Fig.15-20:
Storable Energy in DC Bus
15.1.6
Continuous Regenerative Power
In terms of average period of time, the sum of the continuous re‐
generative power of all drives mustn't exceed the allowed continu‐
ous power of the regenerative device (regeneration of supply
units or braking resistors of converters).
In applications with servo drives at typical NC machine tools, machining time
is relatively long relative to the cycle time. Accordingly, the continuous regen‐
erative powers are small. For this type of applications, exact calculation is not
required. It is sufficient to make sure that the regenerative peak power is not
exceeded.
Exact calculation is required, for example, for one of the following applica‐
tions:
●
Applications with servo drives which are characterized by many acceler‐
ation and deceleration processes (e.g. nibbling machines or roll feeds)
●
Machine tools with modular main drive
●
Applications which involve lowering of large masses, e.g. loading
bridges, warehousing and transport systems
Before the continuous regenerative power can be calculated, the rotary ener‐
gy of the drives and the potential energy of non-balanced masses must be
calculated.
W
rot
Rotary energy [Ws]
n
eil
Speed at rapid traverse rate [min
-1
]
J
g
Inertia (motor + load) [kgm²]
z
Number of braking processes per cycle
Fig.15-21:
Rotary Energy of the Drives
DOK-INDRV*-SYSTEM*****-PR06-EN-P
Rexroth IndraDrive Drive Systems with HMV01/02 HMS01/02, HMD01, HCS02/03
Bosch Rexroth AG
255/309
Calculations
