感應(ying)電(dian)動機(ji)又稱“異步電(dian)動機(ji)(asynchronousmotor)”,即轉(zhuan)(zhuan)子置于旋轉(zhuan)(zhuan)磁(ci)場中(zhong),在旋轉(zhuan)(zhuan)磁(ci)場的作用(yong)下,獲得一個轉(zhuan)(zhuan)動力矩,因而轉(zhuan)(zhuan)子轉(zhuan)(zhuan)動。
轉(zhuan)(zhuan)子(zi)是(shi)(shi)可轉(zhuan)(zhuan)動(dong)(dong)的(de)導體,通常多(duo)呈鼠籠狀。定子(zi)是(shi)(shi)電(dian)動(dong)(dong)機(ji)(ji)(ji)中(zhong)不轉(zhuan)(zhuan)動(dong)(dong)的(de)部分(fen),主要(yao)任務是(shi)(shi)產生(sheng)一個(ge)旋(xuan)(xuan)轉(zhuan)(zhuan)磁(ci)(ci)(ci)場。旋(xuan)(xuan)轉(zhuan)(zhuan)磁(ci)(ci)(ci)場并不是(shi)(shi)用(yong)機(ji)(ji)(ji)械方法來實現(xian)。而(er)是(shi)(shi)以交流(liu)(liu)電(dian)通于(yu)數對電(dian)磁(ci)(ci)(ci)鐵(tie)中(zhong),使(shi)其(qi)磁(ci)(ci)(ci)極性質(zhi)循環改變,故相(xiang)當于(yu)一個(ge)旋(xuan)(xuan)轉(zhuan)(zhuan)的(de)磁(ci)(ci)(ci)場。這種電(dian)動(dong)(dong)機(ji)(ji)(ji)并不像直流(liu)(liu)電(dian)動(dong)(dong)機(ji)(ji)(ji)有(you)電(dian)刷(shua)或(huo)集電(dian)環,依據所用(yong)交流(liu)(liu)電(dian)的(de)種類(lei)有(you)單(dan)相(xiang)電(dian)動(dong)(dong)機(ji)(ji)(ji)和三相(xiang)電(dian)動(dong)(dong)機(ji)(ji)(ji),單(dan)相(xiang)電(dian)動(dong)(dong)機(ji)(ji)(ji)用(yong)在如洗衣機(ji)(ji)(ji),電(dian)風扇等(deng);三相(xiang)電(dian)動(dong)(dong)機(ji)(ji)(ji)則作為工廠的(de)動(dong)(dong)力設備。
尼(ni)古拉(la)(la)·特斯拉(la)(la)(Nikola Tesla,1856年7月10日~1943年1月7日),塞爾維(wei)亞裔美(mei)籍(ji)發(fa)明家、機械工程師(shi)、電(dian)氣工程師(shi)。他被認為是電(dian)力商業(ye)化的(de)(de)重要推(tui)動(dong)者之一,并因主持(chi)設(she)計了現(xian)代(dai)交流(liu)電(dian)系統而最為人知。在邁(mai)克爾·法(fa)拉(la)(la)第發(fa)現(xian)的(de)(de)電(dian)磁(ci)場理論(lun)的(de)(de)基(ji)礎(chu)上,特斯拉(la)(la)在電(dian)磁(ci)場領域有著(zhu)多(duo)項革命(ming)性的(de)(de)發(fa)明。1887年發(fa)明感應電(dian)動(dong)機,他的(de)(de)多(duo)項相關專利以及(ji)電(dian)磁(ci)學的(de)(de)理論(lun)研究(jiu)工作是現(xian)代(dai)的(de)(de)無(wu)線通信和無(wu)線電(dian)的(de)(de)基(ji)石。
通(tong)過定子(zi)(zi)(zi)(zi)產(chan)(chan)(chan)生(sheng)的旋轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)磁(ci)(ci)場(chang)(其轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)為(wei)同(tong)步(bu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)n1)與轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)繞組(zu)的相(xiang)對運(yun)動(dong)(dong),轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)繞組(zu)切割磁(ci)(ci)感(gan)線產(chan)(chan)(chan)生(sheng)感(gan)應(ying)電(dian)動(dong)(dong)勢,從而使轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)繞組(zu)中產(chan)(chan)(chan)生(sheng)感(gan)應(ying)電(dian)流(liu)。轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)繞組(zu)中的感(gan)應(ying)電(dian)流(liu)與磁(ci)(ci)場(chang)作用,產(chan)(chan)(chan)生(sheng)電(dian)磁(ci)(ci)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)矩,使轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)旋轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)。由于(yu)當轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)逐漸接近同(tong)步(bu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)時,感(gan)應(ying)電(dian)流(liu)逐漸減(jian)小(xiao),所產(chan)(chan)(chan)生(sheng)的電(dian)磁(ci)(ci)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)矩也相(xiang)應(ying)減(jian)小(xiao),當異步(bu)電(dian)動(dong)(dong)機(ji)工作在電(dian)動(dong)(dong)機(ji)狀態(tai)時,轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)小(xiao)于(yu)同(tong)步(bu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)。為(wei)了描述轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)n與同(tong)步(bu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)速(su)(su)n1之間的差別,引入轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)差率(lv)(slip)。
單相(xiang)異步電機的基本結構
單相異(yi)步電(dian)動機(ji)(ji)(ji)就是只需單相交(jiao)流電(dian)源(yuan)供電(dian)的(de)電(dian)動機(ji)(ji)(ji)。單相異(yi)步電(dian)動機(ji)(ji)(ji)由(you)(you)定子(zi)(zi)、轉(zhuan)(zhuan)子(zi)(zi)、軸承、機(ji)(ji)(ji)殼、端蓋等構(gou)成(cheng)。定子(zi)(zi)由(you)(you)機(ji)(ji)(ji)座和帶繞(rao)(rao)組(zu)(zu)的(de)鐵(tie)心(xin)組(zu)(zu)成(cheng)。鐵(tie)心(xin)由(you)(you)硅鋼片沖槽疊壓而(er)成(cheng),槽內(nei)嵌裝兩套空(kong)間(jian)互(hu)隔(ge)90°電(dian)角度的(de)主繞(rao)(rao)組(zu)(zu)(也(ye)稱運行(xing)繞(rao)(rao)組(zu)(zu))和輔繞(rao)(rao)組(zu)(zu)(也(ye)稱起動繞(rao)(rao)組(zu)(zu)成(cheng)副繞(rao)(rao)組(zu)(zu))。主繞(rao)(rao)組(zu)(zu)接交(jiao)流電(dian)源(yuan),輔繞(rao)(rao)組(zu)(zu)串(chuan)接離(li)心(xin)開關S或起動電(dian)容、運行(xing)電(dian)容等之后,再接入電(dian)源(yuan)。轉(zhuan)(zhuan)子(zi)(zi)為籠(long)型鑄(zhu)(zhu)鋁(lv)轉(zhuan)(zhuan)子(zi)(zi),它是將(jiang)鐵(tie)心(xin)疊壓后用(yong)鋁(lv)鑄(zhu)(zhu)入鐵(tie)心(xin)的(de)槽中,并一起鑄(zhu)(zhu)出端環(huan),使轉(zhuan)(zhuan)子(zi)(zi)導條(tiao)短路成(cheng)鼠籠(long)型。
單(dan)相(xiang)異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)又分為單(dan)相(xiang)電(dian)(dian)(dian)阻(zu)起動(dong)(dong)(dong)異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji),單(dan)相(xiang)電(dian)(dian)(dian)容起動(dong)(dong)(dong)異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)、單(dan)相(xiang)電(dian)(dian)(dian)容運轉異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)和單(dan)相(xiang)雙(shuang)值(zhi)電(dian)(dian)(dian)容異(yi)步電(dian)(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)。
三相(xiang)異步電機的基本結(jie)構
三相(xiang)(xiang)(xiang)(xiang)異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)主要(yao)有(you)(you)由定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)和(he)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi),軸(zhou)承組(zu)(zu)(zu)(zu)(zu)成(cheng)(cheng)。定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)主要(yao)由鐵(tie)(tie)(tie)(tie)心(xin)(xin),三相(xiang)(xiang)(xiang)(xiang)繞組(zu)(zu)(zu)(zu)(zu),機(ji)座(zuo)(zuo),端蓋組(zu)(zu)(zu)(zu)(zu)成(cheng)(cheng)。定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)一(yi)般(ban)(ban)由0.35~0.5毫米(mi)厚(hou)表面具(ju)有(you)(you)絕緣層的(de)(de)(de)硅鋼(gang)片(pian)沖(chong)(chong)制、疊壓而成(cheng)(cheng),在(zai)(zai)(zai)鐵(tie)(tie)(tie)(tie)心(xin)(xin)的(de)(de)(de)內圓(yuan)沖(chong)(chong)有(you)(you)均(jun)勻(yun)分(fen)布的(de)(de)(de)槽(cao),用(yong)以(yi)嵌放(fang)定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)。三相(xiang)(xiang)(xiang)(xiang)繞組(zu)(zu)(zu)(zu)(zu)由三個(ge)在(zai)(zai)(zai)空間互隔120°電(dian)(dian)(dian)角度、隊稱排列的(de)(de)(de)結構完全相(xiang)(xiang)(xiang)(xiang)同(tong)繞組(zu)(zu)(zu)(zu)(zu)連接(jie)(jie)(jie)而成(cheng)(cheng),這(zhe)些(xie)繞組(zu)(zu)(zu)(zu)(zu)的(de)(de)(de)各個(ge)線(xian)圈按一(yi)定規律分(fen)別嵌放(fang)在(zai)(zai)(zai)定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)各槽(cao)內。其作(zuo)用(yong)是通入(ru)三相(xiang)(xiang)(xiang)(xiang)交(jiao)流電(dian)(dian)(dian),產(chan)生旋轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)磁場。機(ji)座(zuo)(zuo)通常(chang)(chang)為鑄鐵(tie)(tie)(tie)(tie)件(jian),大型異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)機(ji)座(zuo)(zuo)一(yi)般(ban)(ban)用(yong)鋼(gang)板(ban)焊(han)成(cheng)(cheng),微型電(dian)(dian)(dian)動(dong)(dong)機(ji)的(de)(de)(de)機(ji)座(zuo)(zuo)采用(yong)鑄鋁(lv)件(jian),其作(zuo)用(yong)是固定定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)與(yu)前后端蓋以(yi)支(zhi)(zhi)撐轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi),并起(qi)防護、散(san)熱(re)(re)等作(zuo)用(yong)。封閉式(shi)電(dian)(dian)(dian)機(ji)的(de)(de)(de)機(ji)座(zuo)(zuo)外(wai)面有(you)(you)散(san)熱(re)(re)筋以(yi)增加散(san)熱(re)(re)面積,防護式(shi)電(dian)(dian)(dian)機(ji)的(de)(de)(de)機(ji)座(zuo)(zuo)兩端端蓋開有(you)(you)通風孔,使電(dian)(dian)(dian)動(dong)(dong)機(ji)內外(wai)的(de)(de)(de)空氣(qi)可(ke)直接(jie)(jie)(jie)對(dui)流,以(yi)利于散(san)熱(re)(re)。端蓋主要(yao)起(qi)固定轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi),支(zhi)(zhi)撐和(he)防護作(zuo)用(yong)。轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)主要(yao)由鐵(tie)(tie)(tie)(tie)心(xin)(xin)和(he)繞組(zu)(zu)(zu)(zu)(zu)組(zu)(zu)(zu)(zu)(zu)成(cheng)(cheng)。轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)所(suo)用(yong)材(cai)料與(yu)定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)一(yi)樣,由0.5毫米(mi)厚(hou)的(de)(de)(de)硅鋼(gang)片(pian)沖(chong)(chong)制、疊壓而成(cheng)(cheng),硅鋼(gang)片(pian)外(wai)圓(yuan)沖(chong)(chong)有(you)(you)均(jun)勻(yun)分(fen)布的(de)(de)(de)孔,用(yong)來安置(zhi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)。通常(chang)(chang)用(yong)定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)沖(chong)(chong)落后的(de)(de)(de)硅鋼(gang)片(pian)內圓(yuan)來沖(chong)(chong)制轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)。一(yi)般(ban)(ban)小型異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)的(de)(de)(de)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)直接(jie)(jie)(jie)壓裝在(zai)(zai)(zai)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)軸(zhou)上(shang)(shang)(shang),大、中型異步(bu)電(dian)(dian)(dian)動(dong)(dong)機(ji)(轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)直徑在(zai)(zai)(zai)300~400毫米(mi)以(yi)上(shang)(shang)(shang))的(de)(de)(de)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin)則(ze)借助與(yu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)支(zhi)(zhi)架壓在(zai)(zai)(zai)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)軸(zhou)上(shang)(shang)(shang)。轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)分(fen)為鼠(shu)(shu)籠(long)式(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)和(he)繞線(xian)式(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)。 (1)鼠(shu)(shu)籠(long)式(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi):轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)由插入(ru)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)槽(cao)中的(de)(de)(de)多根導條(tiao)和(he)兩個(ge)環行的(de)(de)(de)端環組(zu)(zu)(zu)(zu)(zu)成(cheng)(cheng)。若去掉轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)鐵(tie)(tie)(tie)(tie)心(xin)(xin),整個(ge)繞組(zu)(zu)(zu)(zu)(zu)的(de)(de)(de)外(wai)形(xing)像一(yi)個(ge)鼠(shu)(shu)籠(long),故稱籠(long)型繞組(zu)(zu)(zu)(zu)(zu)。小型籠(long)型電(dian)(dian)(dian)動(dong)(dong)機(ji)采用(yong)鑄鋁(lv)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu),對(dui)于100KW以(yi)上(shang)(shang)(shang)的(de)(de)(de)電(dian)(dian)(dian)動(dong)(dong)機(ji)采用(yong)銅條(tiao)和(he)銅端環焊(han)接(jie)(jie)(jie)而成(cheng)(cheng)。鼠(shu)(shu)籠(long)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)分(fen)為:阻抗型轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)、單鼠(shu)(shu)籠(long)型轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)、雙鼠(shu)(shu)籠(long)型轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)、深槽(cao)式(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)幾種,起(qi)動(dong)(dong)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)矩等特性(xing)各有(you)(you)不同(tong)。 (2)繞線(xian)式(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi):繞線(xian)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)與(yu)定子(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)(zi)繞組(zu)(zu)(zu)(zu)(zu)相(xiang)(xiang)(xiang)(xiang)似(si),也是一(yi)個(ge)對(dui)稱的(de)(de)(de)三相(xiang)(xiang)(xiang)(xiang)繞組(zu)(zu)(zu)(zu)(zu),一(yi)般(ban)(ban)接(jie)(jie)(jie)成(cheng)(cheng)星形(xing),三個(ge)出(chu)線(xian)頭接(jie)(jie)(jie)到轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)軸(zhou)的(de)(de)(de)三個(ge)集(ji)流環上(shang)(shang)(shang),再通過電(dian)(dian)(dian)刷與(yu)外(wai)電(dian)(dian)(dian)路(lu)聯接(jie)(jie)(jie)。
1 異步電動(dong)(dong)機(ji)起動(dong)(dong)方(fang)式
1.1 軟起動
隨著微(wei)型(xing)計(ji)算(suan)機(ji)控(kong)制(zhi)(zhi)(zhi)技術的(de)(de)(de)(de)(de)(de)迅猛發(fa)展,在相(xiang)關的(de)(de)(de)(de)(de)(de)控(kong)制(zhi)(zhi)(zhi)工程領域中先后(hou)(hou)研制(zhi)(zhi)(zhi)成(cheng)功了一批電(dian)子式軟(ruan)起動控(kong)制(zhi)(zhi)(zhi)器,廣泛應用在電(dian)動機(ji)的(de)(de)(de)(de)(de)(de)起動過程,降壓(ya)(ya)啟動器隨之被替代。當前(qian)電(dian)子式的(de)(de)(de)(de)(de)(de)軟(ruan)起動設施都使用的(de)(de)(de)(de)(de)(de)是(shi)晶閘管的(de)(de)(de)(de)(de)(de)調(diao)壓(ya)(ya)電(dian)路,其(qi)電(dian)路構(gou)成(cheng)如(ru)下所描述:晶閘管六(liu)只,兩(liang)兩(liang)反并聯(lian)后(hou)(hou)串聯(lian)至三相(xiang)電(dian)源上,待系統發(fa)送(song)起動信(xin)號后(hou)(hou),微(wei)機(ji)控(kong)制(zhi)(zhi)(zhi)起動器系統立(li)即進行數據計(ji)算(suan),令(ling)晶閘管輸送(song)觸發(fa)信(xin)號,使晶閘管的(de)(de)(de)(de)(de)(de)導通角得到控(kong)制(zhi)(zhi)(zhi),根據給定的(de)(de)(de)(de)(de)(de)輸出,調(diao)節輸出電(dian)壓(ya)(ya),實現電(dian)動機(ji)的(de)(de)(de)(de)(de)(de)控(kong)制(zhi)(zhi)(zhi)。該起動方式適合各種(zhong)功率值(zhi)的(de)(de)(de)(de)(de)(de)三相(xiang)交流異(yi)步(bu)電(dian)動機(ji)包括六(liu)根和三根連接(jie)方式的(de)(de)(de)(de)(de)(de)起動控(kong)制(zhi)(zhi)(zhi)。
1.2 直接起動
此種(zhong)起(qi)動(dong)方式是電(dian)機(ji)起(qi)動(dong)方式中(zhong)最基礎(chu)最簡單(dan)的,首先借助用刀開關使電(dian)動(dong)機(ji)與(yu)電(dian)網進行連接,此時在額定電(dian)壓下電(dian)動(dong)機(ji)起(qi)動(dong)并運行起(qi)來,該方式特(te)點為(wei):投資少,設備(bei)簡單(dan)、數量(liang)少,雖(sui)然起(qi)動(dong)時間短,但起(qi)動(dong)時的轉矩(ju)較小,電(dian)流(liu)較大,比較適合應用在容量(liang)小的電(dian)動(dong)機(ji)起(qi)動(dong)。
1.3 降壓(ya)起動
由于直(zhi)接起(qi)(qi)動(dong)存(cun)在(zai)較(jiao)大的(de)缺(que)點,降(jiang)壓(ya)起(qi)(qi)動(dong)隨之(zhi)產(chan)生(sheng)。這(zhe)種起(qi)(qi)動(dong)方(fang)式(shi)適用的(de)起(qi)(qi)動(dong)環境為空載和輕(qing)載這(zhe)兩種情況,由于降(jiang)壓(ya)起(qi)(qi)動(dong)方(fang)式(shi)是在(zai)同時(shi)實現了(le)限制起(qi)(qi)動(dong)轉矩和起(qi)(qi)動(dong)電(dian)流(liu)的(de),因(yin)此(ci)起(qi)(qi)動(dong)工作結(jie)束后(hou)需要使工作的(de)電(dian)路恢復到額定(ding)狀(zhuang)態。
三相(xiang)感應(ying)電(dian)動(dong)(dong)機電(dian)氣制(zhi)動(dong)(dong)方式有:能耗制(zhi)動(dong)(dong)、反接(jie)制(zhi)動(dong)(dong)、再生制(zhi)動(dong)(dong)三種。
(1)能耗制動(dong)(dong)時切(qie)斷電動(dong)(dong)機(ji)(ji)的三相交流(liu)電源,將直(zhi)(zhi)流(liu)電送入定(ding)子(zi)繞組。在切(qie)斷交流(liu)電源的瞬間,由(you)于(yu)慣性作用,電動(dong)(dong)機(ji)(ji)仍按(an)原來方(fang)向(xiang)轉(zhuan)動(dong)(dong),這(zhe)種方(fang)式的特點是(shi)制動(dong)(dong)平穩,但(dan)需(xu)直(zhi)(zhi)流(liu)電源、大功率電動(dong)(dong)機(ji)(ji),所需(xu)直(zhi)(zhi)流(liu)設(she)備成本大,低速時制動(dong)(dong)力小(xiao)。
(2)反(fan)接制(zhi)動又分負(fu)載反(fan)接制(zhi)動和電源反(fan)接制(zhi)動兩種。
1)負載反接(jie)制動又稱負載倒拉反接(jie)制動。此轉矩使(shi)(shi)重物以穩定的(de)速度緩慢下(xia)降(jiang)。這種制動的(de)特點是:電(dian)源(yuan)不用(yong)反接(jie),不需要(yao)專(zhuan)用(yong)的(de)制動設(she)備,而(er)且(qie)還可以調(diao)節(jie)制動速度,但只適用(yong)于繞線型電(dian)動機(ji),其轉子(zi)電(dian)路(lu)需串入大(da)電(dian)阻(zu),使(shi)(shi)轉差率(lv)大(da)于1。
2)電(dian)(dian)源反接制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)當電(dian)(dian)動(dong)(dong)(dong)(dong)機(ji)(ji)需(xu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)時(shi)(shi),只要任意對(dui)調兩相電(dian)(dian)源線(xian),使(shi)旋(xuan)轉(zhuan)(zhuan)磁場相反就能很快制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)。當電(dian)(dian)動(dong)(dong)(dong)(dong)機(ji)(ji)轉(zhuan)(zhuan)速等(deng)于(yu)零時(shi)(shi),立即切斷電(dian)(dian)源。這種制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)的(de)特點是:停車快,制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)力(li)較強,無需(xu)制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)設備。但制(zhi)(zhi)(zhi)(zhi)動(dong)(dong)(dong)(dong)時(shi)(shi)由于(yu)電(dian)(dian)流大(da),沖擊力(li)也大(da),易使(shi)電(dian)(dian)動(dong)(dong)(dong)(dong)機(ji)(ji)過(guo)熱,或損(sun)傷(shang)傳動(dong)(dong)(dong)(dong)部分的(de)零部件。
(3)再生制(zhi)動(dong)(dong)又(you)稱(cheng)回饋制(zhi)動(dong)(dong),在重(zhong)物的作用(yong)(yong)下(xia)(當起重(zhong)機(ji)(ji)電動(dong)(dong)機(ji)(ji)下(xia)放重(zhong)物),電動(dong)(dong)機(ji)(ji)的轉(zhuan)(zhuan)速高于旋轉(zhuan)(zhuan)磁場的同步(bu)轉(zhuan)(zhuan)速。這(zhe)時轉(zhuan)(zhuan)子導體(ti)產(chan)生感應電流,在旋轉(zhuan)(zhuan)磁場的作用(yong)(yong)下(xia)產(chan)生反旋轉(zhuan)(zhuan)方向轉(zhuan)(zhuan)矩,但電動(dong)(dong)機(ji)(ji)轉(zhuan)(zhuan)速高,需(xu)用(yong)(yong)變速裝置減速。
1、一般來說,小(xiao)型異步(bu)電(dian)(dian)機指(zhi)的就是感應運轉型異步(bu)電(dian)(dian)機。這種(zhong)電(dian)(dian)機不只(zhi)在啟動時(shi)(shi),在運轉時(shi)(shi)也使用(yong)輔助線(xian)圈和(he)電(dian)(dian)容器(qi)。雖然(ran)啟動轉矩不是很(hen)大(da),但其結構(gou)簡單,信賴度高(gao),效(xiao)率(lv)也高(gao)。
2、隨(sui)負荷的大小,電機(ji)的額定(ding)轉速(su)也(ye)會改變。
3、可以連續(xu)運轉。
4、使用于不需要速度制動的應用場合(he)。
5、用(yong)E種(zhong)絕緣等級,而UL型電機則用(yong)A種(zhong)。
6、有感應運轉型單相(xiang)異步電(dian)機和三相(xiang)異步電(dian)機兩(liang)種。
7、單(dan)相電(dian)機(ji)為感應運(yun)轉型異步電(dian)機(ji),效率高,噪(zao)聲低。
8、單(dan)相異(yi)步電(dian)機運轉時,產生和(he)旋轉方向(xiang)(xiang)相反的(de)轉矩,因此不(bu)可(ke)能在(zai)短(duan)時間(jian)內(nei)改變方向(xiang)(xiang)。應在(zai)電(dian)機完全停止以后(hou),再轉換其旋轉方向(xiang)(xiang)。
9、單相電機的電源有A(110V 60Hz)、B(22V 60Hz)、C(100V 50/60Hz)、D(200V 50/60Hz)、E(115V 60Hz)、X(200-240V50Hz)等。
10、三相電機時使用U(200V 50/60Hz)、T(220V 50/60Hz)、S(380-440V 50/60Hz)電源的異步電機。
項目
事項
絕緣阻抗
在(zai)常(chang)溫(wen)金屬阻和電動機外殼之(zhi)間的(de)絕緣電阻超過100M?
絕緣內壓
在常溫金屬繞(rao)組和電動機箱之間(jian)的電壓
溫度上升
以1500V、50/60Hz輸(shu)入(ru)1min時沒(mei)有任何問題。
絕緣等級
E種(120℃)
過熱保護裝置
開(kai)放(fang)(120±5℃);復(fu)歸(77±5℃)
使用溫度
-10~50℃(UL CE規格電動(dong)機使用溫度為-10~40℃)
(1)電動機投入電源后不轉的原因檢查及修理(li)
電動機投入電源后不轉,一般有(you)下列(lie)原(yuan)因:
1)控(kong)制(zhi)設備的(de)接線錯誤;
2)過(guo)電流繼電器調(diao)整的整定值偏小;
3)電源未(wei)接通,如熔絲(si)燒(shao)斷(duan)、開關有故障或觸頭接觸不良(liang)、引線(xian)斷(duan)路等;
4)電源至(zhi)電動(dong)機(ji)之間(jian)的連(lian)接有故障;
5)電(dian)動機繞組有故障,如相間短路(lu)、接地、接錯線、斷路(lu)等;
6)繞線式轉子異步電動(dong)機起動(dong)誤操作或起動(dong)電阻過小(xiao);
7)電動機軸承有故障(zhang),被卡住(zhu);
8)定(ding)、轉子鐵芯相(xiang)擦(掃膛),等(deng)于增加過大(da)的負載;
9)電動機(ji)負(fu)載過大或機(ji)械(xie)轉(zhuan)動部分(fen)被卡住等。
2)電動機過熱檢查(cha)及(ji)修理(li)
發(fa)現正常運行的電(dian)動機過熱(re),一(yi)般有下列原因:
1)電(dian)源電(dian)壓突(tu)然變高,并(bing)于電(dian)動(dong)機銘牌額(e)定電(dian)壓不相符,或者(zhe)三(san)相電(dian)源電(dian)壓嚴重不平(ping)衡;
2)電動機所拖(tuo)動的負載變動較大,電機暫時處于過(guo)載狀(zhuang)態;
3)由于軸(zhou)承(cheng)產生故(gu)障或間(jian)隙磨損超(chao)限(xian)、轉(zhuan)軸(zhou)發生彎曲、鐵芯局部過熱變形、轉(zhuan)子(zi)軸(zhou)向串動(dong)等原因,使(shi)定、轉(zhuan)子(zi)鐵芯掃(sao)膛(tang);
4)環(huan)境粉塵進入電動(dong)機內(nei)部粘附在絕緣表面上(shang)和(he)堵(du)塞冷卻風(feng)(feng)道、冷卻風(feng)(feng)管等,使(shi)電動(dong)機通(tong)風(feng)(feng)不良(liang),冷卻效果大(da)大(da)降低,造成電機過熱;
5)電動(dong)機冷卻裝置失效,調(diao)節風溫(wen)裝置有故障,造(zao)成電機過熱;
6)三相電動機單相運行;
7)繞組有(you)故障,如短路(lu)、斷(duan)路(lu)、接地、接錯等;
8)氣隙不(bu)均(jun)勻。
經重繞后的電動機發生過(guo)熱,其(qi)原因是:
1)接線錯誤;
2)線圈匝數過多或過少;
3)線圈(quan)導線過細,線圈(quan)節距(ju)過小或過大(da);
4)電動(dong)(dong)機裝配質量不好(hao),鐵芯未對(dui)齊,定轉子鐵芯軸向有差距(ju)引起軸向磁拉力,氣隙(xi)裝配和(he)(he)(he)調(diao)整不均勻(yun)。由于電動(dong)(dong)機絕緣(yuan)(yuan)水平不斷提(ti)高(gao),允許溫升(sheng)(sheng)限度也提(ti)高(gao),所(suo)以電機外(wai)殼溫升(sheng)(sheng)較(jiao)(jiao)高(gao)可能屬正常。但要用酒精(jing)溫度計(ji)測試部(bu)門的(de)外(wai)殼溫升(sheng)(sheng)和(he)(he)(he)軸承溫升(sheng)(sheng),并(bing)和(he)(he)(he)電動(dong)(dong)機的(de)絕緣(yuan)(yuan)等級所(suo)允許的(de)溫升(sheng)(sheng)相對(dui)照比較(jiao)(jiao)后,確(que)認電動(dong)(dong)機是過熱,那么可按以下步(bu)驟進行檢查(cha) [9] 。
1)首先(xian)檢(jian)查三相電(dian)(dian)(dian)源(yuan)(yuan)的電(dian)(dian)(dian)壓(ya)是(shi)否平衡,電(dian)(dian)(dian)壓(ya)波動(dong)的程度是(shi)否大于制造場廠的保(bao)證值(±10[%])。由于電(dian)(dian)(dian)壓(ya)不平衡,產生三相不平衡電(dian)(dian)(dian)流(liu),引起電(dian)(dian)(dian)機(ji)損耗增大和電(dian)(dian)(dian)機(ji)發熱(re),所以(yi)要(yao)及時糾正。電(dian)(dian)(dian)源(yuan)(yuan)頻率變動(dong)對(±5[%])電(dian)(dian)(dian)機(ji)發熱(re)也有(you)影響,但實際(ji)變化不大,所以(yi)在分析時一般可不考慮。
2)檢(jian)(jian)查電機是(shi)否(fou)單相(xiang)運轉,三相(xiang)接觸器的(de)觸頭是(shi)否(fou)接觸好,開(kai)關的(de)熔絲是(shi)否(fou)有(you)一相(xiang)燒斷(duan)(duan),接線(xian)有(you)否(fou)(單相(xiang))斷(duan)(duan)開(kai)。故障檢(jian)(jian)查出后進行(xing)處理(li)。
3)檢查三相電流是否超過(guo)額定值。若超過(guo)額定值時,要檢查其原因。處理(li)這類故障(zhang)時,要查清(qing)造(zao)成(cheng)掃(sao)膛的(de)原因:①轉軸(zhou)彎(wan)曲;②軸(zhou)承故障(zhang)。輕微(wei)的(de)鐵芯掃(sao)膛不影響電機正(zheng)常運行,掃(sao)膛嚴重時,可用車(che)刀將(jiang)轉子(zi)表面輕輕切削(xue)一(yi)層(一(yi)般車(che)削(xue)直徑為(wei)0.2mm左右為(wei)宜)。
4)粉(fen)塵敷滿(man)絕緣影響電(dian)機(ji)散熱(re),過濾網堵塞,通(tong)風道和通(tong)風管堵塞等,都會引起(qi)電(dian)機(ji)過熱(re)。因(yin)此可采取(qu)吹風清(qing)掃措施了消除(chu)粉(fen)塵,必要(yao)時電(dian)機(ji)要(yao)解(jie)體進行(xing)清(qing)洗處(chu)理。
5)如認(ren)為繞組(zu)有故障(zhang)時(shi),可進(jin)行繞組(zu)短路(lu)和接地試驗檢查。根據進(jin)行經(jing)驗表(biao)明,電機(ji)繞組(zu)如有匝(za)間短路(lu),電機(ji)則(ze)會振動,動轉(zhuan)時(shi)間不(bu)少就(jiu)會時(shi)間不(bu)長就(jiu)會冒煙。但(dan)是匝(za)間短路(lu)引起(qi)電機(ji)發熱(re),并且持續長時(shi)期的機(ji)會,是很(hen)少的。
重繞(rao)(rao)大修后的電(dian)(dian)機(ji)溫升超限(xian),可能是絕(jue)緣處理工藝不(bu)好,線圈數據(ju)不(bu)對(dui),接線錯誤以(yi)及裝配質量等問(wen)題(ti)引起(qi)。這(zhe)時電(dian)(dian)機(ji)應解體(ti)對(dui)照原(yuan)始(shi)記錄檢查,以(yi)及查明繞(rao)(rao)組數據(ju)的正確性。