從高(gao)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)通過變(bian)電(dian)(dian)(dian)(dian)站(zhan)或變(bian)壓(ya)器變(bian)為低(di)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)供日常使用的，高(gao)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)由于(yu)危險性高(gao)，因此平(ping)時都是(shi)電(dian)(dian)(dian)(dian)動操(cao)(cao)作進行，但是(shi)變(bian)電(dian)(dian)(dian)(dian)所未送電(dian)(dian)(dian)(dian)前如(ru)果沒有低(di)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)，引一(yi)路低(di)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)進變(bian)電(dian)(dian)(dian)(dian)站(zhan)的話操(cao)(cao)作復(fu)雜(za)，而(er)從高(gao)壓(ya)進線處變(bian)一(yi)個獨立的低(di)壓(ya)電(dian)(dian)(dian)(dian)源(yuan)隱(yin)患較大，因此就不得不采取一(yi)種方法給高(gao)壓(ya)配電(dian)(dian)(dian)(dian)設備提供操(cao)(cao)作電(dian)(dian)(dian)(dian)源(yuan)，于(yu)是(shi)直流屏應運而(er)生。

根(gen)據直(zhi)流(liu)(liu)屏所(suo)配套的(de)高(gao)壓(ya)(ya)柜臺數功率大(da)小(xiao)(xiao)不(bu)同，直(zhi)流(liu)(liu)屏所(suo)配蓄電池的(de)容(rong)量(liang)也(ye)不(bu)一樣(yang)，日(ri)常(chang)生活中常(chang)見的(de)直(zhi)流(liu)(liu)屏常(chang)用(yong)規(gui)格可分為24AH、40AH、65AH、100AH等，對于變(bian)電站或者開閉(bi)所(suo)等高(gao)壓(ya)(ya)柜用(yong)直(zhi)流(liu)(liu)屏，可能規(gui)格需要200AH甚至(zhi)更(geng)高(gao)，具體要看高(gao)壓(ya)(ya)柜的(de)數量(liang)和負載的(de)大(da)小(xiao)(xiao)。