一、串聯電抗器和并聯電抗器的區別在哪里
串(chuan)聯電抗(kang)器(qi)(qi)(qi)與并聯電抗(kang)器(qi)(qi)(qi)有明顯區別,體現在(zai)作(zuo)用和適用范圍上,串(chuan)聯電抗(kang)器(qi)(qi)(qi)主要(yao)起(qi)(qi)限流(liu)和濾波作(zuo)用,并聯電抗(kang)器(qi)(qi)(qi)主要(yao)起(qi)(qi)無功補(bu)償作(zuo)用,下面做(zuo)詳細介紹(shao):
1、串(chuan)(chuan)聯(lian)電(dian)(dian)(dian)抗器(qi)是電(dian)(dian)(dian)力(li)系(xi)統無功(gong)補償裝置的(de)(de)重要(yao)配(pei)套(tao)設備(bei)。電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)容器(qi)與串(chuan)(chuan)聯(lian)電(dian)(dian)(dian)抗器(qi)串(chuan)(chuan)聯(lian)后(hou),能有效地抑制(zhi)電(dian)(dian)(dian)網(wang)中(zhong)的(de)(de)高(gao)次諧(xie)波,限制(zhi)合閘涌流(liu)及操作過電(dian)(dian)(dian)壓(ya),改(gai)善(shan)系(xi)統的(de)(de)電(dian)(dian)(dian)壓(ya)波形,提高(gao)電(dian)(dian)(dian)網(wang)功(gong)率因(yin)數(shu),對電(dian)(dian)(dian)力(li)電(dian)(dian)(dian)容器(qi)及其(qi)它電(dian)(dian)(dian)力(li)設備(bei)的(de)(de)安全(quan)運行起到了較大(da)的(de)(de)作用。
串聯電抗器主要用于限制短路電流(liu),而電容器(qi)(qi)組串聯電抗器(qi)(qi)可(ke)以限制高(gao)次諧波,降低電抗。
2、并聯電(dian)抗器可以(yi)用于(yu)補償長距離輸電(dian)線路的分布電(dian)容補償,防(fang)止空載長線路末端電(dian)壓升高(通常用于(yu)500KV系(xi)統),還可以(yi)有利(li)于(yu)單相(xiang)重合(he)閘和降低操(cao)作過電(dian)壓。
為了提(ti)高(gao)遠距(ju)離輸電(dian)線(xian)(xian)(xian)路(lu)的(de)傳輸能力和改善(shan)線(xian)(xian)(xian)路(lu)的(de)運行情況,削(xue)弱(ruo)空載或輕載時(shi)長線(xian)(xian)(xian)路(lu)的(de)電(dian)容效應所引起的(de)工頻電(dian)壓(ya)升高(gao),改善(shan)沿線(xian)(xian)(xian)電(dian)壓(ya)分布(bu)和輕載線(xian)(xian)(xian)路(lu)中的(de)無功分布(bu)并(bing)(bing)降低線(xian)(xian)(xian)損,減少潛供電(dian)流,加速潛供電(dian)弧的(de)熄滅,提(ti)高(gao)線(xian)(xian)(xian)路(lu)自動重合(he)閘的(de)成功率,并(bing)(bing)聯電(dian)抗器被廣泛應用(yong)于電(dian)網(wang)的(de)遠距(ju)離輸配電(dian)項(xiang)目(mu)。
二、串聯電抗器的電流大嗎
確定電(dian)容器(qi)串聯電(dian)抗器(qi)回(hui)路(lu)的(de)電(dian)流,應(ying)該(gai)把電(dian)容器(qi)和串聯電(dian)抗器(qi)作為一個回(hui)路(lu)整(zheng)體來分析,因為補償回(hui)路(lu)中除了(le)要(yao)承(cheng)載正常的(de)基波無功電(dian)流外,還應(ying)該(gai)允(yun)許它能夠承(cheng)載一定量的(de)某次諧波電(dian)流。
串聯電抗器的(de)電(dian)容器(qi)補償回(hui)路,常(chang)情況下補償容量及通過的(de)電(dian)流如(ru)(ru)何計算(suan)呢,現舉例(li)如(ru)(ru)下:如(ru)(ru)果回(hui)路電(dian)抗器(qi)的(de)電(dian)抗率(lv)為14%,系(xi)統電(dian)壓為400V。
電(dian)容(rong)器承受的電(dian)壓為:400(1-14%)=465.1V,如(ru)果(guo)選擇所配套的電(dian)容(rong)器額定(ding)電(dian)壓為525V(也可以為480V),額定(ding)電(dian)壓525V,容(rong)量(liang)為30Kvar的電(dian)容(rong)器額定(ding)電(dian)流(liu)(liu)為33A,串(chuan)聯電(dian)抗(kang)率14%的后實際(ji)發出30x(465.1/525)2-23.5Kvar,向電(dian)網(wang)只(zhi)能補償23.5x(1-14%)=20.1Kvar的無功功率,此時(shi)通過電(dian)容(rong)器的電(dian)流(liu)(liu)23.5/(V3x0.4651)=29.2(A)。此時(shi)通過的電(dian)流(liu)(liu)遠小于額定(ding)電(dian)流(liu)(liu)33A了。
所以串聯(lian)電抗(kang)器的電流是(shi)不大的。