Operating Instructions ACU
Operation mode power failure regulation.
Voltage controller: Parameter Operation Mode 670 = 2
With mains 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 parameter 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. In field-oriented control methods (2xx, 4xx, 5xx), the output frequency reduction is done
at a current not exceeding the maximum set with parameter Gen. Ref. Current Limit 683.
Gen. Ref. Current Limit 683 is active in Configuration 210, 410, 510 and 610 (FOR and
SERVO).
The threshold values of the voltage controller are calculated starting with the current DC link voltage
with parameters Mains Failure Threshold 671 and Reference Mains Support Value 672.
Mains failure and mains support are signaled via digital signals.
Failure of the mains voltage and power regulation – selected via
Operation Mode 670 of voltage controller.
1)
For linking to frequency inverter functions
2)
For output via a digital output.