變頻器(qi)主要用來給電動(dong)機(ji)調速(su)度，有兩(liang)方面應用：

　　1、節(jie)能(neng)，主要是風機(ji)(ji)(ji)水泵類負(fu)載，采用變(bian)頻(pin)器后比(bi)直接電(dian)(dian)(dian)網運(yun)(yun)行(xing)省(sheng)電(dian)(dian)(dian)，所(suo)以節(jie)能(neng)，省(sheng)電(dian)(dian)(dian)比(bi)率(lv)可以達到50%以上，具體節(jie)能(neng)效果與電(dian)(dian)(dian)機(ji)(ji)(ji)運(yun)(yun)行(xing)的工(gong)藝(yi)有關(guan)。電(dian)(dian)(dian)機(ji)(ji)(ji)經常運(yun)(yun)行(xing)在低(di)速度時能(neng)大量節(jie)能(neng)，如果電(dian)(dian)(dian)機(ji)(ji)(ji)始終(zhong)是滿(man)負(fu)荷運(yun)(yun)行(xing)，那么也沒(mei)有必(bi)要采用變(bian)頻(pin)器。

　　2、工(gong)(gong)(gong)藝要求，在冶金、石油、化工(gong)(gong)(gong)、紡(fang)織(zhi)、電力、建(jian)材、煤炭等行業(ye)，有(you)的工(gong)(gong)(gong)藝不允許(xu)電機(ji)直(zhi)接(jie)啟動，需要由變頻(pin)(pin)器調速和(he)協調工(gong)(gong)(gong)作才能滿(man)足(zu)工(gong)(gong)(gong)藝要求。這(zhe)是必須(xu)采用變頻(pin)(pin)器的。比如冶金行業(ye)需要采用變頻(pin)(pin)器的電機(ji)大概達到70%。