Vdc_Max Controller (Voltage Limitation) - Siemens SINAMICS G220 Operating Instructions Manual

Functions
14.10 Closed-loop drive control
p1281[0...n].0...2
p1285[0...n]
r1286
p1287[0...n]
p1295[0...n]
p1296[0...n]
p1297[0...n]
r1298
p1390[0...n]
p1391[0...n]
p1392[0...n]
14.10.4.4

Vdc_max controller (voltage limitation)

Overview
The Vdc_max control limits the DC link voltage in the converter and prevents unwanted
switching off of the motor.
Requirement
The Vdc_max control is suitable for applications with short-time generator operation of the
motor, e.g. pumps or fans.
Excluding applications with continuous generator operation of the motor, e.g. hoists or
centrifuges.
Description of function
If the converter cannot transfer the electrical energy delivered by the motor during braking, e.g.
to a braking resistor, the converter stores the energy in its DC link capacitors. This causes the DC
link voltage Vdc in the converter to increase.
An excessively high DC link voltage damages the converter as well as the motor.
The Vdc_max control extends the ramp-down time of the motor when braking.
Consequently, the motor feeds only so much energy back into the converter to cover the
losses in the converter. The DC link voltage remains in the permissible range.
The following figure illustrates the motor and converter protection in the case of overvoltage.
500
Vdc controller configuration
Vdc_min controller switch-in level (kinetic buffering) (U/f)
Vdc_min controller switch-in level (kinetic buffering) (U/f)
Vdc_min controller dynamic factor (kinetic buffering) (U/f)
Vdc_min controller time threshold (U/f)
Vdc_min controller response (kinetic buffering) (U/f)
Vdc_min controller speed threshold (U/f)
Vdc controller output (U/f)
Vdc_min controller proportional gain (U/f)
Vdc_min controller integral time (U/f)
Vdc_min controller rate time (U/f)
Operating Instructions, 04/2024, FW V6.2, A5E51781573B AB
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SINAMICS G220 converter