5motor control (mctrl) – Lenze E84DSxxx User Manual
Page 146
5
Motor control (MCTRL)
5.6
Sensorless vector control (SLVC)
146
Lenze · 8400 protec StateLine · Reference manual · DMS 4.2 EN · 03/2013 · TD05
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The following applies to the reset time Ti (
) <= 15 ms:
The reduction of the magnetising current in the field weakening range can be adapted via the
override point of field weakening (
•
> 0 Hz:
The reduction of the magnetising current is shifted to higher field frequencies. Here, there is a
risk of the motor being magnetised too much and having too little voltage reserve for the
torque-creating current.
•
< 0 Hz:
The reduction of the magnetising current is shifted to lower field frequencies.
5.6.4.5
Optimise response to setpoint changes and determine mass inertia
Setting the total moment of inertia under
provides the optimum torque feedforward
control. Depending on the application, an adjustment of the setting under
may be
necessary to optimise the response to position/speed setpoint changes by means of the torque
feedforward control.
[5-11] Typical signal characteristics for different settings of the load moment of inertia
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 (
) > 15 ms.
Without feedforward control:
set too low:
set too high:
Optimum feedforward control:
Actual speed value (nMotorSpeedAct_a signal)
Speed setpoint (nSpeedSetValue_a signal)
Speed controller output (nOutputSpeedCtrl_a signal)
n, M
t
t
n, M
t
n, M
t
n, M