
11-6 Power Electronics and Motor Drives
i I t
Lc m
= − +
cos ω
π
φ
2
3
(
11.2c)
where E
m
(I
m
) and ω are amplitude of the phase voltage (current) and angular frequency, respectively.
Line-to-line input voltages of PWM converter can be described as
u S S u
Sab a b dc
= − ⋅( )
(
11.3a)
u S S u
Sbc b c dc
= − ⋅( )
(
11.3b)
u S S u
Sca c a dc
= − ⋅( )
(11.3c)
where
S
x
= 1 when the upper transistor of one leg in converter is switched ON (x = a, b, c)
S
x
= 0 when the lower transistor of one leg in converter is switched ON (x = a, b, c)
e phase voltages are equal:
u f u
Sa a dc
= ⋅
(11.4a)
u f u
Sb b dc
= ⋅
(11.4b)
u f u
Sc c dc
= ⋅
(11.4c)
where
f
S S S
a
a b c
=
− +2
( )