【直流電(dian)動(dong)機】直流電(dian)動(dong)機工作原(yuan)理 直流電(dian)動(dong)機和交流電(dian)動(dong)機區別(bie)

直流電動機工作原理

直流電機是(shi)根據(ju)通(tong)(tong)電(dian)流(liu)(liu)(liu)的(de)(de)導體在磁場中(zhong)會(hui)受(shou)力的(de)(de)原理(li)來工(gong)作(zuo)的(de)(de)。既(ji)電(dian)工(gong)基礎(chu)中(zhong)的(de)(de)左手定(ding)則(ze)。電(dian)動機的(de)(de)轉(zhuan)(zhuan)子上繞有線圈，通(tong)(tong)入電(dian)流(liu)(liu)(liu)，定(ding)子作(zuo)為磁場線圈也(ye)通(tong)(tong)入電(dian)流(liu)(liu)(liu)，產生定(ding)子磁場，通(tong)(tong)電(dian)流(liu)(liu)(liu)的(de)(de)轉(zhuan)(zhuan)子線圈在定(ding)子磁場中(zhong)，就會(hui)產生電(dian)動力，推動轉(zhuan)(zhuan)子旋轉(zhuan)(zhuan)。轉(zhuan)(zhuan)子電(dian)流(liu)(liu)(liu)是(shi)通(tong)(tong)過(guo)整流(liu)(liu)(liu)子上的(de)(de)碳刷連接到直流(liu)(liu)(liu)電(dian)源的(de)(de)。

直流無刷(shua)電(dian)機(ji)(ji)的(de)(de)控(kong)制原理，要讓(rang)電(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)動(dong)起來，首先控(kong)制部就必(bi)須(xu)根據hall-sensor感應到的(de)(de)電(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)所在位置(zhi)，然后依(yi)(yi)(yi)照定子(zi)(zi)(zi)繞線決定開(kai)啟(或關(guan)閉)換流器(inverter)中功(gong)(gong)率(lv)晶(jing)體(ti)管(guan)的(de)(de)順(shun)(shun)序，inverter中之AH、BH、CH(這(zhe)些稱(cheng)為(wei)上臂(bei)(bei)功(gong)(gong)率(lv)晶(jing)體(ti)管(guan))及AL、BL、CL(這(zhe)些稱(cheng)為(wei)下臂(bei)(bei)功(gong)(gong)率(lv)晶(jing)體(ti)管(guan))，使電(dian)流依(yi)(yi)(yi)序流經電(dian)機(ji)(ji)線圈(quan)產生順(shun)(shun)向(或逆向)旋(xuan)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)磁場，并與(yu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)的(de)(de)磁鐵相(xiang)互作用，如此就能使電(dian)機(ji)(ji)順(shun)(shun)時/逆時轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)動(dong)。當電(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)動(dong)到hall-sensor感應出另一組信號的(de)(de)位置(zhi)時，控(kong)制部又再開(kai)啟下一組功(gong)(gong)率(lv)晶(jing)體(ti)管(guan)，如此循環電(dian)機(ji)(ji)就可以依(yi)(yi)(yi)同(tong)一方向繼續(xu)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)動(dong)直到控(kong)制部決定要電(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)停止則關(guan)閉功(gong)(gong)率(lv)晶(jing)體(ti)管(guan)(或只開(kai)下臂(bei)(bei)功(gong)(gong)率(lv)晶(jing)體(ti)管(guan))；要電(dian)機(ji)(ji)轉(zhuan)(zhuan)(zhuan)(zhuan)(zhuan)子(zi)(zi)(zi)反向則功(gong)(gong)率(lv)晶(jing)體(ti)管(guan)開(kai)啟順(shun)(shun)序相(xiang)反。

基本(ben)上(shang)功(gong)率(lv)(lv)晶體管的(de)(de)(de)開法(fa)可舉例如下：AH、BL一組(zu)(zu)(zu)→AH、CL一組(zu)(zu)(zu)→BH、CL一組(zu)(zu)(zu)→BH、AL一組(zu)(zu)(zu)→CH、AL一組(zu)(zu)(zu)→CH、BL一組(zu)(zu)(zu)，但絕不能開成(cheng)AH、AL或(huo)(huo)(huo)BH、BL或(huo)(huo)(huo)CH、CL。此外因為電子零(ling)件(jian)總有開關的(de)(de)(de)響應時(shi)(shi)間，所以功(gong)率(lv)(lv)晶體管在關與(yu)開的(de)(de)(de)交錯時(shi)(shi)間要將零(ling)件(jian)的(de)(de)(de)響應時(shi)(shi)間考慮進(jin)去(qu)，否(fou)則當上(shang)臂(或(huo)(huo)(huo)下臂)尚未完全關閉，下臂(或(huo)(huo)(huo)上(shang)臂)就(jiu)已開啟，結果就(jiu)造(zao)成(cheng)上(shang)、下臂短(duan)路而使功(gong)率(lv)(lv)晶體管燒(shao)毀。

當電機(ji)轉(zhuan)(zhuan)動起來(lai)，控制部(bu)(bu)會再(zai)根據驅動器設定(ding)的速度(du)及加/減速率所組成(cheng)的命令(Command)與hall-sensor信號變化的速度(du)加以(yi)比對(或(huo)由軟件運算)再(zai)來(lai)決定(ding)由下一組(AH、BL或(huo)AH、CL或(huo)BH、CL或(huo)……)開(kai)關導(dao)(dao)通(tong)(tong)，以(yi)及導(dao)(dao)通(tong)(tong)時間長(chang)(chang)短。速度(du)不(bu)夠則開(kai)長(chang)(chang)，速度(du)過(guo)頭則減短，此部(bu)(bu)份工作就由PWM來(lai)完成(cheng)。PWM是決定(ding)電機(ji)轉(zhuan)(zhuan)速快或(huo)慢的方式(shi)，如何產生這(zhe)樣的PWM才是要達到較(jiao)精準速度(du)控制的核心。

高轉(zhuan)(zhuan)速的(de)(de)速度(du)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)必須(xu)考慮到(dao)系統(tong)的(de)(de)CLOCK 分辨率是否足以(yi)掌握(wo)處(chu)理軟(ruan)件指令(ling)的(de)(de)時間(jian)，另外對于(yu)hall-sensor信(xin)號(hao)變(bian)化的(de)(de)資料存(cun)取方(fang)式(shi)也影(ying)響到(dao)處(chu)理器效能與判定正確性(xing)、實(shi)(shi)時性(xing)。至于(yu)低轉(zhuan)(zhuan)速的(de)(de)速度(du)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)尤(you)其是低速起(qi)動(dong)則因為回傳(chuan)的(de)(de)hall-sensor信(xin)號(hao)變(bian)化變(bian)得更慢(man)，怎樣擷取信(xin)號(hao)方(fang)式(shi)、處(chu)理時機以(yi)及根據電(dian)機特性(xing)適當配置控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)參(can)數值就顯得非常重(zhong)要。或者速度(du)回傳(chuan)改變(bian)以(yi)encoder變(bian)化為參(can)考，使信(xin)號(hao)分辨率增加以(yi)期得到(dao)更佳的(de)(de)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)。電(dian)機能夠運(yun)轉(zhuan)(zhuan)順暢(chang)而且(qie)響應良(liang)好，P.I.D.控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)恰當與否也無法忽視。之前(qian)提(ti)到(dao)直流無刷電(dian)機是閉回路控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)，因此回授信(xin)號(hao)就等于(yu)是告訴控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)部電(dian)機轉(zhuan)(zhuan)速距離(li)目(mu)標速度(du)還差(cha)多(duo)少，這就是誤差(cha)(Error)。知道了誤差(cha)自(zi)然就要補(bu)償，方(fang)式(shi)有傳(chuan)統(tong)的(de)(de)工程控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)如P.I.D.控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)。但(dan)控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)狀態(tai)及環境其實(shi)(shi)是復雜多(duo)變(bian)的(de)(de)，若要控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)堅固耐用則要考慮的(de)(de)因素(su)恐(kong)怕不是傳(chuan)統(tong)的(de)(de)工程控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)能完全掌握(wo)，所以(yi)模糊控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)、專家(jia)系統(tong)及神經網(wang)絡也將(jiang)被(bei)納入(ru)成為智能型P.I.D.控(kong)(kong)(kong)(kong)(kong)制(zhi)(zhi)的(de)(de)重(zhong)要理論。

直流電動機和交流電動機區別

從(cong)結構上說，直流(liu)電機(ji)(ji)的原理(li)相(xiang)對簡單，但(dan)結構復雜(za)，不便于(yu)維(wei)護(hu)。而(er)交流(liu)電機(ji)(ji)原理(li)復雜(za)但(dan)結構相(xiang)對簡單，而(er)且比直流(liu)電機(ji)(ji)便于(yu)維(wei)護(hu)。

直(zhi)流(liu)電(dian)(dian)機是通過電(dian)(dian)刷和換向(xiang)器把電(dian)(dian)流(liu)引入轉(zhuan)子電(dian)(dian)樞中(zhong)，從而使轉(zhuan)子在(zai)(zai)定子磁(ci)場(chang)中(zhong)受力(li)而產(chan)生旋(xuan)轉(zhuan)。交(jiao)(jiao)流(liu)電(dian)(dian)機（以常用(yong)的交(jiao)(jiao)流(liu)異步電(dian)(dian)動(dong)機為例(li)）是把交(jiao)(jiao)流(liu)電(dian)(dian)通入定子繞(rao)組，從而在(zai)(zai)定轉(zhuan)子氣隙中(zhong)產(chan)生旋(xuan)轉(zhuan)磁(ci)場(chang)，旋(xuan)轉(zhuan)磁(ci)場(chang)在(zai)(zai)轉(zhuan)子繞(rao)組中(zhong)產(chan)生感應電(dian)(dian)流(liu)，進而使轉(zhuan)子在(zai)(zai)定子磁(ci)場(chang)中(zhong)受力(li)產(chan)生旋(xuan)轉(zhuan)。

1、直流特點：

（一(yi)）調(diao)(diao)速(su)(su)性能好。所謂“調(diao)(diao)速(su)(su)性能”，是指電(dian)(dian)動機在一(yi)定負載的(de)條(tiao)件下，根據需要(yao)，人為(wei)地(di)改(gai)變電(dian)(dian)動機的(de)轉速(su)(su)。直流(liu)電(dian)(dian)動機可以在重負載條(tiao)件下，實現均勻、平滑的(de)無(wu)級調(diao)(diao)速(su)(su)，而且調(diao)(diao)速(su)(su)范(fan)圍較寬。

（二）起動力矩(ju)大。可以均(jun)勻(yun)而經濟地(di)實現轉速調節。因此(ci)，凡是在重負載下起動或要求均(jun)勻(yun)調節轉速的機械。

例如大型可逆軋鋼機(ji)(ji)、卷(juan)揚機(ji)(ji)、電(dian)(dian)力機(ji)(ji)車、電(dian)(dian)車等，都(dou)用直流(liu)直流(liu)電(dian)(dian)動(dong)機(ji)(ji)電(dian)(dian)動(dong)機(ji)(ji)拖(tuo)動(dong)。

2、交流特點：

交流電(dian)動(dong)機(ji)的(de)工作效率較高，又沒有煙塵、氣味，不污染(ran)環境(jing)，噪聲也較小。由于(yu)它的(de)一(yi)系列優點，所以在工農業生產(chan)、交通運輸、國防、商業及家用電(dian)器、醫療電(dian)器設(she)備等各(ge)方(fang)面廣泛(fan)應用。