1
05.01
1.3 Engineering a drive
1-34
©
Siemens AG 2012 All Rights Reserved
SIMODRIVE 611 Configuration Manual (PJU) – 02/2012 Edition
1.3.2
Dynamic operation
The peak infeed power must also be calculated for acceleration and decelera-
tion operations.
S
Feed axes
The peak infeed power expected for feed axes can be roughly calculated
according to the following formula:
P
S FD
= 0.6 V
DC link
⋅
I
max
⋅
ñ/n
N
⋅
10
–3
[kW]
Where:
P
S FD
peak infeed power (calculated) [kW] for feed axes
0.6
empirical factor: DC link energy and
and EMF of the motor are taken into account
V
DC link
DC link voltage [V] (600 V)
I
max
peak current [A] set for an axis
ñ/n
N
max. axis speed referred to the
motor rated speed
S
Feed axes with linear motors
P
S FD
=
F
MAX
⋅
V
MAX, FMAX
+ (I
MAX
/I
N
)
2
⋅
P
VN
[kW]
= 0.5 ... 0.9
⋅
U
ZK
⋅
I
MAX
⋅
v/V
MAX, FMAX
~
⋅
10
–3
[kW]
Where:
F
MAX
maximum force [N]
V
MAX, FMAX
maximum velocity at the maximum force [m/min]
I
max
peak current [A] set for an axis
I
N
rated current [A] set for an axis
P
VN
rated motor power loss [kW]
v/V
MAX, FMAX
max. axis velocity referred to the maximum velocity at the
maximum force
~
S
Main spindles
The peak infeed power expected for main spindles is calculated according
to the following formula:
–
Motors
v
4 kW
P
S MSD
=
1.45
⋅
P
S motor shaft MSD
[kW]
–
Motors
> 4 kW
P
S MSD
=
1.25
⋅
P
S motor shaft MSD
[kW]
Where:
P
S MSD
peak power (calculated) for main spindles [kW]
1.25 or 1.45
factor to take into account the motor efficiency
P
S motor shaft MSD
peak power [kW] used at the shaft of the
main spindle motor
1 Overview of the Drive System
10.04