4.4.4 3-5* Ramp 2
To select ramp parameters, see
parameter group 3-4* Ramp
1
.
3-50 Ramp 2 Type
Option:
Function:
Select the ramp type, depending on
requirements for acceleration/
deceleration. A linear ramp gives
constant acceleration during
ramping. An S-ramp gives non-
linear acceleration, compensating
for jerk in the application.
[0]
*
Linear
[1]
S-ramp Const
Jerk
Acceleration with lowest possible
jerk.
[2]
S-ramp Const
Time
S-ramp based on the values set in
parameter 3-51 Ramp 2 Ramp Up
Time
and
.
NOTICE
If
[1] S-ramp Const Jerk
is selected and the reference
during ramping is changed, the ramp time may be
prolonged to realize a jerk-free movement, which may
result in a longer start or stop time.
Additional adjustment of the S-ramp ratios or switching
initiators may be necessary.
3-51 Ramp 2 Ramp Up Time
Range:
Function:
Size
related
*
[ 0.01 - 3600
s]
Enter the ramp-up time, that is the
acceleration time from 0 RPM to
the nominal motor speed n
s
. Select
a ramp-up time such that the
output current does not exceed the
current limit in
during
ramping. The value 0.00
corresponds to 0.01 s in speed
mode. See ramp-down time in
parameter 3-52 Ramp 2 Ramp Down
Time
Par . 3 − 51 =
t
acc
s x n
s
RPM
ref RPM
3-52 Ramp 2 Ramp Down Time
Range:
Function:
Size
related
*
[ 0.01 - 3600
s]
Enter the ramp-down time, that is
the deceleration time from the
nominal motor speed n
s
to 0 RPM.
Select a ramp-down time such that
no overvoltage occurs in the
frequency converter due to
regenerative operation of the
motor, and such that the generated
current does not exceed the current
limit set in
. The value 0.00 corresponds to
0.01 s in speed mode. See ramp-up
time in
Par . 3 − 52 =
t
dec
s x n
s
RPM
ref RPM
3-55 Ramp 2 S-ramp Ratio at Accel. Start
Range:
Function:
50 %
*
[ 1 - 99 %]
Enter the proportion of the total
ramp-up time (
) in which the
acceleration torque increases. The
larger the percentage value, the
greater the jerk compensation
achieved, and thus the lower the
torque jerks in the application.
3-56 Ramp 2 S-ramp Ratio at Accel. End
Range:
Function:
50 %
*
[ 1 - 99 %]
Enter the proportion of the total
ramp-up time (
) in which the
acceleration torque decreases. The
larger the percentage value, the
greater the jerk compensation
achieved, and thus the lower the
torque jerks in the application.
3-57 Ramp 2 S-ramp Ratio at Decel. Start
Range:
Function:
50 %
*
[ 1 - 99 %]
Enter the proportion of the total
ramp-down time
(
parameter 3-52 Ramp 2 Ramp Down
) where the deceleration
torque increases. The larger the
percentage value, the greater the
jerk compensation achieved, and
thus the lower the torque jerks in
the application.
Parameter Descriptions
VLT® AutomationDrive FC 361
56
Danfoss A/S © 03/2019 All rights reserved.
MG06J202
4
4
Summary of Contents for VLT AutomationDrive FC 361
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