自耐酸塑料。在复分析系统具有以下探针：为CO/CO2该系统在实际模式可自动校准，每天使用的是内置的比较调查。校准时间是引发内部期间使用的价值，可手动改变。在校准时没有测量值。一个特别的功能将被转换成复测模式，以单一的模式，在一定的探测气体入口时可以连续测量，反之亦然。
自动化相关的论文题目
自动化是一门涉及学科较多、应用广泛的综合性科学技术。作为一个系统工程，它由5个单元组成。下面，我为大家分享自动化相关的论文题目，希望对大家有所帮助！
.自动化专业人才培养探索
.自动化流水线实训系统的设计
.电力自动化继电保护的安全管理
.浅析电气自动化控制系统的设计思想
.基于PLC的工业自动化控制技术探讨
.工业自动化控制技术向智能家居的演进
.矿井主扇风机自动化与信息化改造
.基于IEC的变电站自动化系统安全风险评估
.浅析集控站综合自动化系统运行中存在的问题
.数字化变电站自动化技术的应用
.如何提高综合自动化变电站的抗电磁干扰能力
.自动化专业人才培养方案和课程体系的改革与实践
.配电网自动化技术问题初探
.楼宇自动化系统的监控方式及节能分析
.地铁自动化控制相关系统的对比及应用
.基于调度策略的自动化仓库系统优化问题研究
.基于组态软件的综合自动化平台的设计与实现
.基于PLC和运动控制器的电气自动化实验平台的设计
.矿井自动化项目技术管理模式浅论
.铁路变电站自动化监控系统的研制
.馈线自动化自适应快速保护控制方案
.高速制管机上的自动化系统解决方案
.智能变电站是变电站综合自动化的发展目标
.煤矿自动化与信息化技术回顾与展望
.以先进自动化技术确保中线调水畅通
.绿色理念背景下电厂自动化控制系统研究
.大型自动化控制系统故障报警技术应用研究
.煤矿电气自动化控制系统优化设计
.配网自动化相关技术的研究
.中心城市大型配电自动化设计方案与应用
.自动化专业卓越工程师课程体系的改革与实践
.综合自动化变电站电压量传输新方式
.浅谈析电气自动化中的接地及保护
.办公自动化在飞行中的应用
.天津城市核心区配电自动化技术实施与进展
.配电自动化系统中配电终端配置数量规划
.倍福科技自动化技术助力高性能设备状态监测
.渠道自动化控制系统与运行设计探析
.自动化仓储系统优化方法的研究
.配网自动化建设与运行管理问题探微
.浅谈变电站综合自动化系统的`结构形式
.变电站综合自动化通信系统运行维护分析
.无功补偿技术在电气自动化中的应用
.基于PIE的高分遥感泥石流自动化变化检测方法研究
.电力自动化技术的新发展
.配电自动化试点工程技术特点及应用成效分析
.藁城新区水厂的自动化建设
.配电自动化若干问题的探讨
.工业自动化仪表故障分析及解决方法探析
.建筑电气自动化系统安装的施工技术探讨
.浅谈自动化仪表日常维护与故障解决
.浅谈电力自动化管理系统
.浅谈自动化控制系统及热工仪表的维护与管理
.电气自动化工程控制系统的现状及其发展趋势
.动力部一降压变电站综合自动化系统改造及应用
.新型智能配电自动化终端自描述功能的实现
.水电厂电气自动化控制设备的可靠性探讨
.国外配网自动化建设模式对我国配网建设的启示
.现场总线与工厂底层自动化及信息集成技术
.铝工业电气自动化的现状与发展趋势
Electric Automation 电气自动化 ELECTRIC AUTOMATION DEVICE AND METHOD FOR ADJUSTING THE FUNCTIONS OF THE ELECTRIC AUTOMATION DEVICE The invention relates to an electric automation device comprising a control unit that is controlled by a computer. In order to create an automation device that can be set to predefined functions in a particularly flexible manner while requiring less testing, a computer hardware component (2) is provided with control software comprising a basic functional area which includes an operating system (3), a device driver (4), and communication modules (5) so as to form a basic automation device (1) while the basic automation device (1) is complemented with any application modules (7a, 7b, 7c, 8, 9) that can be connected to the basic functional area via a software interface (6) in order to obtain the automation device. The invention also relates to a method for producing or adjusting the functions of such an electric automation device. 电气自动化专业介绍 一、专业概况 随着高新技术的发展和生产自动化程度的提高，我国国民经济发展，正在和继续需要大批技术应用型实用人才。电气自动化技术是现代制造技术中不可缺少的重要技术门类，也是一个国家科技实力乃至综合竞争力的综合反映，在工业发展中具有前导地位。电气自动化技术，集机、电、计算机、信息处理等多学科于一体，是多学科相互交叉、渗透、结系淖酆涎Э疲?诠?窬?媒ㄉ柚姓加兄匾?牡匚弧R虼耍?梢运档缙?远??际跏嵌ヌ炝⒌氐氖乱担?枪?窬?梅⒄购腿嗣裆?钏?教岣叩奈镏侍跫?? ?br> （一）、培养目标本专业培养德、智、体、美、劳全面发展，具有良好职业道德和综合业务素质，具备较强的创新意识和创业能力，掌握电气自动化技术、计算机控制技术的基础理论，能在生产、建设、管理、服务第一线从事常用电气自动化设备、常用电气设备、供配电系统和装置、计算机控制系统、PLC控制系统的安装、调试、运行和维护的实用型高技能专门人才。 （二）、培养要求及职业能力分析 1、培养要求：本专业主要学习电气自动化的专业技术知识，应具有较强的本专业技术应用能力。 2、职业能力分析 （1）具有良好的身体素质、职业道德和人文素质，较强的语言文字表达能力和一定的社会交往能力及继续学习能力。 （2）具有较强的用英语进行人际和人机交流能力，具有阅读和翻译本专业有关英文资料的能力。 （3）具有较强的在信息化社会中工作、学习、生活所必备的计算机应用能力；熟练使用电子电气CAD软件；掌握一门程序设计语言。 （4）具有分析和测试常见的电工电子线路，能设计一般电工电子应用线路，能熟练使用常规电工电子仪器、仪表，具有熟练的电工基本操作技能。 （5）熟悉常用低压电器的基本原理及使用；能熟练阅读电气控制线路的原理图与接线图；具有对常规电气设备、供配电设备等电气控制系统进行安装、调试、维护能力。 （6）具有正确选用、安装、调试、维护电力电子装置和典型交、直流调速系统的能力。 （7）具有熟练的可编程控制器应用能力。 （8）具有以嵌入式计算机数字控制技术为核心的新技术基本应用能力，对相应控制系统具有调试维护能力。 （9）具有对一般的机械零件图、产品装配图与机械、液压和气压传动系统回路的识读能力，了解常用机械设备的结构特点及工艺过程，了解常见的机械和电气的配合关系。 （10）了解企业管理的基本知识，具有一定的质量意识。 （三）、课程设置 课程设置共分五部分：公共必修课、专业必修课、专业限定选修课、专业选修课及公共选修课。 1、公共必修课包括：思想道德修养、法律基础、邓小平理论、马克思主义哲学、体育、英语、高等数学、计算机操作基础等。 2、专业必修课包括：电工基础、模拟电子技术、数字电子技术、电机及拖动基础、机械制图及公差、机械工程基础、嵌入式计算机原理及应用、C语言程序设计、自动检测与转换技术、现代电力电子技术、可编程序控制器应用、自动控制原理与系统、C语言、工厂电气控制技术、电子电气CAD、变配电技术、变频调速原理与应用、工业控制网络、DSP原理与应用及专业英语等。其中主干课程为：电工基础、模拟电子技术、数字电子技术、电机及拖动基础、嵌入式计算机原理及应用、自动检测与转换技术、现代电力电子技术、可编程序控制器应用、自动控制原理与系统等。 3、专业限选课包括：计算机控制技术、工业自动化仪表、控制电机、智能控制等。 4专业任选课包括：电工电子工艺、多媒体技术、楼宇自动化、计算机系统仿真、计算机维修、程序设计（VB）等。 5、公共选修课包括：包括两个能力模块：经济管理科学类和人文与社会科学类。 （四）、实践教学环节 1、专业主要实践教学包括：电工实验、模拟电子技术实验、数字电子技术实验、电机与电力拖动实验、可编程序控制器应用实验、嵌入式计算机原理实验、现代电力电子技术实验、电工基础课程设计、电子技术课程设计、嵌入式计算机原理课程设计、可编程序控制器应用课程设计、自控系统课程设计、综合系统实训、金工实习、电工电子实习、专业参观、综合生产实习、毕业设计等。 2、非专业实践教学包括：入学教育、军训、暑期社会实践、社团活动、体育活动、文艺活动等。 （五）、职业技能证书 本专业证书包含三个方面： 1、公共必修证书：PET、计算机一级证书。 2、专业必修证书：CAD初级、维修电工中级。 3、任选证书：CET四级证书、计算机三级证书(单片机方向）、CAD中级证书、维修电工高级证书、气液电控制技术。 （六）、本专业师资力量 学院拥有一支学术造诣高、教学经验丰富、实践能力强的师资队伍。电气自动化技术专业现有师资26人，其中副高职称以上有17人，“双师型”教师10人。能够满足公共基础课、专业基础课和专业课的理论及实践教学的需要。 二、职业前景 1、对口行业 电气自动化技术是传统而具有新内涵的专业，本专业培养拥护党的基本路线，德、智、体、美等全面发展，具备从事电气自动化技术所需要的理论知识和职业技术能力，主要在生产、建设、服务和管理等第一线工作的高级技术应用性专门人才。本专业的毕业生可就职于国防、航天、航空、航海、铁道、机械、轻工、化工、电子、电力、电信、钢铁、石油、矿山、煤炭、地质、勘测等广泛的工业、农业、科学研究领域，也可就职于现代物流及现代服务业。 2、就业前景 在上海市经济委员会的《上海制造业战略升级的行动纲要》中指出：加快推动制造业的战略升级是贯彻党的十六大精神，坚定地走新型工业化道路，实现向制造业强国转变的国家战略需要，也是上海建立新型产业体系，提高城市综合竞争力，坚持“四个中心”的客观要求。上海制造业战略升级的重点包括：高新技术产业重点发展电子信息和现代生物与现代医药制造业；交通运输设备制造业重点发展汽车、轨道交通、船舶、民用飞机；装备制造业重点发展大型成套设备、电站设备、新能源和新型环保设备制造业；原材料制造业重点发展石油化工和精细化工、精品钢材制造业；生产性服务业重点发展制造业物流、技术服务等产业；大力发展就业广、清洁型的都市型工业。根据电气自动化的内涵，上述产业无不包含电气自动化技术，同时也对电气自动化技术专业的人才提出了更高的要求。据上海市政府组织的《面向新世纪上海紧缺人才需求趋势与开发研究对策》的报告显示，复合型技术人才是紧缺的专业人才，而电气自动化技术专业是培养复合型技术人才的有效载体。可以预见在未来数年内，电气自动化专业毕业生就业前景良好。
.好.多学习讥构比如:ABC天卞英语中心 都会先让你做个英语测试，很喜欢这里的老师，客服都很热心，我觉得在线的方式性介比较高，你也可以找几个了解一下吧..
电气工程：1Electrical Engineering My decision to pursue graduate study in the United States is underscored by my desire to be a part of the graduate program at your institution. Purdue University offers the flexibility needed for such a vast and rapidly changing field. The research facilities and the faculty at the university are par excellent. Communications is an industry that has changed our lives. In a very short period it has changed the way we have looked at things since centuries. It is one industry that is going to shape our future for centuries to come. Hence my desire to do masters in electrical engineering with communications as my major. My interest in electronics blossomed during my high school years. It was the time when technology had begun to make an impact on the lives of people in India. Hence engineering with electronics as my major was the first choice for my undergraduate studies. Right since the beginning of my undergraduate study electronics is a subject that has fascinated me with its power of applications. The subjects that I have studied include Linear Electronics, Digital Electronics. These laid the foundation for my courses in Electronic Communication & Communication Systems at a later stage. My undergraduate studies already focus on the communications aspect of electronics. A masters degree in electrical engineering with communications as major field is the next logical step. For the past four months I have been working as a project trainee at the Indian Institute for Advanced Electronics. I am working on the design and development of a "PC Controlled Digital Serial Data Generator". This short stint has given me invaluable practical experience. It has given me the confidence to pursue a masters degree and also kindled a desire to do research. During the course of my work at IIAE, I have come across several scientists. Most of them work in different areas of communications. Interactions with them have made me realize the vastness and the scope of communications. My discussions with them convinced me that specializing in communications will suit me very well. The subject of research which interests me very much is spread spectrum communication systems. Coding theory and combinations is another research subject which arouses my curiosity. The subject Communication Theory which I am studying at present introduces these topics in theory. I am eager to find out more about the applications of coding theory to spread spectrum communication systems. In addition I have been a student member of the IEEE (Institute of Electrical and Electronics Engineers, Inc.) for the past three years. Through its workshops/seminars and publications like the 'The Spectrum' it has exposed me to a lot of emerging technologies in the field of communications. It is a strong belief in my family that the American education system has the best to offer in the whole world. This belief arises out of the experience that my parents had when they did their Masters of Science in the University of Pennsylvania during the years 1967-69. If I can get an opportunity to be a part of that intellectually stimulating environment, I am sure my talents will be put to optimal use. India is a developing country with an enormous potential in the information technology business. To serve the needs of this developing industry and more important its vast population, communications is going to become of utmost importance. Thus conditions here are very conducive to supplement my aspirations when I return after completing my graduate studies. 2Electrical Engineering As a graduate student, I will undertake research and coursework in Electrical Engineering to enhance my competencies in this field. I intend to complete my master's degree in order to pursue my doctorate. The research that I am most interested in pursuing at Northeastern University surrounds the optical properties of MEMS devices, and the development of substrate-based fast electro-optical interfaces. My interest in this area stems from my undergraduate study in MEMs development for tri-axial accelerometers. Engineering has been a key interest of mine since childhood. While still in grade school I enjoyed listening to my father, an electrical engineer, teach me about advances in technology, and was always eager to hear more. I was introduced to my first computer at the age of five, and have loved interacting with them ever since. My decision to study engineering as a career was no surprise to those who knew me. In college I found that I was always studying something I enjoyed. I believe it is because I enjoy my life and my work that I have been successful. Spending hours in the laboratory is not something that I dread, but instead I take pride in my work and its successful completion. One example of this that is still fresh in my mind is the successful design of a fully functional microprocessor in the Xilinx environment. All told, the project took over 150 hours of each design-team member's time. However, I did not look on it as a drain, but an experience for learning and a focus for my professional and technical development. When we finished the project we felt the sense of worth and pride in completion of a task that was once above our level of knowledge. Pursuing a graduate degree in the research field I have chosen also feels like a challenge, and I know that study will frustrate me at times. However, I feel that my commitment to learning will not be swayed. I feel confident in my ability to be creative in my perspective, and to persevere. My ultimate goal is to be an innovator in the field I have chosen to study. Professionalism and creativity are my most valued strengths. At the heart of my interest is the advancement of man in concert with his environment. My personal philosophy of life will matter greatly during my study and after its completion. That is why I devote time to reflection on my goals and their implications. Money has never been a motivator for my work, nor do I think it will be in the future. However, as a professional and a graduate, I realize that my earning potential will be significant. That is why I also commit myself to charity and fairness. In the past I have been a member of the Boy Scouts of America, and have achieved the rank of Eagle Scout. In the course of my experience in that organization, I learned respect and moral value. Now, as a member of the IEEE, I value my professional standing and its commensurate moral implications. Ethics in engineering is as important as technical skill, and as such I intend to uphold my own ethical obligations to the best of my ability. As a Northeastern University student, I would commit all that I have to offer to my study. I intend to pursue research in MEMS technology. At Rowan University as an undergraduate student I have already conducted some research and development of MEMS sensors for military applications, resulting in publication. An article, written by myself and my project member David Bowen and edited by our advisor Dr. Robert Krchnavek, was published in the NAVSEA Intelligent Ships Symposium Proceedings of 2001. The paper was titled "Designing a 3-Axis, Monolithic, MEMS-Based Accelerometer" and was under review for endorsement by the US Navy's NAVSEA facility in Philadelphia during that year. Building on my past success in MEMs design, I hope to advance my understanding. Through research at the graduate level, it is my hope to become familiar with, and innovate the design of MEMs Optics in hopes of creating a reliable and practical MEMs Electro-Optical Interface for use in consumer electronics. It is my hope, that through my research, optical waveguides for intradevice communication might be realized. Finally, my intent to pursue graduate study is laid plain. Study of MEMs optics is my intended focus, and I am committed to my goal. In pursuing a doctoral degree, I have closely analyzed myself to determine the reasons for my previous successes and my goals for the future. I have found that I do and have always enjoyed engineering, and that I have a strong desire to pursue my study further. I am prepared to commit myself to that study, and achieve what I have set out to do. 3I Wish to Pursue an MS Degree in Electrical Engineering During my senior year at Purdue University, I made a decision that has impacted the entire course of my education. While my classmates were making definite decisions about their career paths, I chose to implement a five-year plan of development and growth for myself. I designed this plan in order to examine various careers that I thought might interest me, as well as to expand upon my abilities at the time. As I was attaining a BS degree in Electrical Engineering, I decided to focus primarily on fields related to the VLSI (Very Large-Scale Integrated) circuits area. My main goals were either to gain work experience or to further my education by pursuing an MS degree in Electrical Engineering (MSEE). I saw an opportunity to both work and learn through employment at Xilinx Inc. Operating as a product engineer at a successful, high-tech semiconductor company has enabled me to utilize my technical and interpersonal skills in new and challenging ways. The position has also allowed me to interact with a multitude of departments including marketing, integrated circuit (IC) design, software/CAD development, manufacturing, reliability, accounting, and sales. I thus have gained an array of experience that extended beyond the parameters of my own responsibilities. In the workplace, I rely heavily upon the interpersonal techniques I developed as a counselor in a Purdue residence hall, as well as the organizational skills I had acquired through holding various leadership positions in cultural and engineering societies. I have also cultivated an interest in high-technology marketing that has continued to grow throughout my career. My experiences with Xilinx have heightened my hunger for knowledge in the VLSI field. Two months after joining the corporation, I applied to several part-time programs in the vicinity that would allow me to acquire an MSEE degree within two to three years. San Jose State seemed an ideal choice, for its evening MSEE courses would allow me to pursue two independent, full-time positions concurrently. The San Jose program has complimented my Xilinx duties well; both demand large levels of energy and enthusiasm while guiding me to my ultimate goal a high degree of education in VLSI sciences. The resources that I poured into both endeavors have reaped many gains. I have been promoted to a Product-Yield Engineering position within Xilinx's Coarse Grain Static Memory (CGSM) Product Engineering division. My extensive coursework plays a key role in my continued success at Xilinx. Relevant classes in advanced digital and analog VLSI design, as well as sub-micron ULSI technology, have allowed me to understand more completely the workings of Xilinx, a fab-less semiconductor company that also functions as a software and hardware design, testing, and marketing center. The gains in knowledge I have made through the combination of work experience and education have indeed been exponential. The academic records of my senior year at Purdue, coupled with my MSEE coursework, are ample proof of my dedication to learning. I feel I have overcome through hard work and dedication the brief "dry phase" I underwent at Purdue during the close of my sophomore and the first semester of my junior years. My performance at that time is in no way indicative of my usual achievements; they are instead the result of urgent family difficulties that required much foreign travel and serious attention to resolve. In May, I shall graduate with an MSEE degree from San Jose well ahead of my original estimates. This early graduation with Dean's Honors is the result of my firm belief in the value of diligence, as well as my renewed determination to strive for perfection in both work and school. I am now embarking on another five-year plan, during which I hope to fulfill several specific career goals. For instance, being part of a very dynamic and results-oriented Yield team at Xilinx calls for continuous development of computational and statistical techniques. The Yield team is divided to focus on specific process/fabrication issues and process (manufacturing) optimization. My own position is an integral part of the optimization group. Speed and cost issues continue to press high technology atmospheres towards optimization, probability and stochastic processes and systems, and rigorous simulations of mathematical models. The MS in EES&OR offered at your university will grant me the statistical knowledge that is crucial for process and production optimization in a fab-less environment. In addition, product engineering requires fundamental research on mathematical models for linear and non-linear programming, as well as the utilization of efficient computer software. I continuously employ the knowledge I gained at Purdue in Operations Research and advanced mathematics courses. Yet despite the value of these classes and my high performance in them, I now require further education to best fulfill my duties. An MS in the EES&OR field, will give me knowledge that is invaluable to a career in product development, project management and strategic planning. The program will allow me to improve decision-making skills in operations, strategy, and policy issues. I will strengthen my theory and application in countless areas:continuous, discrete, numerical optimization; probabilistic and stochastic processes; dynamic systems and simulation; economics, finance, and investment; decision analysis; dynamic programming and planning under uncertainty; operations and service; corporate and individual strategy; and private and public policy , the EES&OR program will not only help me to excel at Xilinx but will also further any future career. My commitment to work and education over the last three years proves that I will pursue this MS with enthusiasm and technical edge that the MS would provide is I will be working while attending Stanford, I shall mingle education with practical application, and bring to the table interesting problems from my experience and past education. Technical challenges encountered through projects in the EES&OR program will provide motivation and opportunity for methodological data collection, processing and presentation issues presented are integral to my future goals, and the management challenges raised will provide invaluable experience for professional practice. This will in turn build a solid foundation for a life-long career that can overcome any problem in decision-making. In addition, taking courses in economics, finance, and investment analysis will allow much growth of knowledge in investment issues in different industries. The EES&OR program thus appeals not only to my engineering, economics, science and mathematical background, but will compliment my technical abilities with the conceptual frameworks needed to analyze problems in operations, production, strategic planning, and marketing in the realm of emiconductor/IC/engineering systems. I feel that I am prepared to meet the challenges of the curriculum. My coursework in intermediate microeconomics and macroeconomics, international trade, operations research, linear algebra, and probabilistic methods, along with my extensive calculus background, will allow me to function well within the program. My long-term career goals include a move into marketing and product management. I believe that attaining this MS degree is the cornerstone to achieving my goals. It will give me the academic background necessary to succeed in product development, project management, and strategic planning. It will improve decision-making skills necessary for optimizing performance. The integration of two excellent programs in Economics Systems and Operations Research thus suits my current position and ties in with future goals perfectly by improving decision making in operations, strategy and policy. At present I desire to continue at Xilinx; attending a program that provides the flexibility and convenience of the SITN, is therefore imperative. Hence, being at Stanford as an HCP student alsoattracts me. I believe that Stanford is the best environment for me to achieve my goals while gaining exposure to and experience with a diverse student body and faculty. It is my belief that one continues to learn throughout one's life, and the most effective method of learning is through interaction with 's diversity offers an environment for learning, both inside and outside the classroom. I hope to share my varied knowledge with my classmates and to take from them a new understanding of topics that are foreign to me. I believe that no other school provides students with the combination of education and environment offered by Stanford. Its outstanding academic reputation, mingled with its diverse environment and thriving Bay Area location, creates an opportunity for growth that is second to none. I have many ambitions for myself as I embark on this stage of my life. I believe that an education from Stanford will provide invaluable experiences and skills that will allow me to become a successful and innovative business leader in the new millennium. 4Research Department of Biomedical Engineering is designed to research on and solve the bio-electrical and biomagnetic engineering problems in the field of biology and medicine with the aid of engineering principles and methods. Its main task is to explain, from perspective view of engineering, the biological and pathologic processes of the living organisms, especially human beings, and research on and develop the related medical devices and life science devices. Its research directions mainly include the modeling and emulation of the biological system, testing and analysis of biomedical signals, the biomedical imaging and processing , the biological effects of electromagnetic field and the development of artificial organs and medical devices, Bioengineering With the development and integration of electromagnetism, biology and medicine, biological electromagnetism exercises more and more influence on human life and health, environment protection and biological engineering. The research on electromagnetic bioengineering is a new research direction for IEECAS, mainly including research on rules of mutual influence between electromagnetic field and life matter, biological electromagnetic effect and its application in biology, medicine and medical equipment. At present, the research team has set up labs such as biological electromagnetic environment lab, biological electromagnetic signals & electromagnetic property testing lab, electromagnetic biological effect testing lab and biological electromagnetic simulation lab. It is equipped with various electrical and magnetic fields for experiments of biological electromagnetic effects, simulation software and biochemical experiment equipment. With such equipments, it can do biological electromagnetic experiments on live animals and detached live cells, detect, analyze and process the very weak biological electromagnetic signals, analyze and test live organism or detached cell under electromagnetic interaction with biochemical quantitative methods. The recent research work focuses on the effects 方向对不对，不知你要哪种，告诉我，我再接着找多的话email you
用于分布式在线UPS中的并联逆变器的一种无线控制器A Wireless Controller for Parallel Inverters in Distributed Online UPS SystemsJosep M. Guerrero', Luis Garcia de Vicufia", Jose Matas'*, Jaume Miret", and Miguel Castilla". Departament #Enginyeria de Sistemes, Automatica i Informhtica Industrial. Universitat Polithica de CatalunyaC. Comte d'Urgell, -Barcelona. Spain. Email: .. Departament #Enginyeria Electrbnica. Universitat Polit6cnica de CatalunyaAV. Victor BaLguer s/n. 08800I - Vilanova i la Geltrh. SpainAbsiract - In this paper, a novel controller for parallelconnectedonline-UPS inverters without control wireinterconnections is presented. The wireless control technique isbased on the well-known droop method, which consists inintroducing P-oand Q-V schemes into the inverters, in order toshare properly the power drawn to the loads. The droop methodhas been widely used in applications of load sharing betweendifferent parallel-connected inverters. However, this methodhas several drawbacks that limited its application, such as atrade-off between output-voltage regulation and power sharingaccuracy, slow transient response, and frequency and phasedeviation. This last disadvantage makes impracticable themethod in online-UPS systems, since in this case every modulemust be in phase with the utility ac mains. To overcome theselimitations, we propose a novel control scheme, endowing to theparalleled-UPS system a proper transient response, strictlyfrequency and phase synchronization with the ac mains, andexcellent power sharing. Simulation and experimental resultsare reported confirming the validity of the proposed . INTRODUCTIONThe parallel operation of distributed Uninterruptible PowerSupplies (UPS) is presented as a suitable solution to supplycritical and sensitive loads, when high reliability and poweravailability are required. In the last years, many controlschemes for parallel-connected inverters has been raised,which are derived from parallel-schemes of dc-dc converters[I], such as the master-slave control [2], or the democraticcontrol [3]. In contrast, novel control schemes have beenappeared recently, such as the chain-structure control [4], orthe distributed control [ 5 ] . However, all these schemes needcontrol interconnections between modules and, hence, thereliability of the system is reduced since they can be a sourceof noise and failures. Moreover, these communication wireslimited the physical situation ofthe modules [6].In this sense, several control techniques has been proposedwithout control interconnections, such as the droop this method, the control loop achieves good power sharingmaking tight adjustments over the output voltage frequencyand amplitude of the inverter, with the objective tocompensate the active and reactive power unbalances [7].This concept is derived from the power system theory, inwhich the frequency of a generator drops when the powerdrawn to the utility line increases [8].0-7803-7906-3/03/$ 02003 IEEE. 1637However, this control approach has an inherent trade-offbetween voltage regulation and power sharing. In addition,this method exhibits slow dynamic-response, since it requireslow-pass filters to calculate the average value of the activeand reactive power. Hence, the stability and the dynamics ofthe whole system are hardly influenced by the characteristicsof these filters and by the value of the droop coefficients,which are bounded by the maximum allowed deviations ofthe output voltage amplitude and , when active power increases, the droopcharacteristic causes a frequency deviation from the nominalvalue and, consequently, it results in a variable phasedifference between the mains and the inverter output fact can be a problem when the bypass switch mustconnect the utility line directly to the critical bus in stead ofits phase difference. In [9], two possibilities are presented inorder to achieve phase synchronization for parallel lineinteractiveUPS systems. The first one is to locate a particularmodule near the bypass switch, which must to synchronizethe output voltage to the mains while supporting overloadcondition before switch on. The second possibility is to waitfor the instant when phase matching is produced to connectthe , the mentioned two folds cannot be applied to aparallel online-UPS system, since maximum transfer timeought to be less than a % of line period, and all the modulesmust be always synchronized with the mains when it ispresent. Hence, the modules should be prepared to transferdirectly the energy from the mains to the critical bus in caseof overload or failure [lo].In our previous works [11][12], we proposed differentcontrol schemes to overcome several limitations of theconventional droop method. However, these controllers bythemselves are inappropriate to apply to a parallel online-UPS system. In this paper, a novel wireless control scheme isproposed to parallel different online UPS modules with highperformance and restricted requirements. The controllerprovides: 1) proper transient response; 2) power sharingaccuracy; 3) stable frequency operation; and 4) good phasematching between the output-voltage and the utility , this new approach is especially suitable for paralleled-UPS systems with true redundancy, high reliability andpower availability. Simulation and experimental results arereported, confirming the validity of this control . 1. Equivalenl cimuif ofan invener connecled 10 a bust"Fig. 2. P-odraop . REVlEW OF THE CONVENTIONAL DROOP METHODFig. 1 shows the equivalent circuit of an inverter connectedto a common bus through coupled impedance. When thisimpedance is inductive, the active and reactive powers drawnto the load can be expressed asEVcosQ - V2 Q=where Xis the output reactance of an inverter; Q is the phaseangle between the output voltage of the inverter and thevoltage of the common bus; E and V are the amplitude of theoutput voltage of the inverter and the bus voltage, the above equations it can be derived that the activepower P is predominately dependent on the power angle Q,while the reactive power Q mostly depends on the outputvoltageamplitude. Consequently, most of wireless-control ofparalleled-inverters uses the conventional droop method,which introduces the following droops in the amplitude Eand the frequency U of the inverter output voltageu = w -mP (3)E = E ' - n Q , (4)being W* and E' the output voltage frequency and amplitudeat no load, respectively; m and n are the droop coefficientsfor the frequency and amplitude, , a coupled inductance is needed between theinverter output and the critical bus that fixes the outputimpedance, in order to ensure a proper power flow. However,it is bulky and increase:; the size and the cost of the UPSmodules. In addition, tho output voltage is highly distortedwhen supplying nonlinezr loads since the output impedanceis a pure is well known that if droop coefficients are increased,then good power sharing is achieved at the expense ofdegrading the voltage regulation (see Fig. 2).The inherent trade-off of this scheme restricts thementioned coefficients, which can be a serious limitation interms of transient response, power sharing accuracy, andsystem the other hand, lo carry out the droop functions,expressed by (3) and (4), it is necessary to calculate theaverage value over one line-cycle of the output active andreactive instantaneous power. This can be implemented bymeans of low pass filters with a smaller bandwidth than thatof the closed-loop inverter. Consequently, the powercalculation filters and droop coefficients determine, to a largeextent, the dynamics and the stability of the paralleledinvertersystem [ conclusion, the droop method has several intrinsicproblems to be applied a wireless paralleled-system ofonline UPS, which can he summed-up as follows:Static trade-off between the output-voltage regulation(frequency and amplitude) and the power-sharingaccuracy (active an4d reactive).2) Limited transient response. The system dynamicsdepends on the power-calculation filter characteristics,the droop coefficients, and the output of ac mains synchronization. The frequency andphase deviations, due to the frequency droop, makeimpracticable this method to a parallel-connectedonline UPS system, in which every UPS should becontinuously synchronized to the public ac )3)111. PROPOSED CONTROL FOR PARALLEL ONLINE UPSINVERTERSIn this work, we will try to overcome the above limitationsand to synthesize a novel control strategy withoutcommunication wires that could be appropriate to highperformanceparalleled industrial UPS. The objective is toconnect online UPS inverters in parallel without usingcontrol interconnections. This kind of systems, also namedinverter-preferred, should be continuously synchronized tothe utility line. When an overload or an inverter failureoccurs, a static bypass switch may connect the input line tothe load, bypassing the inve:rter [14][15].Fig. 3 shows the general diagram of a distributed onlineUPS system. This system consists of two buses: the utilitybus, which is connected lo the public ac mains; and thesecure bus, connected to the distributed critical loads. Theinterface between these buses is based on a number of onlineUPS modules connected in parallel, which providescontinuously power to the: loads [16]. The UPS modulesinclude a rectifier, a set of batteries, an inverter, and a staticbypass ac mainsutility busI I Ij distributed loads !Fig. 3. Online distributed UPS /I 4(4Fig. 4. Operation modes of an online UPS.(a) Normal operation. (b) Bypass operation. (c) Mains failureThe main operation modes of a distributed online UPS1) Normal operation: The power flows to the load, fromthe utility through the distributed UPS ) Mains failure: When the public ac mains fails, theUPS inverters supply the power to the loads, from thebatteries, without operation: When an overload situation occurs,the bypass switch must connect the critical busdirectly to the ac mains, in order to guarantee thecontinuous supply of the loads, avoiding the damageof the UPS this reason, the output-voltage waveform should besynchronized to the mains, when this last is are listed below (see Fig. 5):3)Nevertheless, as we state before, the conventional droopmethod can not satisfy the need for synchronization with theutility, due to the frequency variation of the inverters, whichprovokes a phase obtain the required performance, we present a transientP-w droop without frequency-deviation in steady-state,proposed previously by OUT in [ 111w=o -mP (5)where is the active power signal without the dccomponent,which is done by. -I t -1sP= p ,( s + t - ' ) ( s + o , )being zthe time constant of the transient droop transient droop function ensures a stable frequencyregulation under steady-state conditions, and 'at the sametime, achieves active power balance by adjusting thefrequency of the modules during a load transient. Besides, toadjust the phase of the modules we propose an additionalsynchronizing loop, yieldingo=w'-m%k,A$, (7)where A$ is the phase difference between the inverter and themains; and k, is the proportional constant of the frequencyadjust. The steady-state frequency reference w* can beobtained by measuring the utility line second term of the previous equality trends to zero insteady state, leading tow = w' - k4($ -@'), (8)being $and $* the phase angles of the output voltage inverterand the utility mains, into account that w = d $ / d t , we can obtain thenext differential equation, which is stable fork, positived$ *dt dt- + km$ = - + k,$' . (9)Thus, when phase difference increases, frequency willdecrease slightly and, hence, all :he UPS modules will besynchronized with the utility, while sharing the power drawnto the . CONTROLLIEMRP LEMENTATIONFig. 5 depicts the block diagram of the proposedcontroller. The average active power P , without the dccomponent, can be obtained by means of multiplying theoutput voltage by the output current, and filtering the product........................................................................................io",.LSj'nchronirorion loop.......................................................................................Fig. 5. Block diagram of the proposed a band-pass filter. In a similar way, the averagereactive power is obtained, hut in this case the output-voltagemust be delayed 90 degrees, and using a low-pass order to adjust the output voltage frequency, equation(7) is implemented, which corresponds to the frequencymains drooped by two transient-terms: the transient activepower signal term; and the phase difference term, whichis added in order to synchronize the output voltage with theac mains, in a phase-locked loop (PLL) fashion. The outputvoltageamplitude is regulated by using the conventionaldroop method (4).Finally, the physical coupled inductance can be avoided byusing a virtual inductor [17]. This concept consists inemulated an inductance behavior, by drooping the outputvoltage proportionally to the time derivative of the outputcurrent. However, when supplying nonlinear loads, the highordercurrent-harmonics can increase too much the outputvoltageTHD. This can be easily solved by using a high-passfilter instead of a pure-derivative term of the output current,which is useful to share linear and nonlinear loads [I 1][12].Furthermore, the proper design of this output inductance canreduce, to a large extent, the unbalance line-impedanceimpact over the power sharing . SIMULATION AND EXPERIMENTARELS ULTSThe proposed control scheme, (4) and (7), was simulatedwith the parameters listed in Table 1 and the scheme shownin Fig. 6, for a two paralleled inverters system. Thecoefficients m, n, T, and kv were chosen to ensure stability,proper transient response and good phase matching. Fig. 7shows the waveforms of the frequency, circulating currents,phase difference between the modules and the utility line,and the evolution of the active and reactive powers. Note theexcellent synchronization between the modules and theACmiiinr 4 j. ...L...... ..........................B...u...n...... ................................... iFig. 6. Parallel operation oftwa online UPS modules,mains, and, at the same time, the good power sharingobtained. This characteristik let us to apply the controller tothe online UPS paralleled I-kVA UPS modules were built and tested in order toshow the validity of the proposed approach. Each UPSinverter consisted of a single-phase IGBT full-bridge with aswitching frequency of 20 kHz and an LC output filter, withthe following parameters: 1. = 1 mH, C = 20 WF, Vi" = 400V,v, = 220 V, I50 Hz. The controllers of these inverters werebased on three loops: an inner current-loop, an outer PIcontroller that ensures voltage regulation, and the loadsharingcontroller, based on (4) and (7). The last controllerwas implemented by means of a TMS320LF2407A, fixedpoint40 MHz digital sigrial processor (DSP) from TexasInstruments (see Fig. 8), using the parameters listed in TableI. The DSP-controller also includes a PLL block in order tosynchronize the inverter with the common bus. When thisoccurs, the static bypass switch is tumed on, and the droopbasedcontrol is 7 Wa\cfc)rms for , ;mnectcd in parallel. rpchrontred io Ihc ac mdnl.(a) Frequencics ufhoth UPS (b) Clrculattng currcni among modulcs. (CJ Phmc d!Nercn;: betucen ihc UPS a#>dth e ai mum(d) Ikiril uf the phze diNmncc (e) md (0 Activc and rcactlw pouerr "I ooih UPSNote that the iimc-acs arc deliheratcly JiNercni due in thc disiinct timuion*uni) ofthe \ THE PARALLELESDYS Order I IFilter Cut-off Frequency I 0, I 10 I ragsFig. 8 shows the output-current transient response of theUPS inverters. First, the two UPS are operating in parallelwithout load. Notice that a small reactive current is circlingbetween the modules, due to the measurement , a nonlinear load, with a crest factor of 3, is connectedsuddenly. This result shows the good dynamics and loadsharingof the paralleled system when sharing a . 8. Output current for the two paralleled UPS, during the connection of Bcommon nonlinear load with a crest factor of 3. (Axis-x: 20 mddiv. Axis-y:5 Mdiv.).VI. CONCLUSIONSIn this paper, a novel load-sharing controller for parallelconnectedonline UPS systems, was proposed. The controlleris based on the droop method, which avoids the use ofcontrol interconnections. In a sharp contrast with theconventional droop method, the controller presented is ableto keep the output-voltage frequency and phase strictlysynchronized with the utility ac mains, while maintaininggood load sharing for linear and nonlinear loads. This fact letus to extend the droop method to paralleled online the other hand, the proposed controller emulates aspecial kind of impedance, avoiding the use of a physicalcoupled inductance. results reported here show theeffectiveness of the proposed approach.
用于分布式在线UPS中的并联逆变器的一种无线控制器已经发送。