外文翻譯----工業(yè)企業(yè)無功補償

1、<p>　　附錄一 英文資料翻譯</p><p>　　Industrial enterprises of reactive power compensation</p><p><b>　　Abstract</b></p><p>　　The improvement of industrial enterprises is to i

2、mprove 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 comp

3、ensation and the role and view of the current power system,industrial enterprises,the problems for the proposed improvements and measures. Introduction In industrial enterprises,the vast majority of electrical equ

4、ipment belo</p><p>　　Load 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,which can not

5、only reduce the line losses， and investment; when the load change is large， dynamic compensation method should be used， stable voltage [3]. </p><p>　　Reduce line losses</p><p>　　Is located at a

6、rated voltage,active power is constant,due to power factor changes,the line loss rate of change ΔP% for the </p><p>　　As can be seen from Table 1 to improve the power factor in lowering power consumption,imp

7、roving economic efficiency plays an important role. </p><p>　　Table 1 Power factor and power loss percentage of the corresponding data</p><p>　　If a constant active power condition,the original

8、power factor cosφ1 of 0.59,compensated power factor cosφ2 of 0.98,its line loss rate reduction ΔΡ% to 64%. Dynamic compensation device.</p><p>　　Group to track the power capacitor compensation， power factor

9、can be different from the stability provided in the context of the power factor to achieve adequate compensation purposes. </p><p>　　Lines， transformer capacity increase </p><p>　　Lines,transfor

10、mer capacity increased ΔS for the </p><p>　　Additional compensation device,may improve the power factor,power factor on the business of direct economic benefit is obvious. Because the state electricity syste

11、m,starting from the rational use of energy,according to the power company to adjust the price due to high and low values. The compensation device for enterprise and the entire power system economic operation all have sig

12、nificant economic effects . </p><p>　　To improve the voltage quality To improve the voltage quality is the dynamic reactive power compensation equipment installed around the role of place in the line vo

13、ltage compensation has increased slightly . </p><p>　　Where tgφ1 - compensation device is not installed before the φ1 angle tangent; </p><p>　　tgφ2 - compensation equipment installed after the φ

14、2 angle tangent; </p><p>　　R， x --- line resistance， reactance. </p><p>　　Industrial enterprises for the power system problems and solution </p><p>　　Fig 1 for a diagram of power su

15、pply systems for heavy machine tool plant. At present,the total capacity of the plant transformer 17660kVA,a total of 20 transformers (1 # ~ 20， # transformers),each transformer capacity range of 50 ~ 1250 kVA， changing

16、the ratio of 10kV / 014kV. Transformer low voltage side of the load is mainly motor， shown in the M1,M2 Mn shown. In general the rate of transformer load is basically maintained at 28% ~ 29%, and the maximum load of 700

17、0kW. </p><p>　　High and low voltage compensation to replace a combination of high concentration of compensation </p><p>　　From the figure we can see the plant supply network focused on high-volt

18、age power factor compensation is compensation that is only in the high-voltage busbar 10kV substation capacitor banks on the pick,while the low pressure has not taken any compensation measures. The fixed capacitor compen

19、sation method there have been compensation or due compensation, and right below the second power supply bus power factor compensation circuit does not work. As the low power factor caused by the line losses a</p>

20、<p><b>　　Figure 1 </b></p><p>　　Power Supply System of a Heavy Machine Tool Plant diagram</p><p>　　To change the power supply as much as possible to avoid the "big horse-dr

21、awn cart" phenomenon </p><p>　　In making our selection,we should consider leaving a certain margin,to prevent heavy damage to equipment when,so most of the time caused by equipment,and severe underrun u

22、nderrun the formation of the "big horse-drawn cart" Run. As the plant load factor of the transformer is basically 28% ~ 29%,and shows the transformer capacity is too large,transformer capacity can not be fully

23、utilized,not only a waste of investment in equipment has increased the power loss. Rational choice by the transformer c</p><p>　　To avoid the no-load operation of equipment </p><p>　　At present，

24、 the plant is running a serious load of some equipment. Improving the power factor,the first consideration should be given a reasonable run the equipment to improve power factor of power the device itself. The plant main

25、 load is AC motor,its power factor load with it change, motor idling,the power factor of about 0.1 ~ 0.3 between the rated load at 0.8 ~ 0.85 between the motor and thus should be made near the rated load state run. We sh

26、ould improve the motor power factor,the simplest </p><p><b>　　工業(yè)企業(yè)無功補償</b></p><p><b>　　摘要 </b></p><p>　　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)用實例說明了工業(yè)企業(yè)

27、無功補償?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，提出了改進意見和措施。</p><p><b>　　1 引言</b></p><p>　　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。

28、因而就地進行無功補償、提高功率因數(shù)對降損節(jié)能有著極為重要的意義。</p><p>　　2 補償方式的選擇</p><p>　　無功補償分為集中補償、分散補償和就地補償三種。集中補償，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)達到規(guī)定值以上。這種補償方式只能補償高、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

29、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)荷的減少而獲得補償效果。就地補償是把無功補償器直接接在異步電動機旁或進線端子上。集中補償方式所用電容器組的容量較分組補

30、償或就地補償要小，它的利用率則更高，缺點是對變、配電所各饋線并未得到補償，僅減輕了電網(wǎng)的無功負(fù)荷。分散補償方式中的電容器組的利用率比就地補償高，因此總需要量較就地補償要小，是一種經(jīng)濟合理的補償方式。無功補償應(yīng)遵循“全面規(guī)劃，合理布局，分級補償，就地平衡;集中補償與分散補償相結(jié)合，以分散補償為主；</p><p>　　3 補償容量的確定</p><p>　　在電力網(wǎng)中無功功率的消耗是很大的

31、，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償，提高用戶負(fù)荷的功率因數(shù)，這樣可以減少發(fā)電機無功出力和減少輸、變、配電設(shè)備中的無功電力消耗，從而達到降低損耗的目的。補償?shù)臒o功功率容量為</p><p>　　式中—最大負(fù)荷日平均有功功率；—未裝設(shè)補償裝置前的功率因數(shù)實測值；—裝設(shè)補償裝置后所達到的功率因數(shù)

32、值。</p><p>　　4 無功補償裝置的作用</p><p>　　可以根據(jù)負(fù)荷變化情況決定采用靜態(tài)還是動態(tài)補償方式。當(dāng)負(fù)荷變化較為平穩(wěn)時，應(yīng)采用靜態(tài)補償方式，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)補償方式，穩(wěn)定電壓。</p><p><b>　　4.1 降低線損</b></p><p&g

33、t;　　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ΔP %為</p><p>　　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)濟效益具有十分重要的作用。</p><p>　　表4.1　功率因數(shù)與有功損耗百分率的對應(yīng)數(shù)據(jù)</p><p>　　若在恒定有功功率條件下，原有的功率因數(shù)為0.60，補償后的功率因數(shù)為1，0時，其線損率

34、降低ΔΡ%為64 %。采用動態(tài)補償裝置，將電力電容器分組跟蹤補償，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)，達到充分補償?shù)哪康摹?lt;/p><p>　　4.2 線路、變壓器的增容</p><p>　　線路、變壓器的增容量ΔS 為</p><p>　　加設(shè)補償裝置后，可提高功率因數(shù)，對企業(yè)的直接功率因數(shù)經(jīng)濟效益是明顯的。因為國家電價制度中，從合理利用能源出

35、發(fā)，依據(jù)企業(yè)的功率因數(shù)值來調(diào)整電價高低。這種補償裝置對企業(yè)和整個電力系統(tǒng)的經(jīng)濟運行都有著重大的經(jīng)濟效。</p><p>　　4.3 改善電壓質(zhì)量</p><p>　　改善電壓質(zhì)量是指裝設(shè)動態(tài)無功補償裝置前后，作用在補償?shù)攸c的線路電壓稍有提高。</p><p>　　式中—未裝設(shè)補償裝置前角的正切；</p><p>　　—裝設(shè)補償裝置后角的正切

36、；</p><p>　　R 、x —線路的電阻、電抗。</p><p>　　5 工業(yè)企業(yè)供用電系統(tǒng)存在的問題與解決措施</p><p>　　圖1為某重型機床廠供電系統(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50～1250 kVA ，變比為10kV/ 014kV。變壓器低壓側(cè)負(fù)載主要

37、為電動機，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。</p><p>　　5.1 采用高、低壓相結(jié)合的補償方式取代高壓集中補償</p><p>　　從圖中可以看到該廠供電網(wǎng)絡(luò)的功率因數(shù)補償是高壓集中補償，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償措施。這種固定電容器補償?shù)姆椒〞霈F(xiàn)過補

38、償或欠補償?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)集中補償和低壓側(cè)分散補償相結(jié)合的補償方式。</p><p>　　圖5.1　某重型機床廠供電系統(tǒng)示意圖</p><p>　　5.2 改變供電方式，盡可能避免“大馬拉小車”的現(xiàn)象</p>&l

39、t;p>　　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，這樣大部分時間都造成設(shè)備欠載和嚴(yán)重欠載形成“大馬拉小車”運行。由于該廠變壓器的負(fù)載率基本上在28 %～29 %之間，說明變壓器的裝機容量過大，變壓器容量不能充分利用，既浪費了設(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。</p><p>　　5.3 避免設(shè)備的空載運行

40、</p><p>　　目前，該廠某些設(shè)備的空載運行嚴(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，其功率因數(shù)隨它的負(fù)載而改變，電動機在空轉(zhuǎn)時，功率因數(shù)約在0.1～0.3 之間，額定負(fù)載時在0.8～0.85 之間，因而應(yīng)使電動機接近額定負(fù)荷狀態(tài)下運行。要把電動機功率因數(shù)提高，最簡單的辦法是用電容器和電動機并聯(lián)，所以避免設(shè)備的空載運行是提高設(shè)備功率因數(shù)的重要途徑