【直(zhi)流(liu)電動機(ji)】直(zhi)流(liu)電動機(ji)工作原理 直(zhi)流(liu)電動機(ji)和交流(liu)電動機(ji)區(qu)別

直流電動機工作原理

直流電機是根(gen)據通(tong)電(dian)(dian)(dian)流(liu)的(de)導體在磁場(chang)中會受力(li)的(de)原理(li)來(lai)工作(zuo)的(de)。既電(dian)(dian)(dian)工基礎中的(de)左手定(ding)(ding)(ding)則(ze)。電(dian)(dian)(dian)動機的(de)轉子上繞有(you)線圈(quan)，通(tong)入(ru)電(dian)(dian)(dian)流(liu)，定(ding)(ding)(ding)子作(zuo)為(wei)磁場(chang)線圈(quan)也(ye)通(tong)入(ru)電(dian)(dian)(dian)流(liu)，產生定(ding)(ding)(ding)子磁場(chang)，通(tong)電(dian)(dian)(dian)流(liu)的(de)轉子線圈(quan)在定(ding)(ding)(ding)子磁場(chang)中，就會產生電(dian)(dian)(dian)動力(li)，推動轉子旋轉。轉子電(dian)(dian)(dian)流(liu)是通(tong)過整流(liu)子上的(de)碳刷連接(jie)到直流(liu)電(dian)(dian)(dian)源的(de)。

直流無刷電(dian)(dian)(dian)機(ji)(ji)的控制(zhi)原(yuan)理(li)，要(yao)讓電(dian)(dian)(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)動起來，首先控制(zhi)部就(jiu)必須根據hall-sensor感(gan)應到(dao)的電(dian)(dian)(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)所在位(wei)置，然后依照(zhao)定子(zi)(zi)(zi)繞線(xian)決定開啟(或(huo)關(guan)(guan)閉)換流器(inverter)中(zhong)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan)的順(shun)序，inverter中(zhong)之AH、BH、CH(這些稱(cheng)為(wei)上臂(bei)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan))及(ji)AL、BL、CL(這些稱(cheng)為(wei)下臂(bei)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan))，使電(dian)(dian)(dian)流依序流經電(dian)(dian)(dian)機(ji)(ji)線(xian)圈產(chan)生順(shun)向(或(huo)逆(ni)向)旋轉(zhuan)(zhuan)(zhuan)磁(ci)場(chang)，并與轉(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)的磁(ci)鐵相互作用，如此就(jiu)能(neng)使電(dian)(dian)(dian)機(ji)(ji)順(shun)時/逆(ni)時轉(zhuan)(zhuan)(zhuan)動。當(dang)電(dian)(dian)(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)轉(zhuan)(zhuan)(zhuan)動到(dao)hall-sensor感(gan)應出另一(yi)組(zu)信號(hao)的位(wei)置時，控制(zhi)部又(you)再開啟下一(yi)組(zu)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan)，如此循環電(dian)(dian)(dian)機(ji)(ji)就(jiu)可以(yi)依同一(yi)方向繼續轉(zhuan)(zhuan)(zhuan)動直到(dao)控制(zhi)部決定要(yao)電(dian)(dian)(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)停止(zhi)則(ze)關(guan)(guan)閉功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan)(或(huo)只開下臂(bei)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan))；要(yao)電(dian)(dian)(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)反(fan)向則(ze)功(gong)率晶(jing)(jing)(jing)體(ti)(ti)管(guan)(guan)(guan)開啟順(shun)序相反(fan)。

基(ji)本上(shang)(shang)(shang)功(gong)率(lv)晶體(ti)(ti)管(guan)的開法可舉例如(ru)下(xia)(xia)(xia)：AH、BL一(yi)(yi)(yi)組(zu)(zu)→AH、CL一(yi)(yi)(yi)組(zu)(zu)→BH、CL一(yi)(yi)(yi)組(zu)(zu)→BH、AL一(yi)(yi)(yi)組(zu)(zu)→CH、AL一(yi)(yi)(yi)組(zu)(zu)→CH、BL一(yi)(yi)(yi)組(zu)(zu)，但絕不能(neng)開成AH、AL或(huo)BH、BL或(huo)CH、CL。此外因為電子(zi)零件(jian)總有開關的響應(ying)時(shi)間(jian)(jian)(jian)，所以功(gong)率(lv)晶體(ti)(ti)管(guan)在(zai)關與開的交(jiao)錯時(shi)間(jian)(jian)(jian)要將(jiang)零件(jian)的響應(ying)時(shi)間(jian)(jian)(jian)考(kao)慮進去(qu)，否則當上(shang)(shang)(shang)臂(bei)(或(huo)下(xia)(xia)(xia)臂(bei))尚未完全關閉，下(xia)(xia)(xia)臂(bei)(或(huo)上(shang)(shang)(shang)臂(bei))就已開啟，結果就造成上(shang)(shang)(shang)、下(xia)(xia)(xia)臂(bei)短路而使功(gong)率(lv)晶體(ti)(ti)管(guan)燒毀。

當電(dian)機(ji)轉(zhuan)動起來(lai)，控(kong)制部(bu)會再根據(ju)驅動器設定的(de)速(su)度及(ji)加(jia)/減速(su)率(lv)所(suo)組(zu)成(cheng)的(de)命令(Command)與hall-sensor信號變化的(de)速(su)度加(jia)以比對(或(huo)由(you)(you)軟件運算(suan))再來(lai)決定由(you)(you)下一組(zu)(AH、BL或(huo)AH、CL或(huo)BH、CL或(huo)……)開(kai)關(guan)導(dao)通，以及(ji)導(dao)通時間長短(duan)。速(su)度不夠則(ze)開(kai)長，速(su)度過頭則(ze)減短(duan)，此部(bu)份工(gong)作就由(you)(you)PWM來(lai)完成(cheng)。PWM是決定電(dian)機(ji)轉(zhuan)速(su)快或(huo)慢(man)的(de)方式，如何產生這(zhe)樣(yang)的(de)PWM才是要(yao)達到較精準速(su)度控(kong)制的(de)核心(xin)。

高轉速的(de)(de)(de)(de)(de)(de)(de)速度(du)(du)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)必(bi)須考(kao)慮(lv)到系統(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)CLOCK 分辨率(lv)是(shi)否足以(yi)掌(zhang)(zhang)握(wo)處(chu)理(li)(li)軟件指令(ling)的(de)(de)(de)(de)(de)(de)(de)時(shi)間，另外對(dui)于hall-sensor信號(hao)(hao)變化(hua)的(de)(de)(de)(de)(de)(de)(de)資料存取(qu)方式(shi)也影響到處(chu)理(li)(li)器效能(neng)(neng)與判(pan)定正確性、實(shi)時(shi)性。至(zhi)于低(di)轉速的(de)(de)(de)(de)(de)(de)(de)速度(du)(du)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)尤(you)其是(shi)低(di)速起動則(ze)因(yin)為回(hui)傳(chuan)的(de)(de)(de)(de)(de)(de)(de)hall-sensor信號(hao)(hao)變化(hua)變得(de)(de)更慢，怎樣擷取(qu)信號(hao)(hao)方式(shi)、處(chu)理(li)(li)時(shi)機(ji)(ji)以(yi)及(ji)根據(ju)電機(ji)(ji)特(te)性適當(dang)(dang)配(pei)置控(kong)(kong)(kong)制(zhi)(zhi)(zhi)參數值就顯得(de)(de)非常重要。或者(zhe)速度(du)(du)回(hui)傳(chuan)改變以(yi)encoder變化(hua)為參考(kao)，使信號(hao)(hao)分辨率(lv)增加以(yi)期得(de)(de)到更佳(jia)的(de)(de)(de)(de)(de)(de)(de)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)。電機(ji)(ji)能(neng)(neng)夠運轉順暢而且(qie)響應(ying)良好，P.I.D.控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)恰當(dang)(dang)與否也無法忽視。之前提到直流(liu)無刷(shua)電機(ji)(ji)是(shi)閉回(hui)路控(kong)(kong)(kong)制(zhi)(zhi)(zhi)，因(yin)此(ci)回(hui)授信號(hao)(hao)就等于是(shi)告訴控(kong)(kong)(kong)制(zhi)(zhi)(zhi)部電機(ji)(ji)轉速距離(li)目標速度(du)(du)還差多(duo)少，這(zhe)就是(shi)誤(wu)差(Error)。知道了(le)誤(wu)差自然就要補償，方式(shi)有傳(chuan)統(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)工(gong)程控(kong)(kong)(kong)制(zhi)(zhi)(zhi)如P.I.D.控(kong)(kong)(kong)制(zhi)(zhi)(zhi)。但(dan)控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)狀態及(ji)環境(jing)其實(shi)是(shi)復雜多(duo)變的(de)(de)(de)(de)(de)(de)(de)，若(ruo)要控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)堅固耐(nai)用則(ze)要考(kao)慮(lv)的(de)(de)(de)(de)(de)(de)(de)因(yin)素恐(kong)怕不是(shi)傳(chuan)統(tong)(tong)的(de)(de)(de)(de)(de)(de)(de)工(gong)程控(kong)(kong)(kong)制(zhi)(zhi)(zhi)能(neng)(neng)完(wan)全掌(zhang)(zhang)握(wo)，所(suo)以(yi)模糊控(kong)(kong)(kong)制(zhi)(zhi)(zhi)、專家系統(tong)(tong)及(ji)神(shen)經網絡也將被納入(ru)成為智(zhi)能(neng)(neng)型P.I.D.控(kong)(kong)(kong)制(zhi)(zhi)(zhi)的(de)(de)(de)(de)(de)(de)(de)重要理(li)(li)論。

直流電動機和交流電動機區別

從結(jie)構(gou)上說，直流電機的原理(li)相對(dui)簡(jian)單，但結(jie)構(gou)復雜(za)，不便于(yu)維(wei)護。而交流電機原理(li)復雜(za)但結(jie)構(gou)相對(dui)簡(jian)單，而且比直流電機便于(yu)維(wei)護。

直流電(dian)(dian)機(ji)是(shi)(shi)通過電(dian)(dian)刷和換(huan)向器把電(dian)(dian)流引入轉(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)電(dian)(dian)樞中，從而(er)使(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)在(zai)定子(zi)(zi)磁(ci)場(chang)中受力而(er)產(chan)(chan)生(sheng)(sheng)旋(xuan)轉(zhuan)(zhuan)(zhuan)(zhuan)。交流電(dian)(dian)機(ji)（以常用的(de)交流異步電(dian)(dian)動機(ji)為例(li)）是(shi)(shi)把交流電(dian)(dian)通入定子(zi)(zi)繞(rao)組(zu)(zu)，從而(er)在(zai)定轉(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)氣隙中產(chan)(chan)生(sheng)(sheng)旋(xuan)轉(zhuan)(zhuan)(zhuan)(zhuan)磁(ci)場(chang)，旋(xuan)轉(zhuan)(zhuan)(zhuan)(zhuan)磁(ci)場(chang)在(zai)轉(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)繞(rao)組(zu)(zu)中產(chan)(chan)生(sheng)(sheng)感應電(dian)(dian)流，進而(er)使(shi)轉(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)在(zai)定子(zi)(zi)磁(ci)場(chang)中受力產(chan)(chan)生(sheng)(sheng)旋(xuan)轉(zhuan)(zhuan)(zhuan)(zhuan)。

1、直流特點：

（一(yi)）調(diao)速性能好。所謂“調(diao)速性能”，是指(zhi)電(dian)(dian)動機(ji)在一(yi)定(ding)負(fu)(fu)載(zai)的(de)(de)條件(jian)下，根據需要，人為地改變電(dian)(dian)動機(ji)的(de)(de)轉速。直流電(dian)(dian)動機(ji)可以(yi)在重(zhong)負(fu)(fu)載(zai)條件(jian)下，實現均(jun)勻、平滑的(de)(de)無級(ji)調(diao)速，而(er)且(qie)調(diao)速范圍較(jiao)寬。

（二）起動(dong)力矩大。可(ke)以均(jun)勻而經濟地實現轉(zhuan)速調節。因(yin)此，凡是在重負載下起動(dong)或要求均(jun)勻調節轉(zhuan)速的機(ji)械(xie)。

例如大型(xing)可(ke)逆(ni)軋鋼(gang)機、卷揚機、電(dian)力機車、電(dian)車等，都(dou)用直流(liu)直流(liu)電(dian)動(dong)(dong)機電(dian)動(dong)(dong)機拖動(dong)(dong)。

2、交流特點：

交流電動機的工作效率較(jiao)高(gao)，又沒有煙塵、氣味，不(bu)污染環(huan)境(jing)，噪聲也較(jiao)小。由(you)于它的一系(xi)列優點，所以(yi)在工農業生產、交通(tong)運輸、國防、商業及(ji)家(jia)用電器(qi)、醫療電器(qi)設備(bei)等各方面廣泛應(ying)用。