Danfoss VLT 5000 Series, Instruction Manual, Page: 140 / 240

slow changes and a constant differentiator gain where
quick changes to the error occur.
Used together with
Process control, closed loop
(pa-
rameter 100).
Description of choice:
Select a limit to differentiator gain as required.
444 Process PID lowpass filter time
(PROC FILTER TIME)
Value:
0.01 - 10.00
0.01
Function:
Oscillations on the feedback signal are dampened by
the lowpass filter in order to reduce their impact on the
process control. This can be an advantage e.g. if there
is a lot of noise on the signal.
Used together with
Process control, closed loop (pa-
rameter 100).
Description of choice:
Select the desired time constant ( IJ ). If a time constant
(
IJ
) of 100 ms is programmed, the break frequency for
the lowpass filter will be 1/0.1 = 10 RAD/sec., corre-
sponding to (10/2 x
ʌ ) = 1.6 Hz.
The process regulator will thus only regulate a feed-
back signal that varies by a frequency lower than 1.6
Hz. If the feedback signal varies by a higher frequency
than 1.6 Hz, the Process regulator will not react.
445 Flying start
(FLYING START)
Value:
Off (DISABLE) [0]
On (ENABLE) [1]
Function:
This function makes it possible to `catch` a motor,
which is spinning freely because of a mains drop-out.
Description of choice:
Select Disable if this function is not required. Select
Enable if the adjustable frequency drive is to be able to
`catch' and control a spinning motor.
446 Switching pattern
(SWITCH PATTERN)
Value:
60° AVM (60° AVM) [0]
SFAVM (SFAVM) [1]
Function:
Choose between two different switching patterns: 60°
AVM and SFAVM.
Description of choice:
Select60° AVM if the option of using a switching fre-
quency up to 14/10 kHz is required. Derating of the
rated output current I
VLT.N
is effected from a switching
frequency of 4.5 kHz.
SelectSFAVM if the option of using a switching fre-
quency up to 5/10 kHz is required. Derating of the rated
output current I
VLT.N
is effected from a switching fre-
quency of 3.0 kHz.
447
Torque, speed feedback Torque com-
pensation
(TOR-SF COMP.)
Value:
-100 - 100%
0%
Function:
This parameter is only used if Torque control, speed
feedback [5] has been selected in parameter 100. Tor-
que compensation is used in connection with calibra-
tion of the frequency converter. By adjusting parame-
ter 447,
Torque compensation , the output torque can
be calibrated.
See section
Setting of parameters, torque regulation,
speed feedback .
Description of choice:
Set the required value.
VLT
®
5000 Series
= factory setting, () = display text, [] = value for use in communication via serial communication port
MG.51.C5.22 - VLT
p
is a registered Danfoss trademark. 137
Progra
mming