Compound Braking - Siemens MICROMASTER 420 Operating Instructions Manual

Issue 07/04
3.14.2

Compound braking

Parameter range:
Warnings
Faults
Function chart number:
For compound braking (this is enabled using P1236) DC braking is superimposed
with regenerative braking (where the drive regenerates into the line supply as it
brakes along a ramp). If the DC link voltage exceeds the compound switch-in
threshold V
of P1236. In this case, braking is possible with a controlled motor frequency and
minimum regenerative feedback. Effective braking is obtained without having to
use additional components by optimizing the ramp-down time (P1121 for OFF1 or
when braking from f
Compound braking is suitable for:
Horizontal motion (e.g. traversing drives, conveyor belts)
Vertical motion (e.g. hoisting gear)
Fig. 3-53
The compound braking switch-in threshold V
parameter P1254 (Auto detect V
supply voltage P0210 or indirectly using the DC link voltage and r1242 (refer to the
formula in Fig. 3-53).
MICROMASTER 420 Operating Instructions
6SE6400-5AA00-0BP0
P1236
-
-
-
(refer to Fig. 3-53), then a DC current is impressed as a function
DC-Comp
to f , P1135 for OFF3) and using compound braking P1236.
1 2
P1236 = 0
Without Compound braking
f
f_set
f_act
i
u
DC-link
Compound braking
With Compound braking
f
f_set
t
i
t
u
DC-link
U
DC-Comp
t
P1254 = : 0 U
DC - Comp
P1254 : 0 U
DC - Comp
is calculated as a function of
DC-Comp
switch-on levels) either directly using the line
DC
3 Functions
P1236 >0
f_act
t
t
t
. 1 13 2 P0210
0.98 r 1242
125