新聞動態 電(dian)機在偏離額定電(dian)壓狀態下運行的(de)不良后果

任(ren)何(he)一款(kuan)電(dian)(dian)器產品，當然包括電(dian)(dian)機產品，都(dou)對(dui)其正(zheng)(zheng)常運(yun)(yun)行的(de)(de)額(e)定電(dian)(dian)壓(ya)進行了(le)規(gui)定，任(ren)何(he)的(de)(de)電(dian)(dian)壓(ya)偏離均(jun)會對(dui)電(dian)(dian)器的(de)(de)正(zheng)(zheng)常運(yun)(yun)行造成(cheng)不良后果。

對于相對較高(gao)端的(de)(de)設備，采(cai)(cai)(cai)用(yong)了(le)必(bi)要(yao)的(de)(de)保(bao)(bao)護(hu)(hu)裝置(zhi)，當電(dian)(dian)源電(dian)(dian)壓(ya)出(chu)現(xian)異常(chang)(chang)時，采(cai)(cai)(cai)用(yong)切(qie)斷電(dian)(dian)源的(de)(de)方式(shi)進(jin)行(xing)了(le)保(bao)(bao)護(hu)(hu)，對于非常(chang)(chang)精密的(de)(de)儀器，則采(cai)(cai)(cai)用(yong)恒壓(ya)電(dian)(dian)源進(jin)行(xing)調整，而電(dian)(dian)機產品(pin)，特別是工業用(yong)電(dian)(dian)機產品(pin)，采(cai)(cai)(cai)用(yong)恒壓(ya)裝置(zhi)的(de)(de)可能(neng)性極(ji)小(xiao)，斷電(dian)(dian)保(bao)(bao)護(hu)(hu)的(de)(de)情況更多(duo)一些。

對于單相電(dian)(dian)(dian)機(ji)，只存(cun)在(zai)電(dian)(dian)(dian)壓(ya)(ya)高與低(di)兩(liang)種情況，而對于三相電(dian)(dian)(dian)機(ji)還存(cun)在(zai)電(dian)(dian)(dian)壓(ya)(ya)的平(ping)衡問題，這三種電(dian)(dian)(dian)壓(ya)(ya)偏離對影響(xiang)的直(zhi)接表(biao)現為(wei)電(dian)(dian)(dian)流增大或電(dian)(dian)(dian)流不(bu)平(ping)衡。

電(dian)(dian)機(ji)(ji)的(de)(de)技術(shu)條(tiao)件中規定，電(dian)(dian)機(ji)(ji)的(de)(de)額(e)定電(dian)(dian)壓(ya)(ya)上下偏差不能(neng)超過10%，電(dian)(dian)機(ji)(ji)的(de)(de)轉矩與電(dian)(dian)機(ji)(ji)端電(dian)(dian)壓(ya)(ya)的(de)(de)平(ping)方成正比，當電(dian)(dian)壓(ya)(ya)過高時，電(dian)(dian)機(ji)(ji)鐵芯將處(chu)于磁(ci)飽和狀態(tai)，定子電(dian)(dian)流的(de)(de)增大將導致繞(rao)組(zu)嚴重發(fa)熱，甚至出現(xian)繞(rao)組(zu)燒毀(hui)的(de)(de)質量問題(ti)；而(er)對于電(dian)(dian)壓(ya)(ya)偏低的(de)(de)情(qing)況(kuang)，一(yi)種是(shi)電(dian)(dian)機(ji)(ji)的(de)(de)啟動可能(neng)會存(cun)在問題(ti)，特(te)別(bie)是(shi)對于帶(dai)載運(yun)行的(de)(de)電(dian)(dian)機(ji)(ji)，為(wei)(wei)了滿足電(dian)(dian)機(ji)(ji)的(de)(de)帶(dai)載運(yun)行，電(dian)(dian)流也必須(xu)要增加，電(dian)(dian)流增加的(de)(de)后果同(tong)樣是(shi)繞(rao)組(zu)的(de)(de)發(fa)熱乃至燒毀(hui)，特(te)別(bie)是(shi)長(chang)期的(de)(de)低壓(ya)(ya)運(yun)行，該問題(ti)更為(wei)(wei)嚴重。

三相電(dian)(dian)(dian)(dian)機電(dian)(dian)(dian)(dian)壓不(bu)(bu)(bu)平(ping)衡(heng)，是典(dian)型(xing)的(de)(de)供電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源問題，當電(dian)(dian)(dian)(dian)壓不(bu)(bu)(bu)平(ping)衡(heng)時，勢必會導致電(dian)(dian)(dian)(dian)機電(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)不(bu)(bu)(bu)平(ping)衡(heng)問題。不(bu)(bu)(bu)平(ping)衡(heng)電(dian)(dian)(dian)(dian)壓的(de)(de)負(fu)序分量在電(dian)(dian)(dian)(dian)機氣隙中(zhong)產生一(yi)個(ge)與(yu)轉(zhuan)子轉(zhuan)向相反的(de)(de)磁場(chang)。電(dian)(dian)(dian)(dian)壓中(zhong)很小的(de)(de)負(fu)序分量可能使得(de)流(liu)(liu)過繞(rao)組的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)比(bi)電(dian)(dian)(dian)(dian)壓平(ping)衡(heng)時的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)大很多。流(liu)(liu)過轉(zhuan)子導條中(zhong)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)頻率(lv)幾乎是額定(ding)(ding)頻率(lv)的(de)(de)2倍(bei)，因此轉(zhuan)子導條中(zhong)的(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)擠流(liu)(liu)效應使得(de)轉(zhuan)子繞(rao)組的(de)(de)損耗增(zeng)加值比(bi)定(ding)(ding)子繞(rao)組損耗增(zeng)加值大很多。定(ding)(ding)子繞(rao)組溫升比(bi)在平(ping)衡(heng)電(dian)(dian)(dian)(dian)壓下運行時的(de)(de)溫升增(zeng)高。

當(dang)電(dian)壓不(bu)平衡時，電(dian)動機(ji)的堵轉(zhuan)(zhuan)轉(zhuan)(zhuan)矩、最(zui)小轉(zhuan)(zhuan)矩以及最(zui)大轉(zhuan)(zhuan)矩都將(jiang)減小。若電(dian)壓不(bu)平衡很嚴重，則電(dian)動機(ji)將(jiang)不(bu)能(neng)正常(chang)工作。

當電(dian)動機(ji)在不平(ping)衡電(dian)壓下滿(man)載運(yun)行時(shi)，由(you)于轉(zhuan)差率隨(sui)著(zhu)轉(zhuan)子附加損(sun)耗(hao)的(de)(de)增(zeng)加而增(zeng)大(da)，因而此(ci)時(shi)轉(zhuan)速會略(lve)微下降。隨(sui)同電(dian)壓（電(dian)流）不平(ping)衡程度的(de)(de)增(zeng)大(da)，電(dian)動機(ji)的(de)(de)噪聲和(he)振(zhen)動可能增(zeng)強。振(zhen)動可能損(sun)害電(dian)動機(ji)或整個驅(qu)動系統(tong)。

為(wei)了(le)有(you)效甄別電機(ji)電壓(ya)不(bu)平(ping)的(de)原(yuan)因(yin)，可(ke)(ke)(ke)能通過電源電壓(ya)檢測(ce)或電流變化情況(kuang)的(de)方(fang)法進(jin)行。大多數(shu)(shu)設(she)備上(shang)都配有(you)電壓(ya)監(jian)控儀表，可(ke)(ke)(ke)以(yi)通過數(shu)(shu)據(ju)對(dui)比進(jin)行分析，而對(dui)于沒有(you)監(jian)控裝置的(de)情況(kuang)，則應采用定期檢測(ce)或測(ce)定電流的(de)方(fang)式進(jin)行；對(dui)于可(ke)(ke)(ke)以(yi)正(zheng)反轉的(de)電機(ji)，在不(bu)影(ying)響(xiang)被拖(tuo)動設(she)備的(de)情況(kuang)下(xia)，可(ke)(ke)(ke)以(yi)任意(yi)調換兩(liang)相供(gong)電線，觀察電流變化情況(kuang)，而間(jian)接分析電壓(ya)的(de)平(ping)衡情況(kuang)，在排(pai)除電壓(ya)不(bu)平(ping)的(de)問題后，可(ke)(ke)(ke)能就會(hui)涉及匝間(jian)、相間(jian)等質(zhi)量問題。