三(san)相干式(shi)變壓(ya)(ya)器是(shi)各種電(dian)(dian)源和(he)電(dian)(dian)氣設備(bei)的(de)(de)主(zhu)要部件(jian)。它(ta)是(shi)一(yi)種利用電(dian)(dian)磁感(gan)應原理改變交流電(dian)(dian)壓(ya)(ya)的(de)(de)裝置。三(san)相干式(shi)變壓(ya)(ya)器的(de)(de)主(zhu)要原理是(shi)電(dian)(dian)磁感(gan)應,利用電(dian)(dian)磁之間的(de)(de)相互感(gan)應來變換(huan)電(dian)(dian)壓(ya)(ya)、電(dian)(dian)流和(he)阻抗。