Siemens SINAMICS G120C DP User Manual

8.20.3.5 Moment of inertia estimator
Overview
From the load moment of inertia and the speed setpoint change, the converter calculates the
accelerating torque required for the motor. Via the speed controller precontrol, the accelerating
torque speci󹪝es the main percentage of the torque setpoint. The speed controller corrects
inaccuracies in the precontrol (feed-forward control).
6SHHGVHWSRLQW
7RUTXHDFWXDOYDOXH
7RUTXH
VHWSRLQW
6SHHGFRQWUROOHU
7RUTXHSUHFRQWURO
6SHHGDFWXDOYDOXH
$FFHOHUDWLQJWRUTXH
0RPHQWRILQHUWLD
HVWLPDWRU
0RPHQWRILQHUWLD
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.
3
7
1
Figure8-55 In󹪞uence of the moment of inertia estimator on the speed control
The more precise the value of the moment of inertia in the converter, the lower the
overshoot after speed changes.
6HWSRLQW
6SHHG
6HWSRLQW
6SHHG
,QDFFXUDWHYDOXHRIWKHPRPHQWRILQHUWLD
LQWKHLQYHUWHU
7KHPRPHQWRILQHUWLDYDOXHLQWKHLQYHUWHU
FRUUHVSRQGVWRUHDOLW\
WW
Figure8-56 In󹪞uence of the moment of inertia on the speed
Function description
The converter calculates the total moment of inertia of the load and motor. The calculation
comprises the following components:
• Current speed
• Actual motor torque
• Reduce the load
Advanced commissioning
8.20Motor control
SINAMICS G120C Converters
Operating Instructions, 02/2023, FW V4.7 SP14, A5E34263257B AK 319

Siemens SINAMICS G120C DP Specifications

General

Protection Rating	IP20
Frequency Range	0 to 650 Hz
Control Modes	V/f, sensorless vector control
Communication Interfaces	PROFIBUS DP
Ambient Temperature	-10 to +50 °C (without derating), -10 to +60 °C (with derating)
Overload Capacity	150 % rated current for 60 s, 200 % rated current for 3 s
Storage Temperature	-40 to +70 °C
Relative Humidity	5% to 95% (non-condensing)
Voltage Range	200 V to 240 V (±10%), 380 V to 480 V (±10%)
Output Voltage	0 V to Supply Voltage