1.A permanent Magnet DC machine (simple model of Brushless DC Machine)is supplied by 400 V DC Bus through a DC/DC converter. The design values arethe followings; Ke=Kt =0.7, L=0.1 Henry,

R= 1 Ohm, speed wm = 500 rad/s Derive continuous. Obtain the torque produced by this motor (neglect L)b.the instantaneous current equation. (take L into consideration)c. What do you do,in order to reduce the speed by half for keeping the torque constant? Obtain the duty cycle of DC/DC step down converter.

Fig: 1