Dynamic Braking - Siemens MICROMASTER 440 Operating Instructions Manual

3 Functions
WARNING
For compound braking, regenerative braking is superimposed on the DC
braking (braking along a ramp). This means that components of the kinetic
energy of the motor and driven load are converted into thermal energy in the
motor. If this power loss is too high or if the braking operation takes too long,
then this can cause the drive to overheat !
When using compound braking it must be expected that there is a higher level
of noise above the compound braking switch-in threshold.
NOTE
Only active in conjunction with V/f control.
Compound braking is de-activated, if
- flying restart is active,
- DC braking is active, and
- Vector control (SLVC, VC) is selected.
The compound switch-in threshold V
V
DC-Comp
a) Auto-detect circuit enabled (P1254 = 1):
-
-
b) Auto-detect function disabled (P1254 = 0):
-
-
-
3.15.3

Dynamic braking

Parameter range:
Warnings
Faults
Function chart number:
For several drive applications, in certain operating states, the motor can
regenerate. Examples of these applications include:
Cranes
Traction drives
Conveyor belts which transport loads downwards
When the motor is in the regenerative mode, the energy from the motor is fed back
into the DC link of the drive converter via the inverter. This means that the DC link
voltage increases and when the maximum threshold is reached, the drive inverter
is shutdown (tripped) with fault F0002. This shutdown (trip) can be avoided by
using dynamic braking. Contrary to DC and compound braking, this technique
requires that an external braking resistor is installed.
206
≠
(P1254 = 0)
V (P1254 = 1) is automatically calculated when the drive inverter
DC-Comp
runs-up - i.e. after the line supply voltage has been connected
Using the auto-detect function, the V
adapts itself to the line supply voltage at the particular installation
location.
= ⋅ ⋅
U . 1 13 2 P 0210
DC , Comp
The V threshold is immediately re-calculated after entering P0210
DC-Comp
P0210 must be adapted to the particular installation location
P1237
A0535
F0022
-
is dependent on P1254
DC-Comp
≠
V (P1254 0)
DC-Comp
threshold automatically
DC-Comp
MICROMASTER 440
Issue 10/06
Operating Instructions
6SE6400-5AW00-0BP0