低壓(ya)無功(gong)補償(chang)柜中低壓(ya)智能(neng)無功(gong)補償(chang)控(kong)制(zhi)器(qi)作用，是為了保(bao)證整(zheng)個(ge)回(hui)(hui)路安全可(ke)靠的(de)運行，以達到無功(gong)補償(chang)的(de)目的(de)，那么電容器(qi)(和串聯電抗器(qi))作為補償(chang)回(hui)(hui)路的(de)核(he)心元件，熔(rong)斷器(qi)對它提供可(ke)靠的(de)保(bao)護性能(neng)是非常必(bi)要的(de)。

　　由于現行相(xiang)關標(biao)準(zhun)里對補(bu)償回路(lu)保護熔斷器的(de)(de)選(xuan)擇(ze)沒(mei)有特別詳(xiang)細的(de)(de)要求，所以在實(shi)際(ji)應用中大家的(de)(de)選(xuan)擇(ze)也不盡(jin)一(yi)致，有時差別甚(shen)至相(xiang)當懸殊。

　　在低壓(ya)配(pei)電系(xi)統中(zhong)的負載類(lei)型變(bian)得越來越復(fu)雜的情況下，補(bu)償回路熔斷(duan)器的選擇(ze)不能一概(gai)而論，要視低壓(ya)無功補(bu)償的具體類(lei)型進行科學的分析和選擇(ze)。

由(you)于這(zhe)種應用的(de)(de)電(dian)(dian)(dian)(dian)容(rong)器(qi)額定(ding)電(dian)(dian)(dian)(dian)壓要遠(yuan)大(da)于配電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)電(dian)(dian)(dian)(dian)壓(如14%電(dian)(dian)(dian)(dian)抗(kang)率應用時，電(dian)(dian)(dian)(dian)容(rong)器(qi)額定(ding)電(dian)(dian)(dian)(dian)壓為525V，遠(yuan)大(da)于400V系(xi)統(tong)(tong)電(dian)(dian)(dian)(dian)壓)，電(dian)(dian)(dian)(dian)容(rong)器(qi)在400V系(xi)統(tong)(tong)中實際(ji)能(neng)夠承載的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(包括基波(bo)和諧波(bo)電(dian)(dian)(dian)(dian)流(liu))要大(da)于其(qi)在額定(ding)電(dian)(dian)(dian)(dian)壓下(如525V)的(de)(de)額定(ding)電(dian)(dian)(dian)(dian)流(liu)。因此，在這(zhe)種無功補償應用中，決定(ding)回路(lu)過載能(neng)力的(de)(de)是串聯電(dian)(dian)(dian)(dian)抗(kang)器(qi)的(de)(de)參數，即(ji)電(dian)(dian)(dian)(dian)抗(kang)器(qi)的(de)(de)大(da)過電(dian)(dian)(dian)(dian)流(liu)能(neng)力。

　　所以熔斷器(qi)的(de)(de)選(xuan)擇應該(gai)以回路的(de)(de)額定電(dian)流(liu)和電(dian)抗(kang)器(qi)的(de)(de)大過(guo)電(dian)流(liu)能(neng)力為依據(ju)。以電(dian)抗(kang)率為14%的(de)(de)25KVAR/400V的(de)(de)補(bu)償回路舉例分析：

　　該回路的電容(rong)器(qi)(qi)額定電流(liu)為36A，如果(guo)電抗器(qi)(qi)的大過電流(liu)能力為1.8倍的額定電流(liu)，則該回路的大允許電流(liu)為1.8×36=64.8A，因此正確的熔斷器(qi)(qi)的額定保護電流(liu)應(ying)為63A。