Lenze 8400 HighLine - Manual (Page 240)

5 Motor control (MCTRL)
5.9 Servo control (SC)
240
Lenze · 8400 HighLine · Referenzhandbuch · DMS 10.0 EN · 06/2014 · TD05/TD14
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If the mass inertia of the drive is unknown, the optimisation can be achieved as follows:
1. Specify speed setpoint.
2. Increase Vp (
C00070/2 ) until the drive is unstable (observe motor noise).
3. Reduce Vp ( C00070/2 ) until the drive runs stable again.
4. Reduce Vp ( C00070/2 ) to approx. half the value.

Tip!
Values recommended by Lenze for the setting of the (proportional) gain:
• For drive systems without feedback: Vp = 6 … 20
• For drive systems with a good disturbance behaviour: Vp > 12
Speed controller reset time Ti
Apart from setting the P component,
C00071/2 provides the possibility to take influence on the I
component of the PI controller.
If the mass inertia of the drive is unknown, the optimisation can be achieved as follows:
1. Specify speed setpoint.
2. Reduce Ti (
C00071/2 ) until the drive is unstable (observe motor noise).
3. Increase Ti ( C00071/2 ) until the drive runs stable again.
4. Increase Ti ( C00071/2 ) to approx. twice the value.

Tip!
Value range recommended by Lenze for the setting of the reset time:
Ti = 20 ms … 150 ms
Differential time constant Tdn (rate time)
The differential time constant Tdn of the speed controller can be set in
C00072 .
If the mass inertia of the drive is unknown, the optimisation can be achieved as follows:
• Increase Tdn ( C00072 ) during operation until optimal control mode is reached.
Using the ramp response for setting the speed controller
If the mechanical components cannot be operated at the stability limit, the ramp response can also
be used for setting the speed controller.

Stop!
If the controller parameters are preset unfavourably, the control can tend to heavy
overshoots up to instability!
• Following and speed errors can adopt very high values.
• If the mechanics are sensitive, the corresponding monitoring functions are to be
activated.