
12-36 Power Electronics and Motor Drives
e factor K
PWM
that appears in the inner loops represents the dynamic gain introduced by the pulse-
width-modulators. e structure and parameters of the regulators are chosen on the basis of the pole-
zero compensation method, in order to ensure an optimal second-order behavior to the corresponding
closed-loop (i.e., a damping factor equal to 0.707). Considering the numerical values given in Table 12.2,
it yields for the inner loops
H s
s
s s
i d,
( )
, ( . )
( , )
= −
+
+
1 128 44 72
6 28 3
2
2
(12.101)
K
PWM
K
PWM
K
PWM
K
v
K
v
K
i
K
i
+
_
Δv
0,ref
= 0
i
s,d,ref
= 0
∆
v0
G΄
0∆0
(s)
G
΄
0d
(s)
G
΄
0d
(s)
+
+
v
0
H
v
(s)
V
0
+
Inner
controllers
–
Outer voltage