電(dian)(dian)(dian)動(dong)(dong)機(ji)差動(dong)(dong)保(bao)(bao)(bao)護(hu)(hu)裝(zhuang)置(zhi)(zhi)主要(yao)用在大(da)型高壓電(dian)(dian)(dian)動(dong)(dong)機(ji)發電(dian)(dian)(dian)廠，化(hua)工廠等地方。如(ru)果發生嚴重(zhong)故障導致(zhi)電(dian)(dian)(dian)機(ji)燒毀，將嚴重(zhong)影響生產的(de)(de)正常(chang)進行(xing)，造成(cheng)巨大(da)的(de)(de)經濟損失(shi)，因(yin)此必須對(dui)其(qi)提供(gong)完(wan)善的(de)(de)保(bao)(bao)(bao)護(hu)(hu)。現有電(dian)(dian)(dian)動(dong)(dong)機(ji)綜合(he)保(bao)(bao)(bao)護(hu)(hu)裝(zhuang)置(zhi)(zhi)主要(yao)針(zhen)對(dui)中小型電(dian)(dian)(dian)動(dong)(dong)機(ji)，為其(qi)提供(gong)電(dian)(dian)(dian)流速(su)斷(duan)，熱過載反時限過流，兩段(duan)式定(ding)時限負序，零序電(dian)(dian)(dian)流，轉子停滯，啟動(dong)(dong)時間過長(chang)，頻繁啟動(dong)(dong)等保(bao)(bao)(bao)護(hu)(hu)功能(neng)。而對(dui)于2000KW以(yi)上特(te)大(da)容(rong)量電(dian)(dian)(dian)動(dong)(dong)機(ji)，則無法滿(man)足(zu)其(qi)內(nei)部故障時對(dui)保(bao)(bao)(bao)護(hu)(hu)靈(ling)敏(min)度與速(su)動(dong)(dong)性(xing)的(de)(de)要(yao)求，因(yin)而研制此裝(zhuang)置(zhi)(zhi)并配合(he)綜合(he)保(bao)(bao)(bao)護(hu)(hu)裝(zhuang)置(zhi)(zhi)，為高壓電(dian)(dian)(dian)動(dong)(dong)機(ji)提供(gong)更可靠更靈(ling)敏(min)的(de)(de)保(bao)(bao)(bao)護(hu)(hu)措施。本裝(zhuang)置(zhi)(zhi)設計(ji)成(cheng)三(san)相(xiang)式縱差，因(yin)為2000KW以(yi)上特(te)大(da)容(rong)量的(de)(de)電(dian)(dian)(dian)動(dong)(dong)機(ji)所在的(de)(de)3KV﹑6KV﹑10KV電(dian)(dian)(dian)網可能(neng)是變壓器中性(xing)點(dian)經高電(dian)(dian)(dian)阻接地的(de)(de)電(dian)(dian)(dian)網，三(san)相(xiang)式縱差保(bao)(bao)(bao)護(hu)(hu)不但能(neng)作為電(dian)(dian)(dian)動(dong)(dong)機(ji)定(ding)子繞(rao)組(zu)及引出線相(xiang)間短路的(de)(de)主保(bao)(bao)(bao)護(hu)(hu)，而且可作為單相(xiang)接地故障的(de)(de)主保(bao)(bao)(bao)護(hu)(hu)，作用于瞬時跳閘。