Optimise Response To Setpoint Changes And Determine Mass Inertia - Lenze 8400 StateLine C Reference Manual

8400 StateLine C | Reference manual
Motor control (MCTRL)
Sensorless vector control (SLVC)
The following applies to the reset time Ti (C00074/2) <= 15 ms:
The reduction of the magnetising current in the field weakening range can be adapted via
the override point of field weakening (C00080):
C00080

frequencies. Here, there is a risk of the motor being magnetised too much and having
too little voltage reserve for the torque-creating current.
C00080

frequencies.

Note!
A function for enabling a stable operation can only be implemented to a limited
extent with a reset time Ti <= 15 ms For applications with speeds above the 2-
fold rated speed, we recommend a reset time Ti (C00074/2) > 15 ms.
5.7.4.5

Optimise response to setpoint changes and determine mass inertia

Setting the total moment of inertia under
feedforward control. Depending on the application, an adjustment of the setting under
C00273 may be necessary to optimise the response to position/speed setpoint changes by
means of the torque feedforward control.
Without feedforward control:
n, M
C00273 set too high:
n, M

Actual speed value (nMotorSpeedAct_a signal)
Speed setpoint (nSpeedSetValue_a signal)
Speed controller output (nOutputSpeedCtrl_a signal)
[5-12] Typical signal characteristics for different settings of the load moment of inertia
170
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> 0 Hz: The reduction of the magnetising current is shifted to higher field
< 0 Hz: The reduction of the magnetising current is shifted to lower field
Œ

Ž
Œ
Ž
L
C00273 provides the optimum torque
C00273 set too low:
Œ
n, M

Ž
t
Optimum feedforward control:
n, M
Œ

Ž
t
Firmware ≤ 11.00 - DMS 8.0 EN - 10/2011
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