电气论文翻译

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.

花点钱找个翻译公司吧。百度上很难找到有专业背景的，翻译的东西没法用，都是让歪果仁翻白眼儿的译文。

The design of a Tianjin chemical fiber textile factory power supply systemAbstractThis design aims to through to Tianjin, a chemical fiber textile factory for distribution system design allows designers to understand the design process of the power supply system of industrial enterprises and basic skills, in the design process not only to deepen the understanding of power supply and distribution of the technology, training of theoretical knowledge of flexible application ability. Design process including: load calculation, scheme demonstration, short circuit calculation, equipment selection, reactive power compensation and the distribution of the design etc.. The sewage treatment plant for secondary load, two power supply into line, plant a total of two step-down substation (35KV/10KV). 10KV/).Because of the power supply power factor greater than , so the compensation in low voltage side capacitor to meet requirements of. The current through the load calculation andthe calculation of the short-circuit point selection of equipment, so as to meet therequirements. In the design process of the safety and reliability of power supply system are fully considered, and strive to make the economy R & D center building electrical designAbstractThe design for the electrical design of a Suzhou R & D center building. Electrical design follow the civil architectural electrical design code (jgj16-2008), and in accordance with the current national standard and standard. According to the size and functional demand of construction, query specification, the building belongs to the high-rise civil buildings, building category for a class of construction, the fire resistance rating for a level, the lightning protection level for secondary and general lighting with three load power supply, fire power and the important load with a load power supply, the connection of the low voltage distribution system protection system design using lightning protection building electrical design includes two parts: the design of power system and the weak system design. These include high voltage low voltage power distribution design, lighting system design, lightning protection and grounding system design; weak part including fire protection system design and cable TV system design, design of a telephone system, network system design, security system design. Design should be according to the construction scale, the use requirement and design principle, calculated according to the technical specifications, and wire and the equipment selection, so as to meet the economic rationality and energy conservation requirements, ensure the power supply reliability.

为您解答如下：天津某化纤毛纺厂供电系统设计 摘 要 本设计旨在通过对天津某化纤毛纺厂供配电系统的设计使设计者了解掌握工业企业供电系统的设计过程及其基本技能，在设计过程中不但加深了对供配电这门技术的理解，还培养了对理论知识灵活应用能力。设计过程包括：负荷计算、方案论证、短路计算、设备选择、无功补偿及变配电所的设计等。此污水处理厂为二级负荷，有两路电源进线，厂区内共设两个降压变电所（35KV/10KV）.（10KV/）。因供电电源要求功率因数大于，因此通过在低压侧加电容进行补偿使之达到要求。通过负荷计算和对各短路点的电流计算选择设备，使之满足要求。在设计过程中充分考虑了供电系统的可靠性与安全性，并力求使之经济合理。关键词：变电所；变压器；负荷计算；短路计算；照度计算；功率补偿苏州某研发中心大楼电气设计摘 要 本设计为苏州某研发中心大楼的电气设计。电气设计遵循《民用建筑电气设计规范》（JGJ16-2008），并符合国家现行的其他规范和标准。根据建筑的规模大小和功能需求，查询规范知，该建筑属于高层民用建筑，建筑类别为一类建筑，耐火等级为一级，防雷等级为二级，一般照明采用三级负荷供电，消防用电和重要负荷采用一级负荷供电,低压配电系统的接线方式采用TN-C-S。防雷系统设计采用避雷网。该建筑电气设计包括两部分：强电系统设计和弱电系统设计。其中强电部分包括低压配电设计、照明系统设计、防雷与接地系统设计；弱电部分包括消防系统设计、有线电视系统设计、电话系统设计、网络系统设计、安防系统设计。设计中要根据建筑的规模、使用要求及设计原则，计算得出相应的技术指标，并进行导线及设备的选型，使之满足经济合理性及节能要求，保证供电的可靠性。关键词：低压配电；照明；消防；防雷与接地Tianjin a certain chemical fiber woolen mill power supply system design Pick to This design aims to through the design of a certain chemical fiber woolen mill power supply system in tianjin to designers to grasp the design process of industrial enterprise power supply system and its basic skills, in the design process not only deepened the understanding of power supply this technology, and train the ability of the flexible application of theoretical knowledge. The design process include: load calculation, short circuit calculation, equipment selection, project demonstration, reactive power compensation and distribution design, etc. The sewage treatment plant as the secondary load, there are two way power supply into line, the factory have two step-down substation (35 KV / 10 KV). (10 KV / KV). Because of the power supply for power factor more than , so through in low voltage side capacitance compensation to meet the requirements. Through load calculation and selection for the current calculation of short-circuit point equipment, to meet the requirements. In the design process fully consider the security and reliability of power supply system, and strive to make economic sense. Key words: substation; Transformer; Load calculation; Short circuit calculation. Intensity of illumination computation; Power compensation A research and development center building electrical design in suzhou Pick to This design for a research and development center building electrical design in suzhou. Electrical design follow the civil construction electrical design specification (JGJ16-2008), and other specifications and conform to the current national standards. According to the scale of construction and the function demand, query, the building belongs to the high-rise civil buildings, category for a class of buildings, fire resistance rating for level 1, level of lightning protection for the secondary, general lighting use level 3 load power supply, fire power and important load using level load power supply, the connection mode of low-voltage distribution system adopts TN - C - S. With lightning protection network in lightning protection system design. The building electrical design includes two parts: the high voltage system design and the weak current system design. High-voltage electrical parts including low-voltage distribution design, lighting system design, lightning protection and grounding system design; Elv part includes the fire protection system design, cable television system design, telephone system, network system design, security system design. Design according to the size of the building, use requirement and design principles, calculation of the technical indicators, and wire and equipment type selection, make it meet the requirements of economic rationality and energy conservation, to ensure the reliability of power supply. Key words: low-voltage distribution; Lighting; The fire; Lightning protection and grounding . -----------------------------------如有疑问欢迎追问！满意请点击右上方【选为满意回答】按钮

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

你好，软件翻译不太现实。有两种有效途径可供选择：1. 网上搜索 DLT 电力行业词汇 第10部分：电力设备。 豆丁和百度都有。 根据国家标准的专业词汇来翻吧。2. cnki翻译助手，专业论文中挑出的专业词汇供您参考。

我昨天帮一个翻译了论文摘要， 翻译完了，TMD还说这不对，那不对。 GG翻译专业，专业八级都过了。 再也不详在做这费时不讨好的事情了。