一、概(gai)述
交流鼠籠(long)式異步電動機如果直(zhi)接起(qi)動會(hui)產生(sheng)很大沖(chong)擊(ji)電流，會(hui)對(dui)電阻及其負載造成沖(chong)擊(ji)，甚至危(wei)害電網安全運行(xing)。生(sheng)產機械對(dui)電動機的(de)(de)起(qi)動也(ye)有各(ge)種不同(tong)的(de)(de)要求，有些需(xu)要平穩起(qi)動的(de)(de)生(sheng)產機械也(ye)不允許(xu)直(zhi)接起(qi)動。
星-三(san)角轉換(huan)起(qi)動，自藕變壓器降(jiang)壓起(qi)動的主要(yao)問題是(shi)起(qi)動過程中起(qi)動電壓和運行電壓轉換(huan)時的電流沖(chong)擊，對電網和機械產生(sheng)沖(chong)擊，產生(sheng)損(sun)害。應用晶閘管交流調壓技術的固態軟起(qi)動器，是(shi)目(mu)前降(jiang)壓起(qi)動方式中合理、先(xian)進(jin)的起(qi)動方式。
二(er)、工作原理
軟啟動調(diao)速實(shi)際上(shang)是(shi)—個(ge)(ge)晶(jing)(jing)閘(zha)管(guan)交流(liu)調(diao)壓(ya)(ya)(ya)器(qi)。改(gai)變晶(jing)(jing)閘(zha)管(guan)的(de)觸發(fa)角，就可調(diao)節晶(jing)(jing)閘(zha)管(guan)調(diao)壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)。用軟起動(dong)(dong)器(qi)起動(dong)(dong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機時：設置一(yi)(yi)個(ge)(ge)初始電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，晶(jing)(jing)閘(zha)管(guan)調(diao)壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)就從這一(yi)(yi)點開始上(shang)升；設置一(yi)(yi)個(ge)(ge)升壓(ya)(ya)(ya)時間(jian)，逐漸(jian)增加晶(jing)(jing)閘(zha)管(guan)調(diao)壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機逐漸(jian)加速；設置—個(ge)(ge)限(xian)流(liu)倍數(shu)，根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)互感器(qi)測(ce)得的(de)實(shi)際電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)值，控制晶(jing)(jing)閘(zha)管(guan)調(diao)壓(ya)(ya)(ya)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)輸出(chu)(chu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機的(de)實(shi)際電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)不超過限(xian)流(liu)值。這樣(yang)在(zai)整個(ge)(ge)起動(dong)(dong)過程中，軟啟(qi)動(dong)(dong)柜(ju)的(de)輸出(chu)(chu)是(shi)一(yi)(yi)個(ge)(ge)平滑的(de)升壓(ya)(ya)(ya)過程（且具有限(xian)流(liu)功能），直到晶(jing)(jing)閘(zha)管(guan)全導(dao)通，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)機在(zai)額定電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)下工作。

典(dian)型應用簡介
水(shui)泵：利用泵控制(zhi)功能，在起動和停止時(shi)，減少液流(liu)沖(chong)擊所產生的(de)泵流(liu)水(shui)錘現象(xiang)，節(jie)省了系統(tong)維修費用； 
球磨機(ji)：利用(yong)電壓斜坡起動，減(jian)少(shao)齒輪(lun)轉矩(ju)的(de)磨損，減(jian)少(shao)維修工作量延長使用(yong)壽(shou)命(ming)； 
風機(ji)：利(li)用固(gu)態軟起動器(qi)取代了傳統(tong)起動器(qi)，減少皮帶磨損和(he)機(ji)械沖擊； 
壓縮機：利用(yong)限流，實現了平滑起動，降低電(dian)機溫(wen)升(sheng)； 
破碎機：利(li)用堵轉保護和(he)快速保護，避免機械故(gu)障和(he)阻(zu)塞造成電動機過熱(re)而燒毀； 
輸送機械：利用軟起(qi)動(dong)和(he)軟停機控制，實(shi)現平滑漸(jian)進的(de)起(qi)動(dong)過程和(he)平滑減速的(de)停車過程，避免了(le)因沖擊而對物料和(he)設備造成的(de)損傷(shang).