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KFU 2-/4-
189
Operation mode power failure regulation.
Voltage controller: Parameter
Operation mode
670 = 2
Ud, f
f
671
672
Mains voltage
Standard ramp
or 674
Resumption of power
Power failure
t
U
d
Gradient limited
by 673 or 683
With the power failure regulation, short-term power failures can be bridged. A power
failure is recognized if the DC link voltage has fallen below the set value of the pa-
rameter
Mains failure threshold
671
. If a power failure is recognized, the controller
tries to regulate the DC link voltage to the figure set with the parameter
Reference
mains support value
672
. For this, the output frequency is continuously reduced and
the motor with its rotating masses put into generator operation. The reduction of the
output frequency is done according to the configuration with a maximum of the cur-
rent set by the parameter
Gen. ref. current limit
683
or the ramp
Mains support de-
celeration
673
.
The threshold values of the voltage controller are calculated starting with the current
DC link voltage with the parameters
Mains failure threshold
671
and
Reference
mains support value
672
.
Output signals
Digital signals indicate mains failure and power failure regulation.
179 - Mains failure
1)
13 - Mains failure
2)
Mains failure and power failure regulation – selected via
Operation Mode
670
of the voltage controller.
1)
For linking with inverter functions
2)
For digital output