Danfoss VLT AutomationDrive FC 302 Programming Manual page 72

Parameter Descriptions
NOTICE
If [1] S-ramp Const Jerk is selected and the reference
during ramping is changed, the ramp time may be
prolonged to realise a jerk-free movement which may
result in a longer start or stop time.
3 3
Additional adjustment of the S-ramp ratios or switching
initiators may be necessary.
3-61 Ramp 3 Ramp up Time
Range:
Size [ 0.01 -
related 3600 s]
*
3-62 Ramp 3 Ramp down Time
Range:
Size [ 0.01 -
related 3600 s]
*
3-65 Ramp 3 S-ramp Ratio at Accel. Start
Range:
50 % [ 1 - 99
*
%]
3-66 Ramp 3 S-ramp Ratio at Accel. End
Range:
50 % [ 1 - 99
*
%]
70
VLT
Function:
Enter the ramp-up time, i.e. the acceleration
time from 0 RPM to the rated motor speed
n . Select a ramp-up time such that the
s
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 3-62 Ramp 3 Ramp down Time.
Function:
Enter the ramp-down time, i.e. the
deceleration time from the rated motor
speed n to 0 RPM. Select a ramp-down
s
time such that no overvoltage arises 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 3-61 Ramp 3 Ramp up Time.
tdec s x ns RPM
Par . 3 − 62 =
ref RPM
Function:
Enter the proportion of the total ramp-up time
(parameter 3-61 Ramp 3 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.
Function:
Enter the proportion of the total ramp-up time
(parameter 3-61 Ramp 3 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.
®
AutomationDrive FC 301/302 Programming Guide
3-67 Ramp 3 S-ramp Ratio at Decel. Start
Range:
50 % [ 1 - 99
*
%]
3-68 Ramp 3 S-ramp Ratio at Decel. End
Range:
50 % [ 1 - 99
*
%]
3.5.6 3-7* Ramp 4
Configure ramp parameters, see parameter group 3-4*
Ramp 1.
3-70 Ramp 4 Type
Option:
[0] Linear
*
[1] S-ramp
Const Jerk
[2] S-ramp
Const
Time
NOTICE
If [1] S-ramp Const Jerk is selected and the reference
during ramping is changed, the ramp time may be
prolonged to realise 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.
3-71 Ramp 4 Ramp up Time
Range:
Size
related - 3600
*
s]
MG33MI02 - Rev. 2013-11-20
Function:
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.
Function:
Enter the proportion of the total ramp-
downdecel 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.
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
Accelerates with lowest possible jerk.
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.
Function:
[ 0.01 Enter the ramp-up time, i.e. the acceleration
time from 0 RPM to the rated motor speed
n . Select a ramp-up time such that the
s
output current does not exceed the current
limit in parameter 4-18 Current Limit during