Friction Characteristic - Siemens SINAMICS G115D Operating Instructions Manual

Advanced commissioning
6.18 Motor control
6.18.2.4

Friction characteristic

Function
In many applications, e.g. applications with geared motors or belt conveyors, the friction
torque of the load is not negligible.
The converter provides the possibility of precontrolling the torque setpoint, bypassing the
speed controller with the friction torque. The precontrol reduces overshooting of the speed
after speed changes.
The converter calculates the current friction torque from a friction characteristic with 10
intermediate points.
The intermediate points of the friction characteristic are defined for positive speeds. In the negative
direction of rotation, the converter uses the intermediate points with a negative sign.
Recording a friction characteristic
After quick commissioning, the converter sets the speeds of the intermediate points to values
suitable for the rated speed of the motor. The friction torque of all intermediate points is still
equal to zero. On request, the converter records the friction characteristic: The converter
accelerates the motor step by step up to the rated speed, measures the friction torque and
writes the friction torque into the intermediate points of the friction characteristic.
Precondition
The motor is permitted to accelerate up to the rated speed without endangering persons or property.
Procedure
1. Set p3845 = 1: The converter accelerates the motor successively in both directions of
rotation and averages the measurement results of the positive and negative directions.
2. Switch on the motor (ON/OFF1 = 1).
3. The converter accelerates the motor.
During measurement, the converter signals the alarm A07961.
When the converter has determined all the intermediate points of the friction
characteristic without fault code F07963, the converter stops the motor.
You have recorded the friction characteristic.
❒
266
Operating Instructions, 12/2020, FW V4.7 SP13, A5E48681219B-002
SINAMICS G115D distributed drive