無功補(bǔ)償外文翻譯適用于畢業(yè)論文外文翻譯中英文對照

w10kv無功補(bǔ)償摘自 電力系統(tǒng)分析和設(shè)計(jì)摘要 改善工業(yè)企業(yè)用電的功率因數(shù)是提高用電效率、節(jié)約電能的重要手段。本文通過理論分析和應(yīng)用實(shí)例說明了工業(yè)企業(yè)無功補(bǔ)償?shù)囊饬x和作用，并針對目前工業(yè)企業(yè)供用電系統(tǒng)存在的問題，提出了改進(jìn)意見和措施。1 引言在工業(yè)企業(yè)中，絕大多數(shù)的用電設(shè)備屬于感性負(fù)荷，這些設(shè)備在運(yùn)行中要吸收大量的無功功率。無功功率的增加使供電系統(tǒng)的功率因數(shù)降低，從而出現(xiàn)系統(tǒng)電壓下降、電氣設(shè)備得不到充分利用、增加線路損耗以及降低供電設(shè)備的供電能力等情況。因而就地進(jìn)行無功補(bǔ)償、提高功率因數(shù)對降損節(jié)能有著極為重要的意義。2 補(bǔ)償方式的選擇無功補(bǔ)償分為集中補(bǔ)償、分散補(bǔ)償和就地補(bǔ)償三種。集中補(bǔ)償，即在高、低壓配電所內(nèi)設(shè)置若干組電容器，電容器接在配電母線上，補(bǔ)償該配電所供電范圍內(nèi)的無功功率，并使總功率因數(shù)達(dá)到規(guī)定值以上。這種補(bǔ)償方式只能補(bǔ)償高、低壓母線之前線路上的無功功率，它們相當(dāng)于把無功功率源移到用電企業(yè)的配電所，使用戶對供電系統(tǒng)要求的無功功率有所減少，達(dá)到供電部門所要求的功率因數(shù)。而它們對配電母線以下的企業(yè)內(nèi)部的變壓器和線路的無功功率不能起到補(bǔ)償作用，仍有大量的無功功率在企業(yè)內(nèi)部線路上流動并產(chǎn)生損耗。分散補(bǔ)償是將電容器組分別安裝在各個車間的配電盤處，這種安裝方式可以使配電變壓器以及變電所至車間的線路都可以由于無功負(fù)荷的減少而獲得補(bǔ)償效果。就地補(bǔ)償是把無功補(bǔ)償器直接接在異步電動機(jī)旁或進(jìn)線端子上。集中補(bǔ)償方式所用電容器組的容量較分組補(bǔ)償或就地補(bǔ)償要小，它的利用率則更高，缺點(diǎn)是對變、配電所各饋線并未得到補(bǔ)償，僅減輕了電網(wǎng)的無功負(fù)荷。分散補(bǔ)償方式中的電容器組的利用率比就地補(bǔ)償高，因此總需要量較就地補(bǔ)償要小，是一種經(jīng)濟(jì)合理的補(bǔ)償方式。無功補(bǔ)償應(yīng)遵循“全面規(guī)劃，合理w布局，分級補(bǔ)償，就地平衡;集中補(bǔ)償與分散補(bǔ)償相結(jié)合，以分散補(bǔ)償為主；高壓補(bǔ)償與低壓補(bǔ)償相結(jié)合，以低壓補(bǔ)償為主；調(diào)壓與降損相結(jié)合，以降損為主”的原則。3 補(bǔ)償容量的確定在電力網(wǎng)中無功功率的消耗是很大的，大約50 %的無功功率消耗在輸、變、設(shè)備上，50 %消耗在電力用戶上。為了減少無功功率消耗，就必須減少無功功率在電網(wǎng)里的流動。最好的辦法從用戶開始增加無功補(bǔ)償，提高用戶負(fù)荷的功率因數(shù)，這樣可以減少發(fā)電機(jī)無功出力和減少輸、變、配電設(shè)備中的無功電力消耗，從而達(dá)到降低損耗的目的。補(bǔ)償?shù)臒o功功率容量 為cQ2211ososcavP式中 最大負(fù)荷日平均有功功率； 未裝設(shè)補(bǔ)償裝置前的功率因數(shù)實(shí)avPc測值； 裝設(shè)補(bǔ)償裝置后所達(dá)到的功率因數(shù)值。2cos4 無功補(bǔ)償裝置的作用可以根據(jù)負(fù)荷變化情況決定采用靜態(tài)還是動態(tài)補(bǔ)償方式。當(dāng)負(fù)荷變化較為平穩(wěn)時，應(yīng)采用靜態(tài)補(bǔ)償方式，這不僅能較好地降低線路損耗，而且投資少;當(dāng)負(fù)荷變化較大時，應(yīng)采用動態(tài)補(bǔ)償方式，穩(wěn)定電壓。4.1 降低線損設(shè)在某一額定電壓下，有功功率恒定不變，由于功率因數(shù)變化，其線路損耗變化率 P %為 21cos%()0%PA從表4.1中可以看出提高功率因數(shù)對于降低電能損耗，提高經(jīng)濟(jì)效益具有十分重要的作用。w表 4.1 功率因數(shù)與有功損耗百分率的對應(yīng)數(shù)據(jù)若在恒定有功功率條件下，原有的功率因數(shù) 為0.60，補(bǔ)償后的功率因數(shù)1cos為 1，0 時，其線損率降低 %為64 %。采用動態(tài)補(bǔ)償裝置，將電力電容器分2cos組跟蹤補(bǔ)償，則可由原來不同的功率因數(shù)穩(wěn)定在所規(guī)定的功率因數(shù)范圍內(nèi)，達(dá)到充分補(bǔ)償?shù)哪康摹?.2 線路、變壓器的增容線路、變壓器的增容量 S 為 12cosA加設(shè)補(bǔ)償裝置后，可提高功率因數(shù)，對企業(yè)的直接功率因數(shù)經(jīng)濟(jì)效益是明顯的。因?yàn)閲译妰r制度中，從合理利用能源出發(fā)，依據(jù)企業(yè)的功率因數(shù)值來調(diào)整電價高低。這種補(bǔ)償裝置對企業(yè)和整個電力系統(tǒng)的經(jīng)濟(jì)運(yùn)行都有著重大的經(jīng)濟(jì)效。4.3 改善電壓質(zhì)量改善電壓質(zhì)量是指裝設(shè)動態(tài)無功補(bǔ)償裝置前后，作用在補(bǔ)償?shù)攸c(diǎn)的線路電壓稍有提高。 12210%UtgxQRA式中 未裝設(shè)補(bǔ)償裝置前 角的正切；1tg1w裝設(shè)補(bǔ)償裝置后 角的正切；2tg2R 、 x 線路的電阻、電抗。5 工業(yè)企業(yè)供用電系統(tǒng)存在的問題與解決措施圖1為某重型機(jī)床廠供電系統(tǒng)示意圖。目前，該廠變壓器總?cè)萘繛?7660kVA ，共有20臺變壓器(1 # 20 # 變壓器) ，每臺變壓器的容量范圍為501250 kVA ，變比為10kV/ 014kV。變壓器低壓側(cè)負(fù)載主要為電動機(jī)，如圖中 M1 、 M2 Mn 所示。一般情況變壓器負(fù)載率基本上維持在28 %29 %之間，最大負(fù)載時為7000kW。5.1 采用高、低壓相結(jié)合的補(bǔ)償方式取代高壓集中補(bǔ)償從圖中可以看到該廠供電網(wǎng)絡(luò)的功率因數(shù)補(bǔ)償是高壓集中補(bǔ)償，即只在變電所10kV 的高壓母線上接電容器組，而低壓卻沒有采取任何補(bǔ)償措施。這種固定電容器補(bǔ)償?shù)姆椒〞霈F(xiàn)過補(bǔ)償或欠補(bǔ)償?shù)那闆r，并且對二次母線以下的供電線路的功率因數(shù)補(bǔ)償不起作用。由于功率因數(shù)低而造成的線路損失和變電設(shè)備的損失是很大的，所以補(bǔ)償時要盡量做到分級，靠近負(fù)載處安裝電容器。因而提出高壓側(cè)集中補(bǔ)償和低壓側(cè)分散補(bǔ)償相結(jié)合的補(bǔ)償方式。圖 5.1 某重型機(jī)床廠供電系統(tǒng)示意圖5.2 改變供電方式，盡可能避免“大馬拉小車”的現(xiàn)象在設(shè)備選型時，要考慮留有一定的容量，防止重載時損壞設(shè)備，這樣大部分時w間都造成設(shè)備欠載和嚴(yán)重欠載形成“大馬拉小車”運(yùn)行。由于該廠變壓器的負(fù)載率基本上在28 %29 % 之間，說明變壓器的裝機(jī)容量過大，變壓器容量不能充分利用，既浪費(fèi)了設(shè)備投資又增加了電能損耗?？梢酝ㄟ^合理選擇變壓器的容量以及減少或限制用電設(shè)備輕載或空載的時間來防止“大馬拉小車”現(xiàn)象。5.3 避免設(shè)備的空載運(yùn)行目前，該廠某些設(shè)備的空載運(yùn)行嚴(yán)重。在提高功率因數(shù)時，首先應(yīng)考慮使設(shè)備合理運(yùn)行，提高耗電設(shè)備本身的功率因數(shù)。該廠主要負(fù)荷是交流電動機(jī)，其功率因數(shù)隨它的負(fù)載而改變，電動機(jī)在空轉(zhuǎn)時，功率因數(shù)約在0.10.3 之間，額定負(fù)載時在0.80.85 之間，因而應(yīng)使電動機(jī)接近額定負(fù)荷狀態(tài)下運(yùn)行。要把電動機(jī)功率因數(shù)提高，最簡單的辦法是用電容器和電動機(jī)并聯(lián)，所以避免設(shè)備的空載運(yùn)行是提高設(shè)備功率因數(shù)的重要途徑。5.4 建議完善配電設(shè)備或?qū)ζ溥M(jìn)行重新改造在現(xiàn)場測量數(shù)據(jù)的過程中，我們發(fā)現(xiàn)很多配電設(shè)備老化現(xiàn)象嚴(yán)重，沒有電流表、電壓表或者讀數(shù)不準(zhǔn)確，如鏜床車間的配電房內(nèi)完全沒有電流表和電壓表。6 經(jīng)濟(jì)效益分析以該廠供電系統(tǒng)中的2 # 變壓器為例，在低壓側(cè)加裝電容器，使該廠采取高壓側(cè)集中補(bǔ)償和低壓側(cè)分散補(bǔ)償相結(jié)合的補(bǔ)償方式，如圖6.1 。圖中2 # 變壓器容量為800kVA ，型號為S9 - 800/ 10 ，額定銅損耗為 = 715kW ，輸電線路型號為cunPAYJV22 。取電價為0.55元/ kW.h 。將功率因數(shù)由補(bǔ)償前的0.59提高到補(bǔ)償后的0.98 ，表6.1是利用測量儀器在現(xiàn)場測得的變壓器運(yùn)行時二次側(cè)數(shù)據(jù)，現(xiàn)通過計(jì)算分析無功補(bǔ)償降損節(jié)能效益。w圖6.1 鑄造車間供電圖表6.1 變壓器運(yùn)行時二次側(cè)數(shù)據(jù)表6.1 高壓供電線路節(jié)電全年節(jié)約電能W = h1PA式中 增加的線路電功率， 2211cos3PIRAh 年運(yùn)行小時數(shù)，取5000h 。經(jīng)計(jì)算全年節(jié)約電能162217kW.h ，一年內(nèi)降低的電能損耗費(fèi)8192萬元。6.2 變壓器節(jié)電變壓器的損耗主要有鐵損和銅損。提高變壓器二次側(cè)的功率因數(shù)，可使總的負(fù)荷電流減少，從而減少銅損。全年節(jié)約變壓器銅損耗電能 h 式中12()cuWPAA補(bǔ)償前變壓器實(shí)際運(yùn)行時的銅損耗電功率1PAw 211cunIPA PCu2 補(bǔ)償后變壓器的銅損耗電功率 212coscunPA經(jīng)計(jì)算全年節(jié)約電能3150kW.h ，一年內(nèi)節(jié)約變壓器銅損耗電費(fèi)173518元。6.3 功率因數(shù)調(diào)整電費(fèi)用戶一年內(nèi)減少因功率因數(shù)偏低多支出的罰金:800 0. 5895000 0.55 17.22 %(增收率) =22131 萬元補(bǔ)償后用戶一年內(nèi)得到的功率因數(shù)獎金:800 0. 589 5000 0.55 2.7 %(減收率) =315萬元兩項(xiàng)總計(jì)為25181萬元由上述計(jì)算可知一年內(nèi)合計(jì)增加純收入34173萬元，根據(jù)補(bǔ)償容量需設(shè)備投資2715萬元，9個月就能收回投資。這說明針對該廠鑄造車間的具體情況在變壓器二次側(cè)采用分散補(bǔ)償?shù)姆绞竭M(jìn)行無功補(bǔ)償是可行的，并且能取得長期且明顯的經(jīng)濟(jì)效果。wIndustrial enterprises of reactive power compensationFrom:Power System Analysis and DesignAbstractThe improvement of industrial enterprises is to improve the power factor of electric power efficiency， an important means of saving energy. In this paper， theoretical analysis and application examples of the industrial enterprises， the significance of reactive power compensation and the role and view of the current power system， industrial enterprises， the problems for the proposed improvements and measures. IntroductionIn industrial enterprises， the vast majority of electrical equipment belongs to perceptual load， these devices in operation to absorb a large number of reactive power. An increase in reactive power supply system power factor to lower system voltage drop to occur， electrical equipment not fully utilized， increasing line losses and lower-powered equipment， power supply capacity and so on. In situ reactive power compensation and thus improve the power factor of the Energy Conservation has extremely important significance. The choice of method of compensation Compensation for reactive power compensation is divided into centralized and decentralized compensation for three kinds of compensation and in situ. Focus on compensation， that is， high and low voltage power distribution set up by several groups within the capacitor， capacitor connected to the power distribution bus， the compensation for the distribution of power within the reactive power， and to reach the wrequired value of the total power factor above. This method of compensation can compensate for high and low voltage bus routes prior to the reactive power， which is equivalent to the reactive power source to move the electricity distribution companies， allowing users to power the system requirements for reactive power has been reduction in the electricity sector to achieve the required power factor. And their distribution within the enterprise bus following the line of transformer and reactive power compensation can not play a role， there is still a large number of reactive power line flows within the enterprise and generate losses. Dispersion compensation is the capacitors were installed at various workshops at the switchboard， which will enable installation of distribution transformer and the substation to the plant lines can be due to a decrease in reactive load compensation effect. Local compensation is the reactive power compensation device directly connected to the induction motor terminals on the side or into the line. Focus on compensation methods used in the capacity of capacitor compensation or in-place than the grouping of compensation should be small， its utilization rate is even higher disadvantage is the change in distribution has not been compensated by the feeders， only lightened the load reactive power grid. Dispersion compensation in the way the utilization of capacitor compensation than the in situ high， so the total requirement of compensation is smaller than the spot is an economical and reasonable remedy. Reactive power compensation should follow the “overall planning， rational distribution， classification of compensation， in-place balance; focus on compensation and dispersion compensation combine to spread-based compensation; high compensation and low voltage compensation combined with low-pressure-based compensation; Regulator combined with lower losses， down are the main loss “principle 1. Compensation capacity to determine In the power grid in the reactive power consumption is a big， about 50% of the reactive power consumed in transmission， transformation and the device， 50% of the consumed electricity users. In order to reduce reactive power consumption， it is necessary to reduce the reactive power in the grid where flow. The best way to start from the user to increase reactive power compensation， improve user load power factor， so that Generator reactive power can be reduced and the reduction of transmission， wtransformation and distribution equipment in the reactive power consumption， so as to achieve the purpose of reducing wear and tear 2. Compensation for reactive power capacity of Qc for2211coscoscavQPLoad changes can be decided according to the static or dynamic compensation mode. When the load change is relatively stable， we should use the static method of compensation， whic