W
R,Anlage
Generated regenerative power of the installation
W
R,Geräte
Allowed regenerative power of the devices
Fig.15-15:
Supply Condition: Regenerative Power
Influence of efficiency
The energy absorption occurring in the steady-state condition in
the majority of cases is less than the calculated energy absorp‐
tion, because all involved components (such as load, gear, motor,
cables) absorb a part of the regenerative power.
Only reduce the generated regenerative power when the efficien‐
cy behavior is known.
Energy Absorption of Braking Re‐
sistor
Within the minimum cycle time T
cycl
, the braking resistor dissipates the electri‐
cally absorbed energy to its environment as heat. The braking resistor makes
available the energy absorption during its duty cycle. The energy absorption
is calculated as follows:
W
R
Absorbed regenerative power
t
on
Allowed duty cycle
P
BS
Allowed peak power of braking resistor
P
BD
Allowed continuous power of braking resistor
T
cycl
Allowed cycle time
Fig.15-16:
Energy Absorption of Braking Resistor
Energy absorption capacity with long cycle times
For cycles with "T > 5 × T
cycl
", the indicated maximum regenera‐
tive power to be absorbed W
R_max
can be used.
Several braking resistors (e.g. HLR) at common DC bus
With several braking resistors at the DC bus, the available energy
absorption is determined as the sum of the individual energy ab‐
sorptions. For this purpose, the same switch-on threshold must
take effect for all involved braking resistors.
Adjustment of switch-on threshold!
For the adjustment of the switch-on threshold, see also the follow‐
ing parameters:
●
P-0-0833, Braking resistor threshold
●
P-0-0858, Data of external braking resistor
15.1.5
Reduction of Generated Power Dissipation - Additional External Ca‐
pacitors at DC Bus
When the drive brakes, the rotary energy present in the mechanical system is
released as regenerative power in the DC bus of the drive controller or group
of drive controllers. It can
Bosch Rexroth AG
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
252/309
Calculations
