Siemens sinumerik 840D sl Function Manual page 370

Detailed description
2.7 Extended stop and retract (ESR)
Example:
For
C= 6000µF (see Table, 1st row) - 20% = 4800 µF
U
Zk
U
min
results in:
E = 1/2 * 4800µF *((550V)
This energy is available under load for a period of
t
min
to initiate emergency retraction.
Where
t
min
P
max
η = efficiency of the drive
For the example above with:
E = 432Ws
P
max
units", 1st line)
η = 0,90
results in:
t
min
as maximum support duration for emergency retraction.
The following table shows a summary of the values for different I/RF units. Nominal and
minimum capacity are taken into account. The maximum possible capacitance (load limit)
consists of the sum of the capacity of the I/RF module and the axis/spindle modules, as well
as the external auxiliary capacitors (to be provided by the user). The minimum capacitance
used in the table takes a component tolerance of -20% into account (worst case).
Table 2-2 Nominal and minimum backup time for different I/RF units
Power P of I/RF max. possible
max
unit [kW] capacity C
16 6000
36 20000
55 20000
80 20000
120 20000
150
=550V (MD1634)
= 350V (assumption)
= E / P * η
max
= buffer period in milliseconds [ms]
= power in kilowatt [kW]
= 16kW (see Table "Nominal and minimal Buffer Times depending on various E/R
= 432Ws / 16kW * 0,9 = 24,3ms
Energy content
[mF] (C ) [Ws]
max max
540
1800
1800
1800
1800
- (350V) ) = 432Ws
2 2
Energy content
(C ) [Ws]
min
432
1440
1440
1440
1440
Backup time t
n
with P [ms]
max
30,38
45,00
29,46
20,25
13,50
Special functions: Axis Couplings and ESR (M3)
Function Manual, 11/2006, 6FC5397-2BP10-2BA0
Buffer time t
min
with P [ms]
max
24,30
36,00
23,56
16,20
10,80