
Ignoring the effect of armature inductance, that is, assuming L ¼0 in Equations 6.255 and 6.258,
yields a first-order model of the motor with transfer functions
V(s)
E
0
(s)
¼
K
T
JRs þ RB þ K
b
K
T
(6:273)
I(s)
E
0
(s)
¼
Js þ B
JRs þ RB þ K
b
K
T
(6:274)
Hence, the motor can be modeled as a first-order component
V(s)
E
0
(s)
¼
K
m
t
m
s þ 1
(6:275)
with time constant t
m
¼t
2
¼0.375 s and K
m
¼ 3:3
3 rad=s=V.
(f) The Simulink diagram for the step responses of the first- and second-order system models using
Euler integration is shown in Figure 6.33.
The simulated responses of the motor to a unit step input in armature voltage occurring at
t ¼0.25 s are shown in Figure 6.34. Euler integration ...