Limiting The Maximum Dc Link Voltage - Siemens SINAMICS G120 CU230P-2 HVAC Operating Instructions Manual

Functions
7.7 Protection functions
Settings
You only have to change the factory settings of the I
oscillate when it reaches the current limit or it is shut down due to overcurrent.
Table 7- 30
Parameter
P0305
P0640
P1340
P1341
r0056.13
r1343
For more information about this function, see function diagram 1690 in the List Manual.
7.7.5

Limiting the maximum DC link voltage

How does the motor generate overvoltage?
An induction motor operates as a generator if it is driven by the connected load. A generator
converts mechanical power into electrical power. The electric power flows back into the
inverter and causes V
Above a critical DC link voltage both the inverter as well as the motor will be damaged.
Before the voltage can reach critical levels, however, the inverter switches the motor off with
the fault message "DC link overvoltage".
Protecting the motor and inverter against overvoltage
The V
reaching critical levels.
The V
regenerative mode, e.g. in hoisting gear or when large flywheel masses are braked. Further
information on inverter braking methods can be found in Section Braking functions of the
converter (Page 225).
216
I controller parameters
max
Description
Rated motor current
Motor current limit
Proportional gain of the I
Integral time of the I
Status: I controller active
max
Speed output of I
Shows the amount to which the I-max controller reduces the speed.
in the inverter to increase.
DC
controller prevents – as far as the application permits – the DC link voltage from
DCmax
controller is not suitable for applications in which the motor is permanently in the
DCmax
Frequency inverters with Control Units CU230P-2 HVAC, CU230P-2 DP, CU230P-2 CAN
controller for speed reduction
max
controller for speed reduction
max
controller
max
Operating Instructions, 01/2011, FW 4.4, A5E02430659B AD
controller if the drive tends to
max