Siemens SINAMICS G115D Operating Instructions Manual page 273

Preconditions
• You have selected encoderless vector control.
• The load torque must be constant whilst the motor accelerates or brakes.
Typical of a constant load torque are conveyor applications and centrifuges, for example.
Fan applications, for example, are not permitted.
• The speed setpoint is free from superimposed unwanted signals.
• The motor and load are connected to each other in a force-locked way.
Drives with slip between the motor shaft and load are not permitted, e.g. as a result of
loose or worn belts.
If the conditions are not met, you must not activate the moment of inertia estimator.
Procedure
1. Set p1400.18 = 1
2. Check: p1496 ≠ 0
3. Activate the acceleration model of the speed controller pre-control: p1400.20 = 1.
You have activated the moment of inertia estimator.
❒
The most important settings
Parameter
r0333[0...n]
p0341[0...n]
p0342[0...n]
p1400[0...n]
SINAMICS G115D distributed drive
Operating Instructions, 12/2020, FW V4.7 SP13, A5E48681219B-002
Description
Rated motor torque [Nm] Displays the rated motor torque.
Motor moment of inertia
[kgm ]
2
Ratio between the total and
motor moment of inertia
Speed control configura-
tion
Setting
Sets the motor moment of inertia (without load).
Note: The converter sets the parameter when selecting a
listed motor. The parameter is then write-protected.
Factory setting: 0
Sets the ratio of moment of inertia load + motor to mo-
ment of inertia of motor without load.
Factory setting: 1
Sets the configuration for the closed-loop speed control.
.18 1 signal: Moment of inertia estimator active
.20 1 signal: Acceleration model on
.22 1 signal: Moment of inertia estimator retain value
when motor switched off
.24 1 signal: Shortened moment of inertia estimation is
active.
p1400.24 = 1 reduces the duration of the moment of iner-
tia estimation.
Disadvantage: If the accelerating torque is not constant
while calculating the moment of inertia, the calculation of
the moment of inertia using p1400.24 = 1 is less precise.
Advanced commissioning
6.18 Motor control
271