A.電樞串電阻調(diào)速 B.改變定子極對(duì)數(shù)調(diào)速 C.降低電源電壓調(diào)速 D.減弱磁通調(diào)速
A.變電 B.配電 C.保護(hù) D.監(jiān)視
A.電流對(duì)稱(chēng) B.電壓對(duì)稱(chēng) C.電流、電壓都對(duì)稱(chēng) D.電流不對(duì)稱(chēng)