一、概(gai)述
交流(liu)鼠籠式異步電(dian)動(dong)機如(ru)果直接起動(dong)會產(chan)生(sheng)很大沖擊電(dian)流(liu)，會對(dui)電(dian)阻及(ji)其負(fu)載造(zao)成(cheng)沖擊，甚(shen)至危害電(dian)網安全(quan)運行。生(sheng)產(chan)機械對(dui)電(dian)動(dong)機的起動(dong)也有各種不同的要求，有些(xie)需要平穩起動(dong)的生(sheng)產(chan)機械也不允(yun)許直接起動(dong)。
星-三(san)角轉(zhuan)換(huan)起(qi)動(dong)，自藕變壓(ya)器降壓(ya)起(qi)動(dong)的主(zhu)要問(wen)題是(shi)起(qi)動(dong)過(guo)程中起(qi)動(dong)電壓(ya)和運(yun)行電壓(ya)轉(zhuan)換(huan)時的電流(liu)沖(chong)擊，對電網和機械產生(sheng)沖(chong)擊，產生(sheng)損害。應用晶閘管交流(liu)調壓(ya)技術的固態軟起(qi)動(dong)器，是(shi)目前降壓(ya)起(qi)動(dong)方式中合理、先進的起(qi)動(dong)方式。
二、工作原理
軟啟(qi)動(dong)調(diao)速(su)實(shi)(shi)際上是—個(ge)晶(jing)閘(zha)管交流調(diao)壓(ya)(ya)(ya)(ya)器(qi)。改(gai)變晶(jing)閘(zha)管的(de)(de)(de)(de)觸(chu)發(fa)角，就(jiu)可調(diao)節晶(jing)閘(zha)管調(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路的(de)(de)(de)(de)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。用軟起動(dong)(dong)器(qi)起動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)機(ji)時：設置一個(ge)初始(shi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，晶(jing)閘(zha)管調(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路的(de)(de)(de)(de)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)就(jiu)從這一點(dian)開(kai)始(shi)上升(sheng)(sheng)；設置一個(ge)升(sheng)(sheng)壓(ya)(ya)(ya)(ya)時間，逐漸增加晶(jing)閘(zha)管調(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路的(de)(de)(de)(de)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，電(dian)(dian)(dian)(dian)(dian)機(ji)逐漸加速(su)；設置—個(ge)限(xian)(xian)流倍數，根據電(dian)(dian)(dian)(dian)(dian)流互感器(qi)測得(de)的(de)(de)(de)(de)實(shi)(shi)際電(dian)(dian)(dian)(dian)(dian)流值，控制晶(jing)閘(zha)管調(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)路的(de)(de)(de)(de)輸(shu)(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，使電(dian)(dian)(dian)(dian)(dian)機(ji)的(de)(de)(de)(de)實(shi)(shi)際電(dian)(dian)(dian)(dian)(dian)流不超過限(xian)(xian)流值。這樣(yang)在整個(ge)起動(dong)(dong)過程中，軟啟動(dong)(dong)柜(ju)的(de)(de)(de)(de)輸(shu)(shu)出(chu)(chu)是一個(ge)平滑(hua)的(de)(de)(de)(de)升(sheng)(sheng)壓(ya)(ya)(ya)(ya)過程（且具有限(xian)(xian)流功能），直(zhi)到晶(jing)閘(zha)管全導通，電(dian)(dian)(dian)(dian)(dian)機(ji)在額(e)定電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)下(xia)工作。

典型應用簡介
水泵(beng)：利用泵(beng)控制功能(neng)，在起(qi)動(dong)和(he)停止時，減(jian)少液流沖擊所產生的(de)泵(beng)流水錘現象(xiang)，節省(sheng)了(le)系統維(wei)修費用； 
球磨機：利用電壓斜坡起(qi)動，減少(shao)齒輪轉矩的磨損，減少(shao)維修工作(zuo)量延長(chang)使用壽(shou)命(ming)； 
風機：利(li)用固態(tai)軟起動器取代(dai)了傳統起動器，減少皮帶(dai)磨損和機械沖擊； 
壓(ya)縮機：利(li)用(yong)限流，實現了平滑起動，降低電機溫升； 
破(po)碎(sui)機：利用堵轉保(bao)(bao)護和快速保(bao)(bao)護，避免機械故障和阻塞造成(cheng)電動機過熱而燒毀； 
輸(shu)送機械：利用(yong)軟起動(dong)和(he)(he)軟停機控制，實現平滑漸(jian)進的(de)起動(dong)過程(cheng)和(he)(he)平滑減(jian)速的(de)停車過程(cheng)，避(bi)免了(le)因沖擊而對物料和(he)(he)設備造成的(de)損傷.