3 optimising torque controller, 5motor interface, Stop – Lenze 9400 User Manual
Page 176
5
Motor interface
5.5
Sensorless vector control (SLVC)
176
Lenze · Servo-Inverter 9400 HighLine · Reference manual · DMS 10.0 EN · 11/2013 · TD05/06
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Setting of actual speed filter
In order to maximise the dynamics of the speed control loop, the actual speed filter should be
operated with a time constant as low as possible (
). The lower the time constant the higher
the gain of the speed controller. Since actual value filters have the task to dampen measuring errors
or interference components, it must be found a compromise between filter task and the resulting
delay.
If a Lenze motor is selected from the motor catalogue, a time constant is automatically preset in
which serves to operate the motor even with a faulty detection (e.g. in case of a bad shield
connection).
When using EMC-compliant systems or high-quality encoders, you can reduce the preset time
constant considerably. For this purpose, the running noise of the motor can be used for setting
at constant speed.
If this is not possible, e.g. due to a too loud environment or because the motor is too far away, the
noise of the actual speed value or the setpoint torque value can be used for evaluation by means of
. Please observe that the speed controller gain Vp (
) in is used for the torque
setpoint.
5.5.3.3
Optimising torque controller
To optimise the torque controller a steep speed ramp is required which reaches into the field
weakening range (e.g. 1.2 * rated speed). For this purpose, the drive must be operated at its current
and voltage limit.
The gain (
) of the torque controller are to be set so that the actual
cross current can preferably follow the cross current setpoint.
• If oscillations occur during the cross current (see illustration
) is to be
reduced until the drive is stable again (see illustration
• Afterwards the reset time (
) can be reduced as long as the drive accelerates in a stable
way.
Stop!
Reduce the maximum current in
for this adjustment to approx. 130 % of the
motor magnetising current (
) to prevent shocks on the drive!
Note!
If no field weakening operation is required, the adjustment must be executed in the base
speed range.