什么是線電壓和相電壓?兩者有什么區別?
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來源：金環宇電線發(fa)布日期(qi)：2019-09-27 16:39
線(xian)(xian)電(dian)(dian)(dian)壓(ya)(ya)(ya)指的(de)(de)是(shi)(shi)多相(xiang)(xiang)(xiang)供電(dian)(dian)(dian)系(xi)統(tong)中任(ren)意(yi)兩相(xiang)(xiang)(xiang)之間的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)，我(wo)們常(chang)見的(de)(de)是(shi)(shi)三(san)相(xiang)(xiang)(xiang)供電(dian)(dian)(dian)系(xi)統(tong)，以三(san)相(xiang)(xiang)(xiang)電(dian)(dian)(dian)為(wei)例：三(san)相(xiang)(xiang)(xiang)電(dian)(dian)(dian)中有A相(xiang)(xiang)(xiang)B相(xiang)(xiang)(xiang)C相(xiang)(xiang)(xiang)，A相(xiang)(xiang)(xiang)B相(xiang)(xiang)(xiang)C相(xiang)(xiang)(xiang)任(ren)意(yi)兩相(xiang)(xiang)(xiang)之間的(de)(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)就是(shi)(shi)線(xian)(xian)電(dian)(dian)(dian)壓(ya)(ya)(ya);交流電(dian)(dian)(dian)中的(de)(de)線(xian)(xian)電(dian)(dian)(dian)壓(ya)(ya)(ya)是(shi)(shi)380V，如(ru)(ru)果(guo)是(shi)(shi)星型連(lian)接的(de)(de)話(hua)，那么線(xian)(xian)電(dian)(dian)(dian)壓(ya)(ya)(ya)就是(shi)(shi)相(xiang)(xiang)(xiang)電(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)√3倍，如(ru)(ru)果(guo)是(shi)(shi)三(san)角形連(lian)接，那么電(dian)(dian)(dian)源的(de)(de)線(xian)(xian)電(dian)(dian)(dian)壓(ya)(ya)(ya)等于(yu)相(xiang)(xiang)(xiang)電(dian)(dian)(dian)壓(ya)(ya)(ya);
相電壓(ya)，對于交流(liu)電來說，相電壓(ya)就是A相B相C相中(zhong)的(de)任意一(yi)相與與零線(xian)(N線(xian))之間的(de)電壓(ya)，電壓(ya)值(zhi)是220V，三相交流(liu)電中(zhong)有三個相電壓(ya)，這三個相電壓(ya)的(de)電壓(ya)值(zhi)相等，頻率相同(tong)，相互間的(de)相位差(cha)是120°;
線電壓(ya)和相電壓(ya)
這個也就是(shi)(shi)380V/220V的(de)供(gong)電(dian)系(xi)(xi)(xi)統(tong)，這種供(gong)電(dian)也是(shi)(shi)我們(men)國家(jia)使用的(de)供(gong)電(dian)方式，而我們(men)居民(min)(min)用電(dian)的(de)供(gong)電(dian)系(xi)(xi)(xi)統(tong)也是(shi)(shi)380V/220V的(de)供(gong)電(dian)系(xi)(xi)(xi)統(tong)，居民(min)(min)用電(dian)常用的(de)接地系(xi)(xi)(xi)統(tong)是(shi)(shi)TN-S系(xi)(xi)(xi)統(tong)或者是(shi)(shi)TN-C-S系(xi)(xi)(xi)統(tong)。
線電壓和(he)相(xiang)電壓的區別(bie)：
遠距離輸送電(dian)過(guo)程中，電(dian)壓(ya)越高(gao)，損耗就(jiu)越低，這就(jiu)是(shi)國家為什么(me)一(yi)直(zhi)在(zai)研(yan)究超高(gao)壓(ya)輸送電(dian)的原(yuan)因(I=U/R)。一(yi)般高(gao)壓(ya)輸送電(dian)到終端(duan)用(yong)(yong)戶端(duan)，再通過(guo)降(jiang)壓(ya)變(bian)壓(ya)器(qi)降(jiang)為市電(dian)220V/380V供給不同(tong)的用(yong)(yong)戶。
于三(san)(san)(san)相(xiang)(xiang)四線(xian)(xian)制(zhi)的(de)(de)(de)電(dian)(dian)(dian)(dian)網中，三(san)(san)(san)根(gen)(gen)(gen)相(xiang)(xiang)線(xian)(xian)中任意(yi)一根(gen)(gen)(gen)與零線(xian)(xian)間的(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)成為(wei)相(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya);三(san)(san)(san)根(gen)(gen)(gen)相(xiang)(xiang)線(xian)(xian)中任意(yi)兩根(gen)(gen)(gen)之(zhi)間的(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)成為(wei)線(xian)(xian)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。三(san)(san)(san)相(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)相(xiang)(xiang)位(wei)相(xiang)(xiang)差(cha)120度(du)，線(xian)(xian)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)是兩個(ge)相(xiang)(xiang)的(de)(de)(de)相(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)矢量和，線(xian)(xian)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)和相(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)的(de)(de)(de)大小(xiao)關系為(wei)：線(xian)(xian)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)=根(gen)(gen)(gen)號3倍的(de)(de)(de)相(xiang)(xiang)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，即380V=根(gen)(gen)(gen)號3倍220V(不好意(yi)思，頭條上(shang)傳(chuan)不了公式(shi)的(de)(de)(de)數學根(gen)(gen)(gen)號3)。
兩(liang)相(xiang)電(dian)(dian)(dian)(dian)(dian)接在(zai)正(zheng)在(zai)運行(xing)的(de)(de)三(san)(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)機(ji)上，電(dian)(dian)(dian)(dian)(dian)機(ji)任(ren)然可以(yi)工作，這就(jiu)是(shi)我們常說的(de)(de)電(dian)(dian)(dian)(dian)(dian)機(ji)缺相(xiang)運行(xing)，但是(shi)這樣的(de)(de)方(fang)式很(hen)容易把電(dian)(dian)(dian)(dian)(dian)機(ji)燒(shao)壞(huai)。三(san)(san)角形接法的(de)(de)三(san)(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)機(ji)缺相(xiang)后，電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)輸出功率(lv)也會(hui)變成原來三(san)(san)相(xiang)電(dian)(dian)(dian)(dian)(dian)供電(dian)(dian)(dian)(dian)(dian)時(shi)的(de)(de)三(san)(san)分之(zhi)二，另外(wai)兩(liang)個(ge)繞組只提(ti)供三(san)(san)分之(zhi)一的(de)(de)功率(lv)，如(ru)此(ci)就(jiu)造成了三(san)(san)相(xiang)不平衡(heng)，電(dian)(dian)(dian)(dian)(dian)流(liu)不平衡(heng)，電(dian)(dian)(dian)(dian)(dian)流(liu)不平衡(heng)，電(dian)(dian)(dian)(dian)(dian)機(ji)當然更容易燒(shao)壞(huai)。
拓展閱讀：
千(qian)(qian)瓦(wa)和度：電(dian)(dian)(dian)功率(lv)(lv)(lv)是(shi)(shi)用(yong)電(dian)(dian)(dian)設備(bei)兩端電(dian)(dian)(dian)壓和通(tong)過電(dian)(dian)(dian)流的(de)乘積，即P=UI,千(qian)(qian)瓦(wa)是(shi)(shi)電(dian)(dian)(dian)功率(lv)(lv)(lv)的(de)單位(wei)。我們所用(yong)的(de)一些家用(yong)電(dian)(dian)(dian)器(qi)銘牌上標(biao)注的(de)都是(shi)(shi)指用(yong)電(dian)(dian)(dian)器(qi)的(de)電(dian)(dian)(dian)功率(lv)(lv)(lv)，比(bi)如空調的(de)功率(lv)(lv)(lv)是(shi)(shi)1.5千(qian)(qian)瓦(wa)等等。度：是(shi)(shi)人們比(bi)較泛(fan)泛(fan)的(de)稱呼，我們平(ping)時關于(yu)電(dian)(dian)(dian)工(gong)的(de)“度”是(shi)(shi)電(dian)(dian)(dian)能的(de)單位(wei)，1千(qian)(qian)瓦(wa)時=1度。
單(dan)(dan)相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)與(yu)三相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)：在負(fu)(fu)荷(he)(he)(he)計算中，單(dan)(dan)相(xiang)(xiang)(xiang)(xiang)用(yong)(yong)電(dian)(dian)(dian)(dian)設(she)備應均(jun)衡分配到三相(xiang)(xiang)(xiang)(xiang)上(shang)，使(shi)(shi)各相(xiang)(xiang)(xiang)(xiang)的(de)計算負(fu)(fu)荷(he)(he)(he)盡量相(xiang)(xiang)(xiang)(xiang)近(jin)。單(dan)(dan)相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)概括起(qi)(qi)來(lai)就是采用(yong)(yong)一(yi)根相(xiang)(xiang)(xiang)(xiang)線(xian)(xian)(xian)(俗稱(cheng)火線(xian)(xian)(xian))和(he)一(yi)根工作(zuo)零線(xian)(xian)(xian)(俗稱(cheng)零線(xian)(xian)(xian))一(yi)起(qi)(qi)給用(yong)(yong)電(dian)(dian)(dian)(dian)設(she)備提供(gong)(gong)電(dian)(dian)(dian)(dian)源，使(shi)(shi)是做功。三相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)概括起(qi)(qi)來(lai)就是采用(yong)(yong)三根相(xiang)(xiang)(xiang)(xiang)線(xian)(xian)(xian)給用(yong)(yong)電(dian)(dian)(dian)(dian)設(she)備提供(gong)(gong)電(dian)(dian)(dian)(dian)源，使(shi)(shi)其做功。單(dan)(dan)相(xiang)(xiang)(xiang)(xiang)用(yong)(yong)電(dian)(dian)(dian)(dian)設(she)備接(jie)于(yu)(yu)線(xian)(xian)(xian)電(dian)(dian)(dian)(dian)壓或相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)(dian)(dian)壓時的(de)負(fu)(fu)荷(he)(he)(he)，相(xiang)(xiang)(xiang)(xiang)應地稱(cheng)為線(xian)(xian)(xian)間負(fu)(fu)荷(he)(he)(he)和(he)相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)。需(xu)要(yao)注意(yi)的(de)是線(xian)(xian)(xian)間負(fu)(fu)荷(he)(he)(he)和(he)相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)都屬于(yu)(yu)單(dan)(dan)相(xiang)(xiang)(xiang)(xiang)負(fu)(fu)荷(he)(he)(he)。
平(ping)均額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)和額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)：平(ping)均額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)的(de)出現只是(shi)為(wei)(wei)了(le)短(duan)路(lu)(lu)計(ji)算(suan)(suan)，解(jie)除(chu)變(bian)(bian)壓(ya)(ya)(ya)器實(shi)際變(bian)(bian)比給(gei)計(ji)算(suan)(suan)帶來的(de)繁瑣。計(ji)算(suan)(suan)短(duan)路(lu)(lu)電(dian)(dian)流時，由于線路(lu)(lu)首端短(duan)路(lu)(lu)情況最為(wei)(wei)嚴重，因此按線路(lu)(lu)首端電(dian)(dian)壓(ya)(ya)(ya)考(kao)慮，即(ji)短(duan)路(lu)(lu)計(ji)算(suan)(suan)電(dian)(dian)壓(ya)(ya)(ya)取比線路(lu)(lu)額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)高5%。需要注(zhu)意(yi)的(de)是(shi)潮流計(ji)算(suan)(suan)中用到的(de)是(shi)額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)，而不是(shi)平(ping)均額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)，也(ye)就是(shi)說只是(shi)在短(duan)路(lu)(lu)計(ji)算(suan)(suan)中為(wei)(wei)計(ji)算(suan)(suan)方便引入平(ping)均額(e)定(ding)(ding)電(dian)(dian)壓(ya)(ya)(ya)的(de)概念，不可混淆(xiao)。
