Speed Controller Pre-Control And Reference Model - Siemens SINAMICS S120 Function Manual

Operating Modes
Vector control
3.2.5

Speed controller pre-control and reference model

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 calculated as follows:
mv + p1496
The torque setpoint is switched/pre-controlled directly to the current controller via
adaptors as supplementary command variables (enabled via p1496).
The motor moment of inertia p0341 is calculated directly during commissioning or
when the entire set of parameters is calculated (p0340 = 1). The factor p0342 bet-
ween the total moment of inertia J and the motor moment of inertia must be deter-
mined manually or by means of speed controller optimization. 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 %.
When p1400.2 = p1400.3 = 0, pre-control balancing is set automatically.
p 1400 .2
p 1495
r 1084
–
Speed Setpoint
Actual speed
1) Only effective for p 1400 .2 = 1
2) Only effective for p 1400 .2 = 0
Fig. 3-32 Speed controller with pre-control
3-132
dn
+ p1496
J
dt
Acceleration pre-control
p 0341 p 0342
1
0
p 1496
1) 1)
p 1428 p 1429
=0
>0
) 2
T
i
T
i
dn
p0341 p0342
dt
Droop
injection
r 1515
r 1518
K
T
p
n
PI speed
r 1547 [0]
controller
–
r [1]
1547
) 2
T
i
SLVC: p 1452
VC : p 1442
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
r 1538
r 0079
Torque
setpoint
r
1539
T
K
p n
p 1470 p 1472
p 1460 p 1462