一、串聯電抗器和并聯電抗器的區別在哪里
串聯(lian)電(dian)抗器與并(bing)聯(lian)電(dian)抗器有明顯區(qu)別,體現(xian)在作(zuo)用(yong)和適用(yong)范(fan)圍上,串聯(lian)電(dian)抗器主要(yao)起限流(liu)和濾波作(zuo)用(yong),并(bing)聯(lian)電(dian)抗器主要(yao)起無功補償作(zuo)用(yong),下(xia)面做詳(xiang)細介紹(shao):
1、串聯(lian)(lian)電(dian)(dian)(dian)(dian)抗(kang)器(qi)是電(dian)(dian)(dian)(dian)力系統(tong)無功(gong)補償裝置(zhi)的重(zhong)要配套設備。電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)容(rong)器(qi)與串聯(lian)(lian)電(dian)(dian)(dian)(dian)抗(kang)器(qi)串聯(lian)(lian)后,能有(you)效地抑(yi)制電(dian)(dian)(dian)(dian)網中的高(gao)次諧波(bo),限制合(he)閘涌流及(ji)操作(zuo)過電(dian)(dian)(dian)(dian)壓,改(gai)善系統(tong)的電(dian)(dian)(dian)(dian)壓波(bo)形(xing),提(ti)高(gao)電(dian)(dian)(dian)(dian)網功(gong)率因數,對電(dian)(dian)(dian)(dian)力電(dian)(dian)(dian)(dian)容(rong)器(qi)及(ji)其它電(dian)(dian)(dian)(dian)力設備的安全運行起到了較大的作(zuo)用(yong)。
串聯電抗器主要用于限(xian)制短路(lu)電流,而(er)電容器(qi)組串聯(lian)電抗器(qi)可以限(xian)制高次諧波,降低電抗。
2、并聯電抗器可以(yi)用于補償長(chang)距離輸電線(xian)路(lu)的分布電容補償,防止空載長(chang)線(xian)路(lu)末端電壓(ya)升高(通常(chang)用于500KV系統),還可以(yi)有利(li)于單相重(zhong)合(he)閘和降低(di)操作過(guo)電壓(ya)。
為了(le)提(ti)高遠距(ju)離(li)輸(shu)電(dian)(dian)線(xian)路(lu)的(de)(de)(de)傳(chuan)輸(shu)能力(li)和(he)改(gai)善(shan)線(xian)路(lu)的(de)(de)(de)運行情況,削弱空(kong)載(zai)(zai)(zai)或(huo)輕載(zai)(zai)(zai)時長線(xian)路(lu)的(de)(de)(de)電(dian)(dian)容效(xiao)應所引起的(de)(de)(de)工頻電(dian)(dian)壓升高,改(gai)善(shan)沿線(xian)電(dian)(dian)壓分(fen)布和(he)輕載(zai)(zai)(zai)線(xian)路(lu)中的(de)(de)(de)無功分(fen)布并(bing)降低線(xian)損,減少潛(qian)供(gong)電(dian)(dian)流(liu),加速潛(qian)供(gong)電(dian)(dian)弧(hu)的(de)(de)(de)熄滅,提(ti)高線(xian)路(lu)自動重合(he)閘的(de)(de)(de)成功率,并(bing)聯電(dian)(dian)抗器被廣泛應用于電(dian)(dian)網的(de)(de)(de)遠距(ju)離(li)輸(shu)配電(dian)(dian)項目(mu)。
二、串聯電抗器的電流大嗎
確定電(dian)(dian)容(rong)器串(chuan)聯電(dian)(dian)抗器回(hui)路的(de)電(dian)(dian)流,應該把電(dian)(dian)容(rong)器和串(chuan)聯電(dian)(dian)抗器作(zuo)為一(yi)(yi)個回(hui)路整體來(lai)分析,因為補償(chang)回(hui)路中除了要承載正常的(de)基波無功電(dian)(dian)流外(wai),還應該允(yun)許它(ta)能夠承載一(yi)(yi)定量的(de)某次諧波電(dian)(dian)流。
串聯電抗器的電(dian)(dian)(dian)容器(qi)補償(chang)(chang)回(hui)(hui)路,常情(qing)況下補償(chang)(chang)容量(liang)及通過的電(dian)(dian)(dian)流如(ru)何(he)計算呢(ni),現舉(ju)例如(ru)下:如(ru)果回(hui)(hui)路電(dian)(dian)(dian)抗器(qi)的電(dian)(dian)(dian)抗率(lv)為14%,系統電(dian)(dian)(dian)壓為400V。
電(dian)容器(qi)(qi)承受的(de)(de)(de)(de)電(dian)壓(ya)為:400(1-14%)=465.1V,如(ru)果選(xuan)擇所配套的(de)(de)(de)(de)電(dian)容器(qi)(qi)額(e)定(ding)電(dian)壓(ya)為525V(也可以為480V),額(e)定(ding)電(dian)壓(ya)525V,容量為30Kvar的(de)(de)(de)(de)電(dian)容器(qi)(qi)額(e)定(ding)電(dian)流(liu)(liu)為33A,串聯電(dian)抗(kang)率14%的(de)(de)(de)(de)后(hou)實際發出30x(465.1/525)2-23.5Kvar,向電(dian)網只能補償(chang)23.5x(1-14%)=20.1Kvar的(de)(de)(de)(de)無功(gong)功(gong)率,此時(shi)通過電(dian)容器(qi)(qi)的(de)(de)(de)(de)電(dian)流(liu)(liu)23.5/(V3x0.4651)=29.2(A)。此時(shi)通過的(de)(de)(de)(de)電(dian)流(liu)(liu)遠小于額(e)定(ding)電(dian)流(liu)(liu)33A了(le)。
所以串(chuan)聯(lian)電抗器的(de)電流是(shi)不(bu)大的(de)。