Siemens SINAMICS G115D Operating Instructions Manual page 244

Advanced commissioning
6.17 Motor control
Function
From the actual speed, the actual motor torque and the frictional torque of the load, the
converter calculates the total moment of inertia of the load and motor.
When using the moment of inertia estimator, we recommend that you also activate the
friction characteristic.
How does the converter calculate the load torque?
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
242
Friction characteristic (Page 239)
(≙ speed change 480 rpm per s)
2
Operating Instructions, 09/2020, FW V4.7 SP13, A5E48681219B
from the actual motor torque.
L
SINAMICS G115D distributed drive