Danfoss FC 300 Programming Manual page 56

Parameter Descriptions
3-40 Ramp 1 Type
Option:
3 3
[0] Linear
*
[1] S-ramp
Const Jerk
[2] S-ramp
Const Time
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:
Applica-
tion [Applica-
depend- tion
ent depend-
*
ant]
3-42 Ramp 1 Ramp Down Time
Range:
Applica-
tion [Applica-
depend- tion
ent depend-
*
ant]
56
FC 300 Programming Guide
Function:
Select the ramp type, depending on require-
ments 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.
Acceleration with lowest possible jerk.
S-ramp based on the values set in
par. 3-41 Ramp 1 Ramp up Time and
par. 3-42 Ramp 1 Ramp Down Time.
Function:
Enter the ramp-up time, i.e. the acceleration
time from 0 RPM to the synchronous motor
speed n . Choose a ramp-up time such that
S
the output current does not exceed the
current limit in par. 4-18 Current Limit during
ramping. The value 0.00 corresponds to 0.01
sec. in speed mode. See ramp-down time in
par. 3-42 Ramp 1 Ramp Down Time.
t acc s x n s RPM
Par
. 3 − 41 =
ref RPM
Function:
Enter the ramp-down time, i.e. the decelera-
tion time from the synchronous motor speed
n to 0 RPM. Choose a ramp-down time such
s
that no over-voltage 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
par. 4-18 Current Limit. The value 0.00
corresponds to 0.01 s in speed mode. See
ramp-up time in par. 3-41 Ramp 1 Ramp up
Time.
t dec s x n s RPM
Par
. 3 − 42 =
ref RPM
MG.33.M9.02 - VLT
3-45 Ramp 1 S-ramp Ratio at Accel. Start
Range:
50 % [Application
*
dependant]
3-46 Ramp 1 S-ramp Ratio at Accel. End
Range:
50 % [Application
*
dependant]
3-47 Ramp 1 S-ramp Ratio at Decel. Start
Range:
50 % [Application
*
dependant]
3-48 Ramp 1 S-ramp Ratio at Decel. End
Range:
50 % [Application
*
dependant]
®
is a registered Danfoss trademark
Function:
Enter the proportion of the total ramp-up
time (par. 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.
Function:
Enter the proportion of the total ramp-up
time (par. 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.
Function:
Enter the proportion of the total ramp-
down time (par. 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.
Function:
Enter the proportion of the total ramp-
down time (par. 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.