變(bian)電(dian)站(zhan)直(zhi)流(liu)母(mu)線(xian)電(dian)壓(ya)的(di)變(bian)動(dong)範(fan)圍(wei)取(qu)決(jue)於(yu)直(zhi)流(liu)負(fu)荷(he)允(yun)許(xu)的(di)電(dian)壓(ya)變(bian)動(dong)範(fan)圍(wei)。對(dui)於(yu)控(kong)製(zhi)負(fu)荷(he),直(zhi)流(liu)母(mu)線(xian)電(dian)壓(ya)的(di)變(bian)動(dong)範(fan)圍(wei)為(wei)(80%~110%)UN(UN為(wei)係(ji)統(tong)標(biao)稱(chen)電(dian)壓(ya));對(dui)於(yu)動(dong)力(li)負(fu)荷(he),直(zhi)流(liu)母(mu)線(xian)電(dian)壓(ya)的(di)變(bian)動(dong)範(fan)圍(wei)為(wei)(85%~112.5%)UN。