【简答题】直流他励电动机数据如下:P N =21KW,U N =220V,I N =115A,n N =980r/min,R a =0.1Ω,系统折算到电动机轴上的总飞轮转矩GD 2 =.7N·m 2 。 (1)求系统的机电时间常数τ m ; (2)若电枢电路串接1Ω的附加电阻,则τ m 变为多少? (3)若在上述基础上再将电动机励磁电流减小一半,τ m 又变为多少(设磁路没有饱和)?传动系统的过渡过程...
【简答题】When an important holiday comes, I usually think of what gifts to buy or prepare for my family members. It is the act itself rather than the thing you buy 小题1: matters. Either a small present, a text ...