Siemens SINAMICS G220 - Page 560

How does the converter calculate the load torque?
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Figure14-155 Calculation of the load torque
In the case of small speed changes, the converter calculates the load torque M
L
from the
actual motor torque.
The calculation takes place under the following conditions:
• Speed ≥ p1226
• Acceleration setpoint < 81/s
2
(≙ speed change 480rpm per s)
• Acceleration × moment of inertia (r1493) < 0.9 × p1560
How does the converter calculate the moment of inertia?
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Figure14-156 Calculation of the moment of inertia
In the case of larger speed changes, the converter initially calculates the accelerating torque
M
B
by subtracting load torqueM
L
and friction torque M
R
from motor torque M
M
:
M
B
= M
M
- M
L
- M
R
Functions
14.10Closed-loop drive control
SINAMICS G220 converter
558 Operating Instructions, 04/2024, FW V6.2, A5E51781573B AB