如何控制直流電機正反轉?
如何控制(zhi)直流電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)正(zheng)(zheng)反(fan)(fan)轉(zhuan)(zhuan)?直流電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)正(zheng)(zheng)反(fan)(fan)轉(zhuan)(zhuan),代表(biao)的(de)是電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)順時(shi)針(zhen)轉(zhuan)(zhuan)動(dong)和逆時(shi)針(zhen)轉(zhuan)(zhuan)動(dong)。電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)順時(shi)針(zhen)轉(zhuan)(zhuan)動(dong)是電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)正(zheng)(zheng)轉(zhuan)(zhuan),電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)逆時(shi)針(zhen)轉(zhuan)(zhuan)動(dong)是電(dian)(dian)(dian)(dian)(dian)機(ji)(ji)反(fan)(fan)轉(zhuan)(zhuan)。正(zheng)(zheng)反(fan)(fan)轉(zhuan)(zhuan)控制(zhi)電(dian)(dian)(dian)(dian)(dian)路圖及其原理分析要(yao)實(shi)現電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)正(zheng)(zheng)反(fan)(fan)轉(zhuan)(zhuan)只要(yao)將接至電(dian)(dian)(dian)(dian)(dian)動(dong)機(ji)(ji)三相電(dian)(dian)(dian)(dian)(dian)源進線中的(de)任(ren)意兩相對調接線即可達(da)到(dao)反(fan)(fan)轉(zhuan)(zhuan)的(de)目的(de)。可以有如下兩種方法(fa):
快貓(mao)下載地址: 一是(shi)電(dian)(dian)樞反接法,即(ji)保(bao)持(chi)勵磁繞(rao)組的端電(dian)(dian)壓性不變,通過(guo)改變電(dian)(dian)樞繞(rao)組端電(dian)(dian)壓的性使電(dian)(dian)動機反轉;
二是勵磁繞(rao)組(zu)(zu)(zu)反接(jie)法,即(ji)保持電(dian)(dian)樞(shu)繞(rao)組(zu)(zu)(zu)端(duan)電(dian)(dian)壓的(de)性不變(bian)(bian),通過(guo)改變(bian)(bian)勵磁繞(rao)組(zu)(zu)(zu)端(duan)電(dian)(dian)壓的(de)性使(shi)電(dian)(dian)動機調向。當(dang)兩者的(de)電(dian)(dian)壓性同時改變(bian)(bian)時,則電(dian)(dian)動機的(de)旋轉方(fang)向不變(bian)(bian)。
他(ta)勵(li)和并(bing)勵(li)直(zhi)流電(dian)(dian)動機一般采用(yong)電(dian)(dian)樞反接(jie)法來實現(xian)正反轉。他(ta)勵(li)和并(bing)勵(li)直(zhi)流電(dian)(dian)動機不宜采用(yong)勵(li)磁繞(rao)(rao)組(zu)(zu)反接(jie)法實現(xian)正反轉的(de)原因(yin)是因(yin)為(wei)勵(li)磁繞(rao)(rao)組(zu)(zu)匝數(shu)較(jiao)(jiao)多,電(dian)(dian)感(gan)量較(jiao)(jiao)大。當勵(li)磁繞(rao)(rao)組(zu)(zu)反接(jie)時,在勵(li)磁繞(rao)(rao)組(zu)(zu)中便會(hui)(hui)產生(sheng)很大的(de)感(gan)生(sheng)電(dian)(dian)動勢.這將(jiang)會(hui)(hui)損壞閘(zha)刀(dao)和勵(li)磁繞(rao)(rao)組(zu)(zu)的(de)絕緣。
快貓下載地址: 也可(ke)以采用不同的(de)傳(chuan)動電機來控(kong)制直流(liu)電機的(de)正反轉:
快貓下載地址: 1、他勵直流電機
快(kuai)貓下載(zai)地址: 通常,可采用下面(mian)兩種方(fang)法(fa)來使直流電流機(ji)反轉:
快貓下載地址: (1)將電樞兩端電壓(ya)反(fan)接,改變電樞電流的方向。
快貓下載地址: (2)改(gai)變勵磁繞組(zu)的(de)性,即改(gai)變主磁場的(de)方(fang)向。
在實際運行(xing)中,由于直流電(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)勵(li)(li)磁(ci)繞組(zu)匝數較多,電(dian)(dian)(dian)感(gan)很大,把(ba)勵(li)(li)磁(ci)繞組(zu)從(cong)電(dian)(dian)(dian)源上斷開將(jiang)產(chan)生較大的(de)(de)自感(gan)電(dian)(dian)(dian)動(dong)勢,使開關產(chan)生很大的(de)(de)火花(hua),并且還可能擊(ji)穿勵(li)(li)磁(ci)繞組(zu)的(de)(de)絕(jue)緣。因此(ci)(ci),要求頻(pin)繁反向的(de)(de)直流電(dian)(dian)(dian)動(dong)機(ji)(ji),應(ying)采用改變(bian)電(dian)(dian)(dian)樞電(dian)(dian)(dian)流方(fang)(fang)向這一方(fang)(fang)法來(lai)實現反轉(zhuan)。此(ci)(ci)外,還必須指出,僅(jin)采用上述方(fang)(fang)法之一即可實現電(dian)(dian)(dian)動(dong)機(ji)(ji)的(de)(de)反轉(zhuan),如(ru)果同時使用這兩種(zhong)方(fang)(fang)法,則反反為(wei)正,反而不能達到電(dian)(dian)(dian)動(dong)機(ji)(ji)反轉(zhuan)的(de)(de)目的(de)(de)。
快貓下載地址: 2、永磁直流電機
快貓下載地址(zhi): 永(yong)磁式(shi)直(zhi)流(liu)電(dian)動機,只要(yao)將電(dian)源正、負連接方向調換,就可以實現(xian)電(dian)機反轉(zhuan)。
快貓下載地址: 3、無刷電機
快(kuai)貓下載地址: 用的是無霍爾控制器(qi),只要調換兩(liang)條電機(ji)線就可以了。
快貓(mao)下載(zai)地址: 用的(de)是(shi)有霍爾控制器,先(xian)調霍爾ac相(xiang)線(xian),再調線(xian)包(bao)AB相(xiang)線(xian)就可以了。
快貓下載地址: 4、串激式直流電動機
快貓下載地址: 則需要(yao)改變(bian)定(ding)子線圈與碳刷(轉(zhuan)子)串(chuan)聯的方向(xiang),假定(ding)原(yuan)電機內部接(jie)線為:
電(dian)源進(jin)線(xian)——定(ding)子線(xian)圈1端——定(ding)子線(xian)圈2端——左邊碳刷——電(dian)樞(shu)(轉子)——右邊碳刷——電(dian)源;
快貓下載地址: 要(yao)改變轉向,就(jiu)需(xu)要(yao)改為:
電(dian)源進線(xian)——定子(zi)(zi)線(xian)圈(quan)1端——定子(zi)(zi)線(xian)圈(quan)2端——右邊碳刷——電(dian)樞(轉子(zi)(zi))——左邊碳刷——電(dian)源;
快貓(mao)下(xia)載地(di)址(zhi): 即(ji)將碳刷(shua)(或定(ding)子線圈)的(de)兩端接線對調即(ji)可(ke)。
快貓下載地址(zhi): 串(chuan)激式直流電機(ji)的轉向(xiang)與(yu)電源(yuan)正、負(fu)連接方向(xiang)無關(guan),實際上可(ke)以使(shi)用在交(jiao)流電路(lu)上。
直流正反轉電機運行中需要注意的問題:
1.改變電機轉向時必須先按下停止按鈕,待電動機停轉后才允許反向啟動。
2.嚴禁同時按下正反轉兩個啟動按鈕,以免發生短路燒壞電機。