Siemens 6MD85, Manual

Page: 393 / 1256

with:
dV
Measured value
Measured differential voltage
dV per second
Parameter for default speed of set point value change
The following figure shows the effect of the functionality. When the voltage range limits fall short by approxi-
mately 1/8 of the voltage range, the stage no longer issues any voltage balancing commands.
[dw_build_voltage-adjusting-com, 1, en_US]
Figure 6-80 Generation of Balancing Commands for Voltage
Balancing Commands for Frequency
The parameters
Max. frequency diff. f2>f1
and
Max. frequency diff. f2<f1
are used to deter-
mine the frequency band that defines the admissible frequency difference for asynchronous parallel
switching. The set point value for the balancing commands is not the middle of the frequency band, but the
value defined with the parameter
Δf set point for balancing
. If you specify a positive value, the
generators are supersynchronously switched in parallel to the network and can immediately transmit active
power to the network.
The parameters
T f pulse min
and
T f pulse max
define the minimum and maximum duration of the
balancing pulse. The parameter
df/dt of the controller
defines the speed for the set point value
change of the frequency control. The functionality uses the measured current frequency difference and the
setting value of the parameter to determine the actuating time. The following equation applies:
[fo_frequency-adujsting-command, 1, en_US]
with:
df
Measured value
Measured differential frequency
Δf set point for
balancing
Parameter for default set point value for the frequency balancing
commands
df/dt of the controller
Parameter for default speed of set point value change
The following figure shows the effect of the functionality.
Control Functions
6.4 Synchronization Function
SIPROTEC 5, High-Voltage Bay Controller, Manual 393
C53000-G5040-C015-9, Edition 11.2017