Motor Power Company DUET_FL 48/10, Руководство пользователя

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speed setpoint. This setting applies to most motors which can be operated using the servo positioning
controller. If a harder control response is required, the gain of the speed controller can be increased
further. The gain limit is due to the fact that the drive tends to oscillate at high speed levels or when the
shaft is excited. The gain that can be reached in the speed control circuit depends on the load
conditions at the motor shaft. This is why you have to check the speed controller setting again when
the drive is installed.
If you parameterize the speed controller while the motor shaft runs at no load, you have to
increase the speed controller gain after you have installed the drive.
Optimization strategiesThe behaviour of the speed controller can be observed best by recording its
response to a speed step. Activate the speed control mode and deactivate any ramp functionality
active in the setpoint selector menu. You can realize a speed step, for example, by assigning setpoint
steps through the RS232 interface. Or you can use the setpoint assignment via an analog input which
you have to short-circuit in order to realize a step.
The reaction of the speed controller can be observed using the oscilloscope function (see chapter
Using the oscilloscope function ). You can display the step response of the speed controller by setting
the oscilloscope channels to the actual speed value (rough) and to the speed setpoint value.
Make sure that you do not change the numbers for the gain factor and the time constant
in too large steps. Use small changes.
You should start with a relatively long integration time in the range of 8 ms to 10 ms and
then increase the gain progressively. Only after you have felt your way towards the right
setting by increasing the gain should you reduce the integration time step by step.
After the numbers have been changed, there may be two different situations:
 If the setting is too hard, the speed controller will become unstable.
 If the setting is too soft, the drive will not be rigid enough which will lead to following
errors.
The speed controller parameters are not independent of each other. A measurement
curve which differs from trial to trial can have various reasons. This is why you should
change only one parameter at a time: Either the gain factor or the time constant.
To adjust the speed controller, increase the gain until oscillation starts and then decrease the gain in
small steps until oscillation ceases. Then decrease the time constant until oscillation starts and
decrease it again in small steps until the controller is stable and rigid enough at a setpoint = 0.
Case 1: Speed controller too soft
User Manual DUET_FL „DUET_FL 48/10“ Version 1.1 Motor Power Company