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(zi)換(huan)相直流電機(ji),后者(zhe)曾(ceng)有人稱(cheng)為(wei)無刷(shua)交流電機(ji)(BLAC),現在稱(cheng)為(wei)永磁同步電機(ji)。
表面看(kan)來,直流(liu)(liu)(liu)無(wu)刷電(dian)(dian)(dian)機(ji)(ji)(ji)(BLDC)和永(yong)(yong)磁(ci)(ci)同步(bu)電(dian)(dian)(dian)機(ji)(ji)(ji)(PMSM)的(de)(de)基本(ben)結構(gou)是相(xiang)同的(de)(de):它們的(de)(de)電(dian)(dian)(dian)機(ji)(ji)(ji)都是永(yong)(yong)磁(ci)(ci)電(dian)(dian)(dian)機(ji)(ji)(ji),轉(zhuan)子(zi)(zi)由永(yong)(yong)磁(ci)(ci)體(ti)組(zu)(zu)成基本(ben)結構(gou),定(ding)(ding)子(zi)(zi)安放(fang)有多相(xiang)交流(liu)(liu)(liu)繞組(zu)(zu);都是永(yong)(yong)久(jiu)磁(ci)(ci)鐵轉(zhuan)子(zi)(zi)和定(ding)(ding)子(zi)(zi)的(de)(de)交流(liu)(liu)(liu)電(dian)(dian)(dian)流(liu)(liu)(liu)相(xiang)互作用產生電(dian)(dian)(dian)機(ji)(ji)(ji)的(de)(de)轉(zhuan)矩;在繞組(zu)(zu)中驅動(dong)電(dian)(dian)(dian)流(liu)(liu)(liu)必(bi)須(xu)與轉(zhuan)子(zi)(zi)位置反饋(kui)同步(bu)。轉(zhuan)子(zi)(zi)位置反饋(kui)信(xin)號可以來自(zi)轉(zhuan)子(zi)(zi)位置傳感器(qi),或(huo)者像在一些(xie)無(wu)傳感器(qi)控制(zhi)方式那樣通過檢測電(dian)(dian)(dian)機(ji)(ji)(ji)相(xiang)繞組(zu)(zu)的(de)(de)反電(dian)(dian)(dian)動(dong)勢等方法得(de)到。本(ben)質上,無(wu)刷直流(liu)(liu)(liu)電(dian)(dian)(dian)動(dong)機(ji)(ji)(ji)也(ye)是一種永(yong)(yong)磁(ci)(ci)同步(bu)電(dian)(dian)(dian)動(dong)機(ji)(ji)(ji),調速實(shi)際也(ye)屬于變(bian)壓變(bian)頻調速范(fan)疇。
二、無刷直流電機和永磁同步電機區別
1、概念區別
直流(liu)無刷電(dian)(dian)(dian)機是指一個系統,準確地(di)稱為直流(liu)無刷電(dian)(dian)(dian)機系統,強調電(dian)(dian)(dian)機和控(kong)制(zhi)器的集(ji)成設計,是一個整(zheng)體,相互依(yi)賴性很高,電(dian)(dian)(dian)機和控(kong)制(zhi)器不能獨立存在和工(gong)作(zuo),評估(gu)其(qi)整(zheng)體技術性能;交流(liu)永磁同步電(dian)(dian)(dian)機是指電(dian)(dian)(dian)機,強調電(dian)(dian)(dian)機本身(shen)是一個獨立工(gong)作(zuo)的設備,可(ke)以離開控(kong)制(zhi)器或變頻器。
2、性能區別
從設計和性(xing)(xing)(xing)能(neng)(neng)的(de)角度來看,直流無刷電(dian)(dian)機(ji)系統主(zhu)(zhu)要考慮如何將普通機(ji)械轉向電(dian)(dian)子(zi),在轉向后保持(chi)機(ji)械轉向電(dian)(dian)機(ji)的(de)優(you)勢,評估的(de)重點(dian)也(ye)是系統的(de)直流電(dian)(dian)機(ji)特(te)性(xing)(xing)(xing),如調速(su)特(te)性(xing)(xing)(xing);交(jiao)流永磁同步電(dian)(dian)機(ji)主(zhu)(zhu)要關注電(dian)(dian)機(ji)本身的(de)性(xing)(xing)(xing)能(neng)(neng),特(te)別是交(jiao)流電(dian)(dian)機(ji)的(de)性(xing)(xing)(xing)能(neng)(neng),如電(dian)(dian)機(ji)的(de)功率(lv)因數、電(dian)(dian)壓波形和效率(lv)角特(te)性(xing)(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(duo)為(wei)方(fang)波(bo)(bo),而交(jiao)流永磁同(tong)(tong)步(bu)電機的(de)反電勢波(bo)(bo)形多(duo)為(wei)正(zheng)弦波(bo)(bo)。波(bo)(bo)形是不同(tong)(tong)的(de),所以它們的(de)功能會有所不同(tong)(tong),
4、控制區別
從控制的(de)角(jiao)度(du)來看,質量好、價格低的(de)直(zhi)流(liu)(liu)無(wu)刷電(dian)機系統基(ji)本上不需(xu)(xu)要算(suan)法,只(zhi)需(xu)(xu)根(gen)據轉子位置考慮(lv)繞組電(dian)流(liu)(liu),如果交流(liu)(liu)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(suan)法,需(xu)(xu)要考慮(lv)電(dian)樞電(dian)流(liu)(liu)的(de)無(wu)功和有功等(deng)。