WEG MVW3000 A0040 V023, User Manual

Page: 85 / 125

MVW3000 | 8-7
8
Special Functions
MVW3000 | 8-7
V
VW
V
V
UV
U
W
V
WU
120º
120º
120º
89º
135,5º
13
5,5
º
V
UV
V
VW
V
VW
V
UV
V
WU
W
W
V
WU
120º
120º
12
0º
U
U
Angle adjustment (c)
3 cells of phase W in bypass (b)
Under normal operation
1
0.5
-0.5
0
-1
U V W
UV
WU
VW
V
V
0
√3
-√3
√3/2
-√3/2
Figure 8.7: Phase (center) and line (below) voltage diagrams during a bypass
The graph of Figure 8.8 on page 8-7 shows the line voltage obtained (in p.u) after the bypass of only one cell,
on inverters with 2 to 12 cells per phase (range of possible values for the MVW3000). The situation without the
angle adjustment is compared to the situation with the adjustment. Such comparison presents the line voltage
gain using this control technique.
Cells per phase
with angle adjustment
without angle adjustment
Vo
lta
ge a
ft
er b
yp
as
s (
p.
u)
0.50
0.55
0.60
0.65
0.75
0.70
8
7 6
5
4
3 2
0.80
0.85
0.90
0.95
1.00
Figure 8.8: Voltage after bypass of one cell