Danfoss VLT 5000 Series User Manual

Function:
The integral time determines how long the PID regu-
lator takes to correct the error. The greater the error,
the quicker the gain increases. The integral time re-
sults in a delay of the signal and thus has a dampening
effect. Used together with Speed control, closed loop
(parameter 100).
Description of choice:
Quick control is obtained through a short integral time.
However, if this time is too short, it can make the proc-
ess unstable.
If the integral time is long, major deviations from the
required reference may occur, since the process reg-
ulator will take long to regulate if an error has occurred.
419 Speed PID differential time
(SPEED DIFF. TIME)
Value:
0.00 (OFF) - 200.00 ms
30 ms
Function:
The differentiator does not react to a constant error. It
only provides a gain if the error changes. The quicker
the error changes, the stronger the gain from the dif-
ferentiator will be.
The gain is proportional to the speed at which errors
change.
Used together with Speed control, closed loop (param-
eter 100).
Description of choice:
Select the desired gain limit.
420 Speed PID D-gain limit
(SPEED D-GAIN LIMIT)
Value:
5.0 - 50.0
5.0
Function:
It is possible to set a limit for the gain provided by the
differentiator. Since the D-gain increases at higher fre-
quencies, limiting the gain may be useful.
This enables obtaining a pure D-link at low frequencies
and a constant D-link at higher frequencies.
Used together with Speed control, closed loop (param-
eter 100).
Description of choice:
Select the desired gain limit.
421 Speed PID lowpass filter time
(SPEED FILT. TIME)
Value:
5 - 200 ms
10 ms
Function:
Oscillations on the feedback signal are dampened by
a lowpass filter so as to reduce their influence on con-
trol. This might be an advantage, e.g. if there is a great
amount on noise on the system. See drawing. Used
together with Speed control, closed loop and Torque
control, speed feedback (parameter 100).
VLT
®
5000 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
132 MG.51.C5.22 - VLT
p
is a registered Danfoss trademark.

Danfoss VLT 5000 Series Specifications

General

Brand	Danfoss
Model	VLT 5000 Series
Category	DC Drives
Language	English