Operation mode power failure regulation.
Voltage controller: Parameter Operation mode 670 = 2
With the power failure regulation, short-term power failures can be bridged. Mains
failure is detected when the DC link voltage has dropped below the set value of pa-
rameter
Mains Failure Threshold 671
. If a mains failure is detected, the controller
tries to regulate the DC link voltage to the value set with parameter Reference Mains
Support Value
672. To that end, the
output frequency is continuously reduced and
the motor with its rotating masses is switched over to generator operation. Using
field oriented Control (FOC, SERVO) the reduction of the output frequency is done
according to the configuration with a maximum o
f the current set by the parameter
Gen. Ref. Current Limit 683.
Gen. Ref. Current Limit 683 is active in configurations 410 and 610 (FOC and SERVO).
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
Digital signals indicate mains failure and power failure regulation.
Mains failure and power failure regulation – selected via
Operation Mode 670 of the voltage controller.
1)
For linking with inverter functions
If the mains voltage is restored before a switch-off is affected by the mains un-
dervoltage detection system, the drive is accelerated to its reference frequency at the
set acceleration or according to the parameter Acceleration on mains resumption
674. If the value of parameter Acceleration on mains resumption 674
default value of 0.00 Hz/s,
the drive is accelerated at the values set for the ramp
parameters Acceleration (clockwise) 420 or Acceleration (anticlockwise) 422.
06/13 Operating Instructions ACU 213