三相(xiang)(xiang)(xiang)除塵電(dian)(dian)源由(you)三個(ge)頻率(lv)相(xiang)(xiang)(xiang)同，振幅相(xiang)(xiang)(xiang)等，相(xiang)(xiang)(xiang)位依次(ci)互差(cha)120度電(dian)(dian)角度的(de)交(jiao)(jiao)流電(dian)(dian)勢(shi)組成的(de)電(dian)(dian)源稱(cheng)為三相(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)源。它(ta)是(shi)由(you)三相(xiang)(xiang)(xiang)交(jiao)(jiao)流發電(dian)(dian)機產生的(de)。日常生活中所用的(de)單相(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)，實際上是(shi)由(you)三相(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)的(de)一相(xiang)(xiang)(xiang)提(ti)供的(de)，由(you)單相(xiang)(xiang)(xiang)發電(dian)(dian)機發出的(de)單相(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)源已經很少(shao)采(cai)用。

優點

三(san)相(xiang)(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)較單(dan)相(xiang)(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)有(you)很多優(you)(you)點(dian)(dian)，它(ta)在發(fa)電(dian)(dian)、輸(shu)(shu)配(pei)電(dian)(dian)以及電(dian)(dian)能轉換成機(ji)(ji)(ji)(ji)械能等方面都有(you)明顯的優(you)(you)越性(xing)。例如：制造(zao)三(san)相(xiang)(xiang)(xiang)(xiang)發(fa)電(dian)(dian)機(ji)(ji)(ji)(ji)、變壓器都較制造(zao)容(rong)量相(xiang)(xiang)(xiang)(xiang)同的單(dan)相(xiang)(xiang)(xiang)(xiang)發(fa)電(dian)(dian)機(ji)(ji)(ji)(ji)、變壓器節省材(cai)料，而(er)且(qie)構造(zao)簡單(dan)，性(xing)能優(you)(you)良(liang)，又如，由(you)同樣材(cai)料所制造(zao)的三(san)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)機(ji)(ji)(ji)(ji)，其容(rong)量比單(dan)相(xiang)(xiang)(xiang)(xiang)電(dian)(dian)機(ji)(ji)(ji)(ji)大(da)50%，在輸(shu)(shu)送同樣功率的情況(kuang)下，三(san)相(xiang)(xiang)(xiang)(xiang)輸(shu)(shu)電(dian)(dian)線(xian)較單(dan)相(xiang)(xiang)(xiang)(xiang)輸(shu)(shu)電(dian)(dian)線(xian)可(ke)節省有(you)色金屬25%，而(er)且(qie)電(dian)(dian)能損耗較單(dan)相(xiang)(xiang)(xiang)(xiang)輸(shu)(shu)電(dian)(dian)時(shi)少。由(you)于三(san)相(xiang)(xiang)(xiang)(xiang)交(jiao)(jiao)流電(dian)(dian)有(you)上(shang)述(shu)優(you)(you)點(dian)(dian)所以獲得了廣泛的應用