Danfoss VLT AutomationDrive FC 301 Programming Manual page 75

Parameter Descriptions
3-45 Ramp 1 S-ramp Ratio at Accel. Start
Range: Function:
50 % [1 - 99. Enter the proportion of the total ramp-up time
*
%] (parameter 3-41 Ramp 1 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 occurring in the
application.
3-46 Ramp 1 S-ramp Ratio at Accel. End
Range: Function:
50 % [1 - 99. Enter the proportion of the total ramp-up time
*
%] (parameter 3-41 Ramp 1 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.
3-47 Ramp 1 S-ramp Ratio at Decel. Start
Range: Function:
50 % [1 - 99. Enter the proportion of the total ramp-down
*
%] time (parameter 3-42 Ramp 1 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.
3-48 Ramp 1 S-ramp Ratio at Decel. End
Range: Function:
50 % [1 - 99. Enter the proportion of the total ramp-down
*
%] time (parameter 3-42 Ramp 1 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.
3.4.5 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
MG33MO02
Programming Guide
3-50 Ramp 2 Type
Option:
[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 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:
3.00
s
*
3-52 Ramp 2 Ramp down Time
Range:
3.00
s
*
3-55 Ramp 2 S-ramp Ratio at Accel. Start
Range:
50 %
*
%]
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Function:
S-ramp based on the values set in
parameter 3-51 Ramp 2 Ramp up Time and
parameter 3-52 Ramp 2 Ramp down Time.
Function:
[0.01 - Enter the ramp-up time, that is the
3600.00 s] acceleration time from 0 RPM to the nominal
motor speed n . Select a ramp-up time such
s
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 3-52 Ramp 2 Ramp down
Time.
t s x n RPM
acc s
Par . 3 − 51 =
ref RPM
Function:
[0.01 - Enter the ramp-down time, that is the
3600.00 s] deceleration time from the nominal motor
speed n to 0 RPM. Select a ramp-down time
s
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 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.
t s x n RPM
dec s
Par . 3 − 52 =
ref RPM
Function:
[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.
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