1，什么是軟起動器?它與變頻器有什么區別?

　　軟(ruan)起(qi)(qi)動(dong)(dong)(dong)器(qi)(qi)是(shi)一種(zhong)集電(dian)(dian)(dian)機起(qi)(qi)動(dong)(dong)(dong)、軟(ruan)停車、輕載節能(neng)和多(duo)種(zhong)保護功能(neng)于(yu)一體的(de)(de)新穎電(dian)(dian)(dian)機控(kong)制(zhi)裝置，稱為 SOFT STARTER。它的(de)(de)主要構(gou)(gou)成(cheng)是(shi)串接于(yu)電(dian)(dian)(dian)源與被(bei)(bei)控(kong)電(dian)(dian)(dian)機之(zhi)間的(de)(de)三(san)相(xiang)(xiang)反并(bing)聯晶(jing)閘管及(ji)其電(dian)(dian)(dian)子控(kong)制(zhi)電(dian)(dian)(dian)路。運用不(bu)(bu)同(tong)的(de)(de)方法，控(kong)制(zhi)三(san)相(xiang)(xiang)反并(bing)聯晶(jing)閘管的(de)(de)導(dao)通角，使被(bei)(bei)控(kong)電(dian)(dian)(dian)機的(de)(de)輸入電(dian)(dian)(dian)壓(ya)(ya)(ya)按不(bu)(bu)同(tong)的(de)(de)要求而變(bian)(bian)(bian)化，就可實現不(bu)(bu)同(tong)的(de)(de)功能(neng)。軟(ruan)起(qi)(qi)動(dong)(dong)(dong)器(qi)(qi)和變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)是(shi)兩種(zhong) 不(bu)(bu)同(tong)用途(tu)的(de)(de)產品(pin)。變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)是(shi)用于(yu)需(xu)要調(diao)速(su)的(de)(de)地方，其輸出(chu)不(bu)(bu)但改(gai)變(bian)(bian)(bian)電(dian)(dian)(dian)壓(ya)(ya)(ya)而且同(tong)時(shi)改(gai)變(bian)(bian)(bian)頻(pin)(pin)率(lv)，起(qi)(qi)動(dong)(dong)(dong)器(qi)(qi)實際(ji)上(shang)是(shi)個調(diao)壓(ya)(ya)(ya)器(qi)(qi)，用于(yu)電(dian)(dian)(dian)機起(qi)(qi)動(dong)(dong)(dong)時(shi)，輸出(chu)只改(gai)變(bian)(bian)(bian)電(dian)(dian)(dian)壓(ya)(ya)(ya)并(bing)沒有(you)改(gai)變(bian)(bian)(bian)功率(lv)。變(bian)(bian)(bian)頻(pin)(pin)器(qi)(qi)具備(bei)(bei)備(bei)(bei)所有(you)軟(ruan)起(qi)(qi)動(dong)(dong)(dong)器(qi)(qi)功能(neng)，但它的(de)(de)價格(ge)比軟(ruan)起(qi)(qi)動(dong)(dong)(dong)器(qi)(qi)貴(gui)得多(duo)，結(jie)構(gou)(gou)也(ye)復雜得多(duo)。

　　2，軟(ruan)起(qi)動與傳統減壓(ya)起(qi)動方式的(de)不同之(zhi)處(chu)在哪里?

　　籠型(xing)電機傳統(tong)(tong)的減(jian)壓(ya)起(qi)動(dong)(dong)(dong)(dong)方(fang)式有V-起(qi)動(dong)(dong)(dong)(dong)，自耦減(jian)壓(ya)起(qi)動(dong)(dong)(dong)(dong)、電抗(kang)器起(qi)動(dong)(dong)(dong)(dong)等。這些起(qi)動(dong)(dong)(dong)(dong)方(fang)式都屬(shu)于有級減(jian)壓(ya)起(qi)動(dong)(dong)(dong)(dong)，存在明(ming)顯缺點，即起(qi)動(dong)(dong)(dong)(dong)過程(cheng)中(zhong)出現二次沖擊電流。軟起(qi)動(dong)(dong)(dong)(dong)與傳統(tong)(tong)減(jian)壓(ya)起(qi)動(dong)(dong)(dong)(dong)方(fang)式的不同之處是(shi):

　　(1)無(wu)沖擊電流:軟起動器在起動電機(ji)時，通過(guo)逐漸(jian) 晶(jing)閘管的(de)導通角，使(shi)電機(ji)起動電流從零線性(xing)上升至設定值。

　　(2)恒(heng)(heng)流(liu)(liu)起(qi)(qi)動:軟起(qi)(qi)動器可以引(yin)入電流(liu)(liu)閉環控制，使電機在(zai)起(qi)(qi)動過程中保持(chi)恒(heng)(heng)流(liu)(liu)，確保電機平穩起(qi)(qi)動。

　　(3)根據負(fu)載(zai)情況及電(dian)網繼(ji)電(dian)保(bao)護特性(xing)選擇，可自由地無級調至(zhi)理想的起動電(dian)流。

　　3、什么是電動機的軟起動?有哪幾(ji)種(zhong)起動方(fang)式?

　　運用(yong)串接于(yu)電(dian)源(yuan)與被控電(dian)機(ji)之間的軟(ruan)(ruan)起(qi)(qi)動(dong)(dong)器，控制其內部晶閘(zha)管導通角(jiao)，使(shi)電(dian)機(ji)入電(dian)壓(ya)從零以(yi)預設(she)函(han)數關(guan)系逐(zhu)新上升，直至起(qi)(qi)動(dong)(dong)結束，予(yu)電(dian)機(ji)全電(dian)壓(ya)，即為(wei)軟(ruan)(ruan)起(qi)(qi)動(dong)(dong)，在(zai)軟(ruan)(ruan)起(qi)(qi)動(dong)(dong)過程(cheng)中(zhong)，電(dian)機(ji)起(qi)(qi)動(dong)(dong)轉(zhuan)矩逐(zhu)漸不(bu)斷(duan)斷(duan)增加，轉(zhuan)速(su)也逐(zhu)浙(zhe)増加。軟(ruan)(ruan)起(qi)(qi)動(dong)(dong)一(yi)般有下(xia)面幾(ji)種起(qi)(qi)動(dong)(dong)方式：

　　(1)斜坡(po)升(sheng)壓軟(ruan)起(qi)動(dong):這種(zhong)起(qi)動(dong)方式簡(jian)單，不具備電(dian)流閉環(huan)控(kong)制，僅調晶閘(zha)管(guan)的導通(tong)角，使之與(yu)時間成(cheng) 函(han)數關系増加。其(qi)缺(que)點是：由于(yu)不限流，在電(dian)機起(qi)動(dong)過程中，有時要產(chan)生較大(da)的沖(chong)擊(ji)電(dian)流使晶閘(zha)管(guan)損壞，對電(dian)網影響較大(da)，實際很少應用。

　　(2)斜坡恒流(liu)軟起(qi)(qi)動(dong)(dong)(dong):這(zhe)種起(qi)(qi)動(dong)(dong)(dong)方式是在(zai)電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)起(qi)(qi)動(dong)(dong)(dong)的(de)初始階段起(qi)(qi)動(dong)(dong)(dong)電(dian)(dian)流(liu)逐漸増加，當電(dian)(dian)流(liu)達到預先所設(she)定(ding)的(de)值后保持恒定(ding)，直至起(qi)(qi)動(dong)(dong)(dong)完畢，起(qi)(qi)動(dong)(dong)(dong)過程中，電(dian)(dian)流(liu)上升變化的(de)速(su)度是可以根據電(dian)(dian)動(dong)(dong)(dong)機(ji)(ji)負載調(diao)整設(she)定(ding)。電(dian)(dian)流(liu)上升速(su)本大，則起(qi)(qi)動(dong)(dong)(dong)轉矩大，起(qi)(qi)動(dong)(dong)(dong)時間(jian)短。該起(qi)(qi)動(dong)(dong)(dong)方式是應(ying)用很多的(de)起(qi)(qi)動(dong)(dong)(dong)方式，尤其適(shi)用于(yu)風機(ji)(ji)、水泵類負載起(qi)(qi)動(dong)(dong)(dong)。

　　(3)階躍起(qi)(qi)動:開機，即以(yi)時(shi)間短(duan)，使起(qi)(qi)動電(dian)流迅速達到沒定值，即為階躍起(qi)(qi)動。通過調(diao)節起(qi)(qi)動電(dian)流設定值，可以(yi)達到快(kuai)速起(qi)(qi)動效果。

　　(4)脈(mo)沖(chong)沖(chong)擊起(qi)(qi)(qi)動:在(zai)(zai)起(qi)(qi)(qi)動開始階，讓晶閘管在(zai)(zai)極短時間(jian)內，以較(jiao)大電流(liu)(liu)導通一(yi)時間(jian)后回(hui)落，再按原設定值線性上升，連入(ru)恒流(liu)(liu)起(qi)(qi)(qi)動。該起(qi)(qi)(qi)動方(fang)式，在(zai)(zai)一(yi)般負中蛟少應用(yong)，適用(yong)于重載并需克服較(jiao)大靜摩擦的起(qi)(qi)(qi)動場合。