Danfoss VLT AutomationDrive FC 361 Programming Guide

3-67 Ramp 3 S-ramp Ratio at Decel. Start
Range: Function:
50 %* [ 1 - 99 %] Enter the proportion of the total
ramp-down time
(parameter 3-62 Ramp 3 Ramp down
Time) 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.
3-68 Ramp 3 S-ramp Ratio at Decel. End
Range: Function:
50 %* [ 1 - 99 %] Enter the proportion of the total
ramp-down decel time
(parameter 3-62 Ramp 3 Ramp down
Time) where the deceleration
torque decreases. The larger the
percentage value, the greater the
jerk compensation achieved, and
thus the lower the torque jerks in
the application.
4.4.6 3-7* Ramp 4
Congure ramp parameters, see parameter group 3-4*
Ramp 1.
3-70 Ramp 4 Type
Option: Function:
Select the ramp type, depending on
requirements for acceleration and
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
Accelerates with lowest possible
jerk.
[2] S-ramp Const
Time
S-ramp based on the values set in
parameter 3-71 Ramp 4 Ramp up
Time and parameter 3-72 Ramp 4
Ramp Down Time.
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.
More adjustments of the S-ramp ratios or switching
initiators may be necessary.
3-71 Ramp 4 Ramp up Time
Range: Function:
Size
related*
[ 0.01 - 3600
s]
Enter the ramp-up time, which is
the acceleration time from 0 RPM
to the rated motor speed n
s
. Select
a ramp-up time such that the
output current does not exceed the
current limit in
parameter 4-18 Current Limit during
ramping. The value 0.00
corresponds to 0.01 s in speed
mode. See ramp-down time in
parameter 3-72 Ramp 4 Ramp Down
Time.
Par . 3 − 71 = 
t
acc
 s xn
s
 RPM
ref  RPM
3-72 Ramp 4 Ramp Down Time
Range: Function:
Size
related*
[ 0.01 - 3600
s]
Enter the ramp-down time, which 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
inverter due to regenerative
operation of the motor, and such
that the generated current does not
exceed the current limit set in
parameter 4-18 Current Limit. The
value 0.00 corresponds to 0.01 s in
speed mode. See ramp-up time in
parameter 3-71 Ramp 4 Ramp up
Time.
Par . 3 − 72 = 
t
dec
 s xn
s
 RPM
ref  RPM
3-75 Ramp 4 S-ramp Ratio at Accel. Start
Range: Function:
50 %* [ 1 - 99 %] Enter the proportion of the total
ramp-up time (parameter 3-71 Ramp
4 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.
3-76 Ramp 4 S-ramp Ratio at Accel. End
Range: Function:
50 %* [ 1 - 99 %] Enter the proportion of the total
ramp-up time (parameter 3-71 Ramp
4 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.
Parameter Descriptions VLT® AutomationDrive FC 361
58 Danfoss A/S © 03/2019 All rights reserved. MG06J202
44

Danfoss VLT AutomationDrive FC 361 Specifications

General

Brand	Danfoss
Model	VLT AutomationDrive FC 361
Category	DC Drives
Language	English