一、概述
交(jiao)流鼠籠式異步電動(dong)機(ji)(ji)如果直(zhi)接(jie)起(qi)動(dong)會產生(sheng)(sheng)很大沖擊電流，會對電阻及其負載造成(cheng)沖擊，甚至(zhi)危害電網安全運行。生(sheng)(sheng)產機(ji)(ji)械(xie)對電動(dong)機(ji)(ji)的(de)起(qi)動(dong)也有各種不(bu)同(tong)的(de)要求，有些(xie)需要平穩(wen)起(qi)動(dong)的(de)生(sheng)(sheng)產機(ji)(ji)械(xie)也不(bu)允(yun)許直(zhi)接(jie)起(qi)動(dong)。
星-三角轉換(huan)起動，自藕變(bian)壓(ya)(ya)(ya)器降(jiang)壓(ya)(ya)(ya)起動的(de)主要(yao)問題是(shi)起動過程中起動電(dian)壓(ya)(ya)(ya)和運行電(dian)壓(ya)(ya)(ya)轉換(huan)時的(de)電(dian)流(liu)沖(chong)(chong)擊(ji)(ji)，對電(dian)網(wang)和機械產(chan)生沖(chong)(chong)擊(ji)(ji)，產(chan)生損害(hai)。應(ying)用晶閘管交流(liu)調壓(ya)(ya)(ya)技術的(de)固態軟起動器，是(shi)目前降(jiang)壓(ya)(ya)(ya)起動方式中合理、先進的(de)起動方式。
二、工(gong)作原理(li)
軟啟(qi)動(dong)調(diao)速(su)實際上(shang)是(shi)(shi)—個(ge)晶(jing)(jing)閘管(guan)(guan)交流(liu)調(diao)壓(ya)器。改變晶(jing)(jing)閘管(guan)(guan)的(de)觸發角(jiao)，就可(ke)調(diao)節晶(jing)(jing)閘管(guan)(guan)調(diao)壓(ya)電(dian)(dian)(dian)(dian)路的(de)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)。用軟起動(dong)(dong)器起動(dong)(dong)電(dian)(dian)(dian)(dian)機(ji)時：設(she)置一個(ge)初始電(dian)(dian)(dian)(dian)壓(ya)，晶(jing)(jing)閘管(guan)(guan)調(diao)壓(ya)電(dian)(dian)(dian)(dian)路的(de)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)就從這一點開始上(shang)升(sheng)；設(she)置一個(ge)升(sheng)壓(ya)時間(jian)，逐漸(jian)增加晶(jing)(jing)閘管(guan)(guan)調(diao)壓(ya)電(dian)(dian)(dian)(dian)路的(de)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)，電(dian)(dian)(dian)(dian)機(ji)逐漸(jian)加速(su)；設(she)置—個(ge)限流(liu)倍數，根(gen)據電(dian)(dian)(dian)(dian)流(liu)互感器測得的(de)實際電(dian)(dian)(dian)(dian)流(liu)值，控(kong)制晶(jing)(jing)閘管(guan)(guan)調(diao)壓(ya)電(dian)(dian)(dian)(dian)路的(de)輸(shu)出(chu)(chu)電(dian)(dian)(dian)(dian)壓(ya)，使電(dian)(dian)(dian)(dian)機(ji)的(de)實際電(dian)(dian)(dian)(dian)流(liu)不(bu)超(chao)過(guo)限流(liu)值。這樣(yang)在(zai)(zai)整個(ge)起動(dong)(dong)過(guo)程(cheng)中，軟啟動(dong)(dong)柜的(de)輸(shu)出(chu)(chu)是(shi)(shi)一個(ge)平滑的(de)升(sheng)壓(ya)過(guo)程(cheng)（且具有限流(liu)功能），直到(dao)晶(jing)(jing)閘管(guan)(guan)全導通，電(dian)(dian)(dian)(dian)機(ji)在(zai)(zai)額(e)定電(dian)(dian)(dian)(dian)壓(ya)下工作。

典型應用(yong)簡介
水泵(beng)：利用泵(beng)控制功(gong)能(neng)，在起動和停止(zhi)時(shi)，減少液流(liu)沖(chong)擊所產生的泵(beng)流(liu)水錘現象，節省(sheng)了系統維修(xiu)費(fei)用； 
球磨機：利用電壓斜坡起動，減(jian)少齒(chi)輪轉矩(ju)的磨損，減(jian)少維修工作量延長使(shi)用壽命(ming)； 
風機：利用固態軟起動器取(qu)代(dai)了傳統起動器，減少皮帶(dai)磨損和機械沖(chong)擊； 
壓(ya)縮機：利用限流，實現了平滑起動(dong)，降低電機溫升； 
破碎機(ji)(ji)：利(li)用堵轉保(bao)護和快速保(bao)護，避免機(ji)(ji)械(xie)故障和阻塞造成電動機(ji)(ji)過熱而(er)燒毀； 
輸(shu)送機械：利用軟起(qi)動(dong)和軟停機控制(zhi)，實現平滑(hua)漸進的(de)起(qi)動(dong)過程(cheng)和平滑(hua)減速的(de)停車(che)過程(cheng)，避免(mian)了因沖擊而對物(wu)料和設備造成的(de)損傷(shang).