一、無刷直流電機是永磁電機嗎
現代電機與控制技術以電流驅動模式的不同,將永磁直流無刷電機分為兩大類:方波驅動電機和正弦波驅動電機。前者稱為直流無刷電機(BLDC)或電子換相直流電機,后者曾有人(ren)稱為無刷交流電機(BLAC),現在稱為永磁(ci)同步電機。
表面看(kan)來(lai),直流(liu)無刷(shua)電(dian)(dian)(dian)(dian)機(ji)(BLDC)和(he)永磁(ci)(ci)(ci)同(tong)(tong)步(bu)電(dian)(dian)(dian)(dian)機(ji)(PMSM)的(de)基本結構(gou)是(shi)相同(tong)(tong)的(de):它們的(de)電(dian)(dian)(dian)(dian)機(ji)都是(shi)永磁(ci)(ci)(ci)電(dian)(dian)(dian)(dian)機(ji),轉(zhuan)子(zi)由永磁(ci)(ci)(ci)體組成基本結構(gou),定(ding)子(zi)安放有多相交流(liu)繞組;都是(shi)永久磁(ci)(ci)(ci)鐵(tie)轉(zhuan)子(zi)和(he)定(ding)子(zi)的(de)交流(liu)電(dian)(dian)(dian)(dian)流(liu)相互(hu)作(zuo)用產生電(dian)(dian)(dian)(dian)機(ji)的(de)轉(zhuan)矩(ju);在繞組中驅(qu)動(dong)(dong)電(dian)(dian)(dian)(dian)流(liu)必須與轉(zhuan)子(zi)位(wei)置(zhi)反饋同(tong)(tong)步(bu)。轉(zhuan)子(zi)位(wei)置(zhi)反饋信號可以來(lai)自轉(zhuan)子(zi)位(wei)置(zhi)傳感器,或(huo)者像在一(yi)些無傳感器控制(zhi)方(fang)式那(nei)樣通過(guo)檢(jian)測電(dian)(dian)(dian)(dian)機(ji)相繞組的(de)反電(dian)(dian)(dian)(dian)動(dong)(dong)勢等方(fang)法得到(dao)。本質(zhi)上(shang),無刷(shua)直流(liu)電(dian)(dian)(dian)(dian)動(dong)(dong)機(ji)也是(shi)一(yi)種永磁(ci)(ci)(ci)同(tong)(tong)步(bu)電(dian)(dian)(dian)(dian)動(dong)(dong)機(ji),調速實際也屬于(yu)變壓變頻調速范疇。
二、無刷直流電機和永磁同步電機區別
1、概念區別
直流無刷電(dian)(dian)機(ji)(ji)是(shi)指一個系(xi)統,準(zhun)確(que)地(di)稱(cheng)為直流無刷電(dian)(dian)機(ji)(ji)系(xi)統,強(qiang)調電(dian)(dian)機(ji)(ji)和控制器的集成設(she)計,是(shi)一個整體(ti),相互依賴(lai)性很高,電(dian)(dian)機(ji)(ji)和控制器不能獨立存在和工作,評估其整體(ti)技(ji)術性能;交流永磁同步電(dian)(dian)機(ji)(ji)是(shi)指電(dian)(dian)機(ji)(ji),強(qiang)調電(dian)(dian)機(ji)(ji)本(ben)身是(shi)一個獨立工作的設(she)備,可以離開控制器或變(bian)頻器。
2、性能區別
從(cong)設計和性(xing)(xing)能(neng)(neng)的(de)(de)(de)角度來看,直流(liu)無刷電(dian)(dian)機(ji)(ji)(ji)系統主要考慮如(ru)何將普通機(ji)(ji)(ji)械轉(zhuan)向(xiang)電(dian)(dian)子,在(zai)轉(zhuan)向(xiang)后保(bao)持機(ji)(ji)(ji)械轉(zhuan)向(xiang)電(dian)(dian)機(ji)(ji)(ji)的(de)(de)(de)優(you)勢(shi),評(ping)估的(de)(de)(de)重點也(ye)是系統的(de)(de)(de)直流(liu)電(dian)(dian)機(ji)(ji)(ji)特(te)性(xing)(xing),如(ru)調速特(te)性(xing)(xing);交(jiao)(jiao)流(liu)永磁同步電(dian)(dian)機(ji)(ji)(ji)主要關(guan)注電(dian)(dian)機(ji)(ji)(ji)本身的(de)(de)(de)性(xing)(xing)能(neng)(neng),特(te)別是交(jiao)(jiao)流(liu)電(dian)(dian)機(ji)(ji)(ji)的(de)(de)(de)性(xing)(xing)能(neng)(neng),如(ru)電(dian)(dian)機(ji)(ji)(ji)的(de)(de)(de)功率(lv)因數、電(dian)(dian)壓(ya)波形(xing)和效(xiao)率(lv)角特(te)性(xing)(xing)。
3、使用電勢波區別
從反電勢波形的角度來看,直流無刷電機多為方波,而交流永磁同步電機的(de)反電勢(shi)波形多為正弦波。波形是(shi)不同的(de),所(suo)以(yi)它們的(de)功能會有所(suo)不同,
4、控制區別
從控制的(de)角度來看,質量(liang)好、價格低的(de)直流無刷電(dian)機系統基本(ben)上(shang)不需(xu)(xu)要算法(fa),只需(xu)(xu)根(gen)據轉子位置(zhi)考慮(lv)繞組電(dian)流,如果(guo)交流永磁同步電(dian)機需(xu)(xu)要變(bian)頻調(diao)速,需(xu)(xu)要一(yi)定的(de)算法(fa),需(xu)(xu)要考慮(lv)電(dian)樞電(dian)流的(de)無功和有(you)功等。