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Lenze · 8400 HighLine · Reference manual · DMS 12.0 EN · 06/2017 · TD23
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5
Motor control (MCTRL)
5.8
Sensorless control for synchronous motors (SLPSM)
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Other functions for differential setpoint feedforward control
From version V12.00.00 onwards,
the following additional functions are available for differential
setpoint feedforward control (torque feedforward control):
, the sensitivity of setpoint feedforward control can be adapted.
, alternatively to the
nSpeedSetValue_a
process signal, the new
nSpeedSetValueInertia_a
process signal for the setpoint feedforward control can be selected at
the
nSpeedSetValueInertia_a
process signal, an optional input
value (e.g. setpoint of the position or process controller) for the torque feedforward control can
be specified.
• For
bTorqueModeOn
= TRUE, the setpoint feedforward control is added to the torque setpoint
nTorqueSetValue_a
. In this way, feedforward control of torque is also possible for torque-
controlled operation (e.g. for winder applications).
Stop!
In the Lenze setting of
, the speed setpoint of the speed controller
(
nSpeedSetValue_a
) is used for the torque feedforward control which is why it is also
called "differential setpoint feedforward control". A very sharp change of the speed
setpoint at the speed controller thus causes a strong torque impulse at the machine!
Causes for a very sharp change of the speed setpoint of the speed controller:
• A control creates the setpoint ramp itself and the speed setpoint is only written every
20 ms to the drive. (In this case, the speed setpoint is changed every 20 ms.)
• Recommendation: Deactivate the torque feedforward control for the speed
if the speed setpoint changes very sharply or the mass inertia
is unknown (e.g. in case of hoists)!
• The reference speed
is much higher than the rated motor speed set in
• Recommendation: Deactivate the torque feedforward control for the speed
setpoint in
if the reference speed
5 times higher than the rated
motor speed
.