Voltage matching
Working range of the voltage matcher
If the bus voltage U_BUS is between settings
Minimum voltage and Maximum
voltage and the generator voltage U_GEN is greater than the setting Dead voltage
value, the adjusting commands are released. The direction of the adjusting
commands depends on the polarity of ΔU. As an additional condition, both
frequencies must be in the range f
n
±5 Hz.
U_BUS
Busbar
U_GEN
Generator
0
Dead voltage value
Range for no-voltage lines
(Dead bus)
Adjusting
commands blocked
A
d
ju
sti
n
g
c
o
mm
an
d
s
blocke
d
Rai
s
e adju
st
ing
c
o
mmands
(RAISE_U
)
Minimum voltage
Minimum voltage
Maximum voltage
Maximum voltage
Nominal voltage (Un), 1 P.U.
A
d
ju
sti
n
g
co
mm
and
s
relea
se
d
A
d
ju
sti
n
g
c
o
m
m
a
n
d
s
bloc
ked
L
o
w
e
r
a
d
justing
comma
n
ds
(LO
W
ER
_
U
)
Di
rection
of
the
adjus
ting
co
mm
and
s
d
e
p
e
nds
o
n
polarity
of
the
∆
U
Figure 864: Working range of the voltage matcher
If
Auto Syn mode is set to either "Semi-automatic synchronizing mode" or
"Automatic synchronizing mode", the voltage raise or lower command pulses are
generated from the function based on the voltage difference across the breaker
and AVR response characteristics. If the voltage difference (ΔU) is negative, it
means the reference side voltage is greater than the running side voltage. So
the voltage matching generates the voltage raise command pulse
RAISE_U
. If the
voltage difference (ΔU) is positive, it means the reference side voltage is lower
than the running side voltage. So the voltage matching generates the voltage lower
command pulse
LOWER_U
.
1MRS759142 F
Control functions
REX640
Technical Manual
1571