自动化专业英文毕业论文

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》

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.

以后希望到我毕业的时候能跟你要 哈哈

什么意思？要英文的？题目要汉语翻译？

电气工程及其自动化毕业设计（东北电力大学毕业论文） 2009 年 03 月 19 日 星期四 16:22 论文主要内容包括 1.摘要 2.英文翻译 3.原始资料 4.计算书 5.说明书 6.参考文献 7.图纸 简单区域电力网络系统的一次或二次设计毕业论文 目录: 第一章. 设计依据 第二章. 原始资料 第三章 接入系统设计 第四章 地方供电系统设计 第五章 主变选择（包括抽头选择或调整方式设计） 第六章 主接线设计（包括所用电设计） 第七章 短路电流计算 第八章 设备选择 第九章 继电保护配置 [正文]: 第一章.设计依据 根据××大学电气工程及自动化专业毕业任务书 第二章.原始资料 为了满足工农业生产发展的需要，经上级批准，决定新建 110KV 盐北变电所。 一． 设计资料 （一） 新建的盐北变电所各电压级负荷数据，回路，同时率等见表 3。 盐北变电所每年负荷增长率 5％,需考虑五年发展规划 变电所总负荷 s110=K 1（s35+s10） （1+5%） （二） 新建的盐北变电所，受电方案有两种： （1）从 110K 盐城东郊变受电距离 30KM（本课题做）（2）从 110KV 灌南变受电距离 35KM（本课题不 ； 做） ，电力系统接线图见图 1 （三） 电力系统，各厂、所、输电线等主设备技术参数见表 1、2、3、4、5。 （四） 其它原始资料： 所址：地形地势平坦、土址电阻率为 ×10 欧?厘米，所址高于百年一遇最高洪水位。所 址所在地气候，平均气温 15℃，最高气温 35℃，最低气温-15℃。 交通：紧靠国家二级公路，进所公路 公里。 水源：变电所附近有河流供方方便，水量充足。 二．设计内容 （一） 接入系统设计： 确定接入系统输电线路回路数及导线截面。 （二） 地区供电系统设计： 根据地区负荷性质及供电距离，确定供电线路数及导线截面。 （三） 通过技术、经济比较，确定变电所主变压器台数及容量、型号、规格。 （四） 通过电压计算、选择主变分接头或调压方式。 （五） 根据所确定的主变方案和进出线回路数，通过技术分析、论证，确定待建变电所的 主接线。 （六） 确定待建变电所的所用电方案（所用变压器台数、型号、容量和自用电接线型式， 所用电负荷按 变电所容量计） 。 （七） 电气设备选择 1． 为选择电器设备和继电器保护整定需要，计算三相短路电流。 2． 选择变电所电气一次设备（断路器、隔离开关、PT、CT、母线、避雷器及中性点接地 设备） 。 （八） 继电保护 根据继电保护要求，确定变电所各元件继电保护配置。 ...... [摘要]: 本设计说明书是根据毕业设计任务书的要求，结合“电气设备”“电力系统暂态分析”“电 、 、 力系统稳态分析”“继电保护”“电气工程专业毕业设计指南”等有关书籍而制定的，是我 、 、 三年大学学习的总结。 三年中，在授课老师的指导下，学到了很多的知识，对我的学习生涯和社会实践生活有很大 的促进使我不断的挑战自我、充实自己，不仅思想上有了大的收获，知识上也有质的突破。 同时也注重于将所学习的知识运用与实际工作中 ，增强了处理分析问题的能力。 这次设计的新建 110KV 变电所本着为国民经济各个部门提供充足的电能，最大限度地满足 用户的用电需要，保证供电的可靠性，保证良好的电能质量，提高电力系统运行经济性的原 则进行设计。是针对接入系统设计：确定接入系统输电线路回路数及导线截面。地区供电系 统设计： 根据地区负荷性质及供电距离， 确定供电线路数及导线截面。 通过技术、 经济比较， 确定变电所主变压器台数及容量、 型号、 规格。 通过电压计算、 选择主变分接头或调压方式。 根据所确定的主变方案和进出线回路数，通过技术分析、论证，确定待建变电所的主接线。 确定待建变电所的所用电方案（所用变压器台数、型号、容量和自用电接线型式，所用电负 荷按 变电所容量计） 。电气设备选择：为选择电器设备和继电器保护整定需要，计算三 相短路电流。选择变电所电气一次设备（断路器、隔离开关、PT、CT、母线、避雷器及中 性点接地设备） 。继电保护根据继电保护要求，确定变电所各元件继电保护配置。 Prolegomenon This design explains is basis of graduate design assignment book, combine bear on book that 《electric equipment》 、 《electric system steady condition analyzing》 、 《relay safeguard》 、 《electric engineering specialty enchiridion of graduate design》,this is my summarize of three years in university . In three years, depend on teachers go to supervise, acquire many knowledge, promote me that learning 、 work and live, ceaseless challenge me and enrich me, not only my inwardly harvest and that go up knowledge. Likewise pay attention to in the work. This time design of 110KV substation tenet that in order to afford ample electricity of country every department, ensure power supply, ensure power supply finer quality, and promote electric system economy. This time design of running system design (fix on transmit electricity circuitry loops of running system and section of circuitry); fix on number that mains transformer of substation, and capability 、type、specification; compute voltage、choose tap place, compare economy and technology; fix on power supply blue print of substation; compute electrical current of three route short circuit ; choose electric equipment (breaker、seclusion switch、PT、CT、 generatrix、arrester、grounding equipment )and relay safeguard , fix on relay safeguard configure of substation. [参考文献]: 1.《发电厂电气部分课程设计参考资料》 水力电力出版社 2.《电力系统设计设备参考资料》 河海大学出版社 3.《电力系统稳态分析》 水力电力出版社 4.《电力系统暂态分析》 水力电力出版社 5.《电力工程设计手册》 水力电力西北电力设计院 6.《发电厂电气部分》 水力电力出版社 7.《电力系统继电保护原理》 水力电力出版社 8.《电力系统课程设计及毕业参考资料》 中国电力出版社

正在做这个项目，不过没有英文。