7AI/MOYF40智能型角行程電動執行機構采用了新(xin)變頻調速技(ji)術，電機驅動(dong)功率小于5．5kW。用戶可根(gen)據需(xu)要(yao)設(she)定(ding)力矩特性(xing)，根(gen)據控(kong)(kong)制的閥設(she)定(ding)速度(du)(du)，速度(du)(du)分多轉式、直行程(cheng)、角(jiao)行程(cheng)3種方(fang)式。控(kong)(kong)制系(xi)統由閥位給定(ding)和閥位反饋信(xin)號(hao)構成(cheng)的閉環(huan)系(xi)統，控(kong)(kong)制特性(xing)視運(yun)行方(fang)式、速度(du)(du)而定(ding)，并(bing)具有(you)自動(dong)過(guo)流保護、過(guo)載(zai)保護、壓(ya)、欠壓(ya)、過(guo)熱、缺(que)相、堵轉等保護功能。

該角行程電動執行機構解決(jue)的(de)關鍵性技術問(wen)題主(zhu)要有(you)：

1)閥門柔(rou)性(xing)(xing)開(kai)(kai)關(guan)　柔(rou)性(xing)(xing)開(kai)(kai)關(guan)主(zhu)要是(shi)為了當閥關(guan)閉或(huo)全(quan)開(kai)(kai)時，保證閥門不卡死與(yu)損(sun)傷。執行(xing)機構(gou)內部(bu)的微處理器(qi)根(gen)據測得的變頻器(qi)輸(shu)出(chu)電壓和電流，通過(guo)計算，得出(chu)其(qi)輸(shu)出(chu)力(li)(li)矩(ju)(ju)。一(yi)旦輸(shu)出(chu)力(li)(li)矩(ju)(ju)達到或(huo)大(da)于設(she)定的力(li)(li)矩(ju)(ju)，自動降低速度，以避免閥門內部(bu)過(guo)度的撞(zhuang)擊，從而(er)達到優關(guan)閉，實現(xian)過(guo)力(li)(li)矩(ju)(ju)保護。

2)閥位(wei)(wei)(wei)的(de)(de)極(ji)(ji)限(xian)(xian)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)判斷　閥位(wei)(wei)(wei)的(de)(de)極(ji)(ji)限(xian)(xian)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)是(shi)指全(quan)開和全(quan)關(guan)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)。在(zai)傳(chuan)統執行(xing)(xing)機(ji)(ji)(ji)(ji)構中(zhong)(zhong)，該位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)的(de)(de)檢(jian)測是(shi)通(tong)(tong)過(guo)機(ji)(ji)(ji)(ji)械式(shi)限(xian)(xian)位(wei)(wei)(wei)開關(guan)獲(huo)得的(de)(de)。機(ji)(ji)(ji)(ji)械式(shi)限(xian)(xian)位(wei)(wei)(wei)開關(guan)精度(du)低，在(zai)運(yun)行(xing)(xing)中(zhong)(zhong)易松動(dong)(dong)，可靠性差。在(zai)文中(zhong)(zhong)，電(dian)動(dong)(dong)執行(xing)(xing)機(ji)(ji)(ji)(ji)構極(ji)(ji)限(xian)(xian)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)通(tong)(tong)過(guo)檢(jian)測位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)信號(hao)的(de)(de)增量獲(huo)得。其原(yuan)理是(shi)，單(dan)片機(ji)(ji)(ji)(ji)將本(ben)次檢(jian)測的(de)(de)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)信號(hao)與上(shang)次檢(jian)測的(de)(de)信號(hao)相比較，如果(guo)未(wei)發生變化或(huo)變化較小，即認為(wei)己達到極(ji)(ji)限(xian)(xian)位(wei)(wei)(wei)置(zhi)(zhi)(zhi)(zhi)，立即切斷異步(bu)電(dian)機(ji)(ji)(ji)(ji)的(de)(de)供電(dian)電(dian)源，保證閥門的(de)(de)安全(quan)關(guan)閉或(huo)全(quan)開。省去了機(ji)(ji)(ji)(ji)械式(shi)限(xian)(xian)位(wei)(wei)(wei)開關(guan)，無需在(zai)調試時對其進行(xing)(xing)復雜(za)的(de)(de)調整。

3)電(dian)(dian)機(ji)保護的(de)實現　為了防(fang)止電(dian)(dian)機(ji)因過熱而燒(shao)毀，單(dan)片(pian)機(ji)通過溫(wen)度(du)傳(chuan)(chuan)感器(qi)連續檢測電(dian)(dian)機(ji)的(de)實際運行溫(wen)度(du)，如(ru)果溫(wen)度(du)傳(chuan)(chuan)感器(qi)檢測到電(dian)(dian)機(ji)溫(wen)度(du)過高，自動切斷供電(dian)(dian)電(dian)(dian)源。溫(wen)度(du)傳(chuan)(chuan)感器(qi)內(nei)置于電(dian)(dian)機(ji)內(nei)部。

4)準確定(ding)位　傳統的(de)電動(dong)執行機構在(zai)異(yi)步電機通電后會(hui)很快達到(dao)其額定(ding)動(dong)作速(su)度(du)，當(dang)接近(jin)停止位置時，電機斷電后，由于(yu)機械慣性，其閥門不可能立即(ji)停下來，會(hui)出現不同程(cheng)度(du)的(de)程(cheng)，這一程(cheng)通常采用控制電機反向轉動(dong)來校正。機電一體化的(de)大流量電動(dong)執行機構根據當(dang)前(qian)(qian)位置與(yu)給定(ding)位置的(de)差值以及(ji)(ji)運行速(su)度(du)的(de)大小(xiao)前(qian)(qian)確定(ding)減速(su)點的(de)位置及(ji)(ji)減速(su)段變化速(su)率ki，使閥門在(zai)較低的(de)速(su)度(du)下實現的(de)微調和定(ding)位，從而將(jiang)程(cheng)降到(dao)低。