Parameter list
7.2 Parameter list
SINAMICS V20 Inverter
Operating Instructions, 07/2012, A5E03728167
173
Parameter
Function
Range
Factory
default
Can be
changed
Scaling
Data
set
Data
type
Acc.
Level
Note:
P1227 = 300.0: function is deactivated
P1227 = 0.0: pulses are locked immediately
If P1217 > P1227, P1227 will take precedence.
P1230[0...2] BI: Enable DC braking
-
0
U, T
-
CDS
U32 /
Bin
3
Enables DC braking via a signal applied from an external source. Function remains active while external
input signal is active. DC braking causes the motor to stop rapidly by applying a DC braking current
(current applied also holds shaft stationary).
When the DC braking signal is applied, the inverter output pulses are blocked and the DC current is not
applied until the motor has been sufficiently demagnetized. This delay time is set in P0347
(demagnetization time). If this delay is too short, overcurrent trips can occur. The level of DC braking is set
in P1232 (DC braking current - relative to the rated motor current) which is set to 100 % by default.
Caution:
With the DC braking, the kinetic energy of the motor is converted into heat in the motor. The inverter could
overheat if it remains in this status for an excessive period of time!
P1232[0...2] DC braking current [%]
0 - 250
100
U, T
-
DDS
U16
2
Defines level of DC current relative to rated motor current (P0305). The DC braking can be issued
observing the following dependencies:
•
OFF1 / OFF3 ==> see P1233
•
BICO ==> see P1230
P1233[0...2] Duration of DC braking
[s]
0.00 -
250.00
0.00
U, T
-
DDS
Float 2
Defines duration for which DC braking is active following an OFF1 or OFF3 command.
When an OFF1 or OFF3 command is received by the inverter, the output frequency starts to ramp to 0 Hz.
When the output frequency reaches the value set in P1234, the inverter injects a DC braking current
P1232 for the time duration set in P1233.
Caution:
See P1230
Notice:
The DC braking function causes the motor to stop rapidly by applying a DC braking current.
When the DC braking signal is applied, the inverter output pulses are blocked and the DC current not
applied until the motor has been sufficiently demagnetized (demagnetization time is calculated
automatically from motor data).
Note:
P1233 = 0 means that DC braking is not activated.
P1234[0...2] DC braking start
frequency [Hz]
0.00 -
599.00
599.00
U, T
-
DDS
Float 2
Sets start frequency for DC braking.
When an OFF1 or OFF3 command is received by the inverter, the output frequency starts to ramp to 0 Hz.
When the output frequency reaches the value set in start frequency of DC braking P1234, the inverter
injects a DC braking current P1232 for the time duration set in P1233.
P1236[0...2] Compound braking
current [%]
0 - 250
0
U, T
-
DDS
U16
2
Defines DC level superimposed on AC waveform after exceeding DC-link voltage threshold of compound
braking. The value is entered in [%] relative to rated motor current (P0305). Compound braking switch-on
level (V_DC,Comp):
If P1254 = 0 --> V_DC,Comp = 1.13 * sqrt(2) * V_mains = 1.13 * sqrt(2) * P0210
otherwise V_DC,Comp = 0.98 * r1242
The Compound Brake is an overlay of the DC brake function with regenerative braking (effective braking at
the ramp) after OFF1 or OFF3. This enables braking with controlled motor frequency and a minimum of
energy returned to the motor. Through optimization of the ramp-down time and the compound braking an
efficient braking without additional HW components is possible.
