四象限變頻器運行原(yuan)理

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對(dui)于電(dian)(dian)機(ji)(ji)來說，所(suo)謂四(si)(si)象(xiang)限(xian)是(shi)指其運(yun)行(xing)機(ji)(ji)械特性(xing)曲線在數學(xue)軸上(shang)的(de)四(si)(si)個(ge)象(xiang)限(xian)都可運(yun)行(xing)。第(di)(di)(di)一(yi)象(xiang)限(xian)正(zheng)轉電(dian)(dian)動狀(zhuang)(zhuang)態(tai)(tai)，第(di)(di)(di)二象(xiang)限(xian)回饋制(zhi)動狀(zhuang)(zhuang)態(tai)(tai)，第(di)(di)(di)三象(xiang)限(xian)反轉電(dian)(dian)動狀(zhuang)(zhuang)態(tai)(tai)，第(di)(di)(di)四(si)(si)象(xiang)限(xian)反接制(zhi)動狀(zhuang)(zhuang)態(tai)(tai)。能夠具有使得電(dian)(dian)機(ji)(ji)工作在四(si)(si)象(xiang)限(xian)的(de)變頻器才稱得上(shang)四(si)(si)象(xiang)限(xian)變頻器。  

?? 變(bian)(bian)頻(pin)調(diao)(diao)(diao)速(su)(su)在調(diao)(diao)(diao)速(su)(su)范圍、調(diao)(diao)(diao)速(su)(su)精(jing)度、控制(zhi)靈活、工(gong)作(zuo)效率(lv)、使(shi)(shi)用(yong)方(fang)便等方(fang)面(mian)(mian)都有(you)很大(da)的(de)優點，使(shi)(shi)變(bian)(bian)頻(pin)調(diao)(diao)(diao)速(su)(su)成為(wei)(wei)最有(you)發展(zhan)前途的(de)一種交(jiao)流(liu)(liu)調(diao)(diao)(diao)速(su)(su)方(fang)式。  ??普(pu)通的(de)兩象限變(bian)(bian)頻(pin)器(qi)采(cai)用(yong)二極(ji)管整(zheng)流(liu)(liu)橋(qiao)將(jiang)交(jiao)流(liu)(liu)電(dian)(dian)(dian)轉(zhuan)化成直(zhi)流(liu)(liu)，然后采(cai)用(yong)IGBT逆變(bian)(bian)技術將(jiang)直(zhi)流(liu)(liu)轉(zhuan)化成電(dian)(dian)(dian)壓(ya)頻(pin)率(lv)皆可調(diao)(diao)(diao)整(zheng)的(de)交(jiao)流(liu)(liu)電(dian)(dian)(dian)控制(zhi)交(jiao)流(liu)(liu)電(dian)(dian)(dian)動機。這種變(bian)(bian)頻(pin)器(qi)只能(neng)(neng)工(gong)作(zuo)在電(dian)(dian)(dian)動狀態，所(suo)以(yi)稱之為(wei)(wei)兩象限變(bian)(bian)頻(pin)器(qi)。由于兩象限變(bian)(bian)頻(pin)器(qi)采(cai)用(yong)二極(ji)管整(zheng)流(liu)(liu)橋(qiao)，無(wu)法(fa)實(shi)現(xian)能(neng)(neng)量的(de)雙向流(liu)(liu)動，所(suo)以(yi)沒有(you)辦法(fa)將(jiang)電(dian)(dian)(dian)機回饋(kui)系統的(de)能(neng)(neng)量送(song)回電(dian)(dian)(dian)網。我司四象限變(bian)(bian)頻(pin)器(qi)采(cai)用(yong)IGBT做整(zheng)流(liu)(liu)橋(qiao)，IGBT功(gong)率(lv)模塊可以(yi)實(shi)現(xian)能(neng)(neng)量的(de)雙向流(liu)(liu)動，配合(he)高(gao)速(su)(su)度、高(gao)運算能(neng)(neng)力(li)的(de)DSP產生PWM控制(zhi)脈沖(chong)。一方(fang)面(mian)(mian)可以(yi)調(diao)(diao)(diao)整(zheng)輸入的(de)功(gong)率(lv)因(yin)數，消除對(dui)電(dian)(dian)(dian)網的(de)諧波污染，讓(rang)變(bian)(bian)頻(pin)器(qi)真正成為(wei)(wei)“綠色產品”。另一方(fang)面(mian)(mian)可以(yi)將(jiang)電(dian)(dian)(dian)動機回饋(kui)產生的(de)能(neng)(neng)量反送(song)到(dao)電(dian)(dian)(dian)網，達到(dao)徹(che)底的(de)節能(neng)(neng)效果(guo)。  

? ?四(si)象(xiang)限(xian)變(bian)頻器(qi)在煤(mei)(mei)礦具(ju)有位勢負載(zai)特(te)性的場合，例如大傾角采煤(mei)(mei)面下，采煤(mei)(mei)機(ji)下行時(shi)，逆變(bian)側(ce)產生(sheng)勵(li)磁電(dian)(dian)(dian)(dian)流(liu)，重力(li)牽引電(dian)(dian)(dian)(dian)機(ji)發(fa)電(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)動機(ji)處于發(fa)電(dian)(dian)(dian)(dian)狀態。勢能(neng)(neng)轉化為電(dian)(dian)(dian)(dian)能(neng)(neng)通過整流(liu)側(ce)回(hui)饋的電(dian)(dian)(dian)(dian)網(wang)(wang)。此時(shi)母線電(dian)(dian)(dian)(dian)壓保(bao)持穩定，有效(xiao)防止煤(mei)(mei)機(ji)下滑。同時(shi)，四(si)象(xiang)限(xian)變(bian)頻器(qi)可以減小(xiao)對電(dian)(dian)(dian)(dian)網(wang)(wang)的諧波污染。  

                                                                                

 把(ba)電機的運(yun)行速(su)度方(fang)向用(yong)一條(tiao)數軸X來表(biao)示，數軸的正方(fang)向代表(biao)正轉的轉速(su)，反(fan)方(fang)向表(biao)示反(fan)轉的轉速(su)；   

? ? 把電(dian)(dian)機的電(dian)(dian)磁(ci)轉(zhuan)矩方向用一條數軸(zhou)Y來(lai)表示，數軸(zhou)的正方向代表正的電(dian)(dian)磁(ci)轉(zhuan)矩，反方向表示負的電(dian)(dian)磁(ci)轉(zhuan)矩；   

?? 構(gou)成一個平面坐標系XOY，那么(me)電(dian)(dian)(dian)動機(ji)正常電(dian)(dian)(dian)動狀態(tai)處在第一象(xiang)限（正轉(zhuan)、電(dian)(dian)(dian)動），發電(dian)(dian)(dian)（制(zhi)動）再(zai)生運行在第二象(xiang)限（正轉(zhuan)、發電(dian)(dian)(dian)）. 

??采煤機牽引電機由于正常狀態就不斷正、反轉(zhuan)(zhuan)，上、下(xia)行都有可能(neng)(neng)電動(dong)或發電，處于四象限(xian)運行狀態，各個狀態能(neng)(neng)量(liang)轉(zhuan)(zhuan)換方向不同.   

??用四象限來描述電機運行狀態，和(he)用熟悉的(de)正、反轉，電動、發電描述是一樣(yang)的(de)道理。