Danfoss VLT AutomationDrive FC 302 Programming Manual page 71

Parameter Descriptions
3.5.4 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 Acceleration with lowest possible jerk
Const Jerk
[2] S-ramp S-ramp based on the values set in
Const parameter 3-51 Ramp 2 Ramp Up Time and
Time parameter 3-52 Ramp 2 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 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.
3-51 Ramp 2 Ramp Up Time
Range: Function:
Size [ 0.01 Enter the ramp-up time, i.e. the acceleration
related - 3600 time from 0 RPM to the rated motor speed
*
s] 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 3-52 Ramp 2 Ramp Down Time.
Par . 3 − 51 =
3-52 Ramp 2 Ramp Down Time
Range: Function:
Size [ 0.01 Enter the ramp-down time, i.e. the
related - 3600 deceleration time from the rated motor
*
s] speed n to 0 RPM. Select a ramp-down time
s
such that no overvoltage arises 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 parameter 4-18 Current
Limit. The value 0.00 corresponds to 0.01 s
in speed mode. See ramp-up time in
parameter 3-51 Ramp 2 Ramp Up Time.
Par . 3 − 52 =
®
VLT AutomationDrive FC 301/302 Programming Guide
tacc s x ns RPM
ref RPM
tdec s x ns RPM
ref RPM
MG33MI02 - Rev. 2013-11-20
3-55 Ramp 2 S-ramp Ratio at Accel. Start
Range: Function:
50 % [ 1 - 99 Enter the proportion of the total ramp-up time
*
%] (parameter 3-51 Ramp 2 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
*
%] (parameter 3-51 Ramp 2 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 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.
3-58 Ramp 2 S-ramp Ratio at Decel. End
Range: Function:
50 % [ 1 - 99 Enter the proportion of the total ramp-down
*
%] time (parameter 3-52 Ramp 2 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.
3.5.5 3-6* Ramp 3
Configure ramp parameters, see 3-4* Ramp 1.
3-60 Ramp 3 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 Accelerates with lowest possible jerk.
Const Jerk
[2] S-ramp S-ramp based on the values set in
Const parameter 3-61 Ramp 3 Ramp up Time and
Time parameter 3-62 Ramp 3 Ramp down Time
3 3
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