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论文题目应以最恰当、最简明的词语反映论文中最重要的特定内容的逻辑组合，关于自动化专业的论文题目有哪些?下面我给大家带来自动化专业的论文题目选题参考，希望能帮助到大家!
自动化 毕业 论文题目
1、配网自动化相关技术的研究
2、数字化变电站自动化技术的应用
3、现场总线与工厂底层自动化及信息集成技术
4、电力自动化技术的新发展
5、冶金自动化发展的策略与思考
6、简述电力系统及其自动化发展趋势研究
7、变电所综合自动化系统应用分析与探讨
8、浅谈数字变电站自动化系统
9、自动化专业人才培养方案和课程体系的改革与实践
10、配电网自动化技术问题初探
11、配电自动化系统中配电终端配置数量规划
12、基于组态软件的综合自动化平台的设计与实现
13、生产线自动化及远程监控
14、地铁自动化控制相关系统的对比及应用
15、配电自动化试点工程技术特点及应用成效分析
16、大型自动化控制系统故障报警技术应用研究
17、变电站综合自动化通信系统运行维护分析
18、浅谈变电站综合自动化系统的结构形式
19、如何提高综合自动化变电站的抗电磁干扰能力
20、动力部一降压变电站综合自动化系统改造及应用
21、智能变电站是变电站综合自动化的发展目标
22、中心城市大型配电自动化设计方案与应用
23、浅析电气自动化控制系统的设计思想
24、建筑电气自动化系统安装的施工技术探讨
25、水电厂电气自动化控制设备的可靠性探讨
26、铝工业电气自动化的现状与发展趋势
27、配网自动化建设对供电可靠性的影响研究
28、浅谈电力自动化管理系统
29、铁路变电站自动化监控系统的研制
30、浅析集控站综合自动化系统运行中存在的问题
31、基于IEC 61850的变电站自动化 系统安全 风险评估
32、新型智能配电自动化终端自描述功能的实现
33、天津城市核心区配电自动化技术实施与进展
34、配电自动化若干问题的探讨
35、矿井主扇风机自动化与信息化改造
36、馈线自动化自适应快速保护控制方案
37、自动化系统运行中出现的操作失误、服务失败及补救 措施
38、应用于拣选操作的自动化立体仓库作业优化调度
39、地质环境自动化远程监测项目社会评估--以山东省为例
40、矿井自动化项目技术管理模式浅论
41、自动化仓储系统优化 方法 的研究
42、电气自动化工程控制系统的现状及其发展趋势
43、自动化专业卓越工程师课程体系的改革与实践
44、国外配网自动化建设模式对我国配网建设的启示
45、煤矿自动化与信息化技术回顾与展望
46、基于调度策略的自动化仓库系统优化问题研究
47、配网自动化建设抵御呼伦贝尔寒冬
48、藁城新区水厂的自动化建设
49、综合自动化变电站电压量传输新方式
50、以先进自动化技术确保中线调水畅通
电气自动化专业毕业论文题目
1、 建筑电气工程自动化设计及实现分析
2、 电气自动化在电气工程中的应用
3、 建筑中的电气工程及自动化技术探讨
4、 成品金电气自动控制称量与熔铸的研发与应用
5、 电气自动化工程控制系统的现状及其发展趋势
6、 探究加强企业电气控制线路的合理设计
7、 电动挖掘机在高原环境下的电气特性及系统设计
8、 浅谈电气自动化控制系统的应用及发展
9、 电气自动化工程控制系统现状及其发展趋势探讨
10、 试论电气工程及其自动化的发展趋势
11、 高职电气自动化专业的现状分析及发展
12、 智能化技术在电气工程自动化控制中的应用
13、 智能化技术在电气工程自动化控制中的应用探究
14、 智能化技术在电气工程自动化控制中的应用
15、 智能化技术在电气工程自动化控制中的应用
16、 浅析煤矿生产中电气自动化技术的应用及发展
17、 电气自动化在煤矿生产中的应用
18、 单片机在煤矿电气自动化控制技术中的应用研究
19、 基于人工智能的电气自动化控制研究
20、 工业电气自动化中数字技术的应用与创新
21、 多功能舞台电气控制系统的研究与设计
22、 PLC技术在电气设备自动化控制中的应用
23、 电气自动化技术在铝电解过程中的应用研究
24、 电气自动化控制中的人工智能技术探讨
25、 PLC在选煤厂电气自动化系统中的应用与发展
26、 电气火灾监控系统原理及应用研究
27、 电气自动化控制中的PLC的有效应用
28、 PLC技术的原理、优点及其在电气设备自动化控制中的实践研究
29、 井下电气自动化控制系统优化分析
30、 矿井电气自动化系统优化分析研究
31、 智能化技术在电气工程自动化控制中的具体应用初探
32、 人工智能技术在电气自动化控制中的应用分析
33、 电气工程自动化中人工智能的运用
34、 面对人才需求的高校电气自动化专业创新能力培养模式研究
35、 电气工程及其自动化专业实践教学的探索与思考
电气工程及其自动化论文题目
1、智能化技术电气工程及其自动化的应用探析
2、探讨电气工程及其自动化发展问题分析及应对措施
3、电气工程及其自动化的智能化技术应用分析
4、电气工程及其自动化的质量控制与安全管理
5、PLC技术在电气工程及其自动化控制
6、电气工程的应用及其自动化分析
7、PLC技术在电气工程及其自动化控制中的运用
8、电气工程及其自动化的不足与改善对策分析
9、电气工程及其自动化的质量控制与安全管理
10、浅谈电气工程及其自动化在机械工程中的应用
11、PLC技术在电气工程及其自动化控制中的应用
12、电气工程及其自动化在农村配电网的应用探析
13、电气工程及其自动化技术下的电力系统自动化发展探讨
14、PLC技术在电气工程及其自动化控制中的运用
15、电气工程及其自动化低压电器中继电器的应用
16、电气工程及其自动化存在的问题及应对策略
17、电气工程及其自动化中智能化技术的应用分析
18、继电器在电气工程及其自动化低压电器中的应用研究
19、PLC技术在电气工程及其自动化控制中的应用
20、PLC技术在电气工程及其自动化控制中的应用分析
21、电气工程及其自动化中智能化技术的实际应用
22、电气工程及其自动化的智能化技术应用研究
23、电气工程及其自动化中 网络技术 的应用分析
24、刍议电气工程及其自动化的智能化技术应用
25、电气工程及其自动化的质量控制与安全管理
26、浅析继电器在电气工程及其自动化低压电器中的应用
27、关于电气工程及其自动化技术在发电厂的应用初探
28、电气工程及其自动化低压电器中继电器的应用
29、继电器在电气工程及其自动化低压电器中的应用研究
30、PLC技术在电气工程及其自动化控制系统中的运用
31、PLC技术在电气工程及其自动化控制中的应用
32、继电器在电气工程及其自动化低压电器中的应用分析
33、试论电气工程及其自动化的智能化技术应用
34、电气工程及其自动化专业实践教学的策略
35、电气工程及其自动化中智能化技术的应用
36、我国电气工程及其自动化的发展现状与前景
37、电气工程及其自动化技术在智能建筑中的应用
38、电气工程及其自动化的智能化技术应用
39、论如何提高电气工程及其自动化
40、电气工程及其自动化的质量控制与安全管理
41、智能建筑中电气工程及其自动化技术探讨
42、PLC技术在电气工程及其自动化控制
43、智能建筑中电气工程及其自动化技术的应用分析
44、PLC技术在电气工程及其自动化控制中的应用分析
45、电气工程及其自动化技术在供热建设中的难点分析
46、智能建筑中的电气工程及其自动化技术分析
47、电气工程及其自动化低压电器中继电器的应用探究
48、PLC技术在电气工程及其自动化控制中的运用分析
49、电气工程及其自动化控制中PLC技术的应用
50、智能建筑中电气工程及其自动化技术分析
自动化专业的论文题目选题相关 文章 ：
★ 自动化专业学术论文(2)
★ 机械类专业论文选题题目
★ 电气自动化专业毕业论文范文
★ 电气工程自动化大专毕业论文
★ 自动化专业概论论文范文怎么写
★ 机械制造与自动化专业参考论文(2)
★ 有关电气自动化毕业论文范文
★ 大专机械制造与自动化专业毕业论文(2)
★ 机械制造与自动化专业毕业论文
★ 大专机械制造与自动化专业毕业论文
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
毕业论文 (设计)文档规范格式毕业论文（设计）的整理、装订要求统一采用A4纸打印、左面竖装；毕业论文（设计）的书写格式规范1.毕业论文正文由毕业论文（设计）题目、作者、中文摘要、中文关键词、英文摘要、英文关键词、正文、参考文献9部分组成。(1) 论文题目：一般不超过25个字，要简练准确，可分两行书写；(2) 作者：处于论文题目正下方，须写明系、专业、年级、姓名； (3) 摘要：中文摘要字数应在200字以内，英文摘要实词数应在200个实词以内；(4) 关键词：中、英文均限制在3—5个词语内，各词间用“；”间隔；(5) 正文：论文正文包括引言(或者绪论、概述等)、论文主体、结语等，正文要标题清晰，图表和公式要编号，公式应另起一行书写。字数要求：正文字数要求4000－6000字(6)参考文献：参考文献是撰写论文时围绕论题参考的著作、论文、期刊、网上资料、图片音像资料等。参考文献总数不得少于8篇，鼓励结合学科特点查阅外文参考文献。参考文献在文中出现的地方用上标予以标明，序号用加方括号的阿拉伯数字表示（如[1][2][3]），列于正文文末。毕业论文（设计）的排版格式规范1.版面尺寸：A4(210×297毫米)。2.装订位置：装订线1cm，左面竖装，页边距上下左右均为。3.页码：采用页脚方式设定，采用小4号宋体、用第×页和随后的括号内注明共×页的格式，例如“第1页（共10页）”，处于页面下方、居中、距下边界的位置。4.正文文本：宋体小4号、标准字间距、行间距为固定值26磅、所有标点符号采用宋体全角要求排版。5.论文标题：小2号黑体，居中。6.中文摘要和中文关键词：抬头用5号黑体加粗，内容用5号宋体、两端对齐方式排列，行间距固定值26磅。7.英文摘要和英文关键词：抬头用5号Times New Roman体加粗，内容用5号Times New Roman体、两端对齐方式排列，行间距固定值26磅。8. 正文内标题：见附后格式。（分文理科版本）9.文中图表：所涉及到的全部图、表，不论计算机绘制还是手工绘制，都应规范化，符号、代号标准统一，字体大小与正文协调，手工绘制的要用绘图笔，图表名称和编号准确无误。10.参考文献：位于正文结尾后下空2行，行间距单倍行距，排版见附后格式。
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？
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
1. PLC控制花样喷泉.doc 2. S7-200PLC在数控车床控制系统中的应用3. PLC控制五层电梯设计 4. 超高压水射流机器人切割系统电气控制设计5. 基于PLC的恒压供水系统设计 6. 西门子PLC交通灯毕业设计7. 双恒压供水西门子PLC毕业设计 8. 世纪星组态 PLC控制自动配料系统毕业论文9. 三菱梯形图PLC控制四层电梯 10.三菱PLC五层电梯控制11.全自动洗衣机西门子PLC控制 12.欧姆龙PLC控制交通灯13.基于PLC电机故障诊断系统设计 14.双恒压无塔供水系统plc设计毕业论文15.工业用洗衣机的PLC控制 在配料生产线上的应用 毕业论文17.变频调速恒压供水系统 电梯控制毕业论文19.基于PLC电梯控制设计 20.基于PLC中断技术的集选电梯控制系统实现21.自动送料装车系统PLC控制设计 22.简易电梯控制模型的设计与实现.在数控机床中的应用 24.机械手PLC控制设计控制锅炉输煤系统 控制自动门的课程设计 27.基于PLC的三层电梯控制系统设计 28.交流变频调速PLC控制电梯系统设计毕业论文控制的自动售货机毕业设计论文 在变电站变压器自动化中的应用在电网备用自动投入中的应用305022336
1.机械设计制造及自动化专业毕业论文选题2.双侧驱动式旋耕灭茬机设计3.温室用小型电动旋耕机设计4.玉米对心种子播种机设计5.多功能机械手设计6.越障行走机的结构设计7.秸杆原料育苗钵成型机的设计8.耐磨材料应用现状与发展趋势研究9.代写论文抠抠巴贰衫七贰杉贰零巴10.揉性清洗技术在汽车发动机清洗中的应用11.液体菌种自动接种装置的设计12.果蔬高压电场保鲜技术及装置研究13.新型变质白口铸铁犁铧及旋耕刀材料成份配比的试验研究14.气缸盖试漏机设计15.南瓜种子分选机振动筛片及工作参数的优化设计学术堂提供更多论文知识
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？
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。
Control of Parallel Inverters in Distributed AC Power Systems with Consideration of Line Impedance Effect在分布式交流电力系统中考虑连线阻抗影响时的并联逆变器控制 论文发到你的邮箱了
写一篇论文要干的第一件事就是选题,所谓磨刀不误砍柴工,好的选题能够决定整篇论文的命运,这里有几个超简单、快速的选题方法:1.问导师2.问学长学姐
秘书工作是一项政治性、政策性都很强的工作。秘书工作的性质、作用决定了秘书人员必须具备有较高的政治理论和政策水平，有较高的思想觉悟。下面是我带来的关于文秘专业毕业论文选题的内容，欢迎阅读参考!
1. 试论市场经济下办公室职能作用的加强
2. 秘书参谋的艺术
3. 秘书人员的道德建设
4. 电子文化与“文档一体化”
5. 谈秘书工作的现代化和网络化
6. 论现代秘书创造性思维的运用和开发
7. 现代文员的工作方法和工作艺术
8. 公共关系与人际关系的比较
9. 试论企业文化建设在企业发展中的作用
10. 试论公共关系理论在日常生活中的应用
11. 试论危机处理对企业发展的影响
12. 秘书与上级的沟通技巧
13. 浅谈办公室人际关系的处理
14. 秘书的人际关系
15. 企业秘书的工作特点与素质培养
16. 论秘书的“挡驾”艺术
17. 论秘书的协调艺术
18. 浅谈秘书工作的原则性与灵活性
1.试论秘书信访工作处理与和谐社会建立
2. 试论秘书的信息采集技术和处理艺术
3. 试论秘书如何在网络办公环境中提高信息质量
4. 秘书网络化办公环境下的安全性问题的思考
5. 试论新形势下文秘人员应具备的反应能力
6. 谈行政改革与秘书工作的变迁
7. 浅谈秘书在反腐败斗争中应发挥的作用
8. 浅谈秘书的素养对工作质量的影响
9. 试论秘书的自我心理调适
10. 试论秘书的个人素质
11. 试论性别对秘书工作的影响
12. 试论新世纪秘书的知识结构
13. 试论秘书在现代社会中的作用
14. 试论秘书的公关能力要求
15. 试论现代秘书人员的信息素养
16. 试论秘书工作与人际关系
17. 试论秘书人员的文档管理工作
18. 试论秘书的协调工作
19. 谈秘书的角色意识
20. 试论秘书思维能力的培养与创新思维
1. 论充分发挥秘书的桥梁作用趋势
2. 论秘书工作的适度原则
3. 论秘书的时间管理
4. 秘书与领导关系论
5. 秘书腐败现象的原因及其对策
6. 论秘书人员的职业道德
7. 论超前性思维对秘书参谋工作的有利条件
8. 从现代决策体制看秘书做好参谋工作的有利条件
9. 论公关沟通原则在秘书工作中的运用
10. 谈办公室接待工作的语言技巧
11. 论档案信息资源的开发利用
12. 论办公自动化的发展对秘书工作的影响
13. 妥善解决秘书工作中经常性与突发性的矛盾
14. 论新时期秘书服务领导工作的新特点
15. 秘书写作规律探讨
16. 浅谈企业秘书的职业能力
17. 试论秘书为领导操办事务的职能
18. 试论秘书工作成果的认定与管理
19. 男性从事秘书工作应注意的问题研究
20. 对我国秘书培养模式的思考
21. 试论秘书工作的审美特点
22. 试论秘书工作的创造性空间
23. 浅析领导与秘书的相互影响
24. 浅谈秘书的管理协调职能
25. 秘书腐败现象的成因及其对策
26. 试论现代秘书人才的法律意识
27. 试论档案管理的规范与创新
28. 浅谈公关协调与秘书工作
29. 档案管理的安全性思考
30. 区县级政府文秘人员素质研究
31. 论现代秘书工作的发展趋势
在论文完成之际，我要特别感谢我的指导老师XX老师的热情关怀和悉心指导。在我撰写论文的过程中，X老师倾注了大量的心血和汗水，无论是在论文的选题、构思和资料的收集方面，还是在论文的研究方法以及成文定稿方面，我都得到了X老师悉心细致的教诲和无私的帮助，特别是他广博的学识、深厚的学术素养、严谨的治学精神和一丝不苟的工作作风使我终生受益，在此表示真诚地感谢和深深的谢意。在论文的写作过程中，也得到了许多同学的宝贵建议，同时还到许多在工作过程中许多同事的支持和帮助，在此一并致以诚挚的谢意。感谢所有关心、支持、帮助过我的良师益友。最后，向在百忙中抽出时间对本文进行评审并提出宝贵意见的各位专家表示衷心地感谢！
已经有满意的答案了。
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.