Environmental Engineering Reference
In-Depth Information
L
Pole-A
Pole-B
Pole-C
D3
D5
D1
S1
S3
S5
U
dc
C
a
c
b
S4
S6
S2
D4
D6
D2
0
U
ab
U
co
U
bo
U
ao
B
I
a
U
bc
A
I
b
n
C
I
c
U
ac
U
link
U
mod
U
phase
Figure 6.10 Resonant dc link inverter
Compared to the hard switched VSI inverter, the resonant inverter topologies
do have significant advantages and these have not changed since the inception of
resonant link converters. Table 6.2 is a comparison of the resonant dc link inverter
with a VSI [7].
The key attributes to notice in the comparison of VSI to resonant dc link
inverters are that both are very similar except when it comes to switching losses and
device voltage ratings. The soft switched dc link inverter has significantly lower
switching losses. However, it requires devices with 2.5 pu voltage ratings due to the
resonant
Q
of the dc link. This adds to the cost of the resonant link inverter. The
size of reactive components gives a good hint at the additional cost necessary and
package bulk. For these reasons, the resonant inverters have yet to find application
into hybrid propulsion systems.
