Vdc Control - Siemens Sinamics S110 Function Manual

Drive functions
7.1 Servo control
7.1.14

Vdc control

Description
Vdc control can be activated if overvoltage or undervoltage is present in the supply voltage.
This prevents a fault from occurring due to the supply voltage and ensures that the drive is
always ready to use.
This function is activated by means of the configuration parameter (p1240). It can be
activated if an overvoltage or undervoltage is present. The torque limit of the motor at which
the Vdc controller is active can be affected if discrepancies in the supply voltage are
significant enough. The motor may no longer be able to maintain its setpoint speed or the
acceleration/braking phases could be prolonged.
The Vdc controller is an automatic P controller that influences the torque limits. It only
intervenes when the supply voltage approaches the "upper threshold" (p1244) or "lower
threshold" (p1248) and the corresponding controller is activated via the configuration
parameter (p1240).
An application for the Vdc controller is, for example, as a safety measure in the event of a
power failure (Vdc_min and Vdc_max controller).
The voltage limit values for Vdc control also have an impact on V/f control, although the
dynamic response of Vdc control is slower in this case.
Description of Vdc_min control (p1240 = 2, 3)
Figure 7-22
166
Switching Vdc_min control on/off (kinetic buffering)
Function Manual, 01/2011, 6SL3097-4AB10-0BP3
Function Manual