Compound Braking; Compound Braking Current - Siemens MICROMASTER 440 Parameter Manual

Parameter Description
3.26

Compound braking

P1236[3]

Compound braking current

CStat: CUT
P-Group: FUNC
Defines DC level superimposed on AC waveform after exeeding DC-link voltage threshold of compound
braking. The value is entered in [%] relative to rated motor current (P0305).
If P1254 = 0 :
Compound braking switch-on level
otherwise :
Compound braking switch-on level
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.
Without Compound braking
f
 f_set
i
u
DC-link
Index:
P1236[0] : 1st. Drive data set (DDS)
P1236[1] : 2nd. Drive data set (DDS)
P1236[2] : 3rd. Drive data set (DDS)
Value:
P1236 = 0 :
Compound braking disabled.
P1236 = 1 - 250 :
Level of DC braking current defined as a [%] of rated motor current (P0305).
Dependency:
Compound braking depends on the DC link voltage only (see threshold above). It will be active with
OFF1/OFF3 and at regenerating conditions.
It is disabled, when:
- DC braking is active
- Flying start is active
- Vector mode (SLVC, VC) is selected
Notice:
Increasing the value will generally improve braking performance; however, if you set the value too high, an
overcurrent trip may result. If used with dynamic braking enabled as well compound braking will take
priority. If used with the Vdc max controller enabled the drive behaviour whilst braking may be worsened
paticularly with high values of compound braking.
Compound braking does not function when the drive is in vector control.
146
Datatype: U16
Active: Immediately
P1236 = 0
f

f_act
t
t
U
DC_Comp
t
Unit: %
QuickComm.: No
= ⋅ ⋅
U 1.13 2 V
DC_Com p
= ⋅
U 0.98 r 1242
DC_Comp
P1236 > 0
With Compound braking
f_set
f_act
i
u
DC-link
MICROMASTER 440
Issue 01/06
Level
Min: 0
2
Def: 0
Max: 250
= ⋅ ⋅
. 1 13 2 P0210
m ains
t
t
t
Parameter List
6SE6400-5BB00-0BP0