Siemens SINAMICS G150, Operating Instructions Manual

Page: 450 / 680

Setpoint channel and closed-loop control
7.4 Vector speed/torque control with/without encoder
Converter cabinet units
450
Operating Instructions, 07/2016, A5E03347396A
● Kneader drives
Kp (p1470) = 10
Tn (p1472) = 200 … 400 ms
Note
Check speed control gain
We recommend checking the effective speed control gain (r1468) during operation. If this
value changes during operation, the Kp adaptation is being used (p1400.5 = 1). Kp
adaptation can if necessary be deactivated or its behavior changed.
● When operating with encoder (p1300 = 21)
A smoothing value for the actual speed value (p1442) = 5 … 20 ms ensures quieter
operations for motors with gear units.
7.4.4.1 Speed controller pre-control (integrated pre-control with balancing)
Description
The command behavior of the speed control loop can be improved by calculating the
accelerating torque from the speed setpoint and connecting it on the line side of the speed
controller. This torque setpoint mv is applied directly as an additive reference variable on the
input side/supply side of the current controller by means of adaptation elements (enabled via
p1496).
The torque setpoint (mv) is calculated from:
mv = p1496 x J x (dn/dt) = p1496 x p0341 x p0342 x (dn/dt)
The motor moment of inertia p0341 is calculated when commissioning the drive system. The
factor p0342 between the total moment of inertia J and the motor moment of inertia must be
determined manually or by optimizing the speed controller. The acceleration is calculated
from the speed difference over the time dn/dt.
Note
When using speed controller optimization
When speed controller optimization is carried out, the ratio between the total moment of
inertia and that of the motor (p0342) is determined and acceleration pre-control scaling
(p1496) is set to 100 %.
If p1400.2 = p1400.3 = 0, then the pre-control balancing is automatically set.