高壓變頻器和低壓變頻器有什么區別?又有什么聯系呢?下面，小編就為大家詳細介紹一下：

　　1、高壓變頻(pin)器(qi)與低壓變頻(pin)器(qi)的區別在(zai)哪里呢?

　　變(bian)頻(pin)器(qi)大體上(shang)可分為兩類：高壓(ya)變(bian)頻(pin)器(qi)和低壓(ya)變(bian)頻(pin)器(qi)。

　　從(cong)用途來講(jiang)，適用對象不(bu)一(yi)樣(yang)，高壓電機從(cong)調速原理來講(jiang)，二者都是(shi)一(yi)樣(yang)的(de)。從(cong)拓(tuo)撲結構看(kan)，二者差別很(hen)大(da)，主要是(shi)因為目前(qian)廣泛(fan)應(ying)用的(de)IGBT模(mo)塊(kuai)耐壓不(bu)足造成的(de)。高壓變頻器(qi)由于電壓高，對驅動電路(lu)等的(de)干擾也(ye)大(da)，通(tong)常都采用的(de)光(guang)纖進(jin)行隔離。

　　2、為什么變頻(pin)器的(de)輸(shu)出(chu)電壓與頻(pin)率成比(bi)例的(de)改變?

　　異步(bu)電(dian)(dian)(dian)(dian)動機的(de)(de)(de)轉(zhuan)矩(ju)是電(dian)(dian)(dian)(dian)機的(de)(de)(de)磁(ci)通與(yu)轉(zhuan)子內流過(guo)的(de)(de)(de)電(dian)(dian)(dian)(dian)流之間相互作用而產(chan)生的(de)(de)(de)，在額定頻(pin)率(lv)(lv)下，如果(guo)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya) 而只降低頻(pin)率(lv)(lv)，那(nei)么磁(ci)通就過(guo)大，磁(ci)回路飽和，電(dian)(dian)(dian)(dian)機電(dian)(dian)(dian)(dian)流 ，嚴重時將燒毀電(dian)(dian)(dian)(dian)機。因此(ci)，頻(pin)率(lv)(lv)與(yu)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)要(yao)成比例地改變，即改變頻(pin)率(lv)(lv)的(de)(de)(de)同(tong)時控制變頻(pin)器(qi)的(de)(de)(de)輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，使電(dian)(dian)(dian)(dian)動機的(de)(de)(de)磁(ci)通保持 ，避免磁(ci)飽和現象的(de)(de)(de)產(chan)生。這(zhe)(zhe)就是VVVF的(de)(de)(de)定義。這(zhe)(zhe)里的(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)指的(de)(de)(de)是電(dian)(dian)(dian)(dian)機的(de)(de)(de)線電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)或者相電(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)的(de)(de)(de) 值。

　　3、電(dian)(dian)動機使用工頻(pin)電(dian)(dian)源驅動時，電(dian)(dian)壓下降則(ze)電(dian)(dian)流增加(jia);對于(yu)變頻(pin)器驅動，如果(guo)頻(pin)率下降時電(dian)(dian)壓也下降，那么電(dian)(dian)流是否(fou)增加(jia)?

　　頻率下(xia)降(低(di)速)時,如果輸出相(xiang)同的功率,則電(dian)流(liu)增(zeng)加，但在轉矩 的條件下(xia),電(dian)流(liu)幾乎不(bu)變。

　　4、采(cai)用變頻器運轉時(shi)，電(dian)機的起(qi)(qi)動電(dian)流(liu)、起(qi)(qi)動轉矩(ju)怎樣(yang)?

　　采用(yong)變頻(pin)器運(yun)轉(zhuan)(zhuan)，隨著(zhu)電(dian)(dian)(dian)機(ji)的(de)加速相應提高頻(pin)率和電(dian)(dian)(dian)壓，起(qi)(qi)動(dong)(dong)(dong)電(dian)(dian)(dian)流(liu)被(bei)限(xian)制在150%額定(ding)(ding)電(dian)(dian)(dian)流(liu)以(yi)下(根(gen)據(ju)機(ji)種不同，為(wei)(wei)125%～200%)。用(yong)工頻(pin)電(dian)(dian)(dian)源直接起(qi)(qi)動(dong)(dong)(dong)時，起(qi)(qi)動(dong)(dong)(dong)電(dian)(dian)(dian)流(liu)為(wei)(wei)6～7倍(bei)，因(yin)此，將產生機(ji)械電(dian)(dian)(dian)氣上的(de)沖擊。采用(yong)變頻(pin)器傳動(dong)(dong)(dong)可以(yi)平(ping)滑地起(qi)(qi)動(dong)(dong)(dong)(起(qi)(qi)動(dong)(dong)(dong)時間變長)。起(qi)(qi)動(dong)(dong)(dong)電(dian)(dian)(dian)流(liu)為(wei)(wei)額定(ding)(ding)電(dian)(dian)(dian)流(liu)的(de)1.2～1.5倍(bei)，起(qi)(qi)動(dong)(dong)(dong)轉(zhuan)(zhuan)矩(ju)(ju)為(wei)(wei)70%～120%額定(ding)(ding)轉(zhuan)(zhuan)矩(ju)(ju);對(dui)于帶有轉(zhuan)(zhuan)矩(ju)(ju)自動(dong)(dong)(dong) 功能的(de)變頻(pin)器，起(qi)(qi)動(dong)(dong)(dong)轉(zhuan)(zhuan)矩(ju)(ju)為(wei)(wei) 以(yi)上，可以(yi)帶全負載起(qi)(qi)動(dong)(dong)(dong)。

　　5、V/f模式是(shi)什么意思?

　　頻率下(xia)降時電(dian)(dian)壓(ya)V也成比(bi)(bi)(bi)例下(xia)降，這(zhe)個問題已在(zai)回答4說明。保(bao)持(chi)V/f比(bi)(bi)(bi)恒定(ding)控制(zhi)是(shi)異步電(dian)(dian)機(ji)變頻調速的(de) 基本的(de)控制(zhi)方式(shi)，它(ta)在(zai)控制(zhi)電(dian)(dian)機(ji)的(de)電(dian)(dian)源頻率變化(hua)的(de)同(tong)時控制(zhi)變頻器輸出的(de)電(dian)(dian)壓(ya)，并(bing)使二者之(zhi)比(bi)(bi)(bi)V/f為(wei)恒定(ding)，從(cong)而使電(dian)(dian)機(ji)的(de)磁通保(bao)持(chi)恒定(ding)。在(zai)電(dian)(dian)機(ji)額定(ding)運(yun)行情況下(xia)，電(dian)(dian)機(ji)的(de)定(ding)子電(dian)(dian)阻和漏抗的(de)電(dian)(dian)壓(ya)降比(bi)(bi)(bi)較小，電(dian)(dian)機(ji)的(de)端電(dian)(dian)壓(ya)和電(dian)(dian)機(ji)的(de)感應電(dian)(dian)勢近似相等(deng)。

　　V/f比(bi)恒定(ding)控制(zhi)存在的主(zhu)要問題是低速性能(neng)(neng)較差(cha)。其原因一是低速時異(yi)步電(dian)機定(ding)子電(dian)阻電(dian)壓(ya)降所占比(bi)例變大，已(yi)不(bu)能(neng)(neng)忽(hu)略，不(bu)能(neng)(neng)再認為定(ding)子電(dian)壓(ya)和電(dian)機感應(ying)電(dian)勢(shi)近似相等，仍按V/f比(bi) 控制(zhi)已(yi)不(bu)能(neng)(neng)保持(chi)電(dian)機磁(ci)通(tong)(tong)恒定(ding)。電(dian)機磁(ci)通(tong)(tong)的減(jian)(jian)小(xiao)必然(ran)造成電(dian)機的電(dian)磁(ci)轉(zhuan)矩減(jian)(jian)小(xiao);另外(wai)變頻器功(gong)率器件的 區時間也是影(ying)響(xiang)電(dian)機低速性能(neng)(neng)的重要原因， 區時間造成電(dian)壓(ya)下降同時還(huan)會(hui)引起轉(zhuan)矩脈動(dong)，在 條件下還(huan)會(hui)引起轉(zhuan)速、電(dian)流的振蕩。

　　V/f比恒(heng)定(ding)控(kong)制常用于(yu)通用變頻器上。這類變頻器主要(yao)用于(yu)風機、水泵的調速(su)功能(neng)，以及對調速(su)范圍(wei)要(yao)求(qiu)不高(gao)的場合。V/f比恒(heng)定(ding)控(kong)制的突(tu)出優點是可(ke)以進行電機的開(kai)環速(su)度控(kong)制。

　　6、按比例地改V和f時(shi)，電機的(de)轉矩如(ru)何變(bian)化?

　　頻(pin)(pin)率下(xia)降時 成比例地降低(di)電(dian)壓(ya)，那么由于交(jiao)流阻抗變小(xiao)而(er)電(dian)阻不變，將(jiang)造成在低(di)速下(xia)產生的(de)(de)轉(zhuan)矩有減(jian)小(xiao)的(de)(de)傾向。因此，在低(di)頻(pin)(pin)時給定V/f,要使輸出(chu)電(dian)壓(ya)提高一些(xie),以(yi)便獲(huo)得(de) 的(de)(de)起動(dong)轉(zhuan)矩,這(zhe)種補償(chang)稱(cheng) 起動(dong)。可以(yi)采用各(ge)種方法(fa)實現,有自動(dong)進行的(de)(de)方法(fa)、選(xuan)擇V/f模式或調整電(dian)位器等方法(fa)。

　　7、所(suo)謂開環是什么(me)意(yi)思?

　　給(gei)(gei)所使用(yong)的(de)電機裝設速度(du)傳感器(qi)，將(jiang)實際轉速反饋給(gei)(gei)控制(zhi)裝置進(jin)行控制(zhi)的(de)，稱為閉環，不用(yong)速度(du)傳感器(qi)運轉的(de)就叫作(zuo)開環，通用(yong)變(bian)頻器(qi)多為開環方(fang)式。

　　8、高壓變頻器自(zi)身(shen)的保護功能

　　輸(shu)出(chu)過(guo)(guo)載、輸(shu)出(chu)過(guo)(guo)流、電(dian)(dian)網過(guo)(guo)電(dian)(dian)壓(ya)(ya)(ya)(ya)、電(dian)(dian)網欠電(dian)(dian)壓(ya)(ya)(ya)(ya)、電(dian)(dian)網失電(dian)(dian)、直流母線過(guo)(guo)電(dian)(dian)壓(ya)(ya)(ya)(ya)、直流母線欠電(dian)(dian)壓(ya)(ya)(ya)(ya)、變(bian)壓(ya)(ya)(ya)(ya)器過(guo)(guo)熱(re)、缺相、控制電(dian)(dian)源掉(diao)電(dian)(dian)、驅動故(gu)障(zhang)(zhang)、功率器件過(guo)(guo)熱(re)、散(san)熱(re)風機(ji)故(gu)障(zhang)(zhang)、外部給定(ding)掉(diao)線、接地故(gu)障(zhang)(zhang)、光纖故(gu)障(zhang)(zhang)等等