一臺三相繞線轉(zhuǎn)子異步電動機(jī)有關(guān)數(shù)據(jù)為:PN=75KW,NN=720rmin,I1N=148A,ηN=90.5%,cosΦN=0.85,λm=2.4,E2N=213V,I2N=220A.求: (1)額定轉(zhuǎn)矩; (2)最大轉(zhuǎn)矩; (3)最大轉(zhuǎn)矩對應(yīng)的轉(zhuǎn)差率;