KEB COMBIVERT F5-A User Manual

Speed control
© KEB, 2012-10 COMBIVERT F5-A, -E, -H Page 7.7 - 9
7
7.7.3 PT1outputlter
A PT1 low pass lter is series-connected to the speed controller.
Picture 7.7.3 PT1 output lter
PT1
Low pass lter
Speed controller
cS. 29
cS.06...cS.12
active current
setpoint
High frequency oscillations (caused by spring elements in the mechanics of the drive train) can be ltered by
this way from the active current setpoint signal.
The lter time must be adjusted in parameter cS.29 „act. curr. ref. PT1-time“ (cS.29). A longer lter time causes
a stronger smoothing of the active current signal, but also less dynamic control characteristic and increased
oscillation inclination.
An adaptation of the speed controller is required on changing the Pt1-time. This lter is used e.g. for spindles
in order to avoid jumps in the current setpoint at fast load changes.
7.7.4 Acceleration dependent pre-control
If the mass moment of inertia of a drive is known it can be calculated which torque is required to accelerate the
drive. This function is activated, if a value unequal 0 is entered in parameter cS.28 „pretorq. speed fact.%/". This
parameter must be set to 100% for a complete pre-control.
Picture 7.7.4 Acceleration dependent pre-control
Inertia cS.25
pretorque speed
fact. % cS.28
pretorq. speed PT1-
time cS.27
Speed controller
Low pass lter
actual speed set-
point value
Speed setpoint
value before 1 ms
precontrol
acceleration torque
delta n_set
+
-
+
+
PT1

KEB COMBIVERT F5-A Specifications

General

Brand	KEB
Model	COMBIVERT F5-A
Category	Control Unit
Language	English