一、電力電容器的補償原理
?電(dian)(dian)容器在原(yuan)(yuan)理上相當于產生容性無功電(dian)(dian)流的(de)(de)發電(dian)(dian)機。其無功補償的(de)(de)原(yuan)(yuan)理是把具有容性功率負(fu)荷(he)的(de)(de)裝(zhuang)置(zhi)(zhi)和感性功率負(fu)荷(he)并聯在同一電(dian)(dian)容器上,能量(liang)在兩種(zhong)負(fu)荷(he)間相互轉換。這(zhe)樣,電(dian)(dian)網中的(de)(de)變(bian)壓器和輸電(dian)(dian)線(xian)路的(de)(de)負(fu)荷(he)降低(di)(di),從而輸出有功能力增(zeng)加。在輸出一定(ding)有功功率的(de)(de)情(qing)況下,供電(dian)(dian)系(xi)(xi)統(tong)的(de)(de)損耗(hao)降低(di)(di)。比較起來電(dian)(dian)容器是減輕變(bian)壓器、供電(dian)(dian)系(xi)(xi)統(tong)和工業配電(dian)(dian)負(fu)荷(he)的(de)(de)最簡便、最經濟的(de)(de)方(fang)法。因(yin)此,電(dian)(dian)容器作為(wei)電(dian)(dian)力系(xi)(xi)統(tong)的(de)(de)無功補償勢在必行。當前,采用并聯電(dian)(dian)容器作為(wei)無功補償裝(zhuang)置(zhi)(zhi)已(yi)經非常普(pu)遍。
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二、電力電容器補償的特點
?電(dian)力(li)電(dian)容(rong)(rong)器(qi)(qi)無(wu)功補償裝置具(ju)有安(an)裝方便,安(an)裝地點增(zeng)減方便;有功損耗小,建設周期短;投資小;無(wu)旋轉部件,運行維護(hu)簡便;個(ge)別電(dian)容(rong)(rong)器(qi)(qi)組(zu)損壞(huai),不(bu)影響整個(ge)電(dian)容(rong)(rong)器(qi)(qi)組(zu)運行等優點。
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三、六大無功補償方式
1.高壓分散補償:
? ? ? 高壓(ya)分散補償實(shi)際就是(shi)在單臺變壓(ya)器(qi)高壓(ya)側安裝的(de),用以改善(shan)電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)質量的(de)無功補償電(dian)(dian)(dian)容器(qi)。其主要用于城市高壓(ya)配(pei)電(dian)(dian)(dian)中。
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2.高壓集中補償:
? ? ? 高壓集中補(bu)償(chang)是指將電容器裝(zhuang)于變電站或用戶降壓變電站6 kV~10 kV高(gao)(gao)壓(ya)母線的(de)補償(chang)方(fang)式(shi);電(dian)容器也可裝設于用(yong)戶(hu)總(zong)配電(dian)室低壓(ya)母線,適用(yong)于負(fu)荷較(jiao)集中、離配電(dian)母線較(jiao)近、補償(chang)容量較(jiao)大的(de)場所,用(yong)戶(hu)本(ben)身又有一定的(de)高(gao)(gao)壓(ya)負(fu)荷時(shi),可減(jian)少(shao)對電(dian)力系(xi)統無功的(de)消耗并起到一定的(de)補償(chang)作(zuo)用(yong)。其優點(dian)是易于實行自動投(tou)切,可合理地提高(gao)(gao)用(yong)戶(hu)的(de)功率(lv)因素,利用(yong)率(lv)高(gao)(gao),投(tou)資(zi)較(jiao)少(shao),便于維(wei)護,調節方(fang)便可避免過補,改善電(dian)壓(ya)質量。但(dan)這種(zhong)補償(chang)方(fang)式(shi)的(de)補償(chang)經濟效益較(jiao)差(cha)。
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3.低壓分散補(bu)償:
? ? ? 低(di)壓(ya)(ya)分散(san)補償就是根據(ju)個別(bie)用(yong)(yong)電設(she)備(bei)對無(wu)功(gong)(gong)的(de)(de)需要量,將單臺或多臺低(di)壓(ya)(ya)電容器(qi)(qi)組,分散(san)地安裝在(zai)用(yong)(yong)電設(she)備(bei)附近,以補償安裝部位前邊的(de)(de)所有(you)高低(di)壓(ya)(ya)線路(lu)和變壓(ya)(ya)器(qi)(qi)的(de)(de)無(wu)功(gong)(gong)功(gong)(gong)率。其優點(dian)是用(yong)(yong)電設(she)備(bei)運(yun)行時,無(wu)功(gong)(gong)補償投入,用(yong)(yong)電設(she)備(bei)停運(yun)時,補償設(she)備(bei)也退出,可(ke)減(jian)少配電網(wang)和變壓(ya)(ya)器(qi)(qi)中的(de)(de)無(wu)功(gong)(gong)流動,從而減(jian)少有(you)功(gong)(gong)損耗;可(ke)減(jian)少線路(lu)的(de)(de)導(dao)線截面及變壓(ya)(ya)器(qi)(qi)的(de)(de)容量,占(zhan)位(wei)小。缺點(dian)是(shi)利用率低、投資大,對變速運(yun)行,正反(fan)向運(yun)行,點(dian)動、堵轉(zhuan)、反(fan)接制動的電機則不適應。
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4.低壓集(ji)中補(bu)償(chang):
? ? ? 低壓(ya)(ya)集中(zhong)補(bu)償是(shi)指(zhi)將(jiang)低壓(ya)(ya)電(dian)(dian)容器(qi)(qi)(qi)通(tong)過低壓(ya)(ya)開關接在配(pei)電(dian)(dian)變(bian)壓(ya)(ya)器(qi)(qi)(qi)低壓(ya)(ya)母(mu)線(xian)(xian)(xian)側,以無(wu)(wu)功(gong)(gong)補(bu)償投切裝置(zhi)作(zuo)為控制保(bao)護裝置(zhi),根據低壓(ya)(ya)母(mu)線(xian)(xian)(xian)上的(de)(de)(de)無(wu)(wu)功(gong)(gong)符合而(er)(er)直(zhi)接控制電(dian)(dian)容器(qi)(qi)(qi)的(de)(de)(de)投切。電(dian)(dian)容器(qi)(qi)(qi)的(de)(de)(de)投切是(shi)整(zheng)組進行,做不(bu)到平滑(hua)的(de)(de)(de)調節。低壓(ya)(ya)補(bu)償的(de)(de)(de)優(you)點:接線(xian)(xian)(xian)簡單、運(yun)行維護工作(zuo)量小,使(shi)無(wu)(wu)功(gong)(gong)就地平衡,從而(er)(er)提(ti)高(gao)配(pei)變(bian)利(li)用率,降低網(wang)損(sun),具有較高(gao)的(de)(de)(de)經(jing)濟性,是(shi)目前無(wu)(wu)功(gong)(gong)補(bu)償中(zhong)常(chang)用的(de)(de)(de)手段之一。