一、串聯電抗器和并聯電抗器的區別在哪里
串(chuan)聯電抗器(qi)(qi)與并聯電抗器(qi)(qi)有明顯區別(bie),體(ti)現在作(zuo)用(yong)和適(shi)用(yong)范圍(wei)上,串(chuan)聯電抗器(qi)(qi)主要(yao)起限流和濾波(bo)作(zuo)用(yong),并聯電抗器(qi)(qi)主要(yao)起無(wu)功(gong)補償(chang)作(zuo)用(yong),下(xia)面做詳(xiang)細介紹:
1、串(chuan)聯(lian)電(dian)抗器是(shi)電(dian)力系(xi)統無功補償裝置的(de)重要配套(tao)設備。電(dian)力電(dian)容(rong)器與串(chuan)聯(lian)電(dian)抗器串(chuan)聯(lian)后,能(neng)有效地(di)抑制電(dian)網中(zhong)的(de)高(gao)次諧(xie)波,限制合閘涌(yong)流及(ji)操作過電(dian)壓(ya),改善系(xi)統的(de)電(dian)壓(ya)波形,提高(gao)電(dian)網功率因(yin)數,對電(dian)力電(dian)容(rong)器及(ji)其(qi)它(ta)電(dian)力設備的(de)安全運行(xing)起(qi)到了較(jiao)大的(de)作用(yong)。
串聯電抗器主要用于限制(zhi)短路(lu)電(dian)流(liu),而電(dian)容(rong)器組串聯電(dian)抗器可以限制(zhi)高次諧波,降低電(dian)抗。
2、并聯電抗器可(ke)以(yi)用于(yu)(yu)(yu)補償長(chang)距離輸電線路的分布電容(rong)補償,防止空載長(chang)線路末端電壓升高(gao)(通(tong)常用于(yu)(yu)(yu)500KV系統),還(huan)可(ke)以(yi)有利于(yu)(yu)(yu)單相重合閘和降低操作過(guo)電壓。
為了提高遠距(ju)離輸電(dian)線(xian)路(lu)的傳輸能力和改善線(xian)路(lu)的運行情況(kuang),削弱空載或輕(qing)載時長線(xian)路(lu)的電(dian)容(rong)效應所引起的工頻電(dian)壓(ya)升高,改善沿(yan)線(xian)電(dian)壓(ya)分(fen)布和輕(qing)載線(xian)路(lu)中的無(wu)功(gong)分(fen)布并降(jiang)低線(xian)損,減少(shao)潛供電(dian)流,加速潛供電(dian)弧的熄滅(mie),提高線(xian)路(lu)自動重合(he)閘的成功(gong)率,并聯電(dian)抗器被廣(guang)泛應用于電(dian)網的遠距(ju)離輸配電(dian)項(xiang)目。
二、串聯電抗器的電流大嗎
確定電(dian)(dian)容(rong)器(qi)串(chuan)聯(lian)電(dian)(dian)抗器(qi)回(hui)路的(de)電(dian)(dian)流,應(ying)該(gai)(gai)把電(dian)(dian)容(rong)器(qi)和串(chuan)聯(lian)電(dian)(dian)抗器(qi)作為(wei)(wei)一(yi)個回(hui)路整(zheng)體來分析,因(yin)為(wei)(wei)補(bu)償(chang)回(hui)路中除了要承(cheng)載(zai)正常(chang)的(de)基波(bo)無功電(dian)(dian)流外,還應(ying)該(gai)(gai)允(yun)許它能夠(gou)承(cheng)載(zai)一(yi)定量(liang)的(de)某次(ci)諧(xie)波(bo)電(dian)(dian)流。
串聯電抗器的(de)電(dian)容器補償(chang)回(hui)路,常情況下補償(chang)容量及通過的(de)電(dian)流如何計算呢(ni),現舉例(li)如下:如果回(hui)路電(dian)抗器的(de)電(dian)抗率(lv)為(wei)14%,系統電(dian)壓為(wei)400V。
電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器承受的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓為:400(1-14%)=465.1V,如果選(xuan)擇所配套的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)壓為525V(也可以為480V),額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)壓525V,容(rong)量為30Kvar的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為33A,串(chuan)聯電(dian)(dian)(dian)(dian)(dian)(dian)抗率14%的(de)(de)后(hou)實際發(fa)出30x(465.1/525)2-23.5Kvar,向電(dian)(dian)(dian)(dian)(dian)(dian)網只能補償(chang)23.5x(1-14%)=20.1Kvar的(de)(de)無功功率,此時(shi)通(tong)過電(dian)(dian)(dian)(dian)(dian)(dian)容(rong)器的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)23.5/(V3x0.4651)=29.2(A)。此時(shi)通(tong)過的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)遠小(xiao)于額(e)定(ding)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)33A了。
所以(yi)串聯電抗器(qi)的(de)電流(liu)是不大的(de)。