A permanent magnet DC motor, whose parameters are shown below, is fed from a DC-DC full bridge converter:
System Parameter Value
Ra 2 Ohm
La 5mH
Jeq 15X10-4kg.m2
B 0
KE 0.4V/(rad/s)
KT 0.3N.m/A
VDC 180V
Vtri 5V
fs 30kHz
The reference speed is 1000rad/s and the load torque is 4Nm.
For the DC Motor above, design in MatLab/Simulink a closed loop feedback system such that the systems response is just critically damped.
Show plots of speed, armature current, armature voltage and torque due to step change up of 500rad/s and then step down of 800rad/s in the speed command from its default reference speed (1000rad/s). Magnify the waveforms at the transition.
Show plots of speed, armature current, armature voltage and torque due to a step change up of 3 Nm in the load toque and then due to a step change down of 5 N.m from its default load torque (4N.m). (in this case default speed is 1000rad/s). Magnify the waveforms at the step change.
