Siemens SINAMICS S120 Function Manual page 124

Operating Modes
Vector control
Speed setpoint
Actual speed value
M_set
p [C]
1503
(0)
p 1 = M _
1501 ctrl active
[ .7] r .
FP 2520 1406 12
M_suppl 1
p [C]
1511
(0)
M_suppl 1 scal
p [C]
1512
(0)
M _suppl 2
p [C]
1513
(0)
Fig. 3-32 Closed-loop speed/torque control
The total of the two torque setpoints is limited in the same way as the speed con-
trol torque setpoint. At speeds in excess of the maximum speed (p1182), a speed
limiter reduces the torque limits to prevent the drive from being accelerated further.
True torque control (with self-adjusting speed) is only possible in closed-loop but
not open-loop control for sensorless vector control (SLVC). In open-loop control,
the torque setpoint adjusts the setpoint speed via a ramp-function generator (in-
tegration time ~ p1499 x p0341 x p0342). For this reason, sensorless torque con-
trol at standstill is only suitable for applications that require an accelerating torque
but no load torque (e.g. traction drives). This restriction does not apply to torque
control with sensor.
3-124
K
T
p n
PI speed
controller
0
--
T
i
1
p1300 = MCtrl
ℵ!Π
M_suppl 2 scal
- - %... %
1 0 000 10 000
p [D .0%)
1514 ] ( 100
r1538
p1547 [0]
r1539
p1547 [1]
r .2
1407
r
1515
© Siemens AG, 2005. All rights reserved
SINAMICS S120 Function Manual, 06/05 Edition
r0079
Torque
setpoint