新聞動態 電機(ji)在(zai)偏離額定電壓狀態下運行(xing)的不(bu)良后果

任(ren)何(he)一款電器(qi)(qi)產(chan)品(pin)，當(dang)然包括電機產(chan)品(pin)，都對其正(zheng)常運(yun)(yun)行的額定(ding)電壓進行了規(gui)定(ding)，任(ren)何(he)的電壓偏離(li)均會對電器(qi)(qi)的正(zheng)常運(yun)(yun)行造成不良后果(guo)。

對(dui)于相對(dui)較高端的(de)設備，采(cai)(cai)用了必要的(de)保(bao)(bao)護裝置(zhi)，當(dang)電(dian)源電(dian)壓(ya)出現異(yi)常時，采(cai)(cai)用切斷電(dian)源的(de)方式進行了保(bao)(bao)護，對(dui)于非常精密的(de)儀器，則(ze)采(cai)(cai)用恒壓(ya)電(dian)源進行調整(zheng)，而電(dian)機產品，特別是工業用電(dian)機產品，采(cai)(cai)用恒壓(ya)裝置(zhi)的(de)可能性極(ji)小，斷電(dian)保(bao)(bao)護的(de)情(qing)況更多一(yi)些(xie)。

對于單相電(dian)機(ji)，只存在電(dian)壓(ya)(ya)高與(yu)低兩(liang)種(zhong)情況，而對于三相電(dian)機(ji)還存在電(dian)壓(ya)(ya)的平衡(heng)問題(ti)，這三種(zhong)電(dian)壓(ya)(ya)偏離對影響的直接(jie)表現為電(dian)流增大或電(dian)流不平衡(heng)。

電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)技術條件中規定，電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)額定電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)上(shang)下偏差不能(neng)超過10%，電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)轉矩與(yu)電(dian)(dian)(dian)(dian)(dian)機(ji)端電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)平(ping)方成正比，當電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)過高(gao)時，電(dian)(dian)(dian)(dian)(dian)機(ji)鐵芯將(jiang)處(chu)于磁飽和狀態(tai)，定子電(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)增(zeng)大(da)將(jiang)導(dao)致繞組(zu)嚴重發(fa)熱(re)，甚至(zhi)出現繞組(zu)燒毀的(de)(de)(de)質量問(wen)題；而對于電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)偏低(di)的(de)(de)(de)情(qing)況(kuang)，一種是電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)啟動可能(neng)會存在問(wen)題，特別是對于帶載運(yun)(yun)行的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)機(ji)，為了滿(man)足電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)帶載運(yun)(yun)行，電(dian)(dian)(dian)(dian)(dian)流也必(bi)須(xu)要增(zeng)加(jia)，電(dian)(dian)(dian)(dian)(dian)流增(zeng)加(jia)的(de)(de)(de)后果同樣是繞組(zu)的(de)(de)(de)發(fa)熱(re)乃至(zhi)燒毀，特別是長期(qi)的(de)(de)(de)低(di)壓(ya)(ya)運(yun)(yun)行，該問(wen)題更(geng)為嚴重。

三相電(dian)(dian)(dian)(dian)機電(dian)(dian)(dian)(dian)壓(ya)不(bu)平(ping)衡(heng)(heng)(heng)，是典型的(de)(de)供(gong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源問(wen)題，當電(dian)(dian)(dian)(dian)壓(ya)不(bu)平(ping)衡(heng)(heng)(heng)時，勢(shi)必會導(dao)致電(dian)(dian)(dian)(dian)機電(dian)(dian)(dian)(dian)流(liu)的(de)(de)不(bu)平(ping)衡(heng)(heng)(heng)問(wen)題。不(bu)平(ping)衡(heng)(heng)(heng)電(dian)(dian)(dian)(dian)壓(ya)的(de)(de)負序分量在電(dian)(dian)(dian)(dian)機氣隙(xi)中(zhong)產生一個與轉(zhuan)子轉(zhuan)向(xiang)相反的(de)(de)磁場。電(dian)(dian)(dian)(dian)壓(ya)中(zhong)很(hen)小的(de)(de)負序分量可能使得流(liu)過(guo)繞(rao)組(zu)(zu)(zu)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)比電(dian)(dian)(dian)(dian)壓(ya)平(ping)衡(heng)(heng)(heng)時的(de)(de)電(dian)(dian)(dian)(dian)流(liu)大很(hen)多(duo)(duo)。流(liu)過(guo)轉(zhuan)子導(dao)條(tiao)中(zhong)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)頻率幾乎是額定(ding)頻率的(de)(de)2倍，因(yin)此轉(zhuan)子導(dao)條(tiao)中(zhong)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)擠(ji)流(liu)效應使得轉(zhuan)子繞(rao)組(zu)(zu)(zu)的(de)(de)損耗(hao)增加值(zhi)比定(ding)子繞(rao)組(zu)(zu)(zu)損耗(hao)增加值(zhi)大很(hen)多(duo)(duo)。定(ding)子繞(rao)組(zu)(zu)(zu)溫升(sheng)比在平(ping)衡(heng)(heng)(heng)電(dian)(dian)(dian)(dian)壓(ya)下運行時的(de)(de)溫升(sheng)增高(gao)。

當電(dian)壓不(bu)平(ping)(ping)衡時，電(dian)動機的堵轉(zhuan)(zhuan)轉(zhuan)(zhuan)矩、最小轉(zhuan)(zhuan)矩以及最大轉(zhuan)(zhuan)矩都將減小。若(ruo)電(dian)壓不(bu)平(ping)(ping)衡很嚴重，則電(dian)動機將不(bu)能正常工作。

當電(dian)(dian)動(dong)機(ji)在不(bu)平(ping)(ping)衡電(dian)(dian)壓下(xia)(xia)滿(man)載(zai)運行時，由于轉(zhuan)差率隨著轉(zhuan)子附(fu)加損耗的(de)增(zeng)加而(er)增(zeng)大，因而(er)此時轉(zhuan)速會(hui)略(lve)微下(xia)(xia)降。隨同電(dian)(dian)壓（電(dian)(dian)流）不(bu)平(ping)(ping)衡程(cheng)度的(de)增(zeng)大，電(dian)(dian)動(dong)機(ji)的(de)噪聲和振動(dong)可能(neng)增(zeng)強。振動(dong)可能(neng)損害電(dian)(dian)動(dong)機(ji)或整(zheng)個驅動(dong)系統。

為了有(you)效甄(zhen)別電(dian)(dian)機(ji)電(dian)(dian)壓(ya)不平(ping)的原(yuan)因，可(ke)能通過電(dian)(dian)源電(dian)(dian)壓(ya)檢(jian)測(ce)或電(dian)(dian)流變(bian)化(hua)情(qing)(qing)況的方(fang)法進行。大(da)多數設備上都(dou)配有(you)電(dian)(dian)壓(ya)監控儀表(biao)，可(ke)以(yi)(yi)(yi)通過數據對比(bi)進行分(fen)析，而對于(yu)沒(mei)有(you)監控裝置的情(qing)(qing)況，則應采用定(ding)期(qi)檢(jian)測(ce)或測(ce)定(ding)電(dian)(dian)流的方(fang)式進行；對于(yu)可(ke)以(yi)(yi)(yi)正反(fan)轉的電(dian)(dian)機(ji)，在不影響被拖動(dong)設備的情(qing)(qing)況下，可(ke)以(yi)(yi)(yi)任意(yi)調換兩(liang)相(xiang)供電(dian)(dian)線，觀察電(dian)(dian)流變(bian)化(hua)情(qing)(qing)況，而間接分(fen)析電(dian)(dian)壓(ya)的平(ping)衡情(qing)(qing)況，在排除電(dian)(dian)壓(ya)不平(ping)的問題(ti)后，可(ke)能就會涉及匝間、相(xiang)間等(deng)質量問題(ti)。