特高潮喷白浆HDvideos,日日av拍夜夜添久久网站,国语对白调教半小时视频,国产人成无码视频在线,国产一级a毛一级a看免费视频

對1、2兩項，似(si)乎(hu)沒(mei)有根據(ju)，現實(shi)中(zhong)上百(bai)、數百(bai)千瓦的(de)電動(dong)機都有全壓直接(jie)啟動(dong)的(de)。對3項，變壓器是空(kong)載嗎(ma)？對4、5項，實(shi)際(ji)當中(zhong)又如何掌控？難(nan)道是實(shi)際(ji)測量(liang)嗎(ma)？

                                                                                                                  

實際上(shang)采用降壓(ya)啟(qi)(qi)動的(de)主(zhu)要(yao)目的(de)，就是(shi)避免影響其(qi)(qi)它設備的(de)正常工作。如(ru)果沒有其(qi)(qi)它設備，只(zhi)有變(bian)壓(ya)器(qi)與電(dian)動機，那(nei)么電(dian)動機的(de)功率(lv)(lv)可以接近變(bian)壓(ya)器(qi)的(de)容量，考(kao)慮(lv)到功率(lv)(lv)因(yin)(yin)(yin)數、效率(lv)(lv)等因(yin)(yin)(yin)素(su)，一般電(dian)動機功率(lv)(lv)為變(bian)壓(ya)器(qi)容量的(de)80%，都可以直接啟(qi)(qi)動，或(huo)(huo)(huo)者變(bian)壓(ya)器(qi)與電(dian)動機同時(shi)啟(qi)(qi)動。現實中(zhong)絕大多(duo)數的(de)大電(dian)機啟(qi)(qi)動時(shi)，變(bian)壓(ya)器(qi)或(huo)(huo)(huo)多(duo)或(huo)(huo)(huo)少(shao)還有其(qi)(qi)它負荷，那(nei)么其(qi)(qi)它負荷的(de)多(duo)少(shao)也是(shi)要(yao)考(kao)慮(lv)的(de)因(yin)(yin)(yin)素(su)之一。

因為籠形(xing)電(dian)動(dong)機的(de)啟動(dong)電(dian)流(liu)是其額(e)定(ding)電(dian)流(liu)的(de)5-7倍，大(da)電(dian)流(liu)會引起大(da)的(de)電(dian)壓降，電(dian)壓降達到一(yi)定(ding)值，其它電(dian)氣設(she)備就有(you)可能停止工作或引起故障。因此有(you)規定(ding)頻(pin)繁啟動(dong)的(de)電(dian)機，造成的(de)電(dian)壓降不(bu)能超過(guo)10%，不(bu)頻(pin)繁啟動(dong)造成的(de)電(dian)壓降不(bu)超15%。

是因為變壓器提供不(bu)(bu)出(chu)大(da)(da)(da)電(dian)機(ji)啟(qi)(qi)動(dong)(dong)(dong)時所(suo)需要(yao)的(de)(de)大(da)(da)(da)電(dian)流，如果變壓器能(neng)(neng)提供大(da)(da)(da)電(dian)機(ji)啟(qi)(qi)動(dong)(dong)(dong)所(suo)需的(de)(de)大(da)(da)(da)電(dian)流，就不(bu)(bu)會(hui)產生(sheng)電(dian)壓降(jiang)或產生(sheng)的(de)(de)電(dian)壓降(jiang)很小。這就是說變壓器容(rong)量(liang)的(de)(de)大(da)(da)(da)小，也決定(ding)了電(dian)壓降(jiang)的(de)(de)大(da)(da)(da)小。那么實際當中絕不(bu)(bu)能(neng)(neng)不(bu)(bu)談變壓器容(rong)量(liang)大(da)(da)(da)小，而只講多大(da)(da)(da)的(de)(de)電(dian)機(ji)要(yao)降(jiang)壓啟(qi)(qi)動(dong)(dong)(dong)。

變(bian)壓(ya)(ya)器(qi)(qi)現有負荷(he)的(de)大小，也是(shi)(shi)(shi)決定(ding)電壓(ya)(ya)降(jiang)大小的(de)條件之(zhi)一。試想變(bian)壓(ya)(ya)器(qi)(qi)空載與(yu)滿(man)載時，分別(bie)啟動同一臺電機，造成的(de)電壓(ya)(ya)降(jiang)肯定(ding)不(bu)一樣。那么只講電動機功率(lv)是(shi)(shi)(shi)變(bian)壓(ya)(ya)器(qi)(qi)容(rong)量的(de)百分之(zhi)幾，而不(bu)提變(bian)壓(ya)(ya)器(qi)(qi)現有負荷(he)是(shi)(shi)(shi)多(duo)少(shao)，來判斷電機是(shi)(shi)(shi)否要降(jiang)壓(ya)(ya)啟動也是(shi)(shi)(shi)行不(bu)通的(de)。

至(zhi)此，要(yao)判(pan)斷電(dian)動(dong)機是否(fou)降壓啟動(dong)，至(zhi)少要(yao)考(kao)慮電(dian)動(dong)機功率(lv)、變壓器容量、現有(you)(you)負(fu)荷三個(ge)因素(su)，缺一不(bu)可！那么看看現在(zai)各種所謂的判(pan)斷方(fang)法(fa)，有(you)(you)沒有(you)(you)把這三者綜合考(kao)慮呢(ni)？

為(wei)方(fang)便均用電流這個參數(shu)。其實(shi)這個問(wen)題的實(shi)質是：多大的電流？會造成(cheng)多大的電壓降(jiang)？也(ye)就(jiu)是電流與電壓降(jiang)的問(wen)題。

大家知道籠形電(dian)(dian)(dian)(dian)機的(de)(de)(de)啟動電(dian)(dian)(dian)(dian)流(liu)是(shi)額定電(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)5-7倍。對變壓(ya)器而言，多(duo)大的(de)(de)(de)負荷電(dian)(dian)(dian)(dian)流(liu)才(cai)會使電(dian)(dian)(dian)(dian)壓(ya)降達到10%、15%呢？這就要用到阻抗電(dian)(dian)(dian)(dian)壓(ya)這個參數，一(yi)般的(de)(de)(de)電(dian)(dian)(dian)(dian)力變壓(ya)器阻抗電(dian)(dian)(dian)(dian)壓(ya)為(wei)5%左右，也就是(shi)當(dang)變壓(ya)器的(de)(de)(de)輸(shu)出(chu)電(dian)(dian)(dian)(dian)流(liu)為(wei)額定值(zhi)時，電(dian)(dian)(dian)(dian)壓(ya)降為(wei)5%，這就是(shi)輸(shu)出(chu)380V的(de)(de)(de)變壓(ya)器，設計(ji)的(de)(de)(de)輸(shu)出(chu)電(dian)(dian)(dian)(dian)壓(ya)是(shi)400V，當(dang)滿載時剛好是(shi)380V。

假設隨著負荷(he)(he)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)(de)增加，變壓(ya)器輸(shu)出電(dian)(dian)(dian)(dian)(dian)壓(ya)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)降是(shi)(shi)(shi)線性變化的(de)(de)(de)，那么(me)當變壓(ya)器的(de)(de)(de)輸(shu)出電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)為2倍(bei)額定電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)時，電(dian)(dian)(dian)(dian)(dian)壓(ya)降是(shi)(shi)(shi)5%，3倍(bei)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)時是(shi)(shi)(shi)10%，4倍(bei)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)時是(shi)(shi)(shi)15%。那么(me)頻繁啟動的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)機允許(xu)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)降為10%，也(ye)就是(shi)(shi)(shi)電(dian)(dian)(dian)(dian)(dian)動機的(de)(de)(de)啟動電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)加上(shang)現有(you)負荷(he)(he)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，只要(yao)小于變壓(ya)器3倍(bei)額定電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，就可以直(zhi)接啟動。這就是(shi)(shi)(shi)最簡單、最接近實際的(de)(de)(de)判斷電(dian)(dian)(dian)(dian)(dian)動機采用何種方法(fa)啟動的(de)(de)(de)方法(fa)。

來源：網絡，版權歸原作(zuo)者所有