有关自动化的英文科技论文题目

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？

Welding Automation Research in the engineering school is largely focused on problems involving sensing, modeling, and control of welding processes, ., welding automation. Faculty and students from electrical engineering, mechanical engineering, and material science are involved in the welding automation research. The overall objective of this research is to provide both greater productivity and enhanced quality for welding in the manufacturing

[1] Corrêa, J., Farret F., Canha L.,et al. An electrochemical-based fuel-cell model suitable for electrical engineering automation approach [J]. IEEE Transactions on industrial electronics. 2004, 51(5): 1103-1112.[2] wider, J., Michalski P.,Wszo ek G. Laboratory support for the didactic process of engineering processes automation at the Faculty of Mechanical Engineering [J]. Journal of Achievements in Materials and Manufacturing Engineering. 2006, 15(1-2): 199-206.给你找了两篇算是沾边文献。第一篇是电气化顶级期刊IEEE文献，被引用过100多次。第二篇被引用过十次。应该适合楼主。如果需要全文可以发邮件到另本人利用业余时间在百度知道里免费给网友查专业文献，纯属业余爱好，发的文献无存稿，请无关人员勿骚扰。

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。

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.