Siemens SINAMICS G110M Operating Instructions Manual page 307

At low speeds, the converter calculates the load torque M
The calculation takes place under the following conditions:
• Speed ≥ p1226
• Acceleration setpoint < 8 1/s
• Acceleration × moment of inertia (r1493) < 0.9 × p1560
How does the converter calculate the moment of inertia?
Figure 8-62
For higher speed changes, the converter initially calculates the accelerating torque M
difference between the motor torque M
M = M
B
Moment of inertia J of the motor and load is obtained from the accelerating torque M
angular acceleration α (α = rate at which the speed changes):
J = M
If all of the following conditions are met, the converter calculates the moment of inertia:
①
•
– The sign of M
– M
②
•
• The converter has calculated the load torque in at least one direction of rotation.
• Acceleration setpoint > 8 1/s
③
The converter calculates the load torque again after acceleration.
Distributed converter for SIMOGEAR geared motors
Operating Instructions, 10/2020, FW V4.7 SP13, A5E31298649B AL
Calculating the moment of inertia
- M - M
M L R
/ α
B
The rated accelerating torque M
is the same as the direction of the actual acceleration
B
> p1560 × rated motor torque (r0333)
B
speed > p1755
(≙ speed change 480 rpm per s)
2
, load torque M
M
must satisfy the following two conditions:
B
(≙ speed change 480 rpm per s)
2
Advanced commissioning
8.19 Motor control
from the actual motor torque.
L
and frictional torque M
L
as
B
:
R
and
B
305