NOTE!
If S-ramp [1] is selected and the reference during ramping
is changed, the ramp time may be prolonged in order 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.
3-41 Ramp 1 Ramp up Time
Range:
Function:
Application
dependent
*
[Application
dependant]
Enter the ramp-up time, i.e., the
acceleration time from 0RPM to the
synchronous motor speed n
S
. Choose
a ramp-up time such that the output
current does not exceed the current
limit in
4-18 Current Limit
during
ramping. The value 0.00 corresponds
to 0.01 sec. in speed mode. See
ramp-down time in
3-42 Ramp 1
Ramp Down Time
.
Par. 3 − 41 =
tacc s x ns RPM
ref RPM
3-42 Ramp 1 Ramp Down Time
Range:
Function:
Application
dependent
*
[Application
dependant]
Enter the ramp-down time, i.e., the
deceleration time from the
synchronous motor speed n
s
to 0
RPM. Choose a ramp-down 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
4-18 Current Limit
. The value 0.00
corresponds to 0.01 s in speed mode.
See ramp-up time in
3-41 Ramp 1
Ramp up Time
.
Par. 3 − 42 =
tdec s x ns RPM
ref RPM
3-45 Ramp 1 S-ramp Ratio at Accel. Start
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-up time (
3-41 Ramp 1 Ramp up
Time
) in which the acceleration torque
increases. The larger the percentage
value, the greater the jerk compen-
sation 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 %
*
[Application
dependant]
Enter the proportion of the total
ramp-up time (
3-41 Ramp 1 Ramp up
Time
) in which the acceleration torque
decreases. The larger the percentage
value, the greater the jerk compen-
sation achieved, and thus the lower
the torque jerks in the application.
3-47 Ramp 1 S-ramp Ratio at Decel. Start
Range:
Function:
50 %
*
[Application
dependant]
Enter the proportion of the total
ramp-down time (
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 %
*
[Application
dependant]
Enter the proportion of the total
ramp-down time (
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.
3.5.4 3-5* Ramp 2
Choosing ramp parameters, see parameter group 3-4*.
3-50 Ramp 2 Type
Option:
Function:
Select the ramp type, depending on
requirements for acceleration/deceleration. A
linear ramp will give constant acceleration
during ramping. An S-ramp will give 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
3-51 Ramp
2 Ramp up Time
and
3-52 Ramp 2 Ramp down
Time
Parameter Descriptions
FC 300 Programming Guide
3-38
MG33MD22 - VLT
®
is a registered Danfoss trademark
3
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