導語：如何才能寫好一篇低壓電容(rong)器，這就需要(yao)搜(sou)集整理(li)更多(duo)的(de)資料和文獻，歡(huan)迎(ying)閱讀由(you)公(gong)務員之家整理(li)的(de)十篇范文，供你借鑒(jian)。

篇1

【關鍵詞】無功補償;低壓電力電容(rong);改善;應用(yong)

1.無功補償

電網輸出的功率包括兩部分：一是有功功率，二是無功功率，直接消耗電能，把電能轉變為機械能，熱能，化學能或聲能，利用這些能作功，這部分功率稱為有功功率;不消耗電能;只是把電能轉換為另一種形式的能，這種能作為電氣設備能夠作功的必備條件，并且，這種能是在電網中與電能進行周期性轉換，這部分功率稱為無功功率，如電磁元件建立磁場占用的電能，電容器建(jian)立電(dian)(dian)(dian)場所占的(de)(de)電(dian)(dian)(dian)能。電(dian)(dian)(dian)流(liu)(liu)在電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)元(yuan)件(jian)中(zhong)作(zuo)功時(shi)，電(dian)(dian)(dian)流(liu)(liu)滯后(hou)于電(dian)(dian)(dian)壓(ya)(ya)90°，而(er)電(dian)(dian)(dian)流(liu)(liu)在電(dian)(dian)(dian)容(rong)(rong)元(yuan)件(jian)中(zhong)作(zuo)功時(shi)，電(dian)(dian)(dian)流(liu)(liu)超前電(dian)(dian)(dian)壓(ya)(ya)90°。在同一(yi)電(dian)(dian)(dian)路中(zhong)，電(dian)(dian)(dian)感(gan)(gan)(gan)(gan)電(dian)(dian)(dian)流(liu)(liu)與電(dian)(dian)(dian)容(rong)(rong)電(dian)(dian)(dian)流(liu)(liu)方向相反，互(hu)差180°。如果在電(dian)(dian)(dian)磁(ci)元(yuan)件(jian)電(dian)(dian)(dian)路中(zhong)有比例地安裝電(dian)(dian)(dian)容(rong)(rong)元(yuan)件(jian)，使兩(liang)者的(de)(de)電(dian)(dian)(dian)流(liu)(liu)相互(hu)抵消(xiao)，使電(dian)(dian)(dian)流(liu)(liu)的(de)(de)矢量(liang)與電(dian)(dian)(dian)壓(ya)(ya)矢量(liang)之間的(de)(de)夾角縮小，把具有容(rong)(rong)性(xing)功率(lv)(lv)負荷(he)(he)的(de)(de)裝置與感(gan)(gan)(gan)(gan)性(xing)功率(lv)(lv)負荷(he)(he)并(bing)聯接在同一(yi)電(dian)(dian)(dian)路，能量(liang)在兩(liang)種負荷(he)(he)之間相互(hu)交換(huan)。這樣(yang)，感(gan)(gan)(gan)(gan)性(xing)負荷(he)(he)所需(xu)要的(de)(de)無(wu)功功率(lv)(lv)可由(you)容(rong)(rong)性(xing)負荷(he)(he)輸出的(de)(de)無(wu)功功率(lv)(lv)補(bu)償(chang)。

2.低壓電力電容

為了電(dian)(dian)(dian)(dian)(dian)網中功率(lv)因(yin)數因(yin)數達(da)到或(huo)接(jie)近一(yi)(yi)，減(jian)少無功損耗，就在(zai)電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)并聯電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)，電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器由充(chong)放電(dian)(dian)(dian)(dian)(dian)效(xiao)應產生(sheng)電(dian)(dian)(dian)(dian)(dian)流(liu)，容(rong)(rong)性電(dian)(dian)(dian)(dian)(dian)流(liu)與(yu)感(gan)性電(dian)(dian)(dian)(dian)(dian)流(liu)相(xiang)(xiang)(xiang)(xiang)(xiang)位相(xiang)(xiang)(xiang)(xiang)(xiang)反可(ke)以相(xiang)(xiang)(xiang)(xiang)(xiang)互(hu)抵(di)消(xiao)，這樣(yang)一(yi)(yi)來供(gong)電(dian)(dian)(dian)(dian)(dian)線(xian)路(lu)(lu)和變壓器發電(dian)(dian)(dian)(dian)(dian)機就不(bu)需要(yao)提供(gong)電(dian)(dian)(dian)(dian)(dian)動機需要(yao)的(de)感(gan)性電(dian)(dian)(dian)(dian)(dian)流(liu)，同樣(yang)負載的(de)情況下發電(dian)(dian)(dian)(dian)(dian)機和變壓器可(ke)以選小，相(xiang)(xiang)(xiang)(xiang)(xiang)應線(xian)路(lu)(lu)電(dian)(dian)(dian)(dian)(dian)纜也會減(jian)少截面積，經濟(ji)效(xiao)益明顯。在(zai)低壓系統中，通過恰(qia)當的(de)無功補(bu)(bu)償(chang)方(fang)法還可(ke)以調整(zheng)三相(xiang)(xiang)(xiang)(xiang)(xiang)不(bu)平(ping)衡電(dian)(dian)(dian)(dian)(dian)流(liu)。在(zai)相(xiang)(xiang)(xiang)(xiang)(xiang)與(yu)相(xiang)(xiang)(xiang)(xiang)(xiang)之間(jian)(jian)跨接(jie)的(de)電(dian)(dian)(dian)(dian)(dian)感(gan)或(huo)者電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)可(ke)以在(zai)相(xiang)(xiang)(xiang)(xiang)(xiang)間(jian)(jian)轉移有功電(dian)(dian)(dian)(dian)(dian)流(liu)。因(yin)此，對于三相(xiang)(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)流(liu)不(bu)平(ping)衡的(de)系統，只要(yao)恰(qia)當地在(zai)各相(xiang)(xiang)(xiang)(xiang)(xiang)與(yu)相(xiang)(xiang)(xiang)(xiang)(xiang)之間(jian)(jian)以及(ji)各相(xiang)(xiang)(xiang)(xiang)(xiang)與(yu)零線(xian)之間(jian)(jian)接(jie)入不(bu)同容(rong)(rong)量的(de)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器，不(bu)但可(ke)以將(jiang)各相(xiang)(xiang)(xiang)(xiang)(xiang)的(de)功率(lv)因(yin)數均補(bu)(bu)償(chang)至接(jie)近1，而且(qie)可(ke)以使各相(xiang)(xiang)(xiang)(xiang)(xiang)的(de)有功電(dian)(dian)(dian)(dian)(dian)流(liu)達(da)到平(ping)衡狀態(tai)。現在(zai)將(jiang)在(zai)配電(dian)(dian)(dian)(dian)(dian)變壓器低壓側和用戶車間(jian)(jian)配電(dian)(dian)(dian)(dian)(dian)屏安裝并聯補(bu)(bu)償(chang)電(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器分組補(bu)(bu)償(chang)作(zuo)一(yi)(yi)介紹。

一(yi)般低壓(ya)電(dian)(dian)力電(dian)(dian)容采用(yong)(yong)延時(shi)投(tou)切(qie)方式，這(zhe)種投(tou)切(qie)靠傳統的(de)(de)接(jie)觸器(qi)的(de)(de)動作，它(ta)具有抑(yi)制電(dian)(dian)容涌(yong)流(liu)(liu)作用(yong)(yong)，延時(shi)投(tou)切(qie)目(mu)的(de)(de)在于(yu)防止接(jie)觸器(qi)過(guo)(guo)于(yu)頻(pin)繁的(de)(de)動作時(shi)，電(dian)(dian)容器(qi)造成損(sun)壞，更重要的(de)(de)是(shi)防備(bei)電(dian)(dian)容不(bu)停地投(tou)切(qie)導致(zhi)供電(dian)(dian)系統振蕩，這(zhe)是(shi)很(hen)危(wei)險的(de)(de)。當(dang)電(dian)(dian)網的(de)(de)負荷呈感性時(shi)，如電(dian)(dian)動機(ji)電(dian)(dian)焊機(ji)等負載，這(zhe)時(shi)電(dian)(dian)網電(dian)(dian)流(liu)(liu)滯后(hou)(hou)電(dian)(dian)壓(ya)一(yi)個角(jiao)度，當(dang)負荷呈容性時(shi)，如過(guo)(guo)量的(de)(de)補(bu)(bu)償(chang)裝置的(de)(de)控制器(qi)，這(zhe)時(shi)電(dian)(dian)網的(de)(de)電(dian)(dian)流(liu)(liu)超(chao)(chao)前(qian)電(dian)(dian)壓(ya)一(yi)個角(jiao)度，即功(gong)率(lv)(lv)因(yin)數超(chao)(chao)前(qian)或滯后(hou)(hou)是(shi)指電(dian)(dian)壓(ya)電(dian)(dian)流(liu)(liu)的(de)(de)相(xiang)位關系，通(tong)過(guo)(guo)補(bu)(bu)償(chang)裝置的(de)(de)控制器(qi)檢測(ce)供電(dian)(dian)系統的(de)(de)物(wu)(wu)理(li)量，來決(jue)定電(dian)(dian)容器(qi)的(de)(de)投(tou)切(qie)，這(zhe)個物(wu)(wu)理(li)量可(ke)以(yi)是(shi)功(gong)率(lv)(lv)因(yin)數或無(wu)功(gong)電(dian)(dian)流(liu)(liu)或無(wu)功(gong)功(gong)率(lv)(lv)。

如圖1所示(shi)：成(cheng)套的(de)(de)(de)低(di)壓電(dian)(dian)(dian)容(rong)(rong)(rong)由(you)這樣(yang)的(de)(de)(de)四(si)組(zu)電(dian)(dian)(dian)容(rong)(rong)(rong)組(zu)成(cheng)，每(mei)組(zu)電(dian)(dian)(dian)容(rong)(rong)(rong)4C14C2并(bing)(bing)聯(lian)星形連接(jie)與電(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)4D1串聯(lian)，這樣(yang)容(rong)(rong)(rong)抗(kang)器(qi)(qi)(qi)組(zu)合(he)來進(jin)行無(wu)功補(bu)償，電(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)補(bu)償線路相間及相地電(dian)(dian)(dian)容(rong)(rong)(rong)，以(yi)加速潛供電(dian)(dian)(dian)流自動(dong)熄滅，串聯(lian)電(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)通常起(qi)限(xian)流作用。容(rong)(rong)(rong)抗(kang)起(qi)的(de)(de)(de)投(tou)(tou)切受接(jie)觸器(qi)(qi)(qi)4K1的(de)(de)(de)控制(zhi)，接(jie)觸器(qi)(qi)(qi)4K1的(de)(de)(de)吸合(he)由(you)控制(zhi)器(qi)(qi)(qi)的(de)(de)(de)接(jie)點(dian)來控制(zhi)，控制(zhi)器(qi)(qi)(qi)根據功率(lv)因數的(de)(de)(de)大小來決定投(tou)(tou)切電(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)(qi)的(de)(de)(de)組(zu)數。電(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)與電(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)(qi)并(bing)(bing)排安裝且(qie)在一個柜(ju)內(nei)，電(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)(qi)運(yun)行的(de)(de)(de)穩(wen)定與否，溫度(du)至(zhi)(zhi)關重要.電(dian)(dian)(dian)抗(kang)器(qi)(qi)(qi)運(yun)行時溫度(du)溫度(du)可(ke)(ke)以(yi)達到90-100度(du)，接(jie)線端子(zi)溫度(du)可(ke)(ke)以(yi)達到110度(du)，勢(shi)必(bi)造成(cheng)電(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)(qi)在有限(xian)的(de)(de)(de)空間內(nei)散(san)熱不(bu)(bu)良，引起(qi)鼓肚漏油甚至(zhi)(zhi)爆炸，給設備(bei)及人身安全埋(mai)下隱患。電(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)(qi)的(de)(de)(de)壽命縮短(duan)不(bu)(bu)能對設備(bei)進(jin)行投(tou)(tou)切，直接(jie)影響補(bu)償效果(guo)。

圖1

3.成套低壓(ya)電容(rong)運(yun)行環境(jing)改善與保養(yang)

電容(rong)(rong)(rong)器組投入時(shi)(shi)(shi)環(huan)境溫(wen)度不(bu)能低于-40℃，運(yun)行時(shi)(shi)(shi)環(huan)境溫(wen)度：1小時(shi)(shi)(shi)，平均不(bu)超(chao)(chao)過+40℃，2小時(shi)(shi)(shi)平均不(bu)得(de)(de)超(chao)(chao)過+30℃，及一年平均不(bu)得(de)(de)超(chao)(chao)過+20℃。如超(chao)(chao)過時(shi)(shi)(shi)，應采(cai)用人工冷卻(que)（安裝(zhuang)風扇(shan)）或(huo)將電容(rong)(rong)(rong)器組與(yu)電網斷開。 電容(rong)(rong)(rong)器的運(yun)行溫(wen)度不(bu)得(de)(de)超(chao)(chao)過65度。

為(wei)了延長電(dian)容(rong)(rong)(rong)器(qi)的(de)使用(yong)壽(shou)命，現將電(dian)容(rong)(rong)(rong)器(qi)與(yu)電(dian)抗器(qi)之間安裝(zhuang)(zhuang)隔(ge)熱板，防止(zhi)熱量直(zhi)接(jie)(jie)(jie)進行交(jiao)換;還有一個措(cuo)施(shi)就是(shi)人工(gong)安裝(zhuang)(zhuang)冷卻(que)(que)風(feng)扇(shan)對(dui)容(rong)(rong)(rong)抗器(qi)進行冷卻(que)(que)，控制(zhi)方式為(wei)任一組電(dian)容(rong)(rong)(rong)投入，接(jie)(jie)(jie)觸(chu)器(qi)的(de)輔(fu)助(zhu)常(chang)(chang)開接(jie)(jie)(jie)點啟動風(feng)扇(shan)，四組接(jie)(jie)(jie)觸(chu)器(qi)的(de)輔(fu)助(zhu)常(chang)(chang)開節(jie)點并(bing)聯，保證(zheng)只(zhi)要(yao)電(dian)容(rong)(rong)(rong)器(qi)投切，風(feng)扇(shan)就可靠(kao)運行。除以上兩點來提高(gao)電(dian)容(rong)(rong)(rong)器(qi)壽(shou)命來講，日常(chang)(chang)的(de)維護與(yu)保養也(ye)是(shi)十分重(zhong)要(yao)的(de)。

3.1 電容器應(ying)有值(zhi)班人員，應(ying)做好設(she)備運(yun)行(xing)情(qing)況記(ji)錄。

3.2 對運行(xing)(xing)的電容器組的外(wai)觀巡視檢查，應按規程規定每(mei)天都要進行(xing)(xing)，如發(fa)現箱殼膨脹應停止使用，以(yi)免發(fa)生故障。

3.3 檢查電(dian)容器組每相負荷可用安培表(biao)進行(xing)。

3.4 安裝地點的溫(wen)度檢查和電容器外殼上最(zui)熱點溫(wen)度的檢查可以通過(guo)水銀(yin)溫(wen)度計等(deng)進行，并且做(zuo)好溫(wen)度記錄(lu)（特別是(shi)夏季）。

3.5 電容器的(de)工作電壓和電流，在使用(yong)時(shi)不得超過1.1倍額定(ding)電壓和1.3倍額定(ding)電流。

3.6 接(jie)上電(dian)容(rong)器后，將引起電(dian)網電(dian)壓升高，特別是負(fu)荷較(jiao)輕時(shi)，在此種情況(kuang)下，應(ying)將部(bu)分電(dian)容(rong)器或全部(bu)電(dian)容(rong)器從電(dian)網中斷(duan)開。

3.7 電(dian)容(rong)(rong)器套管和(he)支持(chi)絕緣子(zi)表面應清潔(jie)(jie)、無(wu)破損(sun)、無(wu)放電(dian)痕跡，電(dian)容(rong)(rong)器外(wai)殼應清潔(jie)(jie)、不變形、無(wu)滲油，電(dian)容(rong)(rong)器和(he)鐵架子(zi)上面不應積(ji)滿灰塵和(he)其他臟東西(xi)。

3.8 必須仔細地(di)注意接有電容(rong)器(qi)組的電氣線路上所有接觸(chu)處（通電匯流排(pai)、接地(di)線、斷路器(qi)、熔斷器(qi)、開關(guan)等）的可靠性。因為在線路上一個接觸(chu)處出(chu)了故障，甚至螺母(mu)旋得不緊，都可能(neng)使電容(rong)器(qi)早期損壞和(he)使整個設備發生事故。

3.9 如(ru)果電容器在運行(xing)一(yi)段(duan)時間后，需要(yao)進行(xing)耐壓試驗，則應按(an)規定(ding)值進行(xing)試驗。

3.10 對電容(rong)器電容(rong)和(he)熔(rong)絲的(de)(de)檢查，每個月不得少于一次。在(zai)一年內要測電容(rong)器的(de)(de)損失(shi)角正切值(zhi)(zhi)2～3次，目(mu)的(de)(de)是檢查電容(rong)器的(de)(de)可靠(kao)情況，每次測量都(dou)應在(zai)額(e)定電壓(ya)下(xia)或(huo)近于額(e)定值(zhi)(zhi)的(de)(de)條件下(xia)進行。

3.11 由于繼電器(qi)動作而使電容(rong)器(qi)組的斷路器(qi)跳開(kai)，此時在(zai)未(wei)找(zhao)出跳開(kai)的原因(yin)之前，不得重新合上。

3.12 在運行或運輸過程中如發(fa)現電(dian)容器(qi)外殼(ke)漏油(you)，可以用錫鉛焊(han)(han)料釬焊(han)(han)的方法修理(li)。

圖2

4.結語

低壓(ya)(ya)電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)容器(qi)是重(zhong)要的無(wu)功補償(chang)設備。它在提高(gao)負荷的功率(lv)因數，減少能(neng)量損耗和壓(ya)(ya)降，改(gai)善電(dian)(dian)(dian)(dian)能(neng)質(zhi)量和提高(gao)設備利用率(lv)改(gai)善電(dian)(dian)(dian)(dian)壓(ya)(ya)質(zhi)量提高(gao)線(xian)路(lu)和變(bian)壓(ya)(ya)器(qi)的輸(shu)送能(neng)力等方面發揮(hui)了的重(zhong)要作用。因此加強電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)容器(qi)的維護和運行管理是有著深(shen)遠意義的。

參考文獻

篇2

【關鍵詞】大(da)容量變壓器;低壓側(ce);電壓等(deng)級;選擇

1.前言

隨著(zhu)我(wo)國經濟(ji)的(de)發(fa)展(zhan)，城(cheng)市化進程逐步加(jia)快，用(yong)電(dian)負(fu)荷快速增長，但是符合(he)變電(dian)站建設(she)(she)的(de)土(tu)地卻日漸稀少(shao)。采(cai)用(yong)大容量(liang)變壓器能(neng)夠增加(jia)單座變電(dian)站的(de)輸送能(neng)力，減少(shao)變電(dian)站建設(she)(she)座數，降低單位變電(dian)容量(liang)投(tou)資，節約土(tu)地資源，解決負(fu)荷增長與城(cheng)市發(fa)展(zhan)的(de)矛盾;還(huan)能(neng)有效延(yan)緩(huan)電(dian)網建設(she)(she)、優化基建項目，從而對規(gui)劃新建變電(dian)站的(de)落點、容量(liang)安排以及投(tou)資產生影響，為城(cheng)市規(gui)劃與經濟(ji)建設(she)(she)提供(gong)更(geng)好的(de)支撐。

2.國內500kV大容量變壓器(qi)的應(ying)用(yong)

目前(qian)，國(guo)內電(dian)(dian)網500kV變(bian)壓(ya)(ya)(ya)器(qi)(qi)主要采(cai)用容(rong)量(liang)(liang)為750MVA和1000MVA兩種形式，隨著大(da)(da)容(rong)量(liang)(liang)變(bian)壓(ya)(ya)(ya)器(qi)(qi)（1200MVA和1500MVA）制造(zao)技(ji)術的成熟，部分發達地區(qu)逐步(bu)試(shi)點采(cai)用大(da)(da)容(rong)量(liang)(liang)變(bian)壓(ya)(ya)(ya)器(qi)(qi);，2006年華北電(dian)(dian)網采(cai)用了1200MVA變(bian)壓(ya)(ya)(ya)器(qi)(qi);2010年4月投(tou)產(chan)的上海靜安(an)地下變(bian)電(dian)(dian)站(zhan)規(gui)劃3組1500MVA變(bian)壓(ya)(ya)(ya)器(qi)(qi)。這些大(da)(da)容(rong)量(liang)(liang)變(bian)壓(ya)(ya)(ya)器(qi)(qi)一(yi)般布置(zhi)在(zai)負(fu)荷密集地區(qu)的終端變(bian)電(dian)(dian)站(zhan)內。與已有(you)常規(gui)500kV變(bian)電(dian)(dian)站(zhan)低壓(ya)(ya)(ya)側電(dian)(dian)壓(ya)(ya)(ya)等級選擇相比有(you)差(cha)別(bie)：1）低壓(ya)(ya)(ya)側短(duan)路(lu)容(rong)量(liang)(liang)偏小，投(tou)切單組電(dian)(dian)容(rong)器(qi)(qi)波動大(da)(da);2）為提高(gao)短(duan)路(lu)容(rong)量(liang)(liang)，增加變(bian)壓(ya)(ya)(ya)器(qi)(qi)制造(zao)難度和造(zao)價(jia)。

3.擬建500kV變電站概述

擬建的500kV變電站位于我(wo)國第(di)三(san)大副省級國家(jia)綜合(he)配套改革試驗區(qu)-兩江新區(qu)。根據電網(wang)規(gui)(gui)劃(hua)及新區(qu)負荷發展水(shui)平，該站遠(yuan)景(jing)規(gui)(gui)模為：3臺1500MVA主(zhu)(zhu)變，500kV規(gui)(gui)劃(hua)出線(xian)10回，采(cai)用一個(ge)半斷路(lu)器(qi)(qi)接線(xian)方式(shi)。其中(zhong)220kV規(gui)(gui)劃(hua)出線(xian)18回，220kV電氣主(zhu)(zhu)接線(xian)采(cai)用雙(shuang)母線(xian)雙(shuang)分段接線(xian)，使用無功(gong)補償：按每(mei)臺主(zhu)(zhu)變4組(zu)108Mvar低壓電容(rong)器(qi)(qi)，1組(zu)60Mvar低壓電抗器(qi)(qi)。

4.變壓(ya)(ya)器(qi)低壓(ya)(ya)側電壓(ya)(ya)等級的選擇

4.1 低壓(ya)側(ce)電壓(ya)波動

電(dian)(dian)(dian)(dian)網2014年(nian)小負荷方式下，變壓器低壓側(ce)分別采用110kV、66kV和35kV電(dian)(dian)(dian)(dian)壓等(deng)級，計算對應的(de)(de)短路電(dian)(dian)(dian)(dian)流及容量。根據《電(dian)(dian)(dian)(dian)能質量 電(dian)(dian)(dian)(dian)壓波(bo)動(dong)和閃變》GB/T12326-2008“變電(dian)(dian)(dian)(dian)站低壓側(ce)投(tou)切(qie)(qie)單組無(wu)功補償裝(zhuang)置引起(qi)所接母線電(dian)(dian)(dian)(dian)壓的(de)(de)變動(dong)值不宜超(chao)過額定電(dian)(dian)(dian)(dian)壓的(de)(de)2.5%”的(de)(de)要求，計算投(tou)切(qie)(qie)單組108Mvar電(dian)(dian)(dian)(dian)容器下，選擇不同電(dian)(dian)(dian)(dian)壓等(deng)級的(de)(de)電(dian)(dian)(dian)(dian)壓波(bo)動(dong)值，如表1所示。

表1 不同(tong)電壓等級的(de)母(mu)線(xian)電壓變(bian)化（變(bian)壓器阻(zu)抗采(cai)用常規值）

當變壓(ya)(ya)器(qi)低壓(ya)(ya)側(ce)(ce)選用(yong)35kV電(dian)壓(ya)(ya)等級時，投切單組電(dian)容器(qi)對低壓(ya)(ya)側(ce)(ce)母線(xian)波(bo)動不滿(man)足(zu)要(yao)求，其他情(qing)況下(xia)，電(dian)壓(ya)(ya)波(bo)動率均(jun)能滿(man)足(zu)規程的要(yao)求。

4.2 變壓器阻抗(kang)

低壓(ya)側采用35kV電(dian)(dian)(dian)壓(ya)等(deng)級，為使低壓(ya)側母線(xian)電(dian)(dian)(dian)壓(ya)波(bo)(bo)動(dong)滿足要求，需提高低壓(ya)側短(duan)路(lu)電(dian)(dian)(dian)流(liu)（容量）。然而(er)，短(duan)路(lu)電(dian)(dian)(dian)流(liu)與(yu)短(duan)路(lu)阻(zu)抗(kang)成反比，提高短(duan)路(lu)電(dian)(dian)(dian)流(liu)，則需減(jian)小短(duan)路(lu)阻(zu)抗(kang)，電(dian)(dian)(dian)網所受的(de)影(ying)響將會增(zeng)大(da)，系統(tong)中(zhong)開關開斷的(de)短(duan)路(lu)電(dian)(dian)(dian)流(liu)也大(da)。當變壓(ya)器短(duan)路(lu)時，繞(rao)組(zu)會遭受巨大(da)的(de)電(dian)(dian)(dian)動(dong)力并產(chan)生更高的(de)短(duan)路(lu)溫升，給(gei)變壓(ya)器制造(zao)(zao)的(de)結(jie)構和造(zao)(zao)價帶(dai)來大(da)幅度(du)的(de)增(zeng)長。一般在電(dian)(dian)(dian)網中(zhong)很少采用小阻(zu)抗(kang)變壓(ya)器的(de)方法來滿足電(dian)(dian)(dian)壓(ya)波(bo)(bo)動(dong)的(de)需求。

4.3 各電壓等級設(she)備(bei)造(zao)價

根據我國(guo)對電(dian)壓等級(ji)(ji)的劃分，一般(ban)把110kV電(dian)壓等級(ji)(ji)稱(cheng)為高壓電(dian)網(wang)，35kV和66kV電(dian)壓等級(ji)(ji)為中壓電(dian)網(wang);66kV和35kV設(she)(she)備在(zai)絕緣考慮上相差不大，造價(jia)(jia)也相近，110kV電(dian)壓等級(ji)(ji)由于絕緣的原因(yin)造價(jia)(jia)比66kV和35kV高不少。由最新的“電(dian)網(wang)工(gong)程(cheng)設(she)(she)備材料信(xin)息價(jia)(jia)”110kV、66kV和35kV斷路器設(she)(she)備的信(xin)息價(jia)(jia)如表(biao)2所示。

每組(zu)(zu)(zu)變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)需要5組(zu)(zu)(zu)配電(dian)(dian)(dian)裝置，4組(zu)(zu)(zu)電(dian)(dian)(dian)容器(qi)(qi)(qi)和1組(zu)(zu)(zu)電(dian)(dian)(dian)抗器(qi)(qi)(qi)，若低(di)壓(ya)(ya)(ya)側采(cai)用(yong)(yong)(yong)35kV電(dian)(dian)(dian)壓(ya)(ya)(ya)等(deng)級，低(di)壓(ya)(ya)(ya)側造(zao)價(jia)約1972萬(wan)(wan)元（5×20+1×200+4×418）;采(cai)用(yong)(yong)(yong)66kV電(dian)(dian)(dian)壓(ya)(ya)(ya)等(deng)級，造(zao)價(jia)約2262萬(wan)(wan)元;采(cai)用(yong)(yong)(yong)110kV電(dian)(dian)(dian)壓(ya)(ya)(ya)等(deng)級，造(zao)價(jia)約3100萬(wan)(wan)元。綜合考慮低(di)壓(ya)(ya)(ya)側電(dian)(dian)(dian)壓(ya)(ya)(ya)波(bo)動(dong)、變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)短路阻抗和設備(bei)造(zao)價(jia)等(deng)因素(su)，變(bian)壓(ya)(ya)(ya)器(qi)(qi)(qi)低(di)壓(ya)(ya)(ya)側采(cai)用(yong)(yong)(yong)66kV電(dian)(dian)(dian)壓(ya)(ya)(ya)等(deng)級較(jiao)合理。

表2 110kV、66kV和35kV設備(bei)的信(xin)息價表 萬元

5.結語

隨著國民經濟的(de)(de)持續、高速發展。電(dian)(dian)(dian)(dian)網(wang)建(jian)設(she)出現大容量、高密(mi)度供電(dian)(dian)(dian)(dian)需求的(de)(de)新形勢(shi)，特別在“十二五”期(qi)間，電(dian)(dian)(dian)(dian)網(wang)的(de)(de)發展呈現超大變(bian)電(dian)(dian)(dian)(dian)容量的(de)(de)趨勢(shi)更加突出。大容量變(bian)壓(ya)(ya)(ya)器的(de)(de)應用(yong)的(de)(de)逐步普及，為節(jie)省變(bian)電(dian)(dian)(dian)(dian)站占地面積(ji)、節(jie)省送電(dian)(dian)(dian)(dian)線路(lu)走廊，提高輸(shu)變(bian)電(dian)(dian)(dian)(dian)的(de)(de)可靠性，解決(jue)大容量、高密(mi)度輸(shu)變(bian)電(dian)(dian)(dian)(dian)的(de)(de)問題(ti)提供一個(ge)有(you)效、可行的(de)(de)解決(jue)方案。500kV兩江站采用(yong)1500MVA變(bian)壓(ya)(ya)(ya)器，綜合電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)波(bo)動、設(she)備電(dian)(dian)(dian)(dian)動力和設(she)備制造(zao)力和變(bian)壓(ya)(ya)(ya)器自身(shen)的(de)(de)經濟性，變(bian)壓(ya)(ya)(ya)器低壓(ya)(ya)(ya)側推薦采用(yong)66kV電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)等級。

參考文獻

[1]葉軍，張焰，陳承.上海220kV大容量變電(dian)所適用(yong)前(qian)景[J].供用(yong)電(dian)，2006，23（6）：19-21.

[2]孫景強，陳志剛，楊洪(hong)平等.大容(rong)量變(bian)壓器應用時的問題集(ji)應對(dui)措施[J].電網技術，2008，29（10）：22-25.

篇3

關鍵詞：三(san)相(xiang)低壓異步電(dian)動(dong)機(ji) 無功補(bu)償電(dian)容(rong)器

1 概述



異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)功率(lv)因(yin)數很低(di)(di)，在(zai)電(dian)(dian)(dian)網(wang)負(fu)荷(he)(he)中(zhong)(zhong)異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)所(suo)占的(de)(de)(de)比重較大(da)，是城鄉電(dian)(dian)(dian)網(wang)的(de)(de)(de)主(zhu)要無(wu)功負(fu)荷(he)(he)。它使各級網(wang)損(sun)也(ye)相(xiang)應(ying)增大(da)，盡管在(zai)各級變(bian)電(dian)(dian)(dian)所(suo)、配(pei)電(dian)(dian)(dian)變(bian)及各廠礦企業內(nei)均裝(zhuang)有(you)集(ji)中(zhong)(zhong)無(wu)功補(bu)(bu)償裝(zhuang)置(zhi)來(lai)提高(gao)功率(lv)因(yin)數，減(jian)少電(dian)(dian)(dian)網(wang)線(xian)損(sun)，但集(ji)中(zhong)(zhong)補(bu)(bu)償不僅無(wu)法降低(di)(di)低(di)(di)壓(ya)(ya)電(dian)(dian)(dian)網(wang)的(de)(de)(de)線(xian)損(sun)，而且(qie)價格(ge)較貴。特(te)別是在(zai)鄉鎮(zhen)，隨著鄉鎮(zhen)經濟的(de)(de)(de)發展，小(xiao)型(xing)家庭(ting)式的(de)(de)(de)生產方式在(zai)各地(di)較為普(pu)遍，家庭(ting)織機(ji)(ji)(ji)、小(xiao)型(xing)砧(zhen)床(chuang)、車床(chuang)、沖床(chuang)、碾米機(ji)(ji)(ji)、脫粒機(ji)(ji)(ji)等到處都有(you)，加上用戶分(fen)散，低(di)(di)壓(ya)(ya)網(wang)絡較長(chang)，采用集(ji)中(zhong)(zhong)無(wu)功補(bu)(bu)償，仍不能(neng)降低(di)(di)低(di)(di)壓(ya)(ya)電(dian)(dian)(dian)網(wang)的(de)(de)(de)線(xian)損(sun)。低(di)(di)壓(ya)(ya)電(dian)(dian)(dian)網(wang)的(de)(de)(de)高(gao)線(xian)損(sun)率(lv)對(dui)正在(zai)實施的(de)(de)(de)城鄉電(dian)(dian)(dian)網(wang)同(tong)(tong)網(wang)同(tong)(tong)價政策帶(dai)來(lai)困難，因(yin)此，必(bi)須對(dui)鄉鎮(zhen)家庭(ting)的(de)(de)(de)異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)推廣低(di)(di)價的(de)(de)(de)就地(di)無(wu)功補(bu)(bu)償。三相(xiang)低(di)(di)壓(ya)(ya)異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)就地(di)無(wu)功補(bu)(bu)償就是一(yi)臺與(yu)異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)特(te)性相(xiang)配(pei)合的(de)(de)(de)電(dian)(dian)(dian)容器直接并聯于(yu)該電(dian)(dian)(dian)動機(ji)(ji)(ji)，其(qi)保(bao)護僅利(li)用原異(yi)步電(dian)(dian)(dian)動機(ji)(ji)(ji)的(de)(de)(de)保(bao)護，不需要外加其(qi)它保(bao)護裝(zhuang)置(zhi)。

為實施城鄉電網同(tong)網同(tong)價，應大力推廣(guang)異步電動(dong)機就地無功補償，建議電容器制造廠家應生(sheng)產與異步電動(dong)機相配套的產品。

2 三相(xiang)低壓異步電動(dong)機就地無功補償的(de)好處(chu)

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用(yong)(yong)三相低(di)壓異步電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)就地(di)無(wu)功(gong)(gong)補(bu)償(chang)有以下好(hao)(hao)處：①簡單(dan)、價低(di)。因(yin)為(wei)只是在電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)上并聯(lian)一臺合適(shi)的(de)(de)(de)專用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器就可，不需要(yao)外(wai)加(jia)其它(ta)保護裝置，便于推廣；②不僅能提(ti)高低(di)壓電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)的(de)(de)(de)功(gong)(gong)率因(yin)數(shu)(shu)，降低(di)了線(xian)(xian)損(sun)，同(tong)時(shi)也提(ti)高了供電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)的(de)(de)(de)功(gong)(gong)率因(yin)數(shu)(shu)，降低(di)了配(pei)(pei)電(dian)(dian)(dian)(dian)(dian)(dian)網(wang)線(xian)(xian)損(sun)；③對用(yong)(yong)戶來講，節約了內線(xian)(xian)損(sun)耗，減少電(dian)(dian)(dian)(dian)(dian)(dian)費，同(tong)時(shi)可以不會因(yin)功(gong)(gong)率因(yin)數(shu)(shu)不合格而罰款(這對各(ge)廠礦企業內的(de)(de)(de)異步電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)也同(tong)樣)。裝置三相低(di)壓異步電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)專用(yong)(yong)無(wu)功(gong)(gong)補(bu)償(chang)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器，具(ju)有較好(hao)(hao)的(de)(de)(de)經濟效益；④提(ti)高了低(di)壓線(xian)(xian)路(lu)的(de)(de)(de)功(gong)(gong)率因(yin)數(shu)(shu)，減少末(mo)端電(dian)(dian)(dian)(dian)(dian)(dian)壓波動(dong)(dong)，改善了用(yong)(yong)戶的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓，提(ti)高了電(dian)(dian)(dian)(dian)(dian)(dian)壓質(zhi)量(liang)，也增(zeng)加(jia)了產品數(shu)(shu)量(liang)及質(zhi)量(liang)；⑤因(yin)為(wei)補(bu)償(chang)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器隨電(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)投切，只要(yao)補(bu)償(chang)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)器容(rong)(rong)量(liang)配(pei)(pei)置適(shi)當，不存在無(wu)功(gong)(gong)過補(bu)償(chang)，有較為(wei)理想(xiang)的(de)(de)(de)補(bu)償(chang)效果(guo)。

用三相低壓異(yi)步電(dian)(dian)動(dong)機(ji)就地無(wu)功(gong)補償是(shi)一種經濟(ji)、簡單、高效、可靠的(de)(de)無(wu)功(gong)補償方(fang)法，應在(zai)廣大的(de)(de)鄉鎮和工礦企業推廣。為(wei)什么一個合(he)適(shi)容量的(de)(de)電(dian)(dian)容器可以與異(yi)步電(dian)(dian)動(dong)機(ji)直接并(bing)聯，而不需要(yao)外加其它(ta)保護裝置，僅利用原異(yi)步電(dian)(dian)動(dong)機(ji)的(de)(de)保護就可，而且是(shi)一種經濟(ji)的(de)(de)無(wu)功(gong)補償。這是(shi)因為(wei)：

①異(yi)(yi)步電動(dong)機在運行時(shi)所(suo)(suo)需(xu)要(yao)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)從(cong)異(yi)(yi)步電動(dong)機的(de)等效電路(lu)中可知由兩部分(fen)(fen)組成(cheng)：一部分(fen)(fen)是(shi)勵磁支(zhi)路(lu)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)；另一部分(fen)(fen)是(shi)負(fu)(fu)(fu)荷支(zhi)路(lu)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)。小(xiao)(xiao)容(rong)量(liang)的(de)異(yi)(yi)步電動(dong)機主要(yao)是(shi)勵磁支(zhi)路(lu)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)，當負(fu)(fu)(fu)荷從(cong)由零到(dao)滿載(zai)(zai)時(shi)，其變(bian)化(hua)(hua)很(hen)小(xiao)(xiao)，隨負(fu)(fu)(fu)荷的(de)增加而(er)略(lve)有下(xia)降(jiang)；而(er)負(fu)(fu)(fu)荷支(zhi)路(lu)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)隨負(fu)(fu)(fu)荷增加而(er)增加，其值(zhi)一般要(yao)比勵磁支(zhi)路(lu)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)要(yao)小(xiao)(xiao)，異(yi)(yi)步電動(dong)機容(rong)量(liang)越小(xiao)(xiao)，相對的(de)比例(li)也越小(xiao)(xiao)。小(xiao)(xiao)容(rong)量(liang)的(de)異(yi)(yi)步電動(dong)機從(cong)空(kong)載(zai)(zai)到(dao)滿載(zai)(zai)，其總的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)的(de)變(bian)化(hua)(hua)不(bu)大，以(yi)Y801.2(0.75kW)為例(li)，空(kong)載(zai)(zai)時(shi)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)為0.531kvar，而(er)滿載(zai)(zai)時(shi)為0.646kvar。表1為幾種小(xiao)(xiao)容(rong)量(liang)Y型異(yi)(yi)步電動(dong)機在不(bu)同的(de)負(fu)(fu)(fu)載(zai)(zai)率(lv)(lv)(lv)(lv)下(xia)所(suo)(suo)需(xu)的(de)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)。從(cong)表中可知，容(rong)量(liang)小(xiao)(xiao)所(suo)(suo)需(xu)無(wu)功(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)率(lv)(lv)(lv)(lv)在不(bu)同的(de)負(fu)(fu)(fu)載(zai)(zai)下(xia)變(bian)化(hua)(hua)很(hen)小(xiao)(xiao)。

異步(bu)(bu)電(dian)動(dong)機隨著容(rong)量的(de)增大(da)，從(cong)空載(zai)(zai)到(dao)滿載(zai)(zai)所(suo)需(xu)的(de)總無(wu)(wu)功(gong)功(gong)率變(bian)化(hua)相應加大(da)，如Y165L-2(18.5kW)，空載(zai)(zai)時(shi)所(suo)需(xu)無(wu)(wu)功(gong)功(gong)率5.343kvar，而滿載(zai)(zai)時(shi)為10.651kvar。但(dan)一般(ban)空載(zai)(zai)與(yu)滿載(zai)(zai)的(de)無(wu)(wu)功(gong)功(gong)率之(zhi)比約為0.5以上(shang)。因(yin)此，對低(di)壓異步(bu)(bu)電(dian)動(dong)機的(de)無(wu)(wu)功(gong)補(bu)償(chang)，其(qi)并聯電(dian)容(rong)器在運行時(shi)的(de)實際補(bu)償(chang)容(rong)量，只要能(neng)補(bu)償(chang)其(qi)勵磁功(gong)率，就能(neng)使異步(bu)(bu)電(dian)動(dong)機運行的(de)功(gong)率因(yin)數(shu)在負載(zai)(zai)率從(cong)40%～100%都有較高值(0.9以上(shang))，而低(di)負載(zai)(zai)時(shi)，其(qi)功(gong)率因(yin)數(shu)雖不(bu)能(neng)達到(dao)0.9左右，但(dan)由于所(suo)需(xu)的(de)無(wu)(wu)功(gong)功(gong)率量很(hen)小，因(yin)此產生的(de)線損(sun)不(bu)大(da)，而比無(wu)(wu)補(bu)償(chang)時(shi)降低(di)了很(hen)多。

②由于異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)本(ben)身就是(shi)很(hen)好的放電(dian)(dian)(dian)(dian)線圈，所以在(zai)異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)外加電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓(ya)失(shi)去時，三相低壓(ya)異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)專用(yong)無功補償電(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)可以向異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)放電(dian)(dian)(dian)(dian)，使(shi)電(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)端電(dian)(dian)(dian)(dian)壓(ya)很(hen)快下降到零，在(zai)電(dian)(dian)(dian)(dian)網(wang)電(dian)(dian)(dian)(dian)壓(ya)復現(電(dian)(dian)(dian)(dian)網(wang)“重(zhong)合閘(zha)”成功)時，就不(bu)會出(chu)現過電(dian)(dian)(dian)(dian)壓(ya)。因此，異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)與電(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)并聯之間不(bu)能加裝熔斷器(qi)(qi)保護或(huo)(huo)開關，異步(bu)電(dian)(dian)(dian)(dian)動(dong)機(ji)與電(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)應(ying)同時投入或(huo)(huo)斷開。

③由于并聯電(dian)容器(qi)(qi)在(zai)異(yi)步電(dian)動(dong)(dong)機(ji)(ji)的(de)(de)(de)(de)(de)額定電(dian)壓下，所產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)小(xiao)于異(yi)步電(dian)動(dong)(dong)機(ji)(ji)在(zai)額定電(dian)壓下空載(zai)時(shi)需(xu)要(yao)的(de)(de)(de)(de)(de)勵磁功(gong)(gong)(gong)(gong)(gong)率(lv)(略(lve)小(xiao)于空載(zai)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv))。當(dang)電(dian)壓上升時(shi)，電(dian)容器(qi)(qi)所產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)隨電(dian)壓的(de)(de)(de)(de)(de)平(ping)方(fang)增(zeng)加，而異(yi)步電(dian)動(dong)(dong)機(ji)(ji)因(yin)鐵(tie)芯(xin)的(de)(de)(de)(de)(de)磁飽和(he)，其需(xu)要(yao)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)增(zeng)加將大于電(dian)容器(qi)(qi)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)增(zeng)加；當(dang)電(dian)壓下降時(shi)，異(yi)步電(dian)動(dong)(dong)機(ji)(ji)和(he)電(dian)容器(qi)(qi)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)幾乎(hu)都將隨電(dian)壓的(de)(de)(de)(de)(de)平(ping)方(fang)下降。因(yin)此(ci)，并聯電(dian)容器(qi)(qi)的(de)(de)(de)(de)(de)補償(chang)容量在(zai)運(yun)行(xing)時(shi)所產(chan)生(sheng)(sheng)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)，總(zong)小(xiao)于異(yi)步電(dian)動(dong)(dong)機(ji)(ji)的(de)(de)(de)(de)(de)不同負載(zai)下所需(xu)的(de)(de)(de)(de)(de)無(wu)(wu)(wu)功(gong)(gong)(gong)(gong)(gong)功(gong)(gong)(gong)(gong)(gong)率(lv)。因(yin)此(ci)，不會產(chan)生(sheng)(sheng)過補償(chang)。

④由于電容器(qi)的無功(gong)(gong)功(gong)(gong)率比補償(chang)異步電動(dong)機空載無功(gong)(gong)功(gong)(gong)率要略小(xiao)于一(yi)點，也就(jiu)是(shi)說僅(jin)為勵磁功(gong)(gong)率，因(yin)此，也就(jiu)不會(hui)產生異步電動(dong)機的自勵現象。其現象可(ke)用(yong)圖2來(lai)分析。

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QC1、QC2、QC3為(wei)(wei)三相(xiang)(xiang)低壓(ya)(ya)(ya)(ya)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)就地無功(gong)補償電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線，在運行電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)為(wei)(wei)E1B時，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)無功(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)分別為(wei)(wei)I0C、I0B、I0A，其(qi)中(zhong)I0B就是(shi)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，I0C大(da)(da)于(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)I0B、I0A，小(xiao)于(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)I0B。若電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線為(wei)(wei)QC3，當異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)與(yu)(yu)專用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源斷(duan)開后(hou)，為(wei)(wei)簡化(hua)分析，假定(ding)不(bu)(bu)考(kao)慮異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)負(fu)載和損耗(hao)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)損耗(hao)，由(you)(you)于(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)定(ding)子(zi)、轉子(zi)鐵芯的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)回(hui)路殘存的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)場產生(sheng)的(de)(de)(de)(de)微(wei)小(xiao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)E0，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)產生(sheng)微(wei)弱進相(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)進相(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)又(you)(you)促(cu)使(shi)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)通(tong)增(zeng)(zeng)大(da)(da)，而(er)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)的(de)(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)通(tong)增(zeng)(zeng)大(da)(da)又(you)(you)使(shi)其(qi)產生(sheng)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)增(zeng)(zeng)大(da)(da)，異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)磁(ci)(ci)(ci)(ci)(ci)場產生(sheng)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)增(zeng)(zeng)大(da)(da)，又(you)(you)使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)進相(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)進一步(bu)(bu)增(zeng)(zeng)大(da)(da)，這樣，異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)磁(ci)(ci)(ci)(ci)(ci)場產生(sheng)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)進相(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)反復相(xiang)(xiang)互(hu)作(zuo)用，使(shi)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)所(suo)(suo)感(gan)應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)從K點(dian)(dian)不(bu)(bu)斷(duan)呈階(jie)梯上升到(dao)(dao)C點(dian)(dian)(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線QC3與(yu)(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)磁(ci)(ci)(ci)(ci)(ci)飽和曲(qu)線交(jiao)點(dian)(dian))，達到(dao)(dao)相(xiang)(xiang)應E1C，而(er)E1C大(da)(da)大(da)(da)超過異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)E1B，這就是(shi)自勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)現(xian)(xian)象(xiang)。由(you)(you)于(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)在空載的(de)(de)(de)(de)情況下(xia)，也有損耗(hao)，因此，勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)所(suo)(suo)感(gan)應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)實際上將(jiang)比E1C要低。如(ru)果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線為(wei)(wei)QC1、QC2，即使(shi)不(bu)(bu)考(kao)慮異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)負(fu)載和損耗(hao)、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)損耗(hao)，其(qi)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)所(suo)(suo)感(gan)應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)從K點(dian)(dian)不(bu)(bu)斷(duan)呈現(xian)(xian)階(jie)梯上升到(dao)(dao)A(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線QC1與(yu)(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)磁(ci)(ci)(ci)(ci)(ci)飽和曲(qu)線交(jiao)點(dian)(dian))或B(電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)曲(qu)線QC2與(yu)(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)磁(ci)(ci)(ci)(ci)(ci)飽和曲(qu)線交(jiao)點(dian)(dian))點(dian)(dian)，達到(dao)(dao)相(xiang)(xiang)應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)E1A、E1B，就不(bu)(bu)可能出現(xian)(xian)勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)所(suo)(suo)感(gan)應電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)高于(yu)異(yi)步(bu)(bu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)動(dong)(dong)(dong)(dong)(dong)機(ji)(ji)(ji)(ji)(ji)與(yu)(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)容(rong)(rong)(rong)器(qi)(qi)的(de)(de)(de)(de)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)(de)自勵(li)(li)磁(ci)(ci)(ci)(ci)(ci)現(xian)(xian)象(xiang)。

從上可知，只(zhi)要電(dian)(dian)容器僅補償異(yi)(yi)步電(dian)(dian)動機的(de)勵磁功率，就不會(hui)產生異(yi)(yi)步電(dian)(dian)動機的(de)自勵磁現象。

⑤對于(yu)家庭式的(de)(de)(de)(de)(de)異步電(dian)動機(ji)采用(yong)三相(xiang)低(di)(di)壓異步電(dian)動機(ji)就地(di)無(wu)(wu)功(gong)補(bu)償(chang)(chang)的(de)(de)(de)(de)(de)經(jing)濟(ji)性(xing)是(shi)明顯的(de)(de)(de)(de)(de)，因(yin)為(wei)(wei)它(ta)比其(qi)他(ta)復(fu)雜的(de)(de)(de)(de)(de)無(wu)(wu)功(gong)補(bu)償(chang)(chang)要(yao)便宜得(de)很(hen)多。就是(shi)對無(wu)(wu)功(gong)負(fu)荷僅(jin)為(wei)(wei)異步電(dian)動機(ji)的(de)(de)(de)(de)(de)工礦(kuang)、企業(ye)等也是(shi)經(jing)濟(ji)的(de)(de)(de)(de)(de)，因(yin)為(wei)(wei)雖然它(ta)裝置(zhi)的(de)(de)(de)(de)(de)總(zong)無(wu)(wu)功(gong)容(rong)量要(yao)為(wei)(wei)集中(zhong)的(de)(de)(de)(de)(de)無(wu)(wu)功(gong)裝置(zhi)的(de)(de)(de)(de)(de)3～4倍，但集中(zhong)無(wu)(wu)功(gong)補(bu)償(chang)(chang)裝置(zhi)的(de)(de)(de)(de)(de)單位容(rong)量的(de)(de)(de)(de)(de)費(fei)用(yong)卻為(wei)(wei)單臺電(dian)容(rong)器(qi)的(de)(de)(de)(de)(de)4～6倍左(zuo)右，異步電(dian)動機(ji)就地(di)無(wu)(wu)功(gong)補(bu)償(chang)(chang)總(zong)費(fei)用(yong)要(yao)比集中(zhong)的(de)(de)(de)(de)(de)無(wu)(wu)功(gong)補(bu)償(chang)(chang)裝置(zhi)少(shao)。而(er)且用(yong)三相(xiang)低(di)(di)壓異步電(dian)動機(ji)就地(di)無(wu)(wu)功(gong)補(bu)償(chang)(chang)電(dian)容(rong)器(qi)可降低(di)(di)工礦(kuang)、企業(ye)內的(de)(de)(de)(de)(de)低(di)(di)壓電(dian)網損(sun)失，節約了能源，減少(shao)了電(dian)費(fei)支出(chu)。

⑥三相(xiang)低壓異步(bu)電(dian)動機就地(di)無功(gong)補償(chang)電(dian)容器(qi)可選(xuan)用(yong)常(chang)用(yong)的低壓自愈(yu)式金(jin)(jin)屬化(hua)膜電(dian)容器(qi)，該(gai)電(dian)容器(qi)以金(jin)(jin)屬化(hua)聚(ju)丙(bing)烯薄膜作電(dian)極和介質，其產品(pin)(pin)具有(you)自愈(yu)性，并且有(you)重量輕(qing)、體積小、損耗低等(deng)優點，特(te)別是價(jia)格(ge)低。考慮到鄉鎮電(dian)網電(dian)壓波動較大，后半(ban)夜稍偏(pian)高，加上無功(gong)補償(chang)后，電(dian)壓要相(xiang)應提高一點，電(dian)容器(qi)的額定電(dian)壓宜選(xuan)用(yong)常(chang)規的400V產品(pin)(pin)。但要求電(dian)容器(qi)接線端(duan)子、引線等(deng)帶電(dian)體不能外露(lu)，以保安(an)全。

綜合以上(shang)所說，可(ke)(ke)明顯得出(chu)：三相低(di)(di)壓異步(bu)(bu)電動機(ji)(ji)就地無(wu)功補償(chang)是一(yi)種經濟(ji)、簡單、高效、可(ke)(ke)靠(kao)的(de)(de)無(wu)功補償(chang)方(fang)法，不僅適(shi)合鄉鎮(zhen)分散的(de)(de)加(jia)工業(ye)、家(jia)庭式工業(ye)內裝(zhuang)(zhuang)置的(de)(de)異步(bu)(bu)電動機(ji)(ji)，而且(qie)對(dui)工礦的(de)(de)異步(bu)(bu)電動機(ji)(ji)也同樣適(shi)合。它是降低(di)(di)低(di)(di)壓供電網和電表(biao)后的(de)(de)內線損耗的(de)(de)最有效方(fang)法。曾(ceng)在杭州市余杭區、臨安縣(xian)的(de)(de)農村家(jia)庭每臺織(zhi)機(ji)(ji)中裝(zhuang)(zhuang)置三相低(di)(di)壓異步(bu)(bu)電動機(ji)(ji)就地無(wu)功補償(chang)電容器(qi)，取得了較為理想的(de)(de)效果。

3 Y系(xi)列(lie)、J02系(xi)列(lie)常用小型(xing)三相(xiang)異步電(dian)動機就地無功補(bu)償電(dian)容器(qi)配(pei)置容量

由于(yu)異步(bu)電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)補(bu)償(chang)電(dian)(dian)(dian)(dian)(dian)容(rong)器容(rong)量(liang)(liang)要根據各種規(gui)格(ge)(ge)電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)，在不同(tong)(tong)負(fu)載下所需的(de)(de)無(wu)功(gong)(gong)功(gong)(gong)率以及電(dian)(dian)(dian)(dian)(dian)容(rong)器容(rong)量(liang)(liang)誤差等因(yin)素來(lai)選(xuan)擇，不能簡單(dan)地用0.4乘電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)額定(ding)容(rong)量(liang)(liang)來(lai)確定(ding)。這因(yin)為不同(tong)(tong)系(xi)列、不同(tong)(tong)容(rong)量(liang)(liang)、不同(tong)(tong)極數其空載的(de)(de)無(wu)功(gong)(gong)功(gong)(gong)率與電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)額定(ding)功(gong)(gong)率之比相(xiang)差是(shi)很大(da)的(de)(de)，從表1中可明顯(xian)看(kan)出(chu)。三相(xiang)低壓(ya)(ya)異步(bu)電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)專用無(wu)功(gong)(gong)補(bu)償(chang)電(dian)(dian)(dian)(dian)(dian)容(rong)器容(rong)量(liang)(liang)的(de)(de)選(xuan)擇既要考(kao)(kao)慮到(dao)盡量(liang)(liang)減少(shao)不同(tong)(tong)規(gui)格(ge)(ge)數量(liang)(liang)，要考(kao)(kao)慮一種規(gui)格(ge)(ge)盡可能多適用于(yu)幾種異步(bu)電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)型號，同(tong)(tong)時(shi)又要保證異步(bu)電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)在不同(tong)(tong)的(de)(de)負(fu)載時(shi)功(gong)(gong)率因(yin)數滿(man)足補(bu)償(chang)要求和(he)不發生自勵磁現象的(de)(de)過電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。

表2、表3為Y系列、JO2系列常用小型三相異步電動機(15kW及以下(xia))就地(di)無(wu)功補償電容器(qi)容量(liang)配置表，是(shi)根據(ju)各異步電動機在不同負載下(xia)所(suo)需的(de)(de)無(wu)功功率選擇的(de)(de)，對(dui)改(gai)善(shan)功率因(yin)數的(de)(de)效果是(shi)滿意的(de)(de)。

4 結論

異步電(dian)(dian)動(dong)機(ji)就地無功(gong)(gong)補償是一種(zhong)經濟(ji)、簡單、高效、可(ke)靠的無功(gong)(gong)補償方法，應(ying)在(zai)廣大(da)的鄉(xiang)鎮(zhen)和工礦企業(ye)推(tui)廣。建議電(dian)(dian)容(rong)器(qi)制造廠家(jia)應(ying)生產與(yu)異步電(dian)(dian)動(dong)機(ji)相配套的產品；異步電(dian)(dian)動(dong)機(ji)的制造廠家(jia)應(ying)在(zai)設計上考(kao)慮專(zhuan)用補償電(dian)(dian)容(rong)器(qi)的安裝(zhuang)位置；供電(dian)(dian)部門(men)應(ying)制定相應(ying)規定，大(da)力推(tui)廣異步電(dian)(dian)動(dong)機(ji)無功(gong)(gong)補償，以降低低壓電(dian)(dian)網線損。

參考文獻

［1］閻國華，閻恩剛.三相異步(bu)電動(dong)機經濟運行速查(cha)表［M］.北京(jing)：機械工業出版社(she)，1993

［2］吉(ji)林省電機工程學會(hui)，吉(ji)林省電力試驗研究所編(bian)譯.功率(lv)因(yin)數調(diao)整(zheng)技(ji)術(shu)［M］.長春：吉(ji)林科學技(ji)術(shu)出版社，1991

［3］陳(chen)丕璋，周明定，俞鑫昌. 電動機節能技術［M］北(bei)京： 科學出版社，1989.

篇4

一、磁電機的組成

磁電(dian)機由磁鐵轉(zhuan)子、導磁架、線包(bao)和(he)軟鐵芯、電(dian)容器(qi)、斷(duan)電(dian)器(qi)、分電(dian)器(qi)和(he)殼(ke)體組成。如圖1所示。

二、磁電(dian)機的(de)工(gong)作(zuo)原理

磁(ci)電(dian)機產(chan)生高壓(ya)電(dian)是(shi)分兩步進行(xing)的(de)。第一步是(shi)產(chan)生低(di)壓(ya)電(dian)，即改變穿過初級(ji)線(xian)圈的(de)磁(ci)通而使初級(ji)線(xian)圈感應(ying)出(chu)低(di)壓(ya)電(dian)，稱為初級(ji)電(dian)勢;第二步是(shi)把低(di)壓(ya)電(dian)變成高壓(ya)電(dian)，即在適當(dang)的(de)時機斷開(kai)低(di)壓(ya)電(dian)路，使初級(ji)線(xian)圈的(de)感應(ying)電(dian)流(liu)和伴(ban)隨感應(ying)電(dian)流(liu)而產(chan)生的(de)感應(ying)電(dian)磁(ci)場迅速消失，使鐵芯磁(ci)通發生劇烈的(de)變化，從而使次級(ji)線(xian)圈感應(ying)而產(chan)生高壓(ya)電(dian)。

三、低壓電如何變高壓電

初(chu)級(ji)線(xian)(xian)圈(quan)(quan)感(gan)應(ying)電(dian)(dian)(dian)(dian)磁(ci)(ci)通的(de)(de)(de)(de)(de)變化固然可(ke)以(yi)使次(ci)級(ji)線(xian)(xian)圈(quan)(quan)產生(sheng)感(gan)應(ying)電(dian)(dian)(dian)(dian)勢(shi)(shi)(shi)，但由于磁(ci)(ci)通的(de)(de)(de)(de)(de)變化率較小，次(ci)級(ji)線(xian)(xian)圈(quan)(quan)的(de)(de)(de)(de)(de)感(gan)應(ying)電(dian)(dian)(dian)(dian)勢(shi)(shi)(shi)不高(gao)，不足(zu)以(yi)使電(dian)(dian)(dian)(dian)嘴產生(sheng)電(dian)(dian)(dian)(dian)火花(hua)。因此，就(jiu)要采(cai)用(yong)在適當瞬時(shi)(shi)斷開電(dian)(dian)(dian)(dian)路的(de)(de)(de)(de)(de)方(fang)法，即在初(chu)級(ji)線(xian)(xian)圈(quan)(quan)感(gan)應(ying)電(dian)(dian)(dian)(dian)流(liu)最大(da)的(de)(de)(de)(de)(de)時(shi)(shi)刻即感(gan)應(ying)電(dian)(dian)(dian)(dian)磁(ci)(ci)通達到最大(da)值的(de)(de)(de)(de)(de)時(shi)(shi)刻斷電(dian)(dian)(dian)(dian)，能最大(da)限度地提高(gao)次(ci)級(ji)線(xian)(xian)圈(quan)(quan)的(de)(de)(de)(de)(de)感(gan)應(ying)電(dian)(dian)(dian)(dian)勢(shi)(shi)(shi)。從而(er)能產生(sheng)15000V-20000V的(de)(de)(de)(de)(de)高(gao)壓電(dian)(dian)(dian)(dian)，保證電(dian)(dian)(dian)(dian)嘴處(chu)能擊穿空氣隙而(er)形成電(dian)(dian)(dian)(dian)火花(hua)。

斷(duan)(duan)電的任務由磁(ci)電機的斷(duan)(duan)電器來(lai)完成。

四、電容器的工作

在(zai)低壓電路斷電時，初級(ji)線圈自己也會產生相當高的自感電勢，300V-500V，且(qie)觸頭(tou)間的間隙很小，很容易產生較強烈的電火花。

會導致：

1.燒壞觸頭;

2.斷電時電流(liu)不(bu)能立即(ji)中斷而仍按原來的方向流(liu)動，因而初級線(xian)圈的感(gan)應(ying)電磁通的變化率減小，會(hui)削弱(ruo)次級線(xian)圈的感(gan)應(ying)電勢。

為了盡可(ke)能的消(xiao)除在(zai)斷(duan)電(dian)(dian)時初(chu)級線圈(quan)自感應電(dian)(dian)勢(shi)所造成(cheng)的不良后果，在(zai)磁電(dian)(dian)機(ji)(ji)的低(di)壓電(dian)(dian)路上安(an)裝電(dian)(dian)容器(qi)。電(dian)(dian)容器(qi)與(yu)斷(duan)電(dian)(dian)器(qi)觸頭并聯，一端與(yu)初(chu)級線圈(quan)連(lian)接(jie)，另一端與(yu)磁電(dian)(dian)機(ji)(ji)殼體搭鐵。

安裝電(dian)容(rong)器(qi)后，當觸(chu)頭剛(gang)(gang)剛(gang)(gang)分離(li)時，可向電(dian)容(rong)器(qi)充電(dian)，就不足以產生火花;當電(dian)容(rong)器(qi)電(dian)壓(ya)升高以后，觸(chu)頭間的間隙也變大，火花則大為(wei)減(jian)弱(ruo);火花的減(jian)弱(ruo)，意味著(zhu)電(dian)流迅(xun)速消失，因而鐵芯磁(ci)通變化率增大，次級感應電(dian)勢也就提高了。

電容器可以(yi)減(jian)弱電火花，但(dan)不能根本消除。因(yin)此還(huan)需時常注(zhu)意(yi)觸頭的燒傷程度，定期進行擦拭(shi)。

五、磁電機開關

磁電機開關用來(lai)控制(zhi)磁電機的工作。

磁電機開關的工作情況如下（A/B型機相同）：

1.磁(ci)電(dian)(dian)機(ji)(ji)開(kai)關在“OFF”位時，左(zuo)、右(you)磁(ci)電(dian)(dian)機(ji)(ji)的(de)電(dian)(dian)容線通過磁(ci)電(dian)(dian)機(ji)(ji)開(kai)關接(jie)地，左(zuo)、右(you)磁(ci)電(dian)(dian)機(ji)(ji)均不工作;

2.磁(ci)(ci)(ci)電機開關在“L”（左(zuo)磁(ci)(ci)(ci)）位時(shi)，左(zuo)磁(ci)(ci)(ci)電機電容線與地斷(duan)開，左(zuo)磁(ci)(ci)(ci)正(zheng)常(chang)工(gong)作(zuo)，此時(shi)右磁(ci)(ci)(ci)不工(gong)作(zuo);

3.磁電機開(kai)關在(zai)“R”（右磁）位時，右磁電機電容線與地斷開(kai)，右磁正常(chang)工作(zuo)，此時左磁不(bu)工作(zuo);

4.磁(ci)(ci)電(dian)機開(kai)關(guan)在“BOTH”（雙磁(ci)(ci)）位時，左、右(you)磁(ci)(ci)電(dian)機的電(dian)容線均與地(di)斷開(kai)，左、右(you)磁(ci)(ci)電(dian)機正常工作(zuo);

5.磁電(dian)機(ji)(ji)開關在“START”（起(qi)(qi)動）位時，起(qi)(qi)動繼電(dian)器吸合，起(qi)(qi)動機(ji)(ji)工作;此時左右磁電(dian)機(ji)(ji)相(xiang)當于開關位于雙磁位時的狀(zhuang)況，均正(zheng)常工作。

六(liu)、磁(ci)電(dian)機電(dian)子(zi)線路常見故障(zhang)

1.電(dian)容線在接線片(pian)根部斷(duan)，此時該磁(ci)(ci)電(dian)機(ji)無(wu)法(fa)關閉，現象為試車檢查時，該磁(ci)(ci)電(dian)機(ji)不掉轉。

2.誤將屏(ping)蔽線(xian)或滑油(you)溫(wen)度接(jie)(jie)地線(xian)接(jie)(jie)到(dao)磁電機(ji)的電容(rong)線(xian)上，此時，該(gai)磁電機(ji)不工(gong)作。

3.電容線(xian)與屏(ping)蔽線(xian)短(duan)路，此時，該磁電機不工(gong)作。

篇5

關鍵詞：無功功率補償 的(de)技術經(jing)濟 特點(dian)

交(jiao)流異步(bu)電(dian)(dian)(dian)機(ji)(ji)(ji)在工業與民用(yong)建筑系統中(zhong)應用(yong)廣(guang)泛。在民用(yong)范圍(wei)中(zhong)運行(xing)機(ji)(ji)(ji)械多為連續運行(xing)，不調速，操作不頻繁的(de)(de)場(chang)合(he)，如風機(ji)(ji)(ji)、水(shui)泵、冷凍機(ji)(ji)(ji)多為結構簡單，易(yi)維護的(de)(de)異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)。在工礦企業中(zhong)，不少電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)負(fu)荷率(lv)(lv)低(di)，經常(chang)處于(yu)輕載(zai)(zai)或空(kong)載(zai)(zai)狀(zhuang)態，功(gong)率(lv)(lv)因(yin)數普遍不高(gao)。負(fu)荷率(lv)(lv)低(di)，則功(gong)率(lv)(lv)因(yin)數愈(yu)低(di)，無(wu)功(gong)功(gong)率(lv)(lv)相對于(yu)有功(gong)功(gong)率(lv)(lv)的(de)(de)百(bai)分(fen)比更大(da)，顯著地浪費電(dian)(dian)(dian)能。因(yin)此對異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)(ji)(ji)采用(yong)無(wu)功(gong)功(gong)率(lv)(lv)補償以提高(gao)功(gong)率(lv)(lv)因(yin)數，節約電(dian)(dian)(dian)能，減少運行(xing)費用(yong)，提高(gao)電(dian)(dian)(dian)能質量(liang)，符合(he)我國節約能源的(de)(de)國策，同時亦給企業帶(dai)來經濟效益。

1　無功功率補償(chang)的種類(lei)和特點

1.1　集中補償

在(zai)高(gao)低壓(ya)配電(dian)(dian)所內(nei)(nei)設置(zhi)若干組電(dian)(dian)容(rong)(rong)器(qi)，電(dian)(dian)容(rong)(rong)器(qi)接(jie)在(zai)配電(dian)(dian)母線(xian)(xian)上，補償(chang)供電(dian)(dian)范圍(wei)內(nei)(nei)的無功功率(lv)，如圖1所示。1.2　組合就地補償(chang)(分散就地補償(chang))電(dian)(dian)容(rong)(rong)器(qi)接(jie)在(zai)高(gao)壓(ya)配電(dian)(dian)裝置(zhi)或動力(li)箱(xiang)的母線(xian)(xian)上，對附近(jin)的電(dian)(dian)動機(ji)進(jin)行無功補償(chang)，如圖2所示。

1.3　單獨就地補償

將電(dian)容(rong)器(qi)裝于箱內，放置(zhi)在電(dian)動(dong)機(ji)附近，對(dui)其單獨(du)(du)補償(chang)。圖(tu)3為(wei)電(dian)容(rong)器(qi)直接接在電(dian)動(dong)機(ji)端子上或(huo)保護設(she)(she)備(bei)(bei)末端，一般不(bu)需要電(dian)容(rong)器(qi)用(yong)的操(cao)(cao)作(zuo)保護設(she)(she)備(bei)(bei)，稱(cheng)為(wei)直接單獨(du)(du)就(jiu)地(di)補償(chang)。圖(tu)3a為(wei)經(jing)常(chang)操(cao)(cao)作(zuo)者，采(cai)(cai)用(yong)接觸器(qi)；為(wei)非經(jing)常(chang)操(cao)(cao)作(zuo)者，采(cai)(cai)用(yong)空氣斷路器(qi)；為(wei)高(gao)壓電(dian)容(rong)器(qi)直接單獨(du)(du)就(jiu)地(di)補償(chang)，宜(yi)采(cai)(cai)用(yong)真空開關。圖(tu)4為(wei)不(bu)采(cai)(cai)用(yong)控制(zhi)設(she)(she)備(bei)(bei)，由電(dian)動(dong)機(ji)控制(zhi)開關操(cao)(cao)作(zuo)，但電(dian)容(rong)器(qi)必(bi)須采(cai)(cai)用(yong)內裝熔(rong)(rong)絲或(huo)另裝熔(rong)(rong)斷器(qi)。如采(cai)(cai)用(yong)控制(zhi)設(she)(she)備(bei)(bei)，如圖(tu)5所示，為(wei)控制(zhi)式(shi)單獨(du)(du)就(jiu)地(di)補償(chang)，多(duo)用(yong)于降壓起(qi)動(dong)或(huo)有可逆運行(xing)等有特殊操(cao)(cao)作(zuo)要求的電(dian)動(dong)機(ji)。

2　無功(gong)(gong)功(gong)(gong)率補償(chang)的(de)作用(yong)

2.1　改(gai)善功率因(yin)數及相應地減少(shao)電費

根據(ju)國家水電部(bu)，物價局頒布的“功率因數調(diao)整電費(fei)(fei)辦法”規定三(san)種功率因數標(biao)準值，相應(ying)減少電費(fei)(fei)：

(1)高壓供電的用電單位，功率因數(shu)為0.9以(yi)上(shang)。

(2)低壓供電的用電單位(wei)，功率因數(shu)為0.85以上(shang)。

(3)低壓(ya)供電的農(nong)業(ye)用戶，功率(lv)因數為0.8以上。

根據“辦(ban)法”，補償后(hou)的功率因(yin)數以(yi)分別不超出(chu)0.95、0.94、0.92為(wei)宜，因(yin)為(wei)超過(guo)此值，電費并沒(mei)有(you)減少，相反(fan)初次設備增加，是不經濟的。

2.2　降低系(xi)統(tong)的(de)能耗

功(gong)率(lv)因數的提高，能減少線(xian)路損耗及變壓器的銅耗。

設R為(wei)線路(lu)電(dian)阻，ΔP1為(wei)原線路(lu)損(sun)耗(hao)，ΔP2為(wei)功率因(yin)數提高后線路(lu)損(sun)耗(hao)，則線損(sun)減(jian)少

ΔP=ΔP1－ΔP2=3R(I12－I22)(1)

比原(yuan)來損失減少的(de)百(bai)分數為

(ΔP/ΔP1)×100％=1－(I2/I1)2·100％(2)

式中，I1=P/( 3 U1cosφ1)，I2=P/( 3 U2cosφ2)補償后(hou)，由于功率因(yin)數提高(gao)，U2 >U1，為(wei)分析方便，可認為(wei)U2≈U1，則

θ=[1－(cosφ1/cosφ2)2]·100％(3)

當功率因(yin)數從0.8提(ti)高至0.9時，通過上式計算，可求得有功損(sun)耗降(jiang)低21％左(zuo)右。

在輸送(song)功率P= 3UIcosφ不變情況下(xia)，cosφ提高，I相對降低，設I1為補償前變壓器(qi)的電流(liu)，I2為補償后變壓器(qi)的電流(liu)，銅(tong)耗分別為ΔP1，ΔP2；銅(tong)耗與(yu)電流(liu)的平方成正比，即

ΔP1/ΔP2=I22/I12

由于P1=P2，認為U2≈U1時，即

I2/I1=cosφ1/cosφ2

可知，功率因數從0.8提高至0.9時，銅耗(hao)相當于原來(lai)的80％。

2.3　減少(shao)了(le)線路(lu)的壓(ya)降(jiang)

由于(yu)線路傳(chuan)送(song)電(dian)流(liu)小了，系統的線路電(dian)壓(ya)損失相應減小，有利于(yu)系統電(dian)壓(ya)的穩定(輕載(zai)時要防止超前電(dian)流(liu)使電(dian)壓(ya)上升過高)，有利于(yu)大電(dian)機起(qi)動。

2.4　增(zeng)加了(le)供(gong)電功率，減少(shao)了(le)用電貼費

對(dui)于(yu)原有供電設備(bei)來講，同樣的(de)(de)有功功率下，cosφ提高，負荷電流減小，因此向(xiang)負荷傳輸功率所經過(guo)的(de)(de)變壓器、開(kai)關、導線等配電設備(bei)都(dou)增加(jia)了(le)(le)功率儲(chu)備(bei)，發揮了(le)(le)設備(bei)的(de)(de)潛(qian)力。對(dui)于(yu)新建(jian)項目來說，降低了(le)(le)變壓器容量，減少(shao)了(le)(le)投資費用(yong)，同時也減少(shao)了(le)(le)運行后的(de)(de)基本電費。

3　就地補償與集中補償的(de)技術經濟分析

3.1　電容(rong)補(bu)償在(zai)技術上應注意的問(wen)題(ti)

(1)防止產生自勵。

采用電(dian)(dian)(dian)容(rong)器就地(di)補償電(dian)(dian)(dian)動(dong)(dong)機(ji)，切(qie)斷電(dian)(dian)(dian)源后，電(dian)(dian)(dian)動(dong)(dong)機(ji)在慣性作(zuo)用下繼續運行，此(ci)時電(dian)(dian)(dian)容(rong)器的放電(dian)(dian)(dian)電(dian)(dian)(dian)流成為(wei)勵磁(ci)(ci)電(dian)(dian)(dian)流，如(ru)(ru)果(guo)電(dian)(dian)(dian)容(rong)過補償，就可使電(dian)(dian)(dian)動(dong)(dong)機(ji)的磁(ci)(ci)場得到自(zi)勵而產生(sheng)電(dian)(dian)(dian)壓，如(ru)(ru)圖(tu)6所(suo)示。因此(ci)，為(wei)防(fang)止產生(sheng)自(zi)勵，可按下式選用電(dian)(dian)(dian)容(rong)

QC=0.9 3UI0

(2)防止過電壓。

當電容器補償容量過大，會引起電網電壓升高并會導致電容器損壞。我國并聯電容器國標規定：“工頻長期過電壓值最多不超過1.1倍額定電壓。”因此必須符合QC< 0.1Ss的條件。

(3)防止產生諧振。

(4)防止受到系統(tong)諧波影(ying)響。

對于(yu)有諧波源(yuan)的供(gong)電(dian)(dian)線路，應增設電(dian)(dian)抗器等(deng)措施，使諧波影響不致造成電(dian)(dian)容器損壞(huai)。

3.2　兩者比較

就地補(bu)償(chang)較集中補(bu)償(chang)，更具節能效果。

4　電容補償控制及安裝方式的選擇

4.1　就(jiu)地補償(chang)與集中補償(chang)的(de)有關規定

(1)GB12497—90《三相異步電動機經濟運行》第7.6條規(gui)定：50kW以上的電動機應(ying)進行功率因數就(jiu)地(di)補(bu)償。

(2)GB3485—83《評估企業(ye)合理用電技術導則》第2.9條規定：100kW以上的電動機就地補償(chang)無功功率。

(3)GB50052—95《供配電設計規范》第5.03及5.0.10規定(ding)。

(4)國外用電委員會法規與專(zhuan)業(ye)學報均(jun)有類(lei)似規定與刊載(zai)。

4.2　電容(rong)補償方(fang)式的選擇

采(cai)用并(bing)聯電容(rong)(rong)器(qi)作(zuo)為(wei)人工無(wu)(wu)功(gong)(gong)補(bu)(bu)償，為(wei)了盡量減少線(xian)損和電壓(ya)損失，宜(yi)就(jiu)地平衡，即低(di)壓(ya)部分的無(wu)(wu)功(gong)(gong)宜(yi)由(you)低(di)壓(ya)電容(rong)(rong)器(qi)補(bu)(bu)償，高(gao)壓(ya)部分的無(wu)(wu)功(gong)(gong)宜(yi)由(you)高(gao)壓(ya)電容(rong)(rong)器(qi)補(bu)(bu)償。對于容(rong)(rong)量較大(da)，負荷平穩(wen)且經常使用的用電設備的無(wu)(wu)功(gong)(gong)功(gong)(gong)率，宜(yi)就(jiu)地補(bu)(bu)償。補(bu)(bu)償基本無(wu)(wu)功(gong)(gong)的電容(rong)(rong)器(qi)組宜(yi)在配變電所內集中補(bu)(bu)償，在有(you)工業生產機(ji)械化自動化程度高(gao)的流水線(xian)、大(da)容(rong)(rong)量機(ji)組的場(chang)所，宜(yi)分散補(bu)(bu)償。

4.3　電容器組投(tou)切方(fang)式的選擇(ze)

電(dian)容(rong)器組投(tou)切方式分手動(dong)和自動(dong)兩種。

對(dui)于補(bu)償(chang)低(di)壓基本(ben)無功及常年穩定(ding)和投(tou)切(qie)次數(shu)少的高(gao)壓電容器(qi)組，宜(yi)采用手(shou)動(dong)投(tou)切(qie)；為避免過(guo)補(bu)償(chang)或輕載(zai)時(shi)電壓過(guo)高(gao)，易造成(cheng)設(she)備損壞的，宜(yi)采用自動(dong)投(tou)切(qie)。高(gao)、低(di)壓補(bu)償(chang)效果相同(tong)時(shi)，宜(yi)采用低(di)壓自動(dong)補(bu)償(chang)裝置。

4.4　無功自動補償的調節(jie)方式

以節能為主者，采(cai)用(yong)無功(gong)(gong)功(gong)(gong)率參數調(diao)節；當三相平衡(heng)時，也可采(cai)用(yong)功(gong)(gong)率因數參數調(diao)節；為改善電壓偏差為主者，應按電壓參數調(diao)節；無功(gong)(gong)功(gong)(gong)率隨時間穩定變化者，按時間參數調(diao)節。

5　電(dian)容補償容量(liang)的選定

5.1　集中補償(chang)容量確定

先進行(xing)負荷計算，確定有功(gong)功(gong)率(lv)(lv)P30和(he)無功(gong)功(gong)率(lv)(lv)Q30，補(bu)償(chang)前自然功(gong)率(lv)(lv)因(yin)數為cosφ1，要補(bu)償(chang)到的功(gong)率(lv)(lv)因(yin)數為cosφ2。則(ze)

QC=αP30(tgφ1－tgφ2)

α為平均負荷因數。

5.2　電動機(ji)就地補償電容(rong)器容(rong)量確定

就地補償(chang)電(dian)(dian)(dian)容(rong)器(qi)容(rong)量選擇的(de)主(zhu)要(yao)參數(shu)是(shi)(shi)勵磁(ci)電(dian)(dian)(dian)流(liu)，因(yin)為不(bu)(bu)使電(dian)(dian)(dian)容(rong)器(qi)造成自勵是(shi)(shi)選用電(dian)(dian)(dian)容(rong)器(qi)容(rong)量的(de)必要(yao)條件。負載率(lv)越(yue)低(di)，功(gong)(gong)率(lv)因(yin)數(shu)越(yue)低(di)；極(ji)數(shu)愈多，功(gong)(gong)率(lv)因(yin)數(shu)越(yue)低(di)；容(rong)量愈小(xiao)，功(gong)(gong)率(lv)因(yin)數(shu)越(yue)低(di)。但由于無功(gong)(gong)功(gong)(gong)率(lv)主(zhu)要(yao)消耗在勵磁(ci)電(dian)(dian)(dian)流(liu)上，隨(sui)負載率(lv)變(bian)化(hua)不(bu)(bu)大，因(yin)此應主(zhu)要(yao)考慮電(dian)(dian)(dian)動機容(rong)量和極(ji)數(shu)這兩個參數(shu)，才能得到(dao)最佳補償(chang)效果。可用式(shi)(4)計(ji)算(suan)。

6　結合(he)工程實例談電(dian)容補償的應用(yong)

以某大(da)型項(xiang)目中(zhong)能(neng)源(yuan)中(zhong)心為(wei)例，該項(xiang)目設備(bei)裝機容(rong)量約為(wei)21000多(duo)千(qian)瓦(wa)(wa)，其中(zhong)高壓(ya)電(dian)(dian)(dian)動機設備(bei)容(rong)量為(wei)5400多(duo)千(qian)瓦(wa)(wa)，其他低壓(ya)設備(bei)容(rong)量為(wei)5000多(duo)千(qian)瓦(wa)(wa)。供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)源(yuan)的電(dian)(dian)(dian)壓(ya)等(deng)級為(wei)10kV。本著“節能(neng)、高效(xiao)”的方針，初次(ci)嘗(chang)試了(le)采用(yong)(yong)燃汽輪(lun)機發電(dian)(dian)(dian)機組自(zi)發電(dian)(dian)(dian)，冷、熱、電(dian)(dian)(dian)三聯供(gong)，做到汽電(dian)(dian)(dian)共(gong)生，實現(xian)能(neng)源(yuan)綜合(he)利用(yong)(yong)。經過(guo)經濟分(fen)析，采用(yong)(yong)10kV作為(wei)高壓(ya)電(dian)(dian)(dian)動機的供(gong)電(dian)(dian)(dian)電(dian)(dian)(dian)壓(ya)等(deng)級，投資較省(sheng)，同時(shi)亦減少(shao)變電(dian)(dian)(dian)環節，也(ye)就減少(shao)了(le)故障(zhang)點(dian)。根據負荷計算，共(gong)采用(yong)(yong)六(liu)路10kV電(dian)(dian)(dian)源(yuan)，分(fen)別對高壓(ya)電(dian)(dian)(dian)動機直(zhi)配。

在(zai)這個項目(mu)中(zhong)(zhong)(zhong)，高(gao)(gao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)動機(ji)(ji)主要用(yong)于空(kong)調(diao)系(xi)(xi)統中(zhong)(zhong)(zhong)的中(zhong)(zhong)(zhong)央空(kong)調(diao)機(ji)(ji)組(zu)，以及主機(ji)(ji)的外部(bu)設(she)備——冷(leng)(leng)(leng)凍水循(xun)(xun)環泵(beng)和冷(leng)(leng)(leng)卻水循(xun)(xun)環泵(beng)多臺設(she)備。這些設(she)備單(dan)機(ji)(ji)容(rong)(rong)量(liang)(liang)很大，離心(xin)機(ji)(ji)組(zu)單(dan)機(ji)(ji)最(zui)大達2810kW(共5臺)，小的870kW(共4臺)，冷(leng)(leng)(leng)凍水循(xun)(xun)環泵(beng)單(dan)機(ji)(ji)560kW(共9臺)，冷(leng)(leng)(leng)凍水循(xun)(xun)環泵(beng)單(dan)機(ji)(ji)亦有(you)380kW(共3臺)，自然功(gong)(gong)(gong)率因數(shu)在(zai)0.8左右。如果在(zai)10kV配電(dian)(dian)(dian)(dian)室集中(zhong)(zhong)(zhong)補償電(dian)(dian)(dian)(dian)容(rong)(rong)，不采(cai)用(yong)高(gao)(gao)壓(ya)(ya)(ya)(ya)無(wu)功(gong)(gong)(gong)自動補償的話(hua)，如此大容(rong)(rong)量(liang)(liang)的電(dian)(dian)(dian)(dian)動機(ji)(ji)起(qi)、停(ting)會(hui)使(shi)10kV側功(gong)(gong)(gong)率因數(shu)不穩(wen)定，有(you)可(ke)能造成過(guo)補償，引(yin)起(qi)系(xi)(xi)統電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)升高(gao)(gao)。同(tong)時(shi)，從配電(dian)(dian)(dian)(dian)室至冷(leng)(leng)(leng)凍機(ji)(ji)房高(gao)(gao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)動機(ji)(ji)的線路(lu)最(zui)近50m，最(zui)遠(yuan)140m，線路(lu)損(sun)耗相當可(ke)觀(guan)，綜合(he)考慮到高(gao)(gao)壓(ya)(ya)(ya)(ya)自動補償元件、技術、價(jia)格均要求高(gao)(gao)，因此采(cai)用(yong)高(gao)(gao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)容(rong)(rong)器就地(di)補償，與(yu)電(dian)(dian)(dian)(dian)動機(ji)(ji)同(tong)時(shi)投切。高(gao)(gao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)容(rong)(rong)器組(zu)放(fang)置在(zai)電(dian)(dian)(dian)(dian)動機(ji)(ji)附(fu)近。這些電(dian)(dian)(dian)(dian)動機(ji)(ji)采(cai)用(yong)自耦降壓(ya)(ya)(ya)(ya)起(qi)動方式，高(gao)(gao)壓(ya)(ya)(ya)(ya)就地(di)補償裝置以并聯電(dian)(dian)(dian)(dian)容(rong)(rong)器為(wei)主體(ti)，采(cai)用(yong)熔斷(duan)器做保護(hu)，裝設(she)避雷器用(yong)于過(guo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)保護(hu)，串聯電(dian)(dian)(dian)(dian)抗器抑制涌流和諧波。這樣做，不僅提高(gao)(gao)了電(dian)(dian)(dian)(dian)動機(ji)(ji)的功(gong)(gong)(gong)率因數(shu)，降低了線路(lu)損(sun)耗，同(tong)時(shi)釋放(fang)了系(xi)(xi)統容(rong)(rong)量(liang)(liang)，縮小了饋電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)纜的截面，節(jie)約了投資。

對于低(di)壓(ya)(ya)設備(bei)，由二臺(tai)(tai)1000kVA及二臺(tai)(tai)1600kVA變(bian)壓(ya)(ya)器配出，低(di)壓(ya)(ya)電(dian)機(ji)布置較分(fen)散，因此，在(zai)變(bian)電(dian)所(suo)變(bian)壓(ya)(ya)器低(di)壓(ya)(ya)側采(cai)用電(dian)容(rong)器組集中(zhong)自動(dong)補償(chang)。雖(sui)然(ran)一些低(di)壓(ya)(ya)電(dian)動(dong)機(ji)的(de)(de)容(rong)量也不(bu)小，就(jiu)地補償(chang)的(de)(de)經(jing)濟效益亦有，但這些設備(bei)主要用于鍋(guo)爐房(fang)(fang)和給排水(shui)設備(bei)，鍋(guo)爐房(fang)(fang)的(de)(de)設備(bei)不(bu)如冷凍機(ji)房(fang)(fang)集中(zhong)，環境較差，管理不(bu)便，因此，在(zai)低(di)壓(ya)(ya)配電(dian)室采(cai)用按功率(lv)因數大(da)小自補償(chang)是較合適的(de)(de)。

篇6

【關鍵詞】：低壓電(dian)氣裝(zhuang)置 過(guo)負荷 短路(lu)保護(hu) 措施

中圖分類號(hao)： S219.033 文(wen)(wen)獻標(biao)識碼： A 文(wen)(wen)章編號(hao)：

 一、低壓電(dian)氣裝(zhuang)置及配(pei)電(dian)線路過(guo)負荷(he)保護

配電(dian)(dian)線路過負(fu)荷(he)(he)(he)保護的(de)目的(de)是保護電(dian)(dian)纜(lan)在允許(xu)的(de)工作溫度下長期運行(xing)，避免(mian)電(dian)(dian)纜(lan)因過負(fu)荷(he)(he)(he)發熱，損壞絕緣性能，降低(di)電(dian)(dian)纜(lan)使用壽命。電(dian)(dian)氣(qi)設備過負(fu)荷(he)(he)(he)原因（以電(dian)(dian)力電(dian)(dian)容(rong)器為例） ，過負(fu)荷(he)(he)(he)就(jiu)是設備承受(shou)的(de)負(fu)荷(he)(he)(he)（功率）超過其額定值的(de)現象。對(dui)于電(dian)(dian)氣(qi)設備，其特點之一就(jiu)是過電(dian)(dian)流。

1、電氣(qi)設備(bei)過負(fu)荷原因

電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)在(zai)合(he)閘投入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網時產生的(de)合(he)閘涌流。一般限制為正常工作電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)6～8倍(bei)，頻率高(gao)，可(ke)以達(da)到2.5～3kHz。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)波(bo)形畸(ji)變(bian)引起電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)網中(zhong)由(you)于大功率可(ke)控硅整流器(qi)(qi)等非線性設備投運及變(bian)壓(ya)器(qi)(qi)鐵(tie)芯的(de)磁飽和等都會使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)波(bo)形發生畸(ji)變(bian)。由(you)于容抗(kang)(kang)與頻率的(de)增加(jia)，諧(xie)(xie)(xie)(xie)(xie)波(bo)次(ci)數(shu)越高(gao)，對該次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)表現(xian)出(chu)來的(de)容抗(kang)(kang)越小(xiao)，諧(xie)(xie)(xie)(xie)(xie)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流就越大。當電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容與電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源及線路阻(zu)抗(kang)(kang)、串接(jie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)器(qi)(qi)阻(zu)抗(kang)(kang)形成諧(xie)(xie)(xie)(xie)(xie)振時，可(ke)能(neng)出(chu)現(xian)對某次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流的(de)放大現(xian)象(xiang)。使(shi)得流過(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流大大超(chao)過(guo)額定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流。如圖所示為h次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流分(fen)布圖。圖中(zhong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)同(tong)一母線上有(you)一諧(xie)(xie)(xie)(xie)(xie)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流源，即h次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)恒流源，流入系統和電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)h次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流分(fen)別為：、 。對中(zhong)低(di)壓(ya)系統的(de)h次(ci)諧(xie)(xie)(xie)(xie)(xie)波(bo)阻(zu)抗(kang)(kang)，有(you)：，即忽略電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)，由(you)純電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)組成，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)容器(qi)(qi)組則一般串有(you)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)抗(kang)(kang)器(qi)(qi)，。

系(xi)統的(de)參數會隨著系(xi)統結(jie)構(gou)和負(fu)荷(he)狀況而(er)變化，因此在由(you)并聯(lian)無功補(bu)償電(dian)(dian)(dian)(dian)容器(qi)(qi)的(de)系(xi)統中要時刻注意避(bi)免諧波放大(da)現(xian)象的(de)發(fa)生。電(dian)(dian)(dian)(dian)容器(qi)(qi)運(yun)行中關(guan)于(yu)過電(dian)(dian)(dian)(dian)流(liu)的(de)規定：電(dian)(dian)(dian)(dian)容器(qi)(qi)在額定頻(pin)率和額定正弦波電(dian)(dian)(dian)(dian)壓下，其有效值電(dian)(dian)(dian)(dian)流(liu)不(bu)大(da)于(yu)1.3倍額定電(dian)(dian)(dian)(dian)流(liu)。很多人將其理解為：總的(de)電(dian)(dian)(dian)(dian)流(liu)有效值不(bu)大(da)于(yu)1.3倍額定值。

2、電氣設(she)備過負荷保(bao)護

過(guo)(guo)負荷對(dui)電氣(qi)設(she)備(bei)的(de)(de)影響主要(yao)是(shi)因為過(guo)(guo)高的(de)(de)溫升而降低(di)電氣(qi)設(she)備(bei)的(de)(de)使用壽命。因此，過(guo)(guo)負荷保(bao)護(hu)的(de)(de)原(yuan)則就是(shi)防止(zhi)電氣(qi)設(she)備(bei)過(guo)(guo)熱(re)。保(bao)護(hu)根(gen)據(ju)(ju)原(yuan)理的(de)(de)不同，可(ke)以(yi)分(fen)為三類：1）溫度保(bao)護(hu)；2）根(gen)據(ju)(ju)熱(re)累積的(de)(de)原(yuan)理動作的(de)(de)保(bao)護(hu)；3）根(gen)據(ju)(ju)電流的(de)(de)大(da)小來(lai)動作的(de)(de)保(bao)護(hu)。

（1）溫度保護

溫(wen)(wen)(wen)(wen)度(du)保(bao)(bao)(bao)護用于保(bao)(bao)(bao)護電(dian)機設備(bei)(bei)是隨國外(wai)引進(jin)的(de)(de)(de)設備(bei)(bei)進(jin)入國內的(de)(de)(de)，其基本思想是：將溫(wen)(wen)(wen)(wen)度(du)敏(min)感(gan)元(yuan)件(jian)(jian)粘在或(huo)者埋(mai)設在被保(bao)(bao)(bao)護設備(bei)(bei)的(de)(de)(de)最(zui)熱(re)部(bu)位，以此來實時監(jian)測設備(bei)(bei)的(de)(de)(de)溫(wen)(wen)(wen)(wen)度(du)。當設備(bei)(bei)過熱(re)時切除電(dian)源(yuan)，以達(da)到(dao)(dao)保(bao)(bao)(bao)護設備(bei)(bei)的(de)(de)(de)目的(de)(de)(de)。這種保(bao)(bao)(bao)護方式能夠較真實地反映設備(bei)(bei)溫(wen)(wen)(wen)(wen)度(du)，作(zuo)為(wei)過負荷保(bao)(bao)(bao)護原理上講是比較理想的(de)(de)(de)。溫(wen)(wen)(wen)(wen)度(du)保(bao)(bao)(bao)護按照采(cai)用的(de)(de)(de)溫(wen)(wen)(wen)(wen)度(du)敏(min)感(gan)元(yuan)件(jian)(jian)性質的(de)(de)(de)不同又分為(wei)2類(lei)： 1）溫(wen)(wen)(wen)(wen)敏(min)元(yuan)件(jian)(jian)為(wei)開關特(te)性，如雙(shuang)金(jin)屬片(pian)，溫(wen)(wen)(wen)(wen)度(du)達(da)到(dao)(dao)一定程度(du)，雙(shuang)金(jin)屬片(pian)動作(zuo)，斷開設備(bei)(bei)電(dian)源(yuan)。2）溫(wen)(wen)(wen)(wen)敏(min)元(yuan)件(jian)(jian)輸出為(wei)模擬信號，采(cai)用的(de)(de)(de)溫(wen)(wen)(wen)(wen)度(du)敏(min)感(gan)元(yuan)件(jian)(jian)有：A）熱(re)敏(min)電(dian)阻——由金(jin)屬氧化(hua)(hua)物、陶瓷半導(dao)體或(huo)炭化(hua)(hua)硅(gui)材(cai)料(liao)(liao)制成。PTC、NTC。B）熱(re)電(dian)阻——由銅(tong)、鎳、鉑(bo)等(deng)金(jin)屬材(cai)料(liao)(liao)制成（如最(zui)常見(jian)的(de)(de)(de)鉑(bo)電(dian)阻）；C）熱(re)電(dian)偶；D）PN結。

 優點(dian)： 保護(hu)的原理最簡單(dan)、直接，能(neng)比較真實地反映設(she)備溫(wen)度，在(zai)一定程度上可以反映短路故障。

缺點：A）準確度的(de)(de)(de)問(wen)(wen)題(ti)：設(she)備(bei)(bei)在(zai)不(bu)(bu)同的(de)(de)(de)工作條件下最熱點可(ke)能(neng)不(bu)(bu)一樣。有些設(she)備(bei)(bei)的(de)(de)(de)最熱點可(ke)能(neng)不(bu)(bu)適合(he)安裝(zhuang)測溫元(yuan)件。B）信號(hao)(hao)(hao)的(de)(de)(de)傳輸問(wen)(wen)題(ti)：被(bei)保(bao)護(hu)設(she)備(bei)(bei)多為高電(dian)壓、大(da)電(dian)流設(she)備(bei)(bei)，對弱電(dian)測量信號(hao)(hao)(hao)可(ke)能(neng)存在(zai)較強的(de)(de)(de)干(gan)擾。在(zai)被(bei)保(bao)護(hu)設(she)備(bei)(bei)故障時電(dian)壓電(dian)流異常，干(gan)擾可(ke)能(neng)更加(jia)嚴(yan)重。保(bao)護(hu)裝(zhuang)置的(de)(de)(de)安裝(zhuang)位(wei)置可(ke)能(neng)與(yu)被(bei)保(bao)護(hu)設(she)備(bei)(bei)距離較遠，可(ke)能(neng)幾十米、上百米，這時就有弱信號(hao)(hao)(hao)的(de)(de)(de)可(ke)靠傳輸與(yu)傳輸成(cheng)本的(de)(de)(de)問(wen)(wen)題(ti)。

（2）根據熱(re)累積的原理。

 反(fan)映電流的熱效應，電流產生的熱量達到一定(ding)時(shi)，保護動作。有兩類：1）熔斷器；2）熱繼電器。

熔斷器優(you)點：簡單、成本低(di)。缺點：準確度低(di)，溫升特性(xing)與被保(bao)護(hu)設(she)備存在差異，保(bao)護(hu)動作后需更(geng)換，較麻煩。

熱(re)(re)繼電器——電流流過繼電器中的發(fa)熱(re)(re)元件，元件發(fa)熱(re)(re)，使雙金屬片受熱(re)(re)動(dong)作。

優點：構造簡單，價格低廉(lian)，使用方便(bian)，廣(guang)泛應用于(yu)電動機的過載和斷相保(bao)護。不存在熔斷器那樣的更換問題。

缺點(dian)：A）同(tong)樣(yang)由于被保護(hu)(hu)設備（主要是電(dian)動機）與熱繼(ji)電(dian)器不(bu)是一(yi)體的(de)，溫(wen)升(sheng)特性與被保護(hu)(hu)設備也存(cun)在(zai)差(cha)異。用(yong)熱繼(ji)電(dian)器很難反映不(bu)同(tong)型(xing)式和(he)容量(liang)的(de)電(dian)機的(de)溫(wen)升(sheng)；當電(dian)機負荷(he)變動大時，保護(hu)(hu)的(de)困(kun)難更多(duo)(duo)；B）影(ying)響熱繼(ji)電(dian)器動作的(de)因素眾多(duo)(duo)，如環(huan)境溫(wen)度(du)、安(an)裝方向都(dou)會影(ying)響其動作時間；C）精度(du)太低，同(tong)型(xing)誤差(cha)可達到20%；

（3）根據電流(liu)的大小(xiao)來動作的保護

A）定時(shi)限：大于某一電(dian)流(liu)值（如過電(dian)流(liu)倍(bei)數：），經(jing)過過一定的延時(shi)后(hou)斷開。

B)階越時限：過(guo)負荷倍數在之間(jian)(jian)時允(yun)(yun)許(xu)時間(jian)(jian)為，在時，允(yun)(yun)許(xu)時間(jian)(jian)為。

C)反時(shi)限：保(bao)護的完全按(an)照設備的過負荷特性曲線來設定動作時(shi)間(jian)。

D)可變時限(xian)：用電流來模(mo)擬(ni)熱(re)累積效(xiao)應，是反時限(xian)的一種。

二、低壓(ya)電氣(qi)配電線路(lu)的短路(lu)保護

1、低(di)壓配電線路短路保護的(de)裝設要求

所有的(de)低(di)壓配電線(xian)路都(dou)應(ying)裝(zhuang)設短(duan)(duan)路保(bao)(bao)護(hu)裝(zhuang)置。短(duan)(duan)路保(bao)(bao)護(hu)裝(zhuang)置的(de)裝(zhuang)設，應(ying)保(bao)(bao)證線(xian)路末端發生(sheng)短(duan)(duan)路時(shi)，保(bao)(bao)護(hu)裝(zhuang)置能可(ke)靠動(dong)(dong)作。短(duan)(duan)路保(bao)(bao)護(hu)裝(zhuang)置應(ying)能避開線(xian)路中短(duan)(duan)時(shi)間(jian)過負荷的(de)影響，如(ru)大(da)容(rong)量異步電動(dong)(dong)機的(de)啟動(dong)(dong)瞬間(jian)等，同時(shi)又能可(ke)靠地保(bao)(bao)護(hu)線(xian)路。低(di)壓配電線(xian)路的(de)短(duan)(duan)路保(bao)(bao)護(hu)，通常采用熔斷器或(huo)低(di)壓斷路器來完(wan)成。

2、短(duan)路保護用熔(rong)斷器熔(rong)體電流的確定

當(dang)采(cai)用電(dian)(dian)(dian)(dian)纜(lan)或穿管(guan)絕(jue)緣(yuan)導線配(pei)電(dian)(dian)(dian)(dian)時，熔(rong)斷器(qi)(qi)熔(rong)體的額(e)(e)定(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)應(ying)小(xiao)(xiao)于或等(deng)(deng)于電(dian)(dian)(dian)(dian)纜(lan)或穿管(guan)絕(jue)緣(yuan)導線允(yun)許載流(liu)(liu)量(liang)的2.5倍(bei)。當(dang)采(cai)用明(ming)敷絕(jue)緣(yuan)導線配(pei)電(dian)(dian)(dian)(dian)時，熔(rong)斷器(qi)(qi)熔(rong)體的額(e)(e)定(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)應(ying)小(xiao)(xiao)于或等(deng)(deng)于導線允(yun)許載流(liu)(liu)量(liang)的1.5倍(bei)，這(zhe)是由(you)于明(ming)敷絕(jue)緣(yuan)導線的絕(jue)緣(yuan)等(deng)(deng)級偏低，絕(jue)緣(yuan)容(rong)易(yi)老化的緣(yuan)故。當(dang)熔(rong)斷器(qi)(qi)用來(lai)保護配(pei)電(dian)(dian)(dian)(dian)線路(lu)(lu)末(mo)(mo)端(duan)的短(duan)路(lu)(lu)事故時，熔(rong)斷器(qi)(qi)熔(rong)體的額(e)(e)定(ding)電(dian)(dian)(dian)(dian)流(liu)(liu)應(ying)小(xiao)(xiao)于或等(deng)(deng)于線路(lu)(lu)末(mo)(mo)端(duan)發生單相接地短(duan)路(lu)(lu)或兩相短(duan)路(lu)(lu)時短(duan)路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)(liu)的1/4倍(bei)。

3、低(di)壓(ya)電網短(duan)路(lu)電流計算的特(te)點

在低(di)(di)(di)壓(ya)(ya)電(dian)(dian)(dian)(dian)網中(zhong)運行的變壓(ya)(ya)器(qi)(qi)低(di)(di)(di)壓(ya)(ya)側發生短路(lu)(lu)時可以(yi)(yi)認(ren)為變壓(ya)(ya)器(qi)(qi)的高(gao)壓(ya)(ya)側端電(dian)(dian)(dian)(dian)壓(ya)(ya)不(bu)變和低(di)(di)(di)壓(ya)(ya)側短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)不(bu)衰(shuai)減。也就(jiu)是說，變壓(ya)(ya)器(qi)(qi)高(gao)壓(ya)(ya)側電(dian)(dian)(dian)(dian)源可視(shi)為無窮大。理論上，變壓(ya)(ya)器(qi)(qi)低(di)(di)(di)壓(ya)(ya)側的所(suo)有低(di)(di)(di)壓(ya)(ya)元件，包括母(mu)線(xian)(xian)和電(dian)(dian)(dian)(dian)纜、電(dian)(dian)(dian)(dian)流(liu)互感器(qi)(qi)的一次線(xian)(xian)圈(quan)、斷路(lu)(lu)器(qi)(qi)和刀(dao)閘(zha)觸頭的接(jie)觸電(dian)(dian)(dian)(dian)阻等，對低(di)(di)(di)壓(ya)(ya)短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)都有影響，但為了(le)簡化計算，使計算出(chu)的短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)值(zhi)(zhi)(zhi)又(you)偏于安全(quan)，容許(xu)(xu)不(bu)考慮占(zhan)回路(lu)(lu)總阻抗不(bu)超過10%的元件。低(di)(di)(di)壓(ya)(ya)電(dian)(dian)(dian)(dian)網一般以(yi)(yi)三相(xiang)短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)為最(zui)大，并與(yu)中(zhong)性點是否接(jie)地無關。在低(di)(di)(di)壓(ya)(ya)電(dian)(dian)(dian)(dian)網中(zhong)，一般不(bu)允許(xu)(xu)忽略電(dian)(dian)(dian)(dian)阻，因此短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)非周(zhou)期分(fen)(fen)量(liang)比高(gao)壓(ya)(ya)電(dian)(dian)(dian)(dian)網衰(shuai)減快得多，故(gu)短路(lu)(lu)電(dian)(dian)(dian)(dian)流(liu)最(zui)大有效值(zhi)(zhi)(zhi)及短路(lu)(lu)沖擊電(dian)(dian)(dian)(dian)流(liu)與(yu)周(zhou)期分(fen)(fen)量(liang)比值(zhi)(zhi)(zhi)一般不(bu)太大。

三、總結

低(di)(di)壓(ya)電(dian)(dian)氣(qi)裝置設備以及配電(dian)(dian)線路(lu)(lu)常見(jian)過負荷、短路(lu)(lu)故障，是影響低(di)(di)壓(ya)電(dian)(dian)氣(qi)裝置正常運行的主要(yao)故障因(yin)素。因(yin)此，為(wei)了(le)保護低(di)(di)壓(ya)電(dian)(dian)氣(qi)以及配電(dian)(dian)線路(lu)(lu)，在發生上(shang)述故障時及時應(ying)及時切斷電(dian)(dian)源，確保人身(shen)和(he)財產的安全，或使這類故障產生的危害最小化。就要(yao)確保了(le)解有關的保護原(yuan)理和(he)應(ying)用必(bi)要(yao)的方法(fa)解除和(he)減少(shao)故障帶來的危害和(he)影響。

【參考文獻】：

[1]童曉鳴.低(di)壓電動機的容量、保(bao)護(hu)及保(bao)護(hu)配置的選(xuan)擇(ze)[J].安徽建筑(zhu)，2011，18(1)：130-131.DOI：10.3969/j.issn.1007-7359.2011.01.062.

篇7

關(guan)鍵詞：無功負荷；就(jiu)地補償；電容(rong)器；經濟效益

中圖分類號：TM71 文獻(xian)標識碼：A

1概述

在電(dian)力用戶(hu)中，為了提高功(gong)率(lv)(lv)因數(shu)，大多數(shu)采用了在0.4千伏(fu)(fu)配電(dian)母線(xian)上(shang)安(an)裝(zhuang)補(bu)償(chang)電(dian)容器的辦法。這種補(bu)償(chang)方式，實際(ji)上(shang)只能改(gai)善用戶(hu)配電(dian)變壓(ya)器及(ji)供電(dian)網絡(luo)中的功(gong)率(lv)(lv)因數(shu)，而對用戶(hu)0.4千伏(fu)(fu)級線(xian)路上(shang)的電(dian)能損耗卻(que)幾乎起不(bu)到(dao)減(jian)少(shao)的作用。用戶(hu)安(an)裝(zhuang)補(bu)償(chang)電(dian)容器主(zhu)要(yao)是滿足供電(dian)部(bu)門對功(gong)率(lv)(lv)因數(shu)考核(he)的要(yao)求，自(zi)身受益少(shao)。

據(ju)資料統計，電動機是低壓電網中無(wu)功電能(neng)的(de)主要(yao)消耗者，選擇將電容器安裝在電動機附近，是節電效果(guo)最好、結線最簡單和容易實現的(de)無(wu)功補償方式。

2就地補償的優(you)越性

2.1 供電部(bu)門可以使(shi)網內輸送的無功(gong)(gong)功(gong)(gong)率(lv)減少(shao)，從而(er)達到全(quan)網因輸送無功(gong)(gong)功(gong)(gong)率(lv)所引起(qi)的有功(gong)(gong)功(gong)(gong)率(lv)網損(sun)最小。

2.2 電容(rong)器和電動機直接并聯在一起，安裝簡單，且同時投入(ru)和停用(yong)，可以保證無功(gong)不倒流，使(shi)用(yong)戶的(de)功(gong)率因數始終處(chu)于滯后的(de)狀態下。

2.3 使(shi)用(yong)戶內部矛盾0.4千伏低(di)壓線路上的(de)無功電(dian)流大量(liang)減少(shao)，從而“釋放”出富余(yu)容量(liang)，可使(shi)供電(dian)能(neng)力增(zeng)加30%左右，減少(shao)了對電(dian)氣設備的(de)投資。

2.4 因為(wei)減(jian)少了線路壓降可(ke)以提高電(dian)(dian)動(dong)機的端電(dian)(dian)壓，相應可(ke)減(jian)少電(dian)(dian)動(dong)機的電(dian)(dian)流，延長電(dian)(dian)動(dong)機的使用壽命。綜上(shang)特點，世界工業(ye)發達國(guo)家如(ru)美國(guo)、日(ri)本(ben)等國(guo)已都把無功就地補(bu)償列入行業(ye)技術法(fa)規(gui)（如(ru)《美國(guo)國(guo)家電(dian)(dian)氣法(fa)規(gui)NEC-460》、《日(ri)本(ben)電(dian)(dian)氣學會(hui)標準JEC-8001-1982》、《日(ri)本(ben)東(dong)京電(dian)(dian)力公司技術法(fa)規(gui)》等），作為(wei)補(bu)償方案的最(zui)佳(jia)選擇并迅速得到推廣(guang)普及。

3 補(bu)償容量的確定

單臺電動機進行無功就地補償，就根據電動機的運行工況(kuang)和技術參數確定。

3．1 載電(dian)流計算

3.1.1 機械負(fu)荷慣性小時(shi)（如風機等）

3.1.2機械負荷慣性大時（如水泵等）

式(shi)中(zhong)：Qc--補償容量（kvar）

KBKB'--補償系數

Ue--電動(dong)機額定電壓（V）

IO--電動機(ji)空(kong)載電流(liu)（A）

電動機的(de)空載電流(liu)IO，由廠家提供，或用鉗型電流(liu)表實測，或參照(zhao)下式(shi)確定(ding)。

式中：Ie--電動機(ji)額定(ding)電流

COSφe--電動機額定負荷時的功率因數(shu)

按電動(dong)機額定(ding)功率計算

式中：Pe--電動機額定功率（kw）

KB--補償系數(shu)，表達式為 )

φe--額(e)定功率(lv)因數角

b--最大轉矩對額(e)定轉矩的倍數。

4 補償接線方式

4.1對直接起(qi)動(dong)的(de)(de)電(dian)動(dong)機(ji)并(bing)聯電(dian)容器(qi)時，可將電(dian)容器(qi)并(bing)到電(dian)動(dong)機(ji)控制器(qi)的(de)(de)負荷側或電(dian)動(dong)機(ji)進線處(chu)（如圖1所示），使電(dian)容器(qi)和電(dian)動(dong)機(ji)一起(qi)投入和停用。

4.2星(xing)-三角(jiao)(jiao)起動的電動機的補償電容器(qi)接線，應在(zai)(zai)電容器(qi)連接線上安裝CJ19接觸器(qi)，使(shi)用時(shi)只能(neng)在(zai)(zai)由(you)星(xing)形起動后轉(zhuan)入角(jiao)(jiao)形正(zheng)常運(yun)轉(zhuan)時(shi)，電容器(qi)才能(neng)并上（如圖2所示），以此避免在(zai)(zai)星(xing)-角(jiao)(jiao)開(kai)路轉(zhuan)換(huan)中，電動機因自勵產生過電壓。

5電容器的連接導(dao)線(xian)、開關(guan)和保護裝置

根據《農村低(di)壓電(dian)力(li)(li)技術規(gui)程》DL499-2001規(gui)定；低(di)壓并聯電(dian)容(rong)器(qi)的(de)開關、保護裝置及連接件的(de)選擇，均應能承受1.5In（電(dian)容(rong)器(qi)額定電(dian)流）的(de)連續過電(dian)流，并能承受投入電(dian)容(rong)器(qi)時可能產生(sheng)的(de)調幅(fu)值及高頻率的(de)過渡過電(dian)流所引起的(de)電(dian)動力(li)(li)和(he)熱效應。

6就地補償經(jing)濟(ji)效益的計算

6.1 求補償后的功率因數

6.2 求補償(chang)后的損耗降低率

6.3 求電流降低率

6.4 求可挖掘的變壓器(qi)容量(liang)

(kVA)

6.5 求可挖潛的有功功率

(kW)

6.6求年節電量

(kWh)

6.7求補償后節約電費

(元)

6.8求補償后電容器的投資

(元)

6.9求補(bu)償后的償還(huan)期限

式中：Kg--無功(gong)經濟當(dang)量，取(qu)0.06kw/kvar

T--年運行時(shi)間（小時(shi)）

C--購電價（元/kWh）

C'--電(dian)容器(qi)購(gou)價（元(yuan)/kWh）

結束語

無功負荷就地補(bu)償(chang)可(ke)使電力(li)用戶滿足供電部門(men)對功率因(yin)數的(de)要求，又可(ke)使用戶內部0.4千伏低壓線路(lu)上的(de)損耗減小，實際節電效(xiao)果可(ke)達10%-20%，使用戶能夠獲得無功補(bu)償(chang)的(de)最佳經濟效(xiao)益(yi)。

參考文獻

[1]原(yuan)固均(jun)，張蓮瑛，蔣明(ming)其.農村(cun)低壓(ya)電力(li)技術規程DL449-2001[M]北京：中國電力(li)出版社.2001年10月.

篇8

關鍵(jian)詞：低壓電網；無功補償；隨機(ji)補償；隨器(qi)補償；跟蹤補償

中(zhong)圖分類號(hao)：TM571 文獻標識碼：A 文章編號(hao)：1009-2374（2012）07-0114-03

一、概述

電壓質(zhi)(zhi)量作為電能(neng)質(zhi)(zhi)量的重(zhong)要指(zhi)標，又和電網(wang)中(zhong)的無功(gong)(gong)功(gong)(gong)率存在著關系。在低(di)壓電網(wang)中(zhong)，大多數用電機器設備屬于感性負載，它的功(gong)(gong)率因數特別低(di)，而這對線路(lu)和配電變壓器必然會產生(sheng)影(ying)響，但是，通(tong)過采用無功(gong)(gong)補償(chang)技術，可(ke)以提(ti)高其(qi)功(gong)(gong)率因數，對節(jie)約電能(neng)降低(di)損耗具有(you)很重(zhong)要的意(yi)義。

在電(dian)網中，變壓器(qi)能(neng)(neng)夠消耗無功(gong)(gong)(gong)功(gong)(gong)(gong)率的(de)(de)(de)20%～25%，電(dian)動機能(neng)(neng)消耗無功(gong)(gong)(gong)總工(gong)量的(de)(de)(de)60%～65%，如果對電(dian)網進(jin)行一定(ding)的(de)(de)(de)無功(gong)(gong)(gong)補償，那(nei)么其損耗會得(de)到大大降(jiang)低(di)，功(gong)(gong)(gong)率數(shu)也會得(de)到很大提高(gao)。如今隨著(zhu)無功(gong)(gong)(gong)補償技術的(de)(de)(de)不斷(duan)進(jin)步，其會大大增大電(dian)力企業的(de)(de)(de)經濟效益。

通(tong)過(guo)對電力網無功(gong)功(gong)率(lv)消(xiao)(xiao)耗的數(shu)據進行分析，可以知道，很多無功(gong)功(gong)率(lv)都會在各級(ji)網絡和輸(shu)配電設(she)備(bei)中(zhong)進行消(xiao)(xiao)耗，而且在低壓電網中(zhong)，其消(xiao)(xiao)耗率(lv)最大(da)。如(ru)果要減(jian)少無功(gong)功(gong)率(lv)在傳輸(shu)過(guo)程中(zhong)的損害，就必須合理配置無功(gong)補償設(she)備(bei)。

二、無功補償的基本原理

不(bu)管是在(zai)工(gong)業負(fu)荷中，還是民用負(fu)荷中，大(da)多數都屬于感性。而所有的電(dian)感負(fu)載都需(xu)(xu)要(yao)進行大(da)量的無(wu)(wu)功(gong)(gong)補償，提(ti)(ti)(ti)(ti)供(gong)這些無(wu)(wu)功(gong)(gong)功(gong)(gong)率一(yi)般(ban)需(xu)(xu)要(yao)通(tong)過兩種(zhong)途徑：輸(shu)(shu)(shu)電(dian)系(xi)統提(ti)(ti)(ti)(ti)供(gong)；補償電(dian)容器提(ti)(ti)(ti)(ti)供(gong)。作為輸(shu)(shu)(shu)電(dian)系(xi)統提(ti)(ti)(ti)(ti)供(gong)，在(zai)設計輸(shu)(shu)(shu)電(dian)系(xi)統時(shi)，不(bu)僅(jin)要(yao)考慮到有功(gong)(gong)功(gong)(gong)率，也不(bu)能忽略無(wu)(wu)功(gong)(gong)功(gong)(gong)率。因為由(you)輸(shu)(shu)(shu)電(dian)系(xi)統傳輸(shu)(shu)(shu)無(wu)(wu)功(gong)(gong)功(gong)(gong)率，會(hui)讓增大(da)輸(shu)(shu)(shu)電(dian)線路(lu)及變壓器的損耗，降低系(xi)統的經濟效益(yi)。但如果由(you)補償電(dian)容器就(jiu)地提(ti)(ti)(ti)(ti)供(gong)無(wu)(wu)功(gong)(gong)功(gong)(gong)率，就(jiu)會(hui)避(bi)免(mian)由(you)輸(shu)(shu)(shu)電(dian)系(xi)統傳輸(shu)(shu)(shu)無(wu)(wu)功(gong)(gong)功(gong)(gong)率，從而會(hui)降低無(wu)(wu)功(gong)(gong)損耗，提(ti)(ti)(ti)(ti)高系(xi)統的傳輸(shu)(shu)(shu)功(gong)(gong)率。

三(san)、低壓(ya)配電網無功補償的方法

要(yao)提高功率因數，一般需(xu)要(yao)采用低壓無功補償(chang)的技術，方法包(bao)括：隨(sui)(sui)機補償(chang)、隨(sui)(sui)器補償(chang)、跟(gen)蹤補償(chang)。

（一）隨機補償

隨機(ji)補(bu)償(chang)，即(ji)是把電(dian)(dian)(dian)(dian)動(dong)機(ji)和低電(dian)(dian)(dian)(dian)壓容器組連接在一(yi)起，同(tong)時，要運(yun)(yun)用控制、保護(hu)裝置(zhi)來和電(dian)(dian)(dian)(dian)機(ji)一(yi)起進(jin)行(xing)(xing)投切。其適用的(de)范圍一(yi)般為(wei)電(dian)(dian)(dian)(dian)動(dong)機(ji)的(de)無(wu)功(gong)消耗，主要為(wei)補(bu)勵磁無(wu)功(gong)，采用這種(zhong)方(fang)法就可(ke)以在一(yi)定程度上減(jian)輕用電(dian)(dian)(dian)(dian)單位的(de)無(wu)功(gong)負荷。其優(you)點可(ke)以總結為(wei)：在用電(dian)(dian)(dian)(dian)設(she)備進(jin)入運(yun)(yun)行(xing)(xing)狀態時，無(wu)功(gong)補(bu)償(chang)也開始運(yun)(yun)行(xing)(xing)，當設(she)備停(ting)止(zhi)運(yun)(yun)作，無(wu)功(gong)補(bu)償(chang)也立即(ji)停(ting)止(zhi)，并且不必(bi)重(zhong)復進(jin)行(xing)(xing)補(bu)償(chang)容量的(de)調整。在投資、空(kong)間占地、安裝和維護(hu)方(fang)面都具有很大的(de)優(you)勢。

（二）隨器補償

隨器補(bu)償，即為借助(zhu)低壓保險，在配電變壓器的二次側接入低壓電容器，采用(yong)這(zhe)種補(bu)償方(fang)法，可以對配電變壓器的空載無功進行補(bu)償。

變(bian)壓器(qi)的空(kong)(kong)載(zai)勵磁無(wu)功(gong)決定了(le)配(pei)電(dian)變(bian)壓器(qi)在空(kong)(kong)載(zai)或者輕載(zai)時(shi)的無(wu)功(gong)負(fu)荷。作(zuo)為用(yong)電(dian)單位無(wu)功(gong)負(fu)荷的主要部(bu)分為配(pei)變(bian)空(kong)(kong)載(zai)無(wu)功(gong)，在輕負(fu)載(zai)的配(pei)電(dian)變(bian)壓器(qi)中，配(pei)變(bian)空(kong)(kong)載(zai)無(wu)功(gong)占據供電(dian)量的損耗很大，其(qi)(qi)會增(zeng)加電(dian)費單價。其(qi)(qi)優(you)點可以總結為：它能很好(hao)地(di)補償配(pei)變(bian)空(kong)(kong)載(zai)無(wu)功(gong)，并(bing)且農網無(wu)功(gong)基荷起到(dao)很好(hao)的限(xian)制作(zuo)用(yong)。同時(shi)，其(qi)(qi)維(wei)護方便(bian)，安裝簡單是無(wu)功(gong)補償的有效手段。

（三）跟蹤補償

跟蹤補(bu)償，可以(yi)將低壓(ya)電容器組補(bu)償在(zai)大用(yong)戶0.4kV母線上(shang)，其方(fang)法是使用(yong)無(wu)功(gong)補(bu)償投切裝置(zhi)，將其作為控制保護裝置(zhi)。一(yi)般而言，配變(bian)用(yong)戶在(zai)100kVA以(yi)上(shang)的都可以(yi)適用(yong)這種補(bu)償方(fang)法。

它的優(you)(you)點是可(ke)以和(he)隨(sui)機(ji)、隨(sui)器(qi)兩種(zhong)方式進(jin)行(xing)互換，并且(qie)可(ke)以達到不錯的補(bu)償效(xiao)果，運行(xing)的十分方便靈活，而且(qie)在維(wei)護和(he)壽命上較前兩者更占(zhan)優(you)(you)勢。但(dan)是由于其控制保護裝置較為(wei)復雜，投資(zi)較大。

四、無(wu)功補償對電網的(de)影響(xiang)

（一）降低電網線(xian)路(lu)損耗

因為電力(li)線(xian)路上有功(gong)(gong)功(gong)(gong)率的(de)損耗(hao)是(shi)跟功(gong)(gong)率因數的(de)平方形成(cheng)反比的(de)，如果(guo)把功(gong)(gong)率因數增大，那么會達到將達電力(li)線(xian)路的(de)有功(gong)(gong)損耗(hao)，因而在傳(chuan)輸過程中能(neng)夠減少電能(neng)的(de)損耗(hao)。

（二）降低(di)電網的功(gong)率損耗

如果無功補償的(de)能量增加了，那么電(dian)網(wang)發送(song)的(de)無功功率(lv)就會相應減少，因而(er)可以達到把電(dian)網(wang)和(he)變壓器中的(de)功率(lv)損耗降低的(de)目的(de)，從而(er)使供(gong)電(dian)效率(lv)得到大大提高。

（三）降低電(dian)網的電(dian)壓損(sun)耗

由于在無功補償運行(xing)后(hou)，會(hui)使電(dian)力網的無功功率減少(shao)，電(dian)力線(xian)路中的電(dian)壓(ya)(ya)損耗也(ye)因(yin)之降(jiang)低，從而使用戶端的電(dian)壓(ya)(ya)質量也(ye)得到(dao)提高。

（四）增大電網輸出的有功功率

根據視在(zai)功(gong)率(lv)s與電網中(zhong)的(de)(de)(de)有功(gong)功(gong)率(lv)P之間(jian)關系可以知道，如果(guo)視在(zai)功(gong)率(lv)不(bu)變，功(gong)率(lv)因(yin)數COS就會增(zeng)大，那(nei)么相應的(de)(de)(de)也(ye)會使電網輸出(chu)(chu)的(de)(de)(de)有功(gong)功(gong)率(lv)P得(de)到增(zeng)大，而在(zai)電網發出(chu)(chu)功(gong)率(lv)中(zhong)的(de)(de)(de)有用功(gong)比例(li)也(ye)得(de)到提高。

五、無功補償應注意的問(wen)題

（一）防止過補償

如果使(shi)用(yong)操(cao)作(zuo)(zuo)電容器來使(shi)電動機得到(dao)補償，在把電源切(qie)斷后，電動機還(huan)會因(yin)為(wei)慣性作(zuo)(zuo)用(yong)持續運行一會，而(er)這時的(de)(de)(de)(de)電容器的(de)(de)(de)(de)放(fang)電電流就變成勵(li)磁電流，電動機的(de)(de)(de)(de)磁場得到(dao)自勵(li)，從而(er)出現電壓(ya)向系統倒送(song)無(wu)功(gong)。剩下的(de)(de)(de)(de)多余的(de)(de)(de)(de)無(wu)功(gong)功(gong)率會使(shi)運行電壓(ya)得到(dao)提高，對(dui)設備(bei)的(de)(de)(de)(de)安全造(zao)成威(wei)脅，對(dui)網絡的(de)(de)(de)(de)損耗也會加大，節能效果也會因(yin)之而(er)降低(di)。

（二）功率因數(shu)補(bu)償要合理

通過(guo)數據(ju)分析可以得(de)知，如果把功(gong)(gong)率(lv)因(yin)(yin)數從0.9提(ti)(ti)高到(dao)(dao)1.0，其所用的補(bu)償(chang)容量跟把功(gong)(gong)率(lv)因(yin)(yin)數從0.8提(ti)(ti)高到(dao)(dao)0.9的補(bu)償(chang)容量相(xiang)差不多(duo)。但分析后(hou)得(de)知，前者降損幅度才為后(hou)者的一半，因(yin)(yin)而(er)不能一定強迫追求(qiu)高補(bu)償(chang)度，而(er)是應該根(gen)據(ju)投資效益來一起采取措施(shi)。一般(ban)而(er)言，補(bu)償(chang)后(hou)的功(gong)(gong)率(lv)因(yin)(yin)數在0.9～0.95之間則為正常。

（三）防止產(chan)生諧振(zhen)

如果遇到供電線路存(cun)在諧(xie)波源，就需要采用增加電抗器等(deng)方法(fa)，使電容器不會因為受(shou)其影(ying)響而損壞(huai)。

（四）防止過電壓

如果(guo)電(dian)(dian)容(rong)(rong)器在補償容(rong)(rong)量過大時，電(dian)(dian)網電(dian)(dian)壓就會升高(gao)，電(dian)(dian)容(rong)(rong)器也因之而損壞，根據(ju)國(guo)標的(de)(de)規定，工頻長期過電(dian)(dian)壓值最多(duo)不能超(chao)過1.1倍(bei)的(de)(de)額定電(dian)(dian)壓。

六、結語

隨著經濟，社(she)會(hui)的(de)發展(zhan)以(yi)及電(dian)(dian)(dian)(dian)力體制(zhi)改革(ge)的(de)不(bu)斷深(shen)入。電(dian)(dian)(dian)(dian)網(wang)技術工作遇到了很多(duo)前所未有的(de)挑戰(zhan)，面(mian)臨著許多(duo)新(xin)問(wen)題。在(zai)低(di)壓(ya)電(dian)(dian)(dian)(dian)網(wang)中(zhong)，由于存在(zai)配(pei)(pei)電(dian)(dian)(dian)(dian)變壓(ya)器多(duo)和(he)輸電(dian)(dian)(dian)(dian)線路長的(de)問(wen)題，電(dian)(dian)(dian)(dian)網(wang)在(zai)傳輸過程中(zhong)就會(hui)將(jiang)很多(duo)電(dian)(dian)(dian)(dian)能(neng)損(sun)(sun)耗(hao)掉，因(yin)而低(di)壓(ya)電(dian)(dian)(dian)(dian)網(wang)的(de)運行狀況和(he)電(dian)(dian)(dian)(dian)能(neng)損(sun)(sun)耗(hao)的(de)多(duo)少是和(he)電(dian)(dian)(dian)(dian)網(wang)工作的(de)穩(wen)定(ding)以(yi)及安全(quan)生產和(he)人們生活用電(dian)(dian)(dian)(dian)有著十分密切的(de)聯系。因(yin)而，在(zai)配(pei)(pei)電(dian)(dian)(dian)(dian)網(wang)中(zhong)實行無功補(bu)償，來提高功率因(yin)數，已經成為降低(di)電(dian)(dian)(dian)(dian)能(neng)損(sun)(sun)耗(hao)、提高輸配(pei)(pei)電(dian)(dian)(dian)(dian)設備的(de)有效方(fang)法。

參考文獻

[1] 孫(sun)立(li)滿，陳繼軍．農(nong)村配電網中無功補償的(de)探討[J]．安徽(hui)電力(li)，2008，（4）．

[2] 劉建強，陳剛．配電(dian)網四(si)種無功(gong)補償技(ji)術方案比較[J]．電(dian)力(li)電(dian)容(rong)器，2003，（3）．

[3] 劉和．淺談低壓電網變配電設備的安裝[J]．黑龍江科技信息，2011，（35）．

[4] 羅(luo)寶君(jun)，張興東．我國低(di)壓電網(wang)中(zhong)無功(gong)補償(chang)的意義(yi)探析[J].科(ke)學與財(cai)富，2011，（12）.

篇9

關鍵(jian)詞 低壓用電設備；無功補償；原(yuan)理；特點；前(qian)景(jing)

中圖(tu)分類號 TL503 文獻標識碼 A 文章編號 1673-9671-(2012)072-0174-01

低壓無功補償(chang)技術是指在低電壓配電網(wang)中安(an)裝無功補償(chang)裝置的一(yi)種方(fang)法，主要有隨(sui)機補償(chang)、隨(sui)器補償(chang)、跟(gen)蹤(zong)補償(chang)三種實現途經(jing)。當前國內一(yi)些(xie)低壓用(yong)電設備的無功損耗達到(dao)損耗的80%以(yi)上(shang)，這跟(gen)我國向新(xin)型節(jie)能國家(jia)大步邁進的理(li)念(nian)是不相稱(cheng)的，所以(yi)研究推廣無功補償(chang)新(xin)技術意(yi)義重大。

1 低壓(ya)無功(gong)功(gong)率補償(chang)的(de)原理(li)和效(xiao)益

1.1 原理解析

現實的(de)電力(li)網中(zhong)接(jie)入(ru)了(le)很多如電動機(ji)、變壓器(qi)等電力(li)負(fu)(fu)荷，這些(xie)負(fu)(fu)荷大部分(fen)屬于感性負(fu)(fu)荷，運行過程中(zhong)這些(xie)設備需吸納(na)一定的(de)無(wu)功功率(lv)(lv)(lv)。比如感性負(fu)(fu)載的(de)異步電動機(ji)會(hui)吸收(shou)電網中(zhong)的(de)無(wu)功功率(lv)(lv)(lv)，其稱為(wei)功率(lv)(lv)(lv)因數滯(zhi)后，即(ji)滯(zhi)后電流(liu)引起的(de)無(wu)功功率(lv)(lv)(lv)，所以進行無(wu)功補償，其原理如圖1所示。

圖1

圖(tu)（a）中R、L表示感性負載(zai)，電(dian)(dian)(dian)(dian)(dian)流(liu)為IL，功(gong)率(lv)因(yin)數角為λ。在負載(zai)支路兩端并(bing)聯電(dian)(dian)(dian)(dian)(dian)容C后，電(dian)(dian)(dian)(dian)(dian)流(liu)Ic超前電(dian)(dian)(dian)(dian)(dian)壓U的(de)角度λ為-900。并(bing)聯電(dian)(dian)(dian)(dian)(dian)容器(qi)后，流(liu)過(guo)RL支路的(de)電(dian)(dian)(dian)(dian)(dian)流(liu)仍為IL，但在并(bing)聯點前的(de)電(dian)(dian)(dian)(dian)(dian)流(liu)就是IL與Ic的(de)相量和，相量關系(xi)見(jian)圖(tu)（b）。

1.2 無功補償的(de)效(xiao)益

無功補(bu)償方式的效益主要體現在以下兩個(ge)方面：

對供電(dian)設(she)備(bei)而言：無功補償能夠減少線(xian)路的電(dian)壓損失，降低供電(dian)設(she)備(bei)如變壓器、開關的電(dian)能損耗，同時還能提(ti)高傳輸過(guo)程中有功功功率比例，最大化(hua)利用好設(she)備(bei)的容量(liang)；另(ling)外(wai)還有，改善供電(dian)環境以(yi)及(ji)提(ti)高供電(dian)效率等功能。

對低壓用電(dian)設備而言(yan)：無功補償可以改(gai)善包(bao)括斷路器、接觸器等(deng)控制(zhi)設備的效用，延長其(qi)電(dian)氣壽命。同時(shi)，還能避免電(dian)壓波形(xing)畸形(xing)，提高電(dian)網的穩(wen)定性。

2 不同(tong)類型的(de)無(wu)功補償裝(zhuang)置

2.1 以電容器(qi)的控制投(tou)入方式為主的補償裝置類型(xing)

以電容(rong)器(qi)的(de)控(kong)制投入方式為主的(de)補償(chang)裝(zhuang)置(zhi)包(bao)括交(jiao)流(liu)接觸器(qi)控(kong)制投入型補償(chang)裝(zhuang)置(zhi)、晶(jing)閘(zha)管(guan)控(kong)制投入型補償(chang)裝(zhuang)置(zhi)、復合開關控(kong)制投入型補償(chang)裝(zhuang)置(zhi)。

2.1.1 交流接(jie)觸器控(kong)制投入型補償裝置

在電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)的(de)(de)安(an)裝過(guo)程(cheng)中(zhong)會產生極大的(de)(de)涌流(liu)(liu)(liu)(liu)(liu)，涌流(liu)(liu)(liu)(liu)(liu)值有時會超(chao)過(guo)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)(de)100倍，對(dui)電(dian)(dian)(dian)(dian)(dian)網(wang)造成干擾，減少電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)的(de)(de)使用(yong)壽命。目前(qian)，我們常(chang)通(tong)過(guo)使用(yong)投(tou)切(qie)專用(yong)接(jie)(jie)觸(chu)(chu)器(qi)(qi)來降低涌流(liu)(liu)(liu)(liu)(liu)。這(zhe)種接(jie)(jie)觸(chu)(chu)器(qi)(qi)在接(jie)(jie)觸(chu)(chu)器(qi)(qi)切(qie)合的(de)(de)過(guo)程(cheng)中(zhong)，先接(jie)(jie)通(tong)輔助觸(chu)(chu)頭，通(tong)過(guo)限流(liu)(liu)(liu)(liu)(liu)電(dian)(dian)(dian)(dian)(dian)阻接(jie)(jie)入電(dian)(dian)(dian)(dian)(dian)路對(dui)電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)進行(xing)預充電(dian)(dian)(dian)(dian)(dian)，主觸(chu)(chu)頭接(jie)(jie)通(tong)再將電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)接(jie)(jie)入電(dian)(dian)(dian)(dian)(dian)路，這(zhe)樣(yang)可將涌流(liu)(liu)(liu)(liu)(liu)限制在電(dian)(dian)(dian)(dian)(dian)容(rong)器(qi)(qi)額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)(liu)的(de)(de)20倍以內。

2.1.2 晶閘管控制(zhi)投(tou)入型(xing)補償裝置

TSC就是晶閘(zha)(zha)管(guan)(guan)控制(zhi)投入型補償裝(zhuang)置，屬于無功補償裝(zhuang)置SVC的一個子類(lei)。這種裝(zhuang)置在晶閘(zha)(zha)管(guan)(guan)兩端(duan)電壓為零時發出瞬間觸發信號。如果晶閘(zha)(zha)管(guan)(guan)導(dao)通電壓降至1V的話，會產生很(hen)大的損耗(hao)，對散熱片(pian)的要求很(hen)高。

2.1.3 復(fu)合開關(guan)控制投入(ru)型(xing)補償裝置

復(fu)合(he)開關控制投入(ru)型補償(chang)裝(zhuang)置(zhi)是為了防(fang)止涌流(liu)入(ru)電(dian)容(rong)器，減少晶閘管(guan)持(chi)續(xu)運作時的耗費(fei)損失問題。電(dian)容(rong)器投入(ru)時，先利(li)用晶閘管(guan)過零觸(chu)發來(lai)實(shi)現無涌流(liu)投入(ru)電(dian)容(rong)器，同時連通機械開關來(lai)保證電(dian)容(rong)器的順利(li)連續(xu)運行(xing)。

2.2 以電容(rong)器(qi)連接方式為出發點的補償裝置

以電(dian)容(rong)(rong)器(qi)連(lian)接(jie)方式為出(chu)發(fa)點的補償裝(zhuang)置(zhi)有三相(xiang)電(dian)容(rong)(rong)器(qi)同(tong)時(shi)投(tou)切型補償裝(zhuang)置(zhi)、單相(xiang)電(dian)容(rong)(rong)器(qi)分相(xiang)投(tou)切型補償裝(zhuang)置(zhi)、調整不(bu)平衡電(dian)流(liu)型補償裝(zhuang)置(zhi)三種裝(zhuang)置(zhi)。

2.2.1 三相電容器(qi)同時(shi)投切型補償裝(zhuang)置

該補(bu)償(chang)裝置主要針對三(san)相(xiang)電(dian)力容器，通過其中(zhong)一(yi)相(xiang)的(de)(de)(de)電(dian)流(liu)(liu)檢(jian)測(ce)來計(ji)算，為了達到(dao)補(bu)償(chang)目的(de)(de)(de)，還要控制電(dian)容器的(de)(de)(de)投(tou)入數量(liang)。因為電(dian)容器給三(san)相(xiang)提供的(de)(de)(de)無功(gong)電(dian)流(liu)(liu)是(shi)差不多(duo)的(de)(de)(de)，所以這類(lei)補(bu)償(chang)裝置只有在三(san)相(xiang)電(dian)流(liu)(liu)基本平(ping)衡的(de)(de)(de)情況下才能實現(xian)。當負(fu)荷的(de)(de)(de)三(san)相(xiang)電(dian)流(liu)(liu)不平(ping)衡的(de)(de)(de)時候，三(san)相(xiang)便無法得到(dao)最佳的(de)(de)(de)平(ping)均補(bu)償(chang)，無法達到(dao)平(ping)衡補(bu)償(chang)。

2.2.2 單相電容器分相投切型補償裝置(zhi)

單(dan)相(xiang)(xiang)(xiang)電容器分(fen)相(xiang)(xiang)(xiang)投切(qie)型補(bu)償(chang)裝(zhuang)置(zhi)(zhi)是經過三相(xiang)(xiang)(xiang)電流分(fen)別檢測來計算并(bing)且目的是控制各(ge)相(xiang)(xiang)(xiang)電容器的投入(ru)量來達到補(bu)償(chang)，這種裝(zhuang)置(zhi)(zhi)相(xiang)(xiang)(xiang)當于安裝(zhuang)3臺單(dan)相(xiang)(xiang)(xiang)補(bu)償(chang)裝(zhuang)置(zhi)(zhi)的效果。

2.2.3 調整不平(ping)衡電流型補償裝(zhuang)置(zhi)

 調整(zheng)不(bu)平(ping)衡電(dian)(dian)流(liu)(liu)型補(bu)償裝置(zhi)是用(yong)三(san)相電(dian)(dian)流(liu)(liu)檢測(ce)綜合計算并(bing)且目的(de)(de)是通過對(dui)各相電(dian)(dian)容器投入方式和適合數量(liang)的(de)(de)嚴格控制來達(da)到(dao)補(bu)償和調節不(bu)平(ping)衡電(dian)(dian)流(liu)(liu)的(de)(de)要求(qiu)。

3 低壓用電設(she)備無功補(bu)償技術(shu)

3.1 低(di)壓用電設(she)備無功補(bu)償的限制條件

低(di)壓(ya)用(yong)電(dian)設(she)備無功補償的(de)限(xian)制條件(jian)要從低(di)壓(ya)電(dian)機的(de)特性來(lai)看，要根據低(di)壓(ya)電(dian)機的(de)各(ge)項特性來(lai)探究其限(xian)制的(de)條件(jian)。其中自(zi)勵現象是限(xian)制的(de)重要條件(jian)。

自(zi)(zi)勵現(xian)象是電(dian)動(dong)機的(de)磁場得(de)到加(jia)強而產(chan)生的(de)高電(dian)壓(ya)(ya)的(de)現(xian)象，自(zi)(zi)勵現(xian)象下(xia)產(chan)生的(de)自(zi)(zi)勵電(dian)壓(ya)(ya)在電(dian)動(dong)機是補償并且是空載的(de)情況下(xia)可(ke)以達(da)到普(pu)通額定電(dian)壓(ya)(ya)的(de)2倍左(zuo)右(you)。當低壓(ya)(ya)用電(dian)設備處于自(zi)(zi)勵現(xian)象的(de)狀態時，其無功(gong)補償的(de)容(rong)量(liang)會減少，只(zhi)有在避免自(zi)(zi)勵電(dian)壓(ya)(ya)的(de)產(chan)生下(xia)補償容(rong)量(liang)才可(ke)以更大。

3.2 低壓用電設(she)備無功補償(chang)的適(shi)用條件

適(shi)用(yong)條件(jian)是指低(di)壓用(yong)電(dian)設(she)備(bei)無(wu)功(gong)(gong)補償(chang)過程中的(de)(de)(de)(de)(de)要求適(shi)用(yong)的(de)(de)(de)(de)(de)范圍，低(di)壓用(yong)電(dian)設(she)備(bei)無(wu)功(gong)(gong)補償(chang)的(de)(de)(de)(de)(de)適(shi)用(yong)條件(jian)主(zhu)要是對(dui)(dui)于(yu)補償(chang)容(rong)(rong)量(liang)的(de)(de)(de)(de)(de)選(xuan)擇。為(wei)了(le)使(shi)網絡的(de)(de)(de)(de)(de)損耗得到最大程度的(de)(de)(de)(de)(de)降(jiang)低(di)、提(ti)高電(dian)網質量(liang)，就(jiu)需(xu)要對(dui)(dui)補償(chang)裝(zhuang)置類型和配置有(you)針對(dui)(dui)性地進(jin)行合理選(xuan)擇。低(di)壓用(yong)電(dian)設(she)備(bei)無(wu)功(gong)(gong)補償(chang)的(de)(de)(de)(de)(de)適(shi)用(yong)條件(jian)主(zhu)要是對(dui)(dui)于(yu)補償(chang)容(rong)(rong)量(liang)的(de)(de)(de)(de)(de)選(xuan)擇，這(zhe)要根據(ju)其運行情況來進(jin)行測(ce)算。根據(ju)以下的(de)(de)(de)(de)(de)公式：

 式(shi)中ψ2為補償后(hou)的(de)功率(lv)因(yin)數角；Ul為實測的(de)電(dian)動(dong)機電(dian)壓；I1為實測的(de)電(dian)動(dong)機電(dian)流。

以上所(suo)顯示的(de)是(shi)補(bu)償(chang)電(dian)(dian)容(rong)器所(suo)需容(rong)量選擇的(de)兩種計算方法。電(dian)(dian)容(rong)器容(rong)量是(shi)無功補(bu)償(chang)技術適用(yong)下的(de)一(yi)個重要標桿，低壓用(yong)電(dian)(dian)設備(bei)的(de)無功補(bu)償(chang)的(de)適用(yong)范圍是(shi)由電(dian)(dian)容(rong)器的(de)容(rong)量決定的(de)。

4 低壓用電設備無功功率補償(chang)技術的前景

隨著(zhu)電力企業進入精細化管(guan)理的(de)階段，對(dui)供電質量(liang)提出了更(geng)高的(de)要(yao)求(qiu)，作為(wei)能(neng)切實改善電能(neng)質量(liang)，保(bao)障(zhang)電網運行的(de)一種成本(ben)低(di)、應用廣、可靠性高的(de)無功補償技術必(bi)將得(de)到越來越多的(de)

重視。

5 總結

本文通過對無(wu)功(gong)補(bu)償(chang)的原理及其(qi)效益、不(bu)同類型(xing)的補(bu)償(chang)裝置(zhi)和低壓(ya)用(yong)(yong)電(dian)設備(bei)的無(wu)功(gong)補(bu)償(chang)所(suo)適用(yong)(yong)的范(fan)圍和限制條件三(san)方面對低壓(ya)用(yong)(yong)電(dian)設備(bei)的無(wu)功(gong)補(bu)償(chang)技術進行了分析(xi)和探究。

參考文獻

[1]林師賢.低壓用電(dian)設備(bei)導線選擇的(de)經(jing)濟(ji)性分(fen)析[J].科(ke)技資訊,2010,34.

[2]魏章懷.低(di)壓用電(dian)設備的安全防(fang)范措施[J].農村(cun)電(dian)氣化,2004,7.

[3]朱鵬軍.電網無功補償新技(ji)術的應用和展望[J].科技(ji)信息(xi).

篇10

關鍵詞：低壓側 ；無功補償 ； 探(tan)析

中圖(tu)分類號：C35文獻(xian)標識(shi)碼： A

電(dian)(dian)(dian)石爐(lu)功率因數是由(you)爐(lu)內電(dian)(dian)(dian)弧及爐(lu)料（生石灰與碳素按一定比(bi)例混合而成）的(de)電(dian)(dian)(dian)阻和電(dian)(dian)(dian)源回路(lu)中變壓器、短(duan)網、導電(dian)(dian)(dian)鱷板、集電(dian)(dian)(dian)環、電(dian)(dian)(dian)極的(de)電(dian)(dian)(dian)阻和電(dian)(dian)(dian)抗值決定。表達(da)式為：

Cosφ=(R+r)／√(R+r)²+x²

式中(zhong)R是爐料(liao)電(dian)阻、r和x是電(dian)源(yuan)回路中(zhong)的電(dian)阻和電(dian)抗(kang)。

電(dian)(dian)(dian)(dian)源回路中的(de)電(dian)(dian)(dian)(dian)阻(zu)和電(dian)(dian)(dian)(dian)抗取決于設計安(an)裝的(de)短網(wang)(wang)和電(dian)(dian)(dian)(dian)極布(bu)置，電(dian)(dian)(dian)(dian)阻(zu)與運行(xing)(xing)時短網(wang)(wang)上(shang)各載流(liu)(liu)部(bu)件的(de)電(dian)(dian)(dian)(dian)流(liu)(liu)密度有關(guan)，變(bian)化可以忽略不計。決定爐子運行(xing)(xing)時功率因(yin)數的(de)主要因(yin)素是(shi)爐料的(de)電(dian)(dian)(dian)(dian)阻(zu)。

電(dian)(dian)石(shi)(shi)爐(lu)比其(qi)他電(dian)(dian)冶爐(lu)的(de)電(dian)(dian)阻(zu)小，功率(lv)因(yin)數也相應低(di)，特別是(shi)大(da)功率(lv)的(de)電(dian)(dian)石(shi)(shi)爐(lu)的(de)自(zi)然功率(lv)因(yin)數比較低(di)，一般(ban)在0.83左右，為(wei)了滿(man)足電(dian)(dian)爐(lu)生(sheng)產需(xu)要，達到高(gao)產、優質、低(di)耗，降(jiang)低(di)生(sheng)產成本，電(dian)(dian)石(shi)(shi)爐(lu)上安裝電(dian)(dian)容補償裝置來提高(gao)功率(lv)因(yin)數。在大(da)功率(lv)電(dian)(dian)石(shi)(shi)爐(lu)采(cai)取以下三種電(dian)(dian)容補償型式：

第(di)一種(zhong)補償型(xing)式：高(gao)(gao)壓(ya)并聯電(dian)容補償裝置，安裝在電(dian)爐(lu)(lu)變壓(ya)器(qi)高(gao)(gao)壓(ya)側，根據(ju)供電(dian)方(fang)(fang)式、用電(dian)負荷情(qing)況選擇補償容量、保護方(fang)(fang)式及(ji)安裝方(fang)(fang)法。雖(sui)然提高(gao)(gao)了(le)電(dian)網(wang)功率因數，改善供電(dian)質量，但是，不能直接(jie)改善電(dian)石爐(lu)(lu)的功率因數，不能提高(gao)(gao)爐(lu)(lu)子的電(dian)效率，發揮電(dian)爐(lu)(lu)生(sheng)產(chan)能力意義不大。

第二(er)種補償(chang)型(xing)式(shi)：中(zhong)壓并聯電容補償(chang)裝置，主要用于三(san)相、分相有載(zai)調壓電石(shi)爐，一般較少(shao)采(cai)取(qu)這種補償(chang)方(fang)式(shi)。

第三種補(bu)(bu)(bu)償(chang)(chang)(chang)型式：低(di)壓(ya)(ya)(ya)(ya)并(bing)(bing)聯(lian)電(dian)(dian)容(rong)補(bu)(bu)(bu)償(chang)(chang)(chang)裝置(zhi)，由于(yu)電(dian)(dian)石(shi)爐(lu)(lu)(lu)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)二(er)(er)次(ci)側具有(you)(you)電(dian)(dian)壓(ya)(ya)(ya)(ya)低(di)、電(dian)(dian)流大，以及負荷、電(dian)(dian)壓(ya)(ya)(ya)(ya)有(you)(you)一(yi)(yi)定(ding)變(bian)(bian)(bian)(bian)化范圍的(de)特點，低(di)壓(ya)(ya)(ya)(ya)并(bing)(bing)聯(lian)電(dian)(dian)容(rong)補(bu)(bu)(bu)償(chang)(chang)(chang)要有(you)(you)與之相(xiang)(xiang)適應的(de)技術(shu)特性(xing)。在(zai)(zai)80、90年代(dai)，采取低(di)壓(ya)(ya)(ya)(ya)并(bing)(bing)聯(lian)電(dian)(dian)容(rong)補(bu)(bu)(bu)償(chang)(chang)(chang)方式，由一(yi)(yi)臺(tai)相(xiang)(xiang)當(dang)容(rong)量、電(dian)(dian)壓(ya)(ya)(ya)(ya)在(zai)(zai)一(yi)(yi)定(ding)范圍內調節的(de)補(bu)(bu)(bu)償(chang)(chang)(chang)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)和(he)并(bing)(bing)聯(lian)電(dian)(dian)容(rong)器(qi)、電(dian)(dian)抗器(qi)等構成。其原理：補(bu)(bu)(bu)償(chang)(chang)(chang)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)一(yi)(yi)次(ci)側與短網并(bing)(bing)接，補(bu)(bu)(bu)償(chang)(chang)(chang)變(bian)(bian)(bian)(bian)壓(ya)(ya)(ya)(ya)器(qi)二(er)(er)次(ci)電(dian)(dian)壓(ya)(ya)(ya)(ya)設計(ji)標稱電(dian)(dian)壓(ya)(ya)(ya)(ya)10.5KV，電(dian)(dian)容(rong)器(qi)額定(ding)電(dian)(dian)壓(ya)(ya)(ya)(ya)11KV。在(zai)(zai)補(bu)(bu)(bu)償(chang)(chang)(chang)變(bian)(bian)(bian)(bian)二(er)(er)次(ci)側安(an)裝一(yi)(yi)臺(tai)真(zhen)空開(kai)關、串聯(lian)電(dian)(dian)抗器(qi)及并(bing)(bing)聯(lian)電(dian)(dian)容(rong)器(qi)，由電(dian)(dian)容(rong)器(qi)產生無功(gong)(gong)功(gong)(gong)率，一(yi)(yi)部(bu)分補(bu)(bu)(bu)償(chang)(chang)(chang)電(dian)(dian)爐(lu)(lu)(lu)變(bian)(bian)(bian)(bian)的(de)無功(gong)(gong)損失(shi)，一(yi)(yi)部(bu)分通過(guo)電(dian)(dian)爐(lu)(lu)(lu)變(bian)(bian)(bian)(bian)由系(xi)統吸收，就可以改善爐(lu)(lu)(lu)子的(de)功(gong)(gong)率因數，提高電(dian)(dian)爐(lu)(lu)(lu)變(bian)(bian)(bian)(bian)的(de)出力，提高爐(lu)(lu)(lu)內的(de)有(you)(you)功(gong)(gong)功(gong)(gong)率。該補(bu)(bu)(bu)償(chang)(chang)(chang)裝置(zhi)投資大，設計(ji)施工(gong)(gong)復雜，維護工(gong)(gong)作量大。

隨著科學(xue)技(ji)術(shu)不斷(duan)發展，電(dian)(dian)石爐(lu)無(wu)(wu)功(gong)(gong)補(bu)償(chang)(chang)技(ji)術(shu)利用現(xian)代(dai)控制技(ji)術(shu)和短網技(ji)術(shu)將(jiang)大容量、大電(dian)(dian)流的超低(di)壓電(dian)(dian)力電(dian)(dian)容器組接入電(dian)(dian)爐(lu)二次側(ce)的無(wu)(wu)功(gong)(gong)功(gong)(gong)率(lv)補(bu)償(chang)(chang)裝置。不再經過補(bu)償(chang)(chang)點(dian)前(qian)的短網、變(bian)壓器及供(gong)電(dian)(dian)網路(lu)，直接將(jiang)該裝置與集電(dian)(dian)環并接，對爐(lu)子(zi)進行無(wu)(wu)功(gong)(gong)功(gong)(gong)率(lv)補(bu)償(chang)(chang)，在(zai)提高功(gong)(gong)率(lv)因數、消除諧波的同時，提高變(bian)壓器的有功(gong)(gong)輸出(chu)率(lv)，降低(di)變(bian)壓器、短網的無(wu)(wu)功(gong)(gong)消耗(hao)。

該裝置并聯補償(chang)電容(rong)(rong)器(qi)(qi)(qi)組采(cai)用(yong)自(zi)愈干(gan)式電容(rong)(rong)器(qi)(qi)(qi)，內置壓力(li)切斷(duan)防爆(bao)裝置，自(zi)愈性強，使用(yong)壽命(ming)長，加裝不(bu)同比值的(de)(de)電抗(kang)，專用(yong)電容(rong)(rong)投切器(qi)(qi)(qi)抑制浪涌電流。采(cai)取就(jiu)地補償(chang)，使電爐的(de)(de)功(gong)率因數在(zai)0.92以上運行，降(jiang)低(di)短網和一次(ci)側的(de)(de)無功(gong)消耗，消除5次(ci)、7次(ci)諧波，調(diao)平三相功(gong)率，抑制閃變，提高變壓器(qi)(qi)(qi)的(de)(de)輸出能力(li)。

該裝置(zhi)設計重點(dian)采用分相(xiang)(xiang)動態補償，使(shi)(shi)三相(xiang)(xiang)功(gong)率(lv)(lv)不平(ping)衡度(du)下降(jiang)，達到三相(xiang)(xiang)功(gong)率(lv)(lv)相(xiang)(xiang)等(deng)，使(shi)(shi)電(dian)石爐(lu)的(de)(de)功(gong)率(lv)(lv)中(zhong)(zhong)心和爐(lu)膛(tang)中(zhong)(zhong)心相(xiang)(xiang)重合，使(shi)(shi)熔池擴大，熱量(liang)集中(zhong)(zhong)，提高爐(lu)內溫度(du)，使(shi)(shi)反應速度(du)加快，達到提高產品質量(liang)，降(jiang)耗和增產的(de)(de)目的(de)(de)。

我省遵義聯(lian)合(he)電(dian)(dian)(dian)(dian)(dian)化設(she)計安裝(zhuang)三臺3*6670KVA電(dian)(dian)(dian)(dian)(dian)石爐，電(dian)(dian)(dian)(dian)(dian)爐變(bian)是(shi)由三臺單相6667KVA變(bian)壓(ya)(ya)器，等(deng)邊三角形布置(zhi)，容量20000KVA，一次(ci)(ci)供(gong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)110KV,35檔有載調壓(ya)(ya)，二(er)次(ci)(ci)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)常用級(ji)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)170V，最高級(ji)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)260V，最低(di)級(ji)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)90V，不停電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)放電(dian)(dian)(dian)(dian)(dian)極(ji)(ji)。單臺電(dian)(dian)(dian)(dian)(dian)石爐生產(chan)能(neng)力40000噸(dun)/年(nian)電(dian)(dian)(dian)(dian)(dian)石，生產(chan)能(neng)力120000噸(dun)/年(nian)標準電(dian)(dian)(dian)(dian)(dian)石。設(she)計選用低(di)壓(ya)(ya)并(bing)聯(lian)電(dian)(dian)(dian)(dian)(dian)容器無功補償(chang)(chang)裝(zhuang)置(zhi)，即直(zhi)接(jie)將(jiang)并(bing)聯(lian)電(dian)(dian)(dian)(dian)(dian)容器與電(dian)(dian)(dian)(dian)(dian)爐變(bian)二(er)次(ci)(ci)側(ce)電(dian)(dian)(dian)(dian)(dian)極(ji)(ji)系(xi)統并(bing)接(jie)。電(dian)(dian)(dian)(dian)(dian)爐變(bian)低(di)壓(ya)(ya)側(ce)進行補償(chang)(chang)，使補償(chang)(chang)點上連接(jie)的無功補償(chang)(chang)裝(zhuang)置(zhi)既能(neng)盡可能(neng)多的補償(chang)(chang)系(xi)統無功，同時要兼(jian)顧短網的合(he)理接(jie)入，減(jian)少冶煉(lian)環境及操(cao)作維護(hu)等(deng)不利因素帶來的影響。

根據(ju)電(dian)(dian)石(shi)爐(lu)額定參數及運(yun)(yun)行(xing)(xing)情況，按照爐(lu)變(bian)長期1.50倍(bei)過載運(yun)(yun)行(xing)(xing)，使運(yun)(yun)行(xing)(xing)功(gong)率因(yin)數由0.83提高(gao)到(dao)0.95，低壓(ya)補(bu)償(chang)安(an)(an)裝采(cai)(cai)用單相補(bu)償(chang)方式，每相分別控制，動(dong)態(tai)(tai)調節(jie)各自功(gong)率因(yin)數。柜(ju)(ju)內主母線(xian)采(cai)(cai)用銅管(guan)母線(xian)，支(zhi)母線(xian)采(cai)(cai)用銅母排。柜(ju)(ju)內安(an)(an)裝溫(wen)度傳感器，實時(shi)(shi)監測柜(ju)(ju)內溫(wen)度變(bian)化，自動(dong)啟動(dong)通(tong)風設備，保(bao)(bao)證設備處于良好的工作環境，并能夠(gou)在溫(wen)度超過設定值時(shi)(shi)系統退出運(yun)(yun)行(xing)(xing)。在控制回路(lu)配(pei)置(zhi)穩壓(ya)電(dian)(dian)源確保(bao)(bao)交(jiao)流配(pei)電(dian)(dian)不正(zheng)常(chang)時(shi)(shi)補(bu)償(chang)設備能夠(gou)可靠工作，補(bu)償(chang)設備運(yun)(yun)行(xing)(xing)時(shi)(shi)，實時(shi)(shi)動(dong)態(tai)(tai)補(bu)償(chang)系統無功(gong)，使功(gong)率因(yin)數提高(gao)到(dao)預(yu)設值.配(pei)置(zhi)電(dian)(dian)爐(lu)專用后臺(tai)監控設備，將電(dian)(dian)爐(lu)運(yun)(yun)行(xing)(xing)參數實時(shi)(shi)傳送到(dao)電(dian)(dian)爐(lu)操作平臺(tai)，指導工作人員操作。

功率因素要達到比較理(li)(li)想狀況(kuang)，綜合考慮電(dian)(dian)爐(lu)的(de)幾何(he)參(can)數，以及(ji)電(dian)(dian)氣參(can)數，必須合理(li)(li)選擇補(bu)償(chang)(chang)(chang)電(dian)(dian)容(rong)(rong)(rong)(rong)器的(de)容(rong)(rong)(rong)(rong)量。該(gai)公司1#電(dian)(dian)爐(lu)低壓電(dian)(dian)容(rong)(rong)(rong)(rong)補(bu)償(chang)(chang)(chang)容(rong)(rong)(rong)(rong)量8000千乏，2#電(dian)(dian)爐(lu)低壓電(dian)(dian)容(rong)(rong)(rong)(rong)補(bu)償(chang)(chang)(chang)容(rong)(rong)(rong)(rong)量6000千乏，3#低壓電(dian)(dian)容(rong)(rong)(rong)(rong)補(bu)償(chang)(chang)(chang)容(rong)(rong)(rong)(rong)量8000千乏。2#電(dian)(dian)爐(lu)先投(tou)入運行(xing)(xing)，在低壓并聯電(dian)(dian)容(rong)(rong)(rong)(rong)器設(she)(she)計(ji)時，從(cong)理(li)(li)論(lun)技術上考慮，功率因數提高不顯著。1#、3#電(dian)(dian)爐(lu)根據(ju)2#爐(lu)運行(xing)(xing)情況(kuang)，以及(ji)在電(dian)(dian)石生產和(he)電(dian)(dian)爐(lu)運行(xing)(xing)最佳工況(kuang)來(lai)設(she)(she)計(ji)無功補(bu)償(chang)(chang)(chang)裝(zhuang)(zhuang)置(zhi)及(ji)補(bu)償(chang)(chang)(chang)容(rong)(rong)(rong)(rong)量。該(gai)裝(zhuang)(zhuang)置(zhi)投(tou)入運行(xing)(xing)，受各臺(tai)電(dian)(dian)爐(lu)安裝(zhuang)(zhuang)、幾何(he)參(can)數、電(dian)(dian)氣參(can)數及(ji)爐(lu)料的(de)影(ying)響，功率因數也不同。

根據1#、2#、3#電(dian)(dian)(dian)石(shi)(shi)爐投入(ru)生產，電(dian)(dian)(dian)爐的(de)生產工藝及工況滿足要求(qiu)，在電(dian)(dian)(dian)爐變容(rong)量20000KVA，二(er)次電(dian)(dian)(dian)壓170V（常用級電(dian)(dian)(dian)壓），二(er)次電(dian)(dian)(dian)流67925A，電(dian)(dian)(dian)流電(dian)(dian)(dian)壓比400，電(dian)(dian)(dian)爐負(fu)荷(he)滿載運行(xing)，投入(ru)低(di)壓無(wu)功補償(chang)后，各臺電(dian)(dian)(dian)石(shi)(shi)爐運行(xing)參數表(biao)一、表(biao)二(er)、

1#、3#電石爐(lu)投入補(bu)償運行參數表一(yi)

電氣參(can)數 電爐自然(ran)

功率因數 補償功

率因數 運行效果

二次電(dian)壓V 二次電(dian)流(liu)A Cosφ 有功功率KW

1級 90 128302 無意(yi)義 無意(yi)義 開爐時 投入(ru)前 投入(ru)后(hou) 提(ti)高值

3級(ji) 100 115473 無意義(yi)(yi) 無意義(yi)(yi) 開爐時 ― ― ―

15級 155 74498 0.8 0.9 0.1 16000 18000 2000

17級 165 69983 0.81 0.9 0.09 16200 18000 1800

18級 170 67925 0.83 0.95 0.13 16600 19000 2400

19級 175 65984 0.85 0.95 0.12 17000 19000 2000

20級 180 64151 0.87 0.95 0.10 17400 19000 1600

25級 205 56328 0.90 不投入 ― ― ― ―

35級(ji) 260 44125 無意義 不(bu)投入 ― ― ― ―

2#電石爐投入補償運行參(can)數表(biao)

運行參(can)數(shu)內容(rong) 電爐自(zi)然

功率因數 補償功

率因數 運行效果

二次電壓V 二次電流A Cosφ 有關功率KW

1級 90 128302 無意義 無意義 開爐時 投入前 投入后(hou) 提高值

3級 100 115473 無(wu)意(yi)義 無(wu)意(yi)義 開爐時 ― ― ―

15級(ji) 155 74498 0.8 0.87 0.07 16000 17400 1400

17級 165 69983 0.81 0.88 0.07 16200 17600 1400

18級(ji) 170 67925 0.83 0.92 0.09 16600 18400 1800

19級 175 65984 0.85 0.92 0.07 17000 18400 1400

20級 180 64151 0.87 0.92 0.5 17400 18400 1000

25級 205 56328 0.90 不投入 ― ― ― ―

35級 260 44125 無意(yi)義 無意(yi)義 ― ― ― ―

通過電石(shi)生產實(shi)踐(jian)證明，大(da)、中(zhong)型在(zai)運(yun)行(xing)(xing)期間(jian)自然(ran)功(gong)率因數(shu)都在(zai)0.9以下，在(zai)設計(ji)電石(shi)爐同(tong)時(shi)，必(bi)須設計(ji)電容補償裝置，提(ti)高運(yun)行(xing)(xing)電爐的功(gong)率因數(shu)。

采(cai)取低(di)壓(ya)并(bing)聯(lian)電(dian)容(rong)(rong)器(qi)補(bu)(bu)償(chang)方(fang)(fang)式，技術成熟、可靠、安全，使(shi)用壽命長、維護管理方(fang)(fang)便。從(cong)表一(yi)、二(er)可以(yi)看出：電(dian)石爐(lu)生產運(yun)(yun)行(xing)在(zai)15級155V以(yi)下級20級205V以(yi)上(shang)投入該裝(zhuang)置(zhi)，對電(dian)爐(lu)的運(yun)(yun)行(xing)意義不大。只(zhi)有(you)(you)電(dian)石爐(lu)運(yun)(yun)行(xing)在(zai)15級155V以(yi)上(shang)及20級180V以(yi)下，在(zai)此區間，電(dian)流/電(dian)壓(ya)比適當(dang)、電(dian)氣(qi)參數(shu)與幾何參數(shu)匹配合理，電(dian)爐(lu)運(yun)(yun)行(xing)工況最佳，同(tong)時，從(cong)表二(er)與表一(yi)比較(jiao)，設計低(di)壓(ya)并(bing)聯(lian)電(dian)容(rong)(rong)器(qi)裝(zhuang)置(zhi)電(dian)容(rong)(rong)器(qi)容(rong)(rong)量(liang)沒有(you)(you)根據(ju)實際(ji)電(dian)爐(lu)運(yun)(yun)行(xing)選擇電(dian)容(rong)(rong)器(qi)容(rong)(rong)量(liang)合理。投入低(di)壓(ya)并(bing)聯(lian)電(dian)容(rong)(rong)器(qi)補(bu)(bu)償(chang)裝(zhuang)置(zhi)，不但提(ti)高功(gong)(gong)率(lv)因數(shu)，還能(neng)提(ti)高電(dian)爐(lu)運(yun)(yun)行(xing)功(gong)(gong)率(lv)14%左右(you)，電(dian)爐(lu)變的有(you)(you)功(gong)(gong)輸出可以(yi)增加10%～20%，增產可以(yi)達到8%～15%，有(you)(you)功(gong)(gong)損耗可以(yi)降(jiang)(jiang)低(di)20%～40%，噸(dun)能(neng)耗可以(yi)降(jiang)(jiang)低(di)1%～3%。電(dian)石爐(lu)動態無功(gong)(gong)功(gong)(gong)率(lv)補(bu)(bu)償(chang)技術，提(ti)高功(gong)(gong)率(lv)因數(shu)、吸(xi)收諧波，提(ti)高電(dian)效率(lv)、熱效率(lv)和節能(neng)降(jiang)(jiang)耗效果上(shang)，有(you)(you)著其他無功(gong)(gong)補(bu)(bu)償(chang)型式難以(yi)比擬的優勢(shi)。節約能(neng)源，取得較(jiao)好經(jing)濟效益。

參考文獻