Minimum Dc-Link Voltage Limit - Siemens Sinamics G120P Operating Instructions Manual

Functions
7.6 Protection functions
Parameters of the Vdc_max control
There are two different groups of parameters for the Vdc_max control, depending on whether
the motor is being operated with V/f control or vector control.
Parameters for
vector control
p1240 = 1
r1242
p1243
---
p1250
p1251
p1252
p1254
p0210
For more information about this function, see the List Manual (function block diagrams 6320
and 6220).
7.6.6

Minimum DC-link voltage limit

With this function, the kinetic energy of the motor is used for buffering the DC-link voltage in
the event of a momentary power failure, thereby decelerating the drive.
Typical cause: Line voltage failure
Remedy: Specify a regenerative torque for the rotating drive to compensate the existing
losses, thereby stabilizing the voltage in the DC link. This process is known as kinetic
buffering.
Kinetic buffering is only possible as long as energy is generated by the movement of the
drive.
370
Parameters for Description
V/f control
p1280 = 1 Vdc_max control Vdc monitoring configuration (factory setting:
1)
1: V
DC max
r1282 V
DC max
Shows the value of the DC-link voltage above which the V
control is active
p1283 V
DC max
Scaling closed-loop control parameters p1290, p1291 and
p1292
p1284 V
DC max
Sets the monitoring time of the V
p1290 V
DC max
p1291 V
DC max
40 ms)
p1292 V
DC max
ms)
p1294 V
DC max
p1254: 1, p1294: 0)
Activates or deactivates automatic detection of the switch-on
levels of the V
0: Automatic detection disabled
1: Automatic detection enabled
p0210 Unit supply voltage
If p1254 or p1294 = 0, the inverter uses this parameter to calcu-
late the intervention thresholds of the V
Set this parameter to the actual value of the input voltage.
control enabled
control switch-on level
control dynamic factor (factory setting: 100 %)
controller time threshold
DC max
control proportional gain (factory setting: 1)
control integral time (factory setting p1251: 0 ms, p1291:
control rate time (factory setting p1252: 0 ms, p1292: 10
control automatic sensing ON-signal level(factory setting
control.
DC max
Operating Instructions, 12/2014, A5E32923362A
DC max
controller
control.
DC max
Inverter cabinet units