Siemens SINAMICS S120 Function Manual page 130

Vector control
4.7 Torque control
Figure 4-11
The total of the two torque setpoints is limited in the same way as the speed control torque
setpoint. Above the maximum speed (p1082), a speed limiting controller reduces the torque
limits in order to prevent the drive from accelerating any 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 (integration time ~ p1499 x p0341 x
p0342). For this reason, sensorless torque control 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.
OFF responses
● OFF1 and p1300 = 22, 23
● OFF1, p1501 = "1" signal and p1300 ≠ 22, 23
130
p1503[C]
(0)
p1501
[FP2520.7] r1406.12
p1511[C]
(0)
p1512[C]
(0)
p1513[C]
(0)
Closed-loop speed/torque control
– Reaction as for OFF2
– No separate braking response; the braking response takes place by a drive that
specifies the torque.
– The pulses are suppressed when the brake application time (p1217) expires. Standstill
is detected when the actual speed value is less than the speed threshold (p1226) or
when the monitoring time (p1227) that started when speed setpoint ≤ speed threshold
(p1226) has expired.
– Power-on disable is activated.
K
T
p
n
0
-
T
i
1
1
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
r1538
r1547[0]
r1547[1]
r1539
r1407.2
r1515
r0079
Drive Functions