Speed Controller Pre-Control (Integrated Pre-Control With Balancing) - Siemens SINAMICS G150 Operating Instructions Manual

Setpoint channel and closed-loop control
7.4 Vector speed/torque control with/without encoder
7.4.3.1

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 to the current controller/the current controller is
pre-controlled using adaptation elements directly as additive reference variable (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 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.
Figure 7-15
When correctly adapted, when accelerating, the speed controller only has to compensate
disturbance variables in its control loop. This is achieved with a relatively minor controlled
variable change at the controller output.
396
p1400.2
p 1495
1
0
1 )
p 1428 p 1429
r 1084
-
Speed controller with pre-control
p 0341 p 0342
r 1518
K
p
p 1496
1 )
=0
+
>0
-
) 2
T
i
SLVC :
T
VC :
i
r 1515
T
n
r 1538
r 0079
r 1547 [ 0 ]
r 1547 [ 1 ] r 1539
) 2
T K
p
i
p 1452 p 1470 p 1472
p 1442 p 1460 p 1462
Converter cabinet units
Operating Instructions, 03/2012, A5E03263466A
T
n