一、概(gai)述
交流鼠籠式(shi)異(yi)步電(dian)動機如果直(zhi)接起(qi)動會產生很大沖(chong)擊(ji)電(dian)流，會對電(dian)阻及其負(fu)載造成沖(chong)擊(ji)，甚至危(wei)害(hai)電(dian)網安(an)全運行。生產機械對電(dian)動機的起(qi)動也有各種不(bu)同的要(yao)求，有些需要(yao)平穩(wen)起(qi)動的生產機械也不(bu)允許直(zhi)接起(qi)動。
星-三角轉換起動(dong)(dong)(dong)，自(zi)藕(ou)變壓(ya)(ya)器降(jiang)壓(ya)(ya)起動(dong)(dong)(dong)的主要問(wen)題是起動(dong)(dong)(dong)過程(cheng)中(zhong)起動(dong)(dong)(dong)電壓(ya)(ya)和運行(xing)電壓(ya)(ya)轉換時的電流沖擊，對電網和機械產(chan)生(sheng)沖擊，產(chan)生(sheng)損害。應用晶閘管交(jiao)流調壓(ya)(ya)技術(shu)的固態(tai)軟(ruan)起動(dong)(dong)(dong)器，是目前降(jiang)壓(ya)(ya)起動(dong)(dong)(dong)方式中(zhong)合理(li)、先(xian)進的起動(dong)(dong)(dong)方式。
二、工(gong)作原理
軟啟動調(diao)(diao)(diao)(diao)(diao)速實(shi)際上是—個(ge)(ge)(ge)晶閘管(guan)(guan)交流調(diao)(diao)(diao)(diao)(diao)壓(ya)(ya)(ya)(ya)器(qi)。改變晶閘管(guan)(guan)的(de)觸發(fa)角(jiao)，就可調(diao)(diao)(diao)(diao)(diao)節晶閘管(guan)(guan)調(diao)(diao)(diao)(diao)(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)路的(de)輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)。用(yong)軟(ruan)起(qi)動器(qi)起(qi)動電(dian)(dian)(dian)機時：設置(zhi)一(yi)(yi)個(ge)(ge)(ge)初始(shi)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，晶閘管(guan)(guan)調(diao)(diao)(diao)(diao)(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)路的(de)輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)就從這(zhe)一(yi)(yi)點開始(shi)上升；設置(zhi)一(yi)(yi)個(ge)(ge)(ge)升壓(ya)(ya)(ya)(ya)時間，逐漸(jian)增加晶閘管(guan)(guan)調(diao)(diao)(diao)(diao)(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)路的(de)輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，電(dian)(dian)(dian)機逐漸(jian)加速；設置(zhi)—個(ge)(ge)(ge)限流倍數(shu)，根(gen)據電(dian)(dian)(dian)流互感器(qi)測得的(de)實(shi)際電(dian)(dian)(dian)流值(zhi)，控制晶閘管(guan)(guan)調(diao)(diao)(diao)(diao)(diao)壓(ya)(ya)(ya)(ya)電(dian)(dian)(dian)路的(de)輸出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)，使電(dian)(dian)(dian)機的(de)實(shi)際電(dian)(dian)(dian)流不超過(guo)限流值(zhi)。這(zhe)樣在整個(ge)(ge)(ge)起(qi)動過(guo)程(cheng)中，軟(ruan)啟動柜的(de)輸出(chu)是一(yi)(yi)個(ge)(ge)(ge)平滑(hua)的(de)升壓(ya)(ya)(ya)(ya)過(guo)程(cheng)（且具有限流功能），直到(dao)晶閘管(guan)(guan)全導通，電(dian)(dian)(dian)機在額定(ding)電(dian)(dian)(dian)壓(ya)(ya)(ya)(ya)下工作。

典型應(ying)用簡介
水(shui)泵：利(li)用泵控制功能，在起動和停止時(shi)，減少液流沖(chong)擊所(suo)產(chan)生的泵流水(shui)錘現象(xiang)，節省了系統維修費(fei)用； 
球磨機(ji)：利用(yong)電壓斜坡起(qi)動，減少(shao)齒輪轉矩(ju)的磨損，減少(shao)維(wei)修工作量延長使用(yong)壽命； 
風(feng)機：利(li)用固態軟起(qi)(qi)動器取代了傳統(tong)起(qi)(qi)動器，減少皮(pi)帶磨(mo)損和機械沖擊(ji)； 
壓縮(suo)機：利用限流，實現了平滑起動(dong)，降低電機溫升； 
破碎機(ji)：利用堵轉保護和快速保護，避免機(ji)械故障(zhang)和阻(zu)塞(sai)造成電動機(ji)過熱而燒毀； 
輸送機(ji)械(xie)：利用軟起動(dong)和(he)軟停機(ji)控制，實現平(ping)滑(hua)漸進的(de)(de)起動(dong)過(guo)程和(he)平(ping)滑(hua)減速的(de)(de)停車過(guo)程，避(bi)免了因沖擊而對物(wu)料和(he)設備造成的(de)(de)損傷.