靜止無功(gong)發生器(qi)的(de)基本(ben)原理是(shi)利用電力半導體(ti)器(qi)件搭(da)建三相橋(qiao)式逆變(bian)電路(lu)(lu),經(jing)濾(lv)波電感或電容與電網并聯,調節功(gong)率半導體(ti)器(qi)件的(de)通斷(duan)實現(xian)控制橋(qiao)式電路(lu)(lu)交流輸出側電壓的(de)大(da)小(xiao),也可直接控制逆變(bian)電路(lu)(lu)輸出電流的(de)大(da)小(xiao),以滿足系(xi)統(tong)所需要的(de)無功(gong),達到動態(tai)補償系(xi)統(tong)無功(gong)功(gong)率的(de)目的(de)。
諧波嚴重場(chang)合無(wu)功補償元(yuan)件改(gai)造方案
如(ru)14%電(dian)(dian)(dian)抗(kang)(kang)率應用(yong)時,電(dian)(dian)(dian)容器額(e)(e)定(ding)(ding)電(dian)(dian)(dian)壓(ya)為525V,遠大于(yu)400V系(xi)統電(dian)(dian)(dian)壓(ya),電(dian)(dian)(dian)容器在(zai)400V系(xi)統中實際能夠承載的電(dian)(dian)(dian)流(liu)(包括(kuo)基(ji)波(bo)和諧波(bo)電(dian)(dian)(dian)流(liu))要大于(yu)其在(zai)額(e)(e)定(ding)(ding)電(dian)(dian)(dian)壓(ya)下(如(ru)525V)的額(e)(e)定(ding)(ding)電(dian)(dian)(dian)流(liu)。因此,在(zai)這種(zhong)無(wu)功補償(chang)應用(yong)中,決(jue)定(ding)(ding)回路(lu)過載能力(li)的是串聯電(dian)(dian)(dian)抗(kang)(kang)器的參數(shu),即(ji)電(dian)(dian)(dian)抗(kang)(kang)器的 大過電(dian)(dian)(dian)流(liu)能力(li)。
凡是(shi)安裝(zhuang)有(you)低壓(ya)變(bian)壓(ya)器地(di)方及(ji)大(da)型用電(dian)設備(bei)旁邊都應該配備(bei)無功補(bu)償(chang)裝(zhuang)置(zhi)(這是(shi)國家電(dian) 力部門的(de)(de)規定) ,特別是(shi)那些(xie)功率因數(shu)較低的(de)(de)工(gong)礦(kuang)、企業(ye)、居(ju)民(min)區必須安裝(zhuang)。大(da)型異(yi)步電(dian)機(ji)(ji)、 變(bian)壓(ya)器、電(dian)焊機(ji)(ji)、沖(chong)床、車(che)(che)床群、空壓(ya)機(ji)(ji)、壓(ya)力機(ji)(ji)、吊車(che)(che)、冶煉(lian)、軋鋼、軋鋁、大(da)型交換機(ji)(ji)、 電(dian)灌設備(bei)、電(dian)氣(qi)機(ji)(ji)車(che)(che)等(deng)尤其需要。居(ju)民(min)區除(chu)白熾 燈照(zhao)明外,空調、冷凍機(ji)(ji)等(deng)也都是(shi)無功功率 不可忽視的(de)(de)耗(hao)用對象。農(nong)村用電(dian)狀況比(bi)較惡劣,多數(shu)地(di)區供(gong)電(dian)不足,電(dian)壓(ya)波動很大(da),功率因 數(shu)尤其低,加裝(zhuang)補(bu)償(chang)設備(bei)是(shi)改(gai)善供(gong)電(dian)狀況、提高電(dian)能利用率的(de)(de)有(you)效(xiao)措施。