Lenze 8400 - Manual (Page 211)

Lenze · 8400 protec HighLine · Reference manual · DMS 3.0 EN · 03/2013 · TD05
211
5 Motor control (MCTRL)
5.8 Sensorless control for synchronous motors (SLPSM)
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Optimisation at variable mass inertia
From version V12.00.00 , mass inertia that changes during the process (e.g. a reel) can be taken into
account when optimising the response to setpoint changes.
How to proceed:
1. In C00273 the known constant total moment of inertia (motor, gearbox, shaft, etc.) must be set
or determined according to previous instructions (" How to optimise ... ").
• The determination requires travelling the typical speed profile without variable mass inertia
(e.g. reels).
2. At the LS_MotorInterface SB, the nInertiaAdapt_a process signal must be interconnected in a
way which ensures that a value of "100 %" is applied at this input.
3. In C00919/1 set the known maximum value of the variable moment of inertia or determine the
value according to previous instructions (" How to optimise ... ").
• The determination requires travelling the typical speed profile including variable mass inertia
(e.g. maximum reels).
4. The nInertiaAdapt_a process signal can be used during the process to dynamically control the
percentage of the variable moment of inertia set in C00919/1 which is to be considered for
setpoint feedforward control.
Example:
• If there is no variable moment of inertia (e.g. no reel), the nInertiaAdapt_a process signal
must be set to "0 %".
• If the maximally variable moment of inertia is available (e.g. maximum reels), the
nInertiaAdapt_a process signal must be set to "100 %".

Tip!
Via the nTorqueSetValue_a process signal at the
LS_MotorInterface SB, any differential
signal can be defined for torque feedforward control. First the speed controller, then this
additive torque is connected which is hence not derived from the differential change in
speed setpoint.
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):
• In C00653/1 , the sensitivity of setpoint feedforward control can be adapted.
• In C00654/1 , alternatively to the nSpeedSetValue_a process signal, the new
nSpeedSetValueInertia_a process signal for the setpoint feedforward control can be selected at
the LS_MotorInterface SB. Via 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).